Hail and Damaging Winds in Iowa, March 31, 2007

Name: Hail and Damaging Winds in Iowa, March 31, 2007
Start: 2007-03-31T13:22
End: 2007-03-31T16:10
Location: Iowa

March 31, 2007 · NWS DMX · 20 events in 14 counties and zones

S. into western Iowa during the afternoon hours of the 31st.

Where it happened

Every event with a place to put it. Tap one for its entry below.

Tornadoes
Tropical storms and surge
Floods
Wind
Hail
Winter weather
Heat and drought
Cold
Fire, smoke and dust
Marine and coastal
Other

Open the live radar over this ground

The toll

Deaths: 0
Injuries: 0
Property damage: $114,000
Crop damage: None recorded
Events: 20

Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.

What happened

The episode as NWS DMX wrote it up.

An intense low pressure lifted out of the south central U.S. into western Iowa during the afternoon hours of the 31st. The upper low virtually captured the surface system by late afternoon. Thunderstorms formed along two boundaries. The first was a warm frontal boundary that lifted into central Iowa by early afternoon. The second was a strong dryline that advanced into southwest and central Iowa by the late afternoon hours. With the steep lapse rates, there was little in the way of CIN and once the clouds began to break. Surface Based CAPE was in the 1000-2000 J/kg range with CAPE in the -10 to -30 C. layer around 200 J/kg. The freezing level was quite low, ranging from 8,700 to 10,000 feet across the CWA. Lifted indices fell to the -6 to -9 C. range by the mid afternoon hours. In spite of the LCL being quite low, in the 500 to 1000 meter range, there were several reports of funnels, but no confirmed touchdowns. Thunderstorms formed in two lines. The first was along the warm front across central Iowa. The second along the dryline. There were numerous reports of pea to marble size hail and surprisingly few reports of larger hail. The hail that did fall was in the three quarter to one inch diameter range. One inch diameter hail covered the ground in Davis County at Bloomfield. Some damage was done to vinyl siding in the city of Bloomfield as well. A few of the storms produced high winds with tree damage and some building damage. A roof was blown off a shed in Polk County in Pleasant Hill. Outbuildings were destroyed by another storm in Story and Marshall Counties, and a garage was blown over in Marshall County in the Marshalltown area. High winds from the dryline storms caused damage in Waukee with damage to house siding and a metal fence in the area.

What forecasters said that day

The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Des Moines, IA wrote its last area forecast discussion before the first event at Mar 31, 2:00 AM CST, 11 hours 22 minutes earlier.

Area forecast discussion, Mar 31, 2:00 AM CST, 11 hours 22 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
300 AM CDT SAT MAR 31 2007

.DISCUSSION...

MAIN FOCUS IS TIMING EXTENT AND AMOUNT OF RAIN TODAY AS RATHER
COMPLEX SYSTEM HAS THE POTENTIAL TO BRING HEAVY RAINS TO THE AREA.
IN LONGER TERM FOCUS REMAINS ON SEVERAL SYSTEM AROUND MID WEEK AND
TRANSITION TO COOLER WEATHER WITH THE THREAT OF SEVERE.

TODAY MODELS HAVE FINALLY COME TOGETHER IN TRACK OF SURFACE AND
UPPER LOW SYSTEMS.  QPF SOMEWHAT LIGHTER THAN PREVIOUS RUNS OF THE
LAST FEW DAYS HOWEVER THERE REMAINS POTENTIAL OVER FFA AREA SO WILL
LEAVE THAT IN AFFECT.  SPC HAS ENTIRE CWA IN SLIGHT RISK WITH MIXED
IDEAS ON THREATS.  POTENTIAL RESTS STRONGLY ON MOVEMENT OF SYSTEMS
WHETHER WE CAN GET ANY HEAT FOR RAPID DESTABILIZATION AND EXACT
MOVEMENT OF SURFACE LOW AS WELL AS DRY SLOT AS PORTRAYED BY MODELS.
DYNAMICAL FIELDS FAIRLY IMPRESSIVE WITH GOOD SHEAR.  SUGGESTION OF
SOME ISOLATED TORNADOES REASONABLE.  TONIGHT LATEST MODEL RUNS
TOGETHER ON LINGERING SYSTEM THOUGH SOME QUESTIONS ON EXACT ENDING
TIME OF RAIN WITH EVEN MORE QUESTIONABLE TIMING ON SUNDAY AS MODELS
HAVE HIGHER POPS ON SUNDAY.  LOOKING AT TIMING HAVE LEFT CHANCES IN
NORTHEASTERN HALF OF CWA FOR SUNDAY MORNING THEN DIMINISHED AREA FOR
SUNDAY AFTERNOON AS DYNAMICAL FIELDS WEAKEN WITH BEST NORTHEAST OF
CWA.  THERE IS SOME QUESTION LEFT IN MY MIND AS TO WHETHER WEAK LOBE
COULD ROTATE AROUND SYSTEM THIS AFTERNOON AND EARLY EVENING WITH
LIGHT PCPN.  TEMPERATURES HAVE STAYED CLOSE TO GUIDANCE WITH SOME
MINOR ADJUSTMENTS FOR CLOUD COVER AND PCPN.  FARTHER OUT RAIN WILL
COME INTO QUESTION ON MONDAY AFTERNOON AND INTO TUESDAY AHEAD OF
SYSTEM THAT WILL BRING COOLING TO THE STATE.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...FLOOD WATCH THROUGH 6 PM SATURDAY

IAZ004>007-0015>017-23>026-033>037-
044>048-057>060-070>073-081>083-092>094-
IAZ004>007-0015>017-23>026-033>037-044>048-
057>060-070>073-081>083-092>094-

&&

FORSTER/154/30

Hazardous weather outlook, Mar 31, 11:48 AM CST, 1 hour 34 minutes before

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE DES MOINES IA
1248 PM CDT SAT MAR 31 2007

IAZ004>006-015-016-023>025-033>036-044>048-057>061-070>074-
081>085-092>096-011800-
EMMET-KOSSUTH-WINNEBAGO-PALO ALTO-HANCOCK-POCAHONTAS-HUMBOLDT-
WRIGHT-SAC-CALHOUN-WEBSTER-HAMILTON-CRAWFORD-CARROLL-GREENE-BOONE-
STORY-AUDUBON-GUTHRIE-DALLAS-POLK-JASPER-CASS-ADAIR-MADISON-
WARREN-MARION-ADAMS-UNION-CLARKE-LUCAS-MONROE-TAYLOR-RINGGOLD-
DECATUR-WAYNE-APPANOOSE-
1248 PM CDT SAT MAR 31 2007

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL IOWA.

.DAY ONE...THIS AFTERNOON AND TONIGHT

THERE IS A SLIGHT RISK OF SEVERE STORMS AS THE AIR BECOMES
UNSTABLE THIS AFTERNOON. CONDITIONS ARE FAVORABLE FOR TORNADOES
AND LARGE HAIL...WITH DAMAGING STRAIGHT LINE WINDS A LESSER THREAT.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY

THERE IS A CHANCE FOR THUNDERSTORMS ON MONDAY AFTERNOON HOWEVER
THERE IS MODEL UNCERTAINTY AS TO WHETHER THE STORMS WILL BECOME
SEVERE.

.SPOTTER INFORMATION STATEMENT...

A CONFERENCE CALL FOR EMERGENCY MANAGEMENT COORDINATORS WILL BE
CONDUCTED AT 115 PM CDT THIS AFTERNOON. SPOTTER ACTIVATION MAY
BECOME NECESSARY THIS AFTERNOON AND EVENING.

IAZ007-017-026>028-037>039-049-050-062-075-086-097-011800-
WORTH-CERRO GORDO-FRANKLIN-BUTLER-BREMER-HARDIN-GRUNDY-BLACK HAWK-
MARSHALL-TAMA-POWESHIEK-MAHASKA-WAPELLO-DAVIS-
1248 PM CDT SAT MAR 31 2007

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL IOWA.

.DAY ONE...THIS AFTERNOON AND TONIGHT

THERE IS A SLIGHT RISK OF SEVERE STORMS AS THE AIR BECOMES
UNSTABLE THIS AFTERNOON. CONDITIONS ARE FAVORABLE FOR TORNADOES
AND LARGE HAIL...WITH DAMAGING STRAIGHT LINE WINDS A LESSER THREAT.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY

THERE IS A CHANCE FOR THUNDERSTORMS ON MONDAY AFTERNOON HOWEVER
THERE IS MODEL UNCERTAINTY AS TO WHETHER THE STORMS WILL BECOME
SEVERE.

.SPOTTER INFORMATION STATEMENT...

A CONFERENCE CALL FOR EMERGENCY MANAGEMENT COORDINATORS WILL BE
CONDUCTED AT 115 PM CDT THIS AFTERNOON. SPOTTER ACTIVATION MAY
BECOME NECESSARY THIS AFTERNOON AND EVENING.

MOYER

The radar

The Des Moines radar (KDMX), 154 km away, was scanning. The volume nearest the first event began at 19:20 UTC.

Open the radar archive at this moment

Event by event

10 thunderstorm wind, 7 hail, 3 funnel cloud. Local standard time, as filed.

Hail, Davis

When: March 31, 1:22 PM CST
Where: Davis County, Bloomfield
Measured: 1 in hail
Property damage: $10,000
Reported by: Emergency Manager
Coordinates: 40.750, -92.420

Hail, Warren

When: March 31, 1:25 PM CST
Where: Warren County, 0.87 mi NE of Milo
Measured: 1 in hail
Property damage: $5,000
Reported by: Emergency Manager
Coordinates: 41.290, -93.440

Hail, Wapello

When: March 31, 1:38 PM CST
Where: Wapello County, 1.48 mi SSW of Ottumwa
Measured: 0.75 in hail
Reported by: Trained Spotter
Coordinates: 41.000, -92.410

Thunderstorm Wind, Jasper

When: March 31, 1:55 PM CST
Where: Jasper County, Monroe
Measured: 52 kt (60 mph) estimated gust
Property damage: $1,000
Reported by: Broadcast Media
Coordinates: 41.520, -93.100

Thunderstorm Wind, Polk

When: March 31, 2:00 PM CST
Where: Polk County, 1.24 mi NE of Youngstown
Measured: 61 kt (70 mph) estimated gust
Property damage: $25,000
Reported by: Law Enforcement
Coordinates: 41.590, -93.510

Hail, Jasper

When: March 31, 2:17 PM CST
Where: Jasper County, 0.69 mi N of Baxter
Measured: 0.88 in hail
Property damage: $1,000
Reported by: Law Enforcement
Coordinates: 41.830, -93.150

Thunderstorm Wind, Story

When: March 31, 2:30 PM CST
Where: Story County, 3.44 mi SE of Zearing
Measured: 61 kt (70 mph) estimated gust
Property damage: $30,000
Reported by: Emergency Manager
Coordinates: 42.130, -93.260

Thunderstorm Wind, Marshall

When: March 31, 2:30 PM CST
Where: Marshall County, 3 mi SE of State Center
Measured: 56 kt (64 mph) estimated gust
Property damage: $10,000
Reported by: Broadcast Media
Coordinates: 41.989, -93.129

Thunderstorm Wind, Marshall

When: March 31, 2:33 PM CST
Where: Marshall County, 3.08 mi E of State Center
Measured: 56 kt (64 mph) estimated gust
Property damage: $10,000
Reported by: Law Enforcement
Coordinates: 42.020, -93.110

Hail, Greene

When: March 31, 2:45 PM CST
Where: Greene County, 1.02 mi E of Adaza
Measured: 1 in hail
Property damage: $3,000
Reported by: Law Enforcement
Coordinates: 42.200, -94.480

Thunderstorm Wind, Marshall

When: March 31, 2:45 PM CST
Where: Marshall County, Marshalltown
Measured: 55 kt (63 mph) estimated gust
Property damage: $3,000
Reported by: Trained Spotter
Coordinates: 42.050, -92.920

Thunderstorm Wind, Hardin

When: March 31, 2:46 PM CST
Where: Hardin County, 3.44 mi SW of New Providence
Measured: 52 kt (60 mph) estimated gust
Property damage: $1,000
Reported by: Trained Spotter
Coordinates: 42.240, -93.210

Hail, Greene

When: March 31, 2:47 PM CST
Where: Greene County, 1.02 mi E of Adaza
Measured: 1 in hail
Property damage: $2,000
Reported by: Law Enforcement
Coordinates: 42.200, -94.480

Thunderstorm Wind, Hardin

When: March 31, 2:55 PM CST
Where: Hardin County, 1.47 mi SSE of Pt Pleasant
Measured: 71 kt (82 mph) estimated gust
Property damage: $5,000
Reported by: Amateur Radio
Coordinates: 42.310, -93.220

Funnel Cloud, Calhoun

When: March 31, 3:10 PM CST
Where: Calhoun County, Knierim
Reported by: Law Enforcement
Coordinates: 42.450, -94.450

Hail, Franklin

When: March 31, 3:21 PM CST
Where: Franklin County, 0.69 mi S of Geneva
Measured: 0.75 in hail
Reported by: Trained Spotter
Coordinates: 42.670, -93.130

Funnel Cloud, Butler

When: March 31, 3:48 PM CST
Where: Butler County, 2 mi W of Clarksville
Reported by: Emergency Manager
Coordinates: 42.780, -92.709

Thunderstorm Wind, Dallas

When: March 31, 3:55 PM CST
Where: Dallas County, Waukee
Measured: 52 kt (60 mph) estimated gust
Property damage: $5,000
Reported by: Broadcast Media
Coordinates: 41.620, -93.900

Thunderstorm Wind, Bremer

When: March 31, 4:08 PM CST
Where: Bremer County, 1.38 mi S of Horton
Measured: 52 kt (60 mph) estimated gust
Property damage: $3,000
Reported by: Public
Coordinates: 42.830, -92.470

Funnel Cloud, Calhoun

When: March 31, 4:10 PM CST
Where: Calhoun County, 3 mi E of Jolley
Reported by: Trained Spotter
Coordinates: 42.480, -94.661

What these are

Hail: Hail three-quarters of an inch or larger, or smaller hail that caused damage, filed with the largest stone measured.
Thunderstorm Wind: Winds from a thunderstorm of 50 knots (58 mph) or more, or lower winds that caused damage or casualties. Measured gusts are marked MG, estimated EG.
Funnel Cloud: A rotating column of cloud extending from a thunderstorm that did not reach the ground.

After NWS Directive 10-1605, the rules offices file Storm Data by.

The same day elsewhere

Every storm in Iowa in 2007 Every state in 2007 This day in weather history Warnings in Iowa, March 2007

Sources

NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 13784, 13785, 13786, 13799, 13791, 13787, 13792, 13800, 13794, 13788, 14176, 13795, 13789, 13796, 13803, 13790, 13804, 13802, 13797, 13805.