Power Outage in Waterloo, IA

Emergency Manager reported tree limbs and a few power lines downed. Ponding observed on area roadways.

Public report via social media of crops flattened, many trees uprooted, a playground set demolished, and power outage.

Media reported a large tree down on some power lines. Delayed report.

Large trees down, power lines down, some damage to home on Gloria Drive.

A semi-tractor trailer was blown over at the intersection of Washington and Broadway. Power was out in numerous places in Waterloo.

The power was out as well.

Trees were reported down on houses and cars with power lines down. Report received from KWWL TV.

Large trees were down in the southern end of Waterloo. Power lines taken down as well. Another tree was downed in Evansdale.

Trees and power lines were down across the Waterloo and Cedar Falls area including the University of Northern Iowa. One tree fell on a house.

An MCS rolled through northern Iowa in the AM hours bringing with it numerous reports of high/damaging winds and some hail. The damaging winds brought down large tree limbs, power lines, large trees and damaged chicken and hog facilities. Lightning struck a house in Kossuth County damaging the chimney.

A powerful upper level system was moving into south central Canada. The upper level winds were increasing as a closed upper low settled into that area. Warm air advection continued across Iowa through the night of the 29th into the morning of the 30th. The atmosphere was very unstable with CAPE values around 4000 J/kg. Downdraft CAPE was between 1000 and 1500 J/kg, with CAPE in the -10 to -30 C layer of the atmosphere in the 600 to 800 J/kg range. Strong shear was present, with an effective shear of 50 to 60 kts. The freezing level was quite high, between 14,000 and 15,000 feet. Precipitable water increased to between 1.5 and 1.8 inches. There was a considerable amount of CAPE in the 0-3 km layer of the atmosphere, between 100 and 175 J/kg. That combined with an LCl of only 750 meters was a favorable environment for tornado development. Thunderstorms formed rapidly in northwest and north central Iowa by the late afternoon and evening hours. They spread and continued to move east through the night. All modes of severe weather occurred with tornadoes occurring during the early and mid evening hours. Two tornadoes were reported in the Stanhope area near the Webster and Hamilton County line. A tornado touched down in Grundy County north of Conrad. Winds caused damage in many areas across the north half of Iowa. Hail was common with most of the storms in spite of the high freezing level. Much of the hail an inch or less in diameter. Larger hail of golf ball to tennis ball size fell in Butler and Bremer Counties. A strong storm formed in Ringgold and Union Counties and dropped golf ball size hail. The event produced very heavy rainfall in many locations. The ground had become nearly saturated from previous rounds of storms during the week prior. Flooding and flash flooding became a problem in several locations.

A cold airmass was in place over Iowa as arctic high pressure slipped east of the state during the early morning hours of the 27th. A strong upper level shortwave lifted out of the southern Rockies, racing northeast at 50 kts, during the overnight hours of the 26th and early morning of the 27th. Temperatures were below freezing over northeast Iowa at sunrise on the 27th. The southwest part of the state was in the mid to upper 30s at that time. Very dry air was in place initially with dewpoint temperatures in the teens. Very warm air moved aloft with 850 mb temperatures of +2 to +5 C. A large area of rain developed southwest of Iowa with the approach of the shortwave. As the area moved northeast into Iowa the precipitation fell in the form of freezing rain. Temperatures that were above freezing fell to freezing or below due to evaporational cooling with the rainfall. Much of Iowa received at least one tenth of an inch of ice, with most of the east half of Iowa receiving two tenths of an inch or more. The heaviest ice accumulation was over the northeast part of the Des Moines CWA, roughly north of U.S. Highway 30 and along and east of the I-35 corridor. These areas received general ice accumulations of one quarter to one third of an inch with spotty half inch amounts north of the Mason City area into Worth and Winnebago Counties. Roads became treacherous with the freezing rain with numerous accidents reported. In addition, walking became very dangerous. In the Des Moines metro area there were at least 35 people treated for injuries caused by falling on the ice. Tree and power line damage was limited due to the light winds during the event. Several hundred homes lost power over the far northeast part of the CWA, with only very spotty outages elsewhere. It was fortunate that the ice storm occurred on a non-business day. Though there were many events cancelled, the impact was reduced since it was on a Sunday.

The cold front that progressed into the state during the evening of the 23rd made little progress overnight. It moved slowly southeast during the day on the 24th and finally passed southeast of the CWA after a surface wave lifted northeast along the front. The airmass was capped initially with the cap finally breaking during the mid afternoon hours. A narrow line of thunderstorms formed by mid afternoon and advanced across the state. There was plenty of moisture available with dewpoint readings in the low to mid 60s in a ribbon ahead of the front. Precipitable water values increased to 1.3 to 1.5 inches. Shear was strong with 60 to 75 kts of shear available. The mean flow in the 850-300 mb layer was over 60 kts. Downdraft CAPE remained quite high with 800 to 1300 J/kg available ahead of the line. CAPE in the -10 to -30 C layer of the atmosphere was between 300 and 500 J/kg, though the freezing level remained in the 14,000 to 15,000 foot range, limiting hail production. The LCL was also relatively high in the 750 to 1250 meter range ahead of the line. Lifted indices fell to -3 to -5 C by late afternoon. The thunderstorms produced brief heavy rainfall and gusty winds in most locations with storm forward motion speeds in the 50-60 MPH range. Winds gusted up to 70 MPH with a few of the stronger storms causing damage to trees and power lines. A storm in Decatur County dropped 1.10 inches of rain in about 20 minutes. There were spotty reports of three quarter to one inch diameter hail as well.

An unstable airmass remained in place across Iowa with dewpoint temperatures remaining in the upper 60s to low 70s. A nearly stationary frontal boundary was in place across the state extending from the east central counties to the southwest corner of the state. Thunderstorms erupted on the north side of the front during the evening. CAPE values were between 2000 and 4000 J/kg, with downdraft CAPE of 1100 to 1600 J/kg. The lifted index was in the -4 to -6 C range. The freezing level was quite high, though it had fallen some during the day. It was just over 14,000 feet by evening. CAPE in the -10 to -30 C layer of the atmosphere was between 300 and 700 J/kg. Moisture was drawn north over the frontal boundary by a low level jet of 25 kts. Precipitable water values increased to 1.6 to 1.9 inches. The storms produced high winds as they progressed across the state. One storm broke several 10 inch branches south of Hubbard in Hardin County. This storm continued eastward and produced strong winds as it moved through Black Hawk County. Winds were measured around 60 MPH in the Waterloo area. Another cluster of storms moved into western Iowa and spread into the central counties. Winds around 75 MPH occurred in Audubon County. The strong winds, at least 60 MPH, continued east into Guthrie County before the storms weakened. There were numerous reports of trees downed, along with power line damage. Extensive damage occurred in Hardin County as winds of 75 MPH caused crop damage, ripped part of the roof off of a machine shed, and flattened several grain bins. A classic wet microburst took place south of Hubbard as well. Winds started around 1030 PM and lasted for about 8 minutes. The damage was concentrated in an area about 2 miles south of Hubbard where 3 farms sustained major damage, and a 4th farm had more minor damage. Specifically, one farm lost 12 trees (snapped). Two trees landed on and destroyed a grain bin. Also, the west-facing machine shed door was collapsed and portions of the roof (including the roof structure itself) were blown off. The next 2 farms to the south also sustained significant damage to trees with many snapped about halfway up the trunk. The farm just to the north also lost several large trees. Based on the duration of the winds, damage to the farms, type and condition of the trees, etc., estimated winds were in the 80-85 MPH range. In terms of crops, most of these farms are growing soybeans which were flattened, and part of the corn crop was blown down. Heavy rain also was reported in Bremer County with reports of around 3 inches of rain in under 2 hours. Around 2 inches of rain fell in an hour in Black Hawk County. Lightning struck a building in Cedar Falls, setting it on fire. There were also reports of two tree fires in the city of Cedar Falls.

A very intense storm system moved through the central Rockies into the Plains. The upper low looked more like a late winter or spring system, completely closed over northwest Kansas by the evening of the 20th. The atmosphere was very unstable by the late afternoon with lifted indices around -11 and CAPE in the 4000 to 5000 J/kg range. Other parameters were quite high as well with downdraft CAPE of 900 to 1500 J/kg and CAPE in the -10 to -30 C layer of the atmosphere of 500 to 1000 J/kg. Initially the atmosphere was capped with 700 mb temperatures of 11 to 14 C. There was a decent amount of shear available with 45 kts present. Precipitable water values were quite high, approaching 2 inches. A 40 to 50 kt inflow jet was present as well. The LCL level was quite low, between 600 and 1000 meters. A strong line of thunderstorms formed into a quasi-linear convective system. It advanced into Iowa and produced high winds and some hail as it lifted east-northeast. The hail was relatively small, an inch or less in diameter, as the freezing level was well over 15,000 feet resulting in quite a bit of melting of the hail as it fell. The strongest winds were in Humboldt east of Ottosen where 80 MPH winds caused considerable tree and power line damage. High winds downed a 50 foot high 66 X 76 foot barn southeast of Armstrong in Emmet County. Grass, debris, and corn was blown across the highway. The line continued to move northeast. A microburst took place in Black Hawk County, causing considerable damage to a farmstead northwest of La Porte City. Small tornadoes were also reported in central Iowa. One tornado touched down in Kossuth County northeast of Ottosen. It damaged a house with the walls blown in and out. Part of the roof was blown off the house. A grain auger was launched into the attic of the house. Grain bins and trees were blown into a convergent path north-northwest of the house. There was no damage on the west side of the farmstead. The tornado track was short with wind damage done on farms within a 2 mile radius. A tornado also touched down in Tama County near Cluttier. The damage was very localized with tree tops snapped off. Some minor house damage occurred with the gutter blown off into a truck. The roof was taken off of an outbuilding. In the town of Cluttier, one half mile to the southwest, large tree limbs were blown down. Debris and corn were directed to the north, consistent with a small tornadic circulation at the farm site with EF0 damage.

A strong low pressure system moved out of the southwest U.S. into Iowa during the overnight hours of the 19th through the day on the 20th. A strong push of warm air took place. The warm air was advected across cold air at the surface. Over northern Iowa, the warm air was not able to scour out the low level cold air. Moisture streamed north during the early morning hours of the 20th. The atmosphere became somewhat unstable with elevated CAPE in the 500 to 1000 J/kg range. A band of thunderstorms developing over central Iowa during the evening hours and lifted north into northern Iowa during the early morning hours. As the storms moved north through central Iowa, brief heavy rain and half inch diameter hail occurred. Over northern Iowa, a mixture of freezing rain, ice pellets, and occasional wet snow occurred. Temperatures were close to freezing, thus not all of the freezing rain was realized as ice. Reports of one quarter of an inch of ice accrual were received from several counties by the mid morning hours, though the area covered by the heavier ice accrual was spotty due to the nature of the thunderstorms. The heaviest ice accrual took place in Emmet County with 1 inch of ice reported in Estherville. Outside of Emmet County, some of the heaviest ice accrual took place southeast of Grafton in Worth County. One half to three quarters of an inch of ice was reported there. The ice only caused spotty power outages considering the widespread nature of the event. Ice knocked out power to about 4000 customers over northern IA during the day, or about 2% of the grid was affected at some point in time. Roads became very treacherous at the beginning of the event. The roads were not a major problem by mid day as temperatures near the freezing point allowed for some melting on road surfaces. As the area of precipitation lifted north, it became convective. A thunderstorm moved through the Waterloo area. Lightning struck a tree in Waterloo, sending part of the tree flying with pieces of bark breaking several windows in a house. One fire was started due to the ice buildup. Ice downed a power line onto a house in Clear Lake around 1700 CST. The power line sparked and started a small fire.

A weak boundary was located across Iowa during the afternoon and evening of the 16th, embedded in a northwest flow regime. The airmass became quite unstable over western into north central Iowa with CAPE in the 3000 to 5000 J/kg range and lifted indices in the -7 to -10 C range. Shear was relatively weak, 20-25 kts. There was significant downdraft CAPE available in the 1000 to 1300 J/kg range, with available CAPE in the -10 to -30 C layer of the atmosphere of 700 to 1000 J/kg. Moisture was transported into the state with precipitable water values reaching 1.25 to 1.5 inches by mid afternoon. The airmass was quite warm, with the freezing level around 14,500 feet. Scattered thunderstorms developed by mid to late afternoon from southeast Minnesota, across northwest Iowa, into eastern Nebraska. Scattered severe weather occurred during the very late afternoon and evening hours. Hail was reported with some of the storms, up to 1.5 inches in diameter. High winds from some of the storms produced scattered tree damage as well. There were two small tornadoes reported. One was in Franklin County, the other on Hancock County. Both of these were only on the ground briefly and caused little damage. In Cerro Gordo and Hancock Counties, heavy rainfall was observed with 2.5 to 3.5 inches falling from the storms. No flooding occurred however. Thunderstorms moved into the Waterloo area. They were dissipating as they moved in, resulting in high winds, non-thunderstorm, west of town. Trees were downed by the wind, as well as power lines downed. Power was out and a large motel sign was damaged by the wind.

A very unstable airmass was in place over Iowa during the late afternoon and evening of the 22nd. Surface temperatures warmed into the upper 80s to low 90s over much of the state with dew point temperatures rising into the mid 70s to low 80s. CAPE values increased to over 6000 J/kg over the southern half of the state with lifted indices around -12 C. Deep moisture flowed into the state both at low levels as well with the presence of a prominent tropical feed on the water vapor satellite imagery. Precipitable water values increased to 1.8 to 2.2 inches over southern Iowa as moisture pooled. Significant shear was present with effective shear of 45 to 60 kts over northern Iowa. Downdraft CAPE was over 1000 J/kg, while the available CAPE in the -10 to -30 C layer of the atmosphere was in the 800 to 1200 J/kg range. Hail was somewhat limited however with the freezing level between 14,500 and 15,500 feet. Temperatures at the 700 mb level rose to +15 C over southwest Iowa by evening. A strong upper level shortwave lifted northeast out of Colorado during the overnight into the early morning hours of the 22nd into the 23rd. A cold front approached Iowa from the northwest and moved into the northwestern counties by sunrise on the 23rd. Thunderstorms were slow to develop initially due to a strong cap in place over the state. After sunset, explosive development took place over northwest into north central Iowa. Several tornadoes touched down over northern Iowa. None of them were on the ground for an extended period of time however. One touched down in the Sac City area of Sac County, another in Humboldt west of Humboldt. A third tornado was on the ground for a few minutes in the Eagle Grove area. A brief touchdown occurred in Franklin County north of Iowa Falls. A tornado touched down just west of Tripoli. It obliterated an abandoned barn with a brief touchdown. The tornado was one of the stronger of the day at EF1 strength. Funnel clouds were numerous in spite of the darkness due to the vivid lightning and the ability to see them. There were several hail reports, with some of the hail reaching golf ball in size in Winnebago and Kossuth Counties. High winds were a more significant problem with the event as it developed in to an upscale MCC. Numerous reports of downed trees and power lines were received. A semi was overturned on I-35 at milepost 154 by high wind, with another 10 miles farther north. Damage to homes and barns was reported in Bremer and Black Hawk Counties as well. One storm produced a narrow microburst just west of Tripoli with winds estimated at 95 to 100 MPH based on a NWS storm survey. Three homes were damaged with 2 of them serious. Some outbuildings were also damaged by this microburst. The storms also produced very heavy rainfall. Flash flooding took place in several counties, including Wright, Franklin, and Palo Alto. Extensive street flooding took place in Clarion in Wright County with power out in most of the city. In addition, U.S. Highway 69 and Iowa Highway 3 were under water. U.S. Highway 18 was overtopped by high water in 2 places between Spencer and Emmetsburg in Palo Alto County. Roads were under water near Sheffield in Franklin County. Rainfall was heavy with amounts of 4 to 7 inches reported in a band extending from eastern Palo Alto, through Humboldt and Wright Counties, into Franklin County. Heavy rain flooded roads and resulted in evacuations in the town of Dumont in Butler County. The rain fell in just a few hours time. Following the flash flooding, areal flooding continued in parts of the area with highways remaining closed. Some local flooding was also reported in Warren County, east of the Carlisle area.

The frontal boundary from the previous night lifted north as a warm front as low pressure over Kansas pushed northeast into Iowa. The low eventually tracked from southwest Iowa in the afternoon to east central Iowa by early evening. To the southeast of the front, temperatures warmed into the upper 70s to mid 80s, with dew point temperatures in the upper 50s to mid 60s. The atmosphere became quite unstable with lifted indices falling to -5 to -8 Celsius and CAPE rising to 2000-3000 J/kg. The situation was very dynamic with a synoptic scale upper level trough to the west and broad southwest flow over the central U.S. The jet at 300 mb was around 100 kts with 500 mb winds southwest at 75+ kts. This aided in producing deep layer shear of 75 to 100 kts over southeast Iowa by late afternoon. Ample inflow was present with moisture transport at the 850 mb level produced by a 35 to 40 kt flow. This increased precipitable water values to between 1 and 1.2 inches. Thunderstorms fired along the frontal boundary during the mid to late afternoon as the front became a cold front. With 300-400 J/kg of CAPE in the -10 to -30 layer of the atmosphere, and 700-1000 J/kg of downdraft CAPE available, the atmosphere was loaded for the production of wind and hail. In addition, the freezing level was a relatively low 12,000 feet. The line of thunderstorms that formed ahead of the advancing cold front became severe quickly, producing large hail. Much of the hail was in the 1 to 1.5 inch diameter range, however there were several reports of golf ball to tennis ball size hail. The largest hail was over northeast Iowa with golf ball size reported in Grundy County, and tennis ball size from the northwest edge of Waterloo toward Cedar Falls in Black Hawk County. Also in Black Hawk County, a few stones were measured to 3.5 inches in diameter in Cedar Falls. As the system unfolded, the storms began to produce high winds. Wind gusts of 75 to 100 MPH occurred with the stronger storms. Multiple homes had siding damage due to hail blown through the siding, and windows were knocked out in Marion County east of Monroe. High winds snapped power poles in Jasper and Poweshiek Counties. A camper was blown off of Interstate 80 at mile post 178, resulting in a multiple car accident. In Poweshiek County, cars were blown off of the road and flipped, power poles snapped, and roofs were taken off of houses near Grinnell. Power was knocked out to several thousand customers in the Grinnell area. Six members of the Grinnell College track team were caught in the storm and sustained injuries from the hail. They were bruised, taken to the hospital, treated and released. Officials in the city of Grinnell estimated damage due to the high winds from this storm at $10,000,000.

Thunderstorms formed over northwest Iowa near an old outflow boundary left behind from the morning convection. Farther south, the airmass was capped with 700 mb temperatures warming to +15 C on the Omaha, NE sounding at 0000 UTC. The atmosphere was slow to recover after the morning convection, but did destabilize to where there was 1000 to 2000 J/kg of CAPE and the lifted indices falling to -4 to -7 C. Downdraft CAPE was not all that impressive, in the 500 to 800 J/kg range. The effective shear in the area was 30 to 45 kts with CAPE in the -10 to -30 C. layer of the atmosphere around 300 J/kg. Thunderstorms formed over southeast South Dakota and moved into northwest Iowa during the evening. The storms were quite strong and produced very large hail to the west of the DMX CWA. They weakened as they moved into a less favorable environment in the DMX CWA. The freezing level was quite high at nearly 15,000 feet, making it difficult for large hail production from the weakening storms. Several locations in Emmet County reported dime to nickel size hail with the storms. In Kossuth County, the storms intensified some and produced quarter size hail. Intense rainfall occurred with some of the storms. In Estherville for example, about 2.5 inches of rain fell in about one and one half hours. Deep moisture was in place in the atmosphere with 1.7 inches of precipitable water available. Thunderstorms continued to develop across northern Iowa into the early morning hours. The hail event transitioned into more of a wind event after midnight. Winds of 60 MPH plus hit the Waterloo area resulting in considerable tree limb damage. A semi-tractor trailer was overturned just northwest of Waterloo by the high winds. Power outages were widespread across Black Hawk County. Shortly after the event it was reported that nearly 20% of Black Hawk County was without power due to the wind damage. Power poles were on fire in Waterloo. Significant damage occurred in the Cedar Falls area as well. At least 350 trees were damaged in the city of Cedar Falls. One hundred of those were on the University of Northern Iowa campus. High winds near 100 MPH toppled a radio station tower. Damage around the city was extensive with numerous trees toppled, falling onto houses and cars. High winds damaged a garage in Cedar Falls. In addition, high winds caused considerable damage around town with 9000 homes without power at one point in the Waterloo/Cedar Falls area. Media reports indicated that the damage totals in the Waterloo/Ceder Falls areas exceeded $5 million. Fortunately there were no injuries reported. In addition to the property damage, wind speeds were high enough to cause extensive crop damage at several locations. By mid August, a Federal Disaster Declaration was made for Black Hawk County due to the extensive wind damage in the county.

A southwest flow aloft pushed warm air over the top of an existing polar air mass that was in place over Iowa. Low pressure developed to the southwest and lifted north during the day on the 8th. The low brought warm and moist air north into the central U.S. Temperatures climbed into the mid 40s to mid 50s over southern Iowa, while remaining below freezing over the north. Light precipitation broke out during the afternoon of the 8th in the form of freezing drizzle and freezing rain over the north. Some snow fell over the far northwest. The main precipitation held off until the evening as it took some time to saturate the column. Freezing rain was widespread across the north half of the state with 0.2 inches or more of ice accumulation across a large part of the state north of U.S. Highway 30. The snow began to transition into sleet and snow over the northwest and a band of heavy snow set up during the evening in the Fort Dodge area and areas to the north and west. Meanwhile, precipitation continued to fall as freezing rain well into the night over the north central and northeast. Ice accrued to about 0.3 inches from north of Waterloo into Bremer County. Roads over the north part of the state became very icy with the freezing rain falling on sub-freezing road surface temperatures. This caused numerous traffic problems. The ice also caused spotty power outages as branches fell onto power lines. During the night, the transition from freezing rain to snow progressed southeast. Heavy snowfall occurred in the Mason City area and points northeast with over 6 inches recorded. Elsewhere, snowfall was generally 4 inches or greater north of U.S. Highway 20. Some of the heavier snowfall totals included, 8 inches in the Algona area, 7 inches in the Ringsted area, and 6 inches in the Lake Mills area toward Mason city, as well as just north of Fort Dodge. During the event, northerly winds of 20 to 30 MPH caused considerable drifting of snow and areas of blowing snow. The combination of the snow, blowing snow, and ice coating resulted in the cancellation of many activities and numerous school closings.

A warm front lifted northeast across Iowa during the day on the 7th as a cold front approached from the northwest. The cold front reached northwest Iowa by the early morning hours of the 8th, however a shortwave lifted northeast across the state during the afternoon and evening of the 7th. The airmass became very unstable by the mid and late afternoon hours as temperatures warmed to the upper 80s to mid 90s and dewpoint temperatures warmed to the upper 60s to mid 70s. CAPE values rose to between 4000 and 6500 J/kg by late afternoon, and lifted indices fell to between -7 and -10 C. The environment was moderately sheared with 25 to 35 kts of shear available. The downdraft CAPE was quite high, and was between 800 and 1300 J/kg. A decent amount of CAPE was available, 300 to 500 J/kg, in the -10 to -30 C. layer of the atmosphere, however the freezing level was very high. Freezing levels ranged from 14,500 feet over northern Iowa to 16,000 feet over the south. With the high freezing level, there was a very deep warm cloud layer with precipitable water values in the 1.6 to 1.8 inch range. The threat for tornadoes with this system was minimal with LCL values around 1500 meters at the beginning of the event, and 2500 meters by early evening. Thunderstorms developed over north central into west central Iowa by the mid afternoon. Very heavy rain fell in north central Iowa where the storms intersected the warm front. Upwards of 4 inches fell in a 2 hour period, however no flooding was reported. As the event unfolded it became a high wind event. The downdraft CAPE was able to be realized with numerous gusts in the 60 to 70 MPH range. There were numerous reports of tree branches broken and several whole trees toppled. Winds of 70 MPH hit the Waterloo-Cedar Falls area. Tree and power line damage was extensive in the area. High winds in Boone County overturned a semi-tractor trailer. No injuries were reported however. Heavy rainfall became a problem, especially after sunset when the line of thunderstorms became stationary over southern Iowa. The heavy rain over the northern part of the state, such as the 2.44 inches that fell in Clarksville in Butler County, did not cause much in the way of flooding. Overnight, a large area of thunderstorms remained over the same areas of south central Iowa. Numerous reports of rain in the 4 to 6 inch range were received in the area with the heaviest rain occurring in the Appanoose and Davis County areas. The schoolnet site in Bloomfield reported 7.68 inches of rain, while the Centerville Schoolnet site reported 7.58 inches. A measured rainfall of 6.9 inches was received from southwest of the Bloomfield area for one of the heavier non-automated totals. Centerville received 6.13 inches from overnight rains as reported by the Cooperative Observer. Appanoose County had received heavy rainfall the day before, as did many of the surrounding areas. The heavy rainfall caused water to flow over may roads and even over a few state highways. Iowa Highway 5 was closed north of Marysville by high water for example. Water also covered U.S. Highway 34 near Albia.

A very unstable airmass moved into Iowa during the day on the 29th as a warm front lifted north into the state during the afternoon. Low pressure approached from the west, along with a cold front so that the triple point was near the western Iowa, eastern Nebraska area by late afternoon. Thunderstorms erupted quickly during the late afternoon and evening hours in the unstable airmass. By evening, the low level jet was in the 40 to 60 kt range, feeding moisture into the state and pushing precipitable water values to around 200% of normal, in the 1.5 to 1.8 inch range. MUCAPE reached 3000 to 3500 J/kg over western Iowa, with lifted indices in the -6 to -10 C. range. The freezing level was quite high, limiting the hail size somewhat with this event, at 14,300 feet. The available CAPE in the -10 to -30 C. layer of the atmosphere was in the 300 to 500 J/kg range. The DCAPE was between 800 and 1000 J/kg. The environment was highly sheared with 50 to 65 kts of shear available during the event. The LCL was also quite low, in the 750 to 1250 meter range. Thunderstorms erupted over western Iowa stretching into north central Iowa first. It did not take long for the storms to become severe with hail and high winds. Most of the hail reported was in the pea to marble size, with the larger stones in the nickel to quarter size range. The primary mode of severe weather was high winds and several tornadoes. The secondary, but significant threat, was heavy rainfall. A band of 3 to 5 inches of rain fell between U.S. Highway 30 and U.S. Highway 20 during the event. The heaviest rainfall total was in Greene County at Jefferson, with 5.90 inches. Tornadoes began to touch down in western Iowa in Crawford County with two brief touchdowns. One was west of Dow City, causing roof and shingle damage to a farmhouse there. The next was east of Denison where a barn roof was removed and a trailer house was destroyed. A tornado in Carroll County caused damage to 3 farmsteads southeast of Templeton. A machine shed was completely destroyed and numerous other buildings sustained damage. Trees also had substantial damage. Two tornadoes touched down in Calhoun County. One near Farnhamville, tore the roof off of a home and downed power lines. The second caused damage to trees, outbuildings, and power lines on four farmsteads. Farther south, a brief touchdown was reported in Dallas County in open fields west of Minburn. Another tornado touched down in Dallas County later on, west of Adel, and was on the ground for about 4 miles. A more substantial tornado touched down near Murray in Clarke County with one reported on the ground for about 9 miles. As the storms moved east, another tornado was on the ground for over 10 miles in Warren and Marion Counties. The most significant tornado occurred in Marion and Mahaska Counties where an EF2 tornado was on the ground for about 18 miles. Several homes were damaged along its path, two mobile homes were destroyed, and considerable damage was done to trees in the area. Up to 10 people were injured with this tornado, mainly in Attica. The official damage count from this tornado included 5 homes destroyed, 15 with major damage, and another 25 with minor damage. Many of the storms produced high winds with several reports of winds in the 65 to 75 MPH range. Considerable tree damage was reported and some structural damage, mainly outbuildings and shingle damage. Two cars were blown off of the road east of Manning by the high winds. Building debris was blown onto Highway D60 near Gowrie, causing a brief closure. High winds in Butler County blew down a machine shed and barn southwest of Aplington, very near to where an EF5 tornado struck just days before. Extensive damage was done to a farmstead there with some damage done to the house itself as well. Lightning struck a man in Carroll. The lightning bolt hit his driveway, blowing out a chunk of concrete out of the driveway and also injured the man. He was taken to hospital, treated, and released with minor injuries. Flooding became a significant issue after the heavy rainfall of the previous few days. Extensive river flooding occurred across the central third of the state. Record crests were recorded on the Iowa River at Marshalltown.

A strong south to southwest flow of moist air was on place across Iowa in advance of an approaching cold front. The cold front moved through the state during the afternoon with a line of thunderstorms forming along the front. The airmass was moderately unstable with CAPE values in the 1000 to 2000 J/kg range and lifted indices in the -4 to -6 C. range. Downdraft CAPE values were in the 600 to 800 J/kg range. There was a decent amount of shear in the atmosphere with 45 to 50 kts indicated. The freezing level was quite high, near 14,000 feet. There were reports of some pea size hail, but no significant hail was reported. Most of the storms along the line produced 30 to 40 MPH winds. A few of the storms produced severe criteria winds with spotty damage to trees and power poles reported. It appears that most of the high wind reports were associated with downbursts.

A fairly strong upper level system moved over the top of a large area of high pressure in the upper atmosphere during the day on the 22nd, then dropped south-southwest across Iowa during the night. An MCS developed over Wisconsin and moved southwest across Iowa overnight. The event was elevated in nature with surface base indicators showing no CAPE or significant instability. Elevated CAPE wa around 1000 J/kg however and there was increasing shear moving into the area with about 30 kts during the initial stages of the event. The LCL was relatively high, around 1000 meters, given the surface inversion had already become established. The storms produced gusty winds, with severe winds occurring as the storms moved across Black Hawk and Tama Counties. The airport at Waterloo reported winds of 62 MPH. Power lines were downed in Tama County near Dysart. DCAPE was 700 to 800 J/kg at the time. There was not a great deal of hail with these storms. CAPE in the -10 to -30 layer of the atmosphere was round 200 J/kg, however the freezing level was quite high in the 14,500 to 15,500 foot range. One of the storms produced severe hail in Union County. Quarter size hail fell in the town of Creston. The storms produced locally heavy rainfall with some urban flooding in Union County where between 2 and 3 inches of rain fell. The storms had plenty of precipitable water to work with as a pool of 1.5 to 1.8 inches was available.

Several boundaries were in position across the state with the main|boundary being that left from the previous nights convection from|northwest into east central Iowa. At the same time, a cold front|approached the state from the northwest while low pressure developed|over eastern Nebraska. The atmosphere became very unstable by the early|afternoon hours with CAPE values in the 3000 to 4500 J/kg range and|lifted indices falling to between -7 and -10 C. Shear across the north|half of Iowa was in the 30 to 40 kt range. During the afternoon,|temperatures rose into the upper 80s to mid 90s, as dew point readings|rebounded in to the mid to upper 70s along the boundary. Thunderstorms|erupted by mid afternoon with a large area of thunderstorms moving from|northwest into parts of north central and eventually in to east central|Iowa. The main mode of severe weather was high winds. There was|between 900 and 1100 J/kg of DCAPE available with fairly strong winds in|the mid levels. Reports of downed trees and power lines were numerous|with wind gust reaching 70 MPH or more with some of the stronger|storms. There was little in the way of hail reported, though pea to|small marble size hail was common. The available cape in the hail|layer, -10 to -30 C. layer of the atmosphere, was significant in the 400|to 600 J/kg range, but the freezing level was very high. Typical of mid|July, the freezing level was between 14,000 and 15,000 feet, which|limited hail production. The storms moved east-southeast at 35 to 45|MPH for the most part with the first round exiting the DMX CWA by early|evening. Thunderstorms began to redevelop during the evening. One of the storms produced penny size hail in the Marshalltown area.

Very unstable conditions from the previous evening remained in place over much of Iowa. A boundary extended northwest to southeast across the state with thunderstorms firing up again during the predawn hours of the 17th. The thunderstorms developed over northeast Iowa and tracked southeast at nearly 60 MPH. Though much of the activity was to the east of the Des Moines CWA, a few of the storms clipped the northeast counties with high winds of 60 MPH or more. Trees were damaged and power lines were blown down.

A strong southerly flow of very moist air pushed into Iowa. Dew point temperatures rose to the mid 60s to near 70 by late afternoon. The airmass became relatively unstable, however the dynamics were somewhat limited. The effective shear was in the 25 to 35 kt range. The freezing level was between 12,000 and 13,000 feet, however the sounding was quite saturated which limited the hail somewhat. The CAPE in the -10 to -30 C. layer was in the 200 to 300 J/kg range with the most unstable CAPE in the 1000 to 2000 J/lg range. Lifted indices were in the -2 to -4 C. range. A slow moving cold front entered western Iowa from the west during the late afternoon. Thunderstorms formed along the front and lifted northeast. Many of the storms produced large amounts of pea size hail, however very few produced any significant size hail. Most of the hail was in the three quarter to one inch diameter range. A bow echo segment formed along the east edge of the system and produced scattered reports of high winds. A semi-tractortrailer was blown off the highway along Interstate 80 at the Stuart exit. The truck overturned, blocking the highway and injuring the driver. He was flown to hospital in Des Moines. High winds snapped power poles southwest of Britt. A severe thunderstorm in the Lake Mills area produced what appears to be a downburst wind gust that took the roof off of a grain bin and blew down 6 power poles. A short time later, the same segment produced 61 MPH winds at the Waterloo Airport.

A very warm and and unstable airmass was on place over Iowa on the evening of the 24th, and had been for several days. The airmass was relatively capped with 700 mb temperatures around +12 C. Surface temperatures warmed into the mid 90s in most areas with dew point readings in the mid to upper 70s. The lifted index was around -6 C by the early evening hours. There was a decent amount of CAPE with values running around 3000 J/kg, however with the cap in place it was difficult to realize the CAPE. The freezing level was quite high, reported at 16,400 feet. A cold front sagged southeast into the state during the day. This front, in combination with a weak upper level system, was enough to generate vigorous convection over northern Iowa. There were several reports of high winds, with numerous trees and power lines downed. A microburst hit the Webster City Airport with a 70 MPH wind gust. The microburst dropped dew points into the mid 50s, which lasted for several hours. Reports of hail were spotty and generally in the three quarter inch diameter range. Two storms were exceptionally strong and dropped 2 inch diameter hail. One occurred west of Breda in Carroll County. The second was in Crawford northeast of Deloit. The hail lasted for about 20 minutes as the storm moved very slowly southwest, cutting a swath nearly two miles wide with the ground becoming white for a period of time. This storm also produced a tornado northeast of Deloit. The tornado touched down in a corn field and cut a swath across the field.

A strong mesoscale convective system developed over the High Plains during the previous night. The system initially drifted northeast, however as the night progressed it began to turn southeast. The airmass was ahead of the system was fairly unstable with surface dew point values in the mid to upper 60s. Lifted indices were in the -3 C. range with CAPE values in the 1000 to 2000 J/kg range. As the MCS turned southeast, it began to gain strength in spite of the fact that it moved through Iowa during the morning hours. It moved through as an arced line of thunderstorms, producing 55 to 65 MPH winds in many locations. There were a few reports of hail, however most of the hail was below an inch in diameter. During the later stages of the systems life, a wake low formed behind the main line. This produced high winds over a large part of the east third of Iowa. Winds gusted to near 60 MPH with numerous reports of tree and power line damage. Trees were reportedly blown down on several homes in Wapello County in the Ottumwa area. The damage was caused by high winds during this event and not during the thunderstorms that came before, however it is possible the trees may have been weakened by the initial thunderstorms. Damage was fairly widespread, albeit fairly minor. Perhaps the reason for the widespread damage was due to the fact that the high winds event featured a southeast wind, whereas most thunderstorms in this area produce wind gusts with a dominant westerly component. As the storms moved through Mahaska County, lightning struck a house north of Rose Hill. A fire was started with damage placed at $1,500.

Low pressure dropped southeast out of the Canadian Prairie Provinces and into the lower Great Lakes. The low itself was not all that deep, about 1005 mb, however there was very strong dynamics associated with it. At 500 mb, a strong short wave dived southeast into the central U.S. on a 110 kt jet. As the low passed and a 1044 mb Arctic high pressure area built into the area, strong winds overspread Iowa from the west. Sustained winds of 40 to 45 MPH were common in the blizzard area, with gusts in the 55 to 65 MPH range. The winds caused considerable blowing and drifting snow with visibilities reduced to near zero in open areas. Travel was not recommended throughout northeast Iowa. Snowfall was not all that great with new snow accumulations under 3 inches for the most part. A narrow area of the CWA received 3 to 5 inches with 5.1 inches reported at Northwood, 5 inches at Iowa Falls, and 2.5 to 4 inches in the Mason City area. The existing snow on the ground was glaciated, thus was not available to blow around. Southwest of the snow area...freezing drizzle coated roads, trees, and power lines over central and southwest Iowa. There were scattered power outages due to fallen limbs, but little significant damage. Traffic accidents were too numerous to mention due to near freezing temperatures allowing the initial snow to melt somewhat before the Arctic cold swept in.

Once again a very unstable airmass was in place over Iowa with a weak frontal boundary extending northeast to southwest across the state an old outflow boundary extending east to west along the southern Iowa border. The atmosphere was weakly capped during the early evening with lifted indices around -10 C and CAPE values around 4000 J/kg. During the evening the low level jet increased to around 40 kts and thunderstorms erupted in northwest Iowa. They were enhanced by a fast moving jet streak moving across southern Minnesota. The thunderstorms formed into a line rather quickly and dropped very heavy rainfall of up to 2 inches per hour and hail during the early stages of the MCS development. There were numerous reports of hail of penny size up to golf ball size in western into north central Iowa. After midnight, the line transitioned into a wind producer and began to move southeast. High winds of 60 to 65 MPH were common as the storms move into central and north central Iowa. Numerous reports were received of trees and power lines downed by the storms, however damage was not widespread.

A late season snow storm developed over the southern Rockies during the night of the 5th into the morning of the 6th. The upper system was quite separated from the surface features. Though the surface low tracked across southern Kansas and eventually through Missouri, the upper level low pressure moved northeast into northeast Nebraska by the morning of the 7th, before sinking slowly southeast across Iowa. A cold air mass was in place to the north of Iowa. A mixture of precipitation occurred across the state. Over the far south, all of the precipitation fell in the form of rain. Precipitation was mixed over the central counties, and predominantly snow over the north. Though there was a mixture of freezing rain and ice pellets in the central counties, the amounts were not all that significant. Significant snowfall occurred north of Interstate 80. Due to the prolonged nature of the event, many areas did not meet the criteria of a winter storm. Snowfall along the I-80 and U.S. Highway 30 corridors was generally in the 3 to 6 inch range. The snow fell over a 24 hour period. Heavy snowfall occurred from about U.S. Highway 20 and north. During a 12 to 18 hour period, snowfall of 7 to 10 inches was common. Some of the heavier snowfall amounts were 10.1 inches in Worth County at Northwood, 9.4 inches in Kossuth County at Swea City, and 9 inches in Webster County at Fort Dodge. Travel was hampered to some extent during the nighttime hours, but with ground temperatures in the low 40s F., conditions improved quickly after sunrise. Blowing and drifting snow was limited because of the heavy, wet nature of the snow. Winds during the height of the storm were from the east at 20 to 45 MPH. This caused significant drifting in open areas for a few hours. Also, the wet snow stuck to trees and power lines. There were scattered reports of tree limbs down and power outages, but nothing widespread.

A polar cold front had moved south across Iowa during the afternoon of the 3rd and early morning of the 4th. A shallow layer of cold air was in place over Iowa. At the same time, a wave formed along the front in Kansas and lifted northeast across Missouri during the day in response to a strong short wave aloft. A southwest flow of warm and moist air flowed over the top of the cold air at the surface. The result was an area of freezing rain with embedded thunderstorms and some hail. Icing was a problem north of U.S. Highway 20. Though the ground temperatures were warm enough that it was not a major travel problem, exposed objects collected ice rapidly. Ice accretions of one quarter to one third of an inch were common across the area. The ice caused some minor problems with downed tree branches and spotty power outages, but nothing serious.

A cold front moved into Iowa slowly from the northwest. The airmass in front of the cold front was quite unstable with temperatures in the low to mid 80s and dew point temperatures around 70. Thunderstorms erupted during the late afternoon and evening hours as the front moved into the state and strong forcing in the way of jet stream dynamics moved into the state. An unseasonably strong upper level trough of low pressure was approaching from the west. Most of the thunderstorms remained below severe levels with winds in the 40 to 50 MPH range. A storm became severe as it organized over Taylor County. Some damage occurred west of Lenox with 60 to 70 MPH reported. Severe thunderstorms were also reported in Adams County, with 60 MPH winds in the Corning area. As the night progressed, the thunderstorms formed into a line extending northeast to southwest across the state. During the late evening hours one of the storms produced winds around 65 MPH in the Waterloo area. Several trees were downed and there was power line damage around the city.

A warm front remained nearly stationary from low pressure in South Dakota..southeast into southwest Iowa and northern Missouri. The airmass was quite capped with 700 mb temperatures in the 11 to 14 degree C. range. Thunderstorms fired over northern Iowa by around midnight. The storms were very elevated and were for the most part hail producers. There were numerous reports of three quarter to one inch diameter size hail across north central into northeast Iowa. A few of the storms produced much larger hail. Golf ball size hail fell in Wright County in the Eagle Grove area. in Cerro Gordo County, Mason City was hard hit by another storm. There were several reports of golf ball size hail causing damage to several homes. Numerous windows were broken and some damage was reported to the siding of several homes as the hail was accompanied by 40 to 50 MPH winds. About three hours later, another cell dropped large hail in Butler County. Considerable damage occurred in the town of Parkersburg as golf ball to baseball size hail pelted the city. Toward the end of the event, a few of the cells became wind producers as they weakened. Severe criteria wind occurred in Butler County as winds of 60 to 70 MPH were reported. Several trees were downed and power was knocked out in the Allison area. Fortunately, much of the area that received heavy rainfall was relatively dry during June. Flash flooding occurred in Butler County with several reports of roads being washed out and flooding of residences basements. Rainfall of two to four inches was common with most of it falling in under 3 hours. During the storms, a minivan was struck by lightning east of Waterloo. The lightning traveled through the van, blowing out the rear window. It also left a 2 foot diameter crater in the roadway on U.S. Highway 20.

An Mesoscale Convective System (MCS) developed southwest of Iowa during the evening of the 10th and lifted northeast across the state during the morning of the 11th. Though no severe weather was associated with the MCS, high winds developed following its passage. As the MCS lifted northeast of the state, strong east to southeast winds developed in the wake of it. The winds knocked down two barns, along with numerous trees and power lines in Latimer in Franklin County. In Chapin, also in Franklin County, high winds blew over a semi-tractortrailer truck at the 176 mile marker of Interstate 35. There were several reports of minor damage across about the north third of Iowa.

The very unstable atmospheric condition over the central U.S. remained unchanged from what it had been during previous days. A strong cold front approached from the west as intense low pressure in the upper atmosphere lifted northeast into South Dakota during the day. Deep moisture was in place over the central U.S. with dew points at the 850 mb level at or approaching 20 degrees C. Numerous boundaries were in place across the state from the previous nights convection. Strong convection developed over Missouri during the early afternoon hours. This convection lifted north into Iowa during the afternoon. A line of severe thunderstorms moved into south central Iowa. This line moved northeast rapidly across the state along with an apparent gravity wave seen in satellite imagery. The main severe weather event was high winds. Though there were a few reports of large hail, most of the hail was no larger than marble size. Numerous reports of 60 to 70 MPH winds were received over south central into northeast Iowa. Tree and power line damage was widespread. As the storms moved through Black Hawk County, high winds swept into La Porte City. Trees were toppled in town. One fell on a police squad car, trapping the officer inside the car for a period of time. The echo pattern of the thunderstorms took on a LEWP (Line Echo Wave Pattern) by late afternoon. The mesoscale vorticity center was quite evident in the radar imagery as it passed over Mahaska County. A small tornado formed near the crest of the wave and touched down northeast of the town of Oskaloosa. Five buildings were damaged at a farm there and 2 x 4's were driven into a hog confinement building. The damage path was approximately one eighth mile long and 100 yards wide.

A very dynamic weather situation took place over Iowa during the afternoon of the 1st. The dynamics were sufficient to overcome the shortcomings in moisture available for the system. A cold front dropped southeast out of the Dakotas into Iowa during the afternoon. Surface dew points were generally in the mid 50s ahead of the front, though a narrow ribbon of upper 50s to lower 60s was found just ahead of the front. As the cold front dropped southeast, a very strong closed low at 500 mb was also dropping into the area. This helped to destabilize the atmosphere as freezing levels fell to the 8000 to 10,000 foot range by evening. A small area of thunderstorms developed by mid day over north central Iowa. The storms intensified rapidly during the maximum heating of the day. Thunderstorms fired southwest of the original area and became severe quickly. For the most part the storms produced hail and small tornadoes. The first tornado touched in Crawford County. The county Emergency Manager reported seeing 7 funnel clouds and two brief touchdowns with the initial cell. The tornadoes were all small and were only on the ground briefly. Several other brief touchdowns occurred in the County before the storm moved east. The strongest tornado touched down on the edge of the town of Denison. A 14 x 50 metal building was destroyed. A fire hydrant was damaged in the vicinity by flying debris. It was reported that water could be seen being sucked out of the hydrant by the tornado. The tornado threat shifted into northeast Iowa for the rest of the afternoon. Several tornadoes touched down in Bremer, Butler, and Black Hawk Counties. Most of these were quite small and did little damage however. The longest track tornado touched down in the Janesville area of Bremer County and tracked over 8 miles to the east, lifting just east of the town of Denver. The countryside is quite open between these two locations. For this reason, damage was minimal as the tornado actually missed both of the towns. With the cold air aloft, hail was a significant factor. There were reports of at least half inch diameter hail with nearly all of the storms. Numerous reports of hail of an inch up to golf ball size were received. The storms produced three inch diameter hail on the north side of Belmond, causing significant damage to the area and reportedly covering the ground. One of the storms became very intense over Butler County during the early afternoon. Softball size hail was reported with this cell, causing significant damage south of the town of Allison. The storms over southwest Iowa underwent a transition into more of a wind event. High winds were reported in Cass County as the storms moved through the Griswold area. By mid afternoon, the storms in southern Iowa had taken on a bow configuration. As the storms moved through Adair County, very strong winds swept through the northeast part of the county. The winds toppled power lines northeast of Greenfield. As the storms continued east, the intensity decreased. The storms still produced gusty winds, but speeds were generally in the 45 to 55 MPH range.

An intense low pressure system lifted northeast out of the Rockies, across northwest Iowa and on into the upper Great Lakes during the afternoon of the 22nd into the 23rd. The dry slot lifted north ahead of the low and passed over Iowa during the early morning hours of the 23rd. Within the dry slot winds of 70 to 85 MPH were common just a few thousand feet above the surface. Shortly after sunrise, a narrow band of showers formed over northeast Iowa. As the showers moved through northeast they produced very gusty winds. In Black Hawk and Bremer Counties, winds were in the 65 to 70 MPH range. Damage was reported around the two counties. Three miles northwest of Washburn in Black Hawk County a farm shed was completely destroyed. In Bremer County, a farm shed was destroyed by the winds near Tripoli and damage to power poles was reported in the Readlyn area. At the onset of the high winds a very narrow squall line developed. Actually, forming near the cold core of the upper low pressure area, convective tops were very low with little if any lightning associated with them. A tornado touched down briefly in Black Hawk County near Gilbertville. One house was damaged and power was cut to three others. The tornado lifted quickly and didn't touch down again until it was east of the Des Moines CWA.

A major wind and significant flash flooding event took shape across Iowa during the afternoon and evening of the 25th. A dynamic upper level system approached Iowa from the northwest during the afternoon. Several boundaries were in the area resulting from weak convection that took place during the morning. Very strong theta-e advection took place over northeast Nebraska during the morning and early afternoon hours. In addition, several other factors came into play. Moisture continued to stream into Iowa from the remnants of Hurricane Carlotta as precipitable water values approached 2.2 inches. Iowa was also under the influence of a coupled jet structure. As a result a strong upper level divergent field was in place over the state. By afternoon, mid and upper level cold air advection began to take place as well. Strong convection took place by mid day over northeast Nebraska into west central Iowa. The line of thunderstorms moved into rich air with surface dew points in the low to mid 70s. The main feature with the storms was high winds. The line of thunderstorms took on a bow echo configuration as it moved across southern Iowa. Most of the southern three tiers of counties reported high winds. Wind speeds of 60 to as much as 85 MPH were reported with the storms. Wind speeds topped out at 85 MPH at New Virginia, in Warren County. Damage was widespread with numerous trees and power lines downed by the winds. Some trees up to 2 feet in diameter were snapped. A flag pole was reported bent 4 inches by the high winds as well. One tornado was reported in Warren County as well. This was a brief tornado near St Marys which caused no damage. The other problem with the storms was the heavy rainfall. Two to three inches of rain fell in many areas. As the storms moved into parts of south central and southeast Iowa, they moved into area that had been inundated by heavy rainfall just two nights before. Flash flooding was reported in Appanoose, Lucas, Mahaska, Monroe, Wayne, Davis, and Wapello Counties. Numerous roads were under water in these counties. U.S. Highway 63 was closed by high water north of Ottumwa. Some of the worst flooding took place in Mahaska County where heavy rain fell on areas that had been flooded two days before. At least 15 roads were reported under water in the county. As the thunderstorms moved through Hamilton County, lightning struck a tree outside of a house in Stratford. It also left a hole in the ground and caused damage inside the house. The lightning strike broke windows out of the front of the house and also caused windows to break in the house next door. Later, the storms moved into the Waterloo area. Lightning struck the chimney of a former school building. The top part of the chimney was blown off by the lightning and a good part of the rest of the chimney was damaged.

The seasons first spring type weather system moved through the area on the 8th into the early morning hours of the 9th. Intense low pressure moved out of the Rockies into the plains of Nebraska. Eventually, the low moved across Iowa and passed to the northeast. The situation had the potential of becoming a serious severe weather event if not for the fact that the dry slot swept northeast across Iowa. In the sinking air under the dry slot, strong southerly winds developed during the day on the 8th. The winds gradually swung around to the southwest and eventually the northwest as the low passed. Winds gusted to near 60 MPH in many areas, with an official measured wind speed of 60 MPH at the Ottumwa Airport. All of the state reported winds of at least 40 to 50 MPH. Sustained winds were in the 30 to 40 MPH range throughout the day until past midnight. Damage was limited with the system since the leaves were not yet on the trees. There were spotty reports of power outages as some tree limbs were blown onto power lines. There was also some other spotty damage, but no major damage reported.