Alert archive / Iowa / Severe Thunderstorm Warnings in 2008

Severe Thunderstorm Warning 17, NWS Des Moines, IA

April 22, 2008Mahaska County, Marion County, Monroe County, Iowa

NWS Des Moines, IA issued this severe thunderstorm warning at Apr 22, 2008, 5:51 AM CDT for Mahaska County, Marion County, Monroe County, Iowa. It was in force for 39 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: Apr 22, 2008, 5:51 AM CDT (10:51 UTC)
Expired: Apr 22, 2008, 6:30 AM CDT
In force: 39 min
Issued by: NWS Des Moines, IA
Area: Storm-based polygon

Counties Mahaska County, IA, Marion County, IA, Monroe County, IA

The radar

The Des Moines radar (KDMX), 93 km from the middle of the area, began a volume at 10:51 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

Did it verify

Not verified. The Iowa Environmental Mesonet's Cow found no qualifying storm report inside this severe thunderstorm warning while it was in force. That is not proof nothing happened: reports are thin where few people live.

Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.

The nearest sounding before it

Davenport, (KDVN), launched 00:00Z, 10.9 hours before the alert went out and 200 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 2279 m above ground
0-6 km bulk shear: 21 kt
0-1 km storm-relative helicity: 40 m²/s²
0-3 km storm-relative helicity: 86 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

000 
WUUS53 KDMX 221051
SVRDMX
IAC123-125-135-221130-
/O.NEW.KDMX.SV.W.0017.080422T1051Z-080422T1130Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
551 AM CDT TUE APR 22 2008

THE NATIONAL WEATHER SERVICE IN DES MOINES HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  MAHASKA COUNTY IN SOUTH CENTRAL IOWA...
  EASTERN MARION COUNTY IN SOUTH CENTRAL IOWA...
  NORTHERN MONROE COUNTY IN SOUTH CENTRAL IOWA...

* UNTIL 630 AM CDT.

* AT 546 AM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING PENNY SIZE HAIL...AND
  DAMAGING WINDS IN EXCESS OF 60 MPH.  THIS STORM WAS LOCATED 7 MILES
  NORTHWEST OF MARYSVILLE...OR 37 MILES SOUTHEAST OF DES MOINES...AND
  MOVING NORTHEAST AT 61 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  BUSSEY BY 550 AM CDT...
  HARVEY AND PELLA AIRPORT BY 555 AM CDT...
  LEIGHTON AND PELLA BY 600 AM CDT...
  9 MILES NORTHWEST OF BEACON AND 9 MILES NORTHWEST OF OSKALOOSA BY
  605 AM CDT...
  NEW SHARON BY 610 AM CDT...

MOVE TO AN INTERIOR ROOM AND STAY AWAY FROM WINDOWS. IF YOU LIVE IN A
MOBILE HOME...SEEK SHELTER IN A STURDY BUILDING.

LAT...LON 4115 9310 4116 9311 4148 9300 4151 9253
      4117 9251 4116 9263 4116 9264 4116 9265
      4112 9310
TIME...MOT...LOC 1051Z 237DEG 53KT 4128 9298

$$

RUSSELL

2 follow-up statements

000 
WWUS53 KDMX 221123
SVSDMX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
623 AM CDT TUE APR 22 2008

IAC125-135-221133-
/O.CAN.KDMX.SV.W.0017.000000T0000Z-080422T1130Z/
MONROE IA-MARION IA-
623 AM CDT TUE APR 22 2008

...THE SEVERE THUNDERSTORM WARNING FOR EASTERN MARION AND NORTHERN
MONROE COUNTIES IS CANCELLED...

AT 620 AM CDT...WEATHER SERVICE DOPPLER RADAR INDICATED THAT THE
THUNDERSTORMS WHICH PROMPTED THE WARNING HAVE EITHER WEAKENED OR
MOVED OUT OF THE AREA...AND NO LONGER POSE AN IMMEDIATE THREAT TO
LIFE OR PROPERTY. THEREFORE...THE SEVERE THUNDERSTORM WARNING HAS
BEEN CANCELLED.

REPORT TORNADOES...WIND IN EXCESS OF 50 MPH...HAIL LARGER THAN ONE
HALF INCH...OR STORM DAMAGE BY CALLING LOCAL LAW ENFORCEMENT AND
ASKING THEM TO RELAY THE REPORT TO THE NATIONAL WEATHER SERVICE.

LAT...LON 4149 9282 4151 9253 4117 9251 4116 9263
TIME...MOT...LOC 1123Z 251DEG 43KT 4138 9257

$$

IAC123-221130-
/O.CON.KDMX.SV.W.0017.000000T0000Z-080422T1130Z/
MAHASKA IA-
623 AM CDT TUE APR 22 2008

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 630 AM CDT
FOR CENTRAL MAHASKA COUNTY...

AT 620 AM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A SEVERE THUNDERSTORM CAPABLE OF PRODUCING PENNY SIZE HAIL. 
THIS STORM WAS LOCATED 6 MILES NORTH OF OSKALOOSA...OR 21 MILES WEST
OF SIGOURNEY...MOVING EAST AT 49 MPH.

IF YOU ARE IN THE PATH OF THIS STORM...PREPARE IMMEDIATELY FOR LARGE
HAIL...DAMAGING WINDS AND DEADLY CLOUD TO GROUND LIGHTNING. PEOPLE
OUTSIDE SHOULD MOVE TO A SHELTER...PREFERABLY INSIDE A STRONG
BUILDING BUT AWAY FROM WINDOWS.

REPORT TORNADOES...WIND IN EXCESS OF 50 MPH...HAIL LARGER THAN ONE
HALF INCH...OR STORM DAMAGE BY CALLING LOCAL LAW ENFORCEMENT AND
ASKING THEM TO RELAY THE REPORT TO THE NATIONAL WEATHER SERVICE.

LAT...LON 4149 9282 4151 9253 4117 9251 4116 9263
TIME...MOT...LOC 1123Z 251DEG 43KT 4138 9257

$$

SMALL

000 
WWUS53 KDMX 221132
SVSDMX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
633 AM CDT TUE APR 22 2008

IAC123-221143-
/O.EXP.KDMX.SV.W.0017.000000T0000Z-080422T1130Z/
MAHASKA IA-
633 AM CDT TUE APR 22 2008

...THE SEVERE THUNDERSTORM WARNING FOR CENTRAL MAHASKA COUNTY HAS
EXPIRED...

AT 629 AM CDT...WEATHER SERVICE DOPPLER RADAR INDICATED THAT THE
THUNDERSTORMS WHICH PROMPTED THE WARNING HAVE WEAKENED...AND NO
LONGER POSE AN IMMEDIATE THREAT TO LIFE OR PROPERTY. THEREFORE...THE
SEVERE THUNDERSTORM WARNING WILL BE ALLOWED TO EXPIRE.

REPORT TORNADOES...WIND IN EXCESS OF 50 MPH...HAIL LARGER THAN ONE
HALF INCH...OR STORM DAMAGE BY CALLING LOCAL LAW ENFORCEMENT AND
ASKING THEM TO RELAY THE REPORT TO THE NATIONAL WEATHER SERVICE.

LAT...LON 4149 9282 4151 9253 4117 9251 4116 9263
TIME...MOT...LOC 1123Z 251DEG 43KT 4137 9257

$$

SMALL

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, 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 this severe thunderstorm warning went out at Apr 22, 4:06 AM CDT, 1 hour 45 minutes earlier.

Area forecast discussion, Apr 22, 4:06 AM CDT, 1 hour 45 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
406 AM CDT TUE APR 22 2008

.DISCUSSION...
500 MB SHORTWAVE MOVING OVERHEAD WILL PUSH SURFACE TROUGH/FRONT EAST
OF OUR AREA THIS MORNING ALONG WITH RAIN CHANCES AND CLOUDS. NAM
TRIES TO REDEVELOP SOME CLOUDS AND LIGHT RAIN IN WAKE OF THE SURFACE
BOUNDARY THIS MORNING...BUT THIS SEEMS DUE TO FLUCTUATION IN
SHORTWAVE TIMING NOT INDICATED BY OTHER MODELS. SURFACE HIGH
PRESSURE WILL MOVE QUICKLY INTO NORTHWESTERN IOWA THIS
AFTERNOON...RESULTING IN DECREASING WINDS LATE IN THE DAY. WITH
RESULTING SHORT DURATION MARGINAL CAA BEHIND SURFACE BOUNDARY
TEMPERATURES SHOULD REBOUND FAIRLY WELL WITH LT WNDS AND FEW CLDS
THIS AFTERNOON. HAVE BUMPED UP DAYTIME HIGHS A DEGREE OR TWO TO
REFLECT THIS.

FAIR WX THEN EXPECTED FOR TONIGHT AND WED AS HIGH PRESSURE SETTLES
INTO IA.  QUESTION THEN TURNS TO CONVECTIVE INITIATION WED NIGHT.
GFS STRONG CONVECTIVE VORT MAX ALONG TX/OK BORDER MAY BE ANCHORING
PCPN TOO FAR SOUTH WITH ECMWF/NAM/GEM/SREF ALL SUGGESTING FARTHER
NWD TRACK WITH FORCING AND MCS.  SEE NO REASON TO BUCK CONSENSUS AT
THIS POINT SO WILL BOOST OVERNIGHT POPS INTO LIKELIES AS LARGE SCALE
FORCING INCREASES...BUT NOT QUITE AS AGGRESSIVE AS ETA/NAM MOS.  MAY
BE SOMEWHAT OF A LULL THU AS OVERNIGHT MCS EXITS READY TO RELOAD
WITH FROPA.  COUPLING OF LOW LEVEL CONVERGENCE AND SYNOPTIC UVM
AHEAD OF POTENT TROUGH SHOULD BE PLENTY TO INITIATE MORE CONVECTION
THU NIGHT SO HAVE LIKELIES AGAIN OVER ENTIRE FORECAST AREA.  DID NOT
CHANGE FORECAST MUCH IN LATER PERIODS...BUT COULD SEE LINGERING
PRECIP FRI MORNING...ENDING BY LATE IN THE DAY.

SOUNDINGS SUGGEST RAISING TEMPS WED BUT NOT QUITE AS HIGH AS
GUIDANCE SUGGESTED WITH THE SAME HOLDING TRUE INTO THU.

&&

.HYDROLOGY...
WITH CONVECTION THIS MORNING AND POSSIBLY SEVERAL MORE ROUNDS WED
NIGHT THROUGH THU NIGHT...FLOODING MAY AGAIN BECOME A CONCERN.
BASED ON IEM/DAILY SOIL EROSION PROJECT SOIL MOISTURE
DATA...SOUTHERN AND EAST CENTRAL SECTIONS ARE PARTICULARLY
SUSCEPTABLE.  WILL ISSUE HYDROLOGIC OUTLOOK /ESF/ AND HIGHLIGHT
THESE AREAS OF CONCERN.  QPF WED NIGHT AND THU IS APPROACHING AN
INCH WHICH DOES NOT INCLUDE THU NIGHT OR LOCALLY HIGHER AMOUNTS.

&&

.AVIATION...22/06Z
CDFNT MAKING LTL PROGRESS AS UPR LVL TROF AND UPPER LEVEL SPEED MAX
LIFTS OUT OF CO.  WILL SEE AN INC IN SHRA/TSRA ACTIVITY DURG THE
FIRST 6 HRS OF THE TAF PD WITH IMPVG CONDS AFT THAT.  HI PRES BLDG
INTO THE AREA ON TUE INTO TUE NGT WL BRING GUD VFR CONDS ACRS THE
STATE.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...NONE.

&&

BSS/JL/MS

Hazardous weather outlook, Apr 22, 5:47 AM CDT, 4 minutes before

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE DES MOINES IA
547 AM CDT TUE APR 22 2008

IAZ027-028-038-039-049-050-061-062-073>075-083>086-094>097-231100-
BUTLER-BREMER-GRUNDY-BLACK HAWK-MARSHALL-TAMA-JASPER-POWESHIEK-
WARREN-MARION-MAHASKA-CLARKE-LUCAS-MONROE-WAPELLO-DECATUR-WAYNE-
APPANOOSE-DAVIS-
547 AM CDT TUE APR 22 2008

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF EASTERN AND
SOUTH CENTRAL IOWA.

.DAY ONE...TODAY AND TONIGHT

SCATTERED THUNDERSTORMS WILL MOVE THROUGH THE AREA EARLY THIS
MORNING. SOME OF THE STORMS MAY PRODUCE UP TO QUARTER SIZED LARGE
HAIL WITH STRONG AND POTENTIALLY DAMAGING WINDS A LESSER THREAT.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

ADDITIONAL THUNDERSTORMS ARE IN THE FORECAST FROM LATE WEDNESDAY
NIGHT THROUGH EARLY FRIDAY. SOME OF THESE STORMS MAY BE
SEVERE...ESPECIALLY THURSDAY NIGHT. MODERATE TO LOCALLY HEAVY
RAINS MAY ALSO OCCUR AND WITH CURRENT SOIL CONDITIONS SO
MOIST...ADDITIONAL FLOODING OF STREAMS AND RIVERS MAY DEVELOP.

.SPOTTER INFORMATION STATEMENT...

A FEW PERIODS OF SPOTTER ACTIVATION MAY BE NEEDED EARLY THIS
MORNING...AND THEN AGAIN LATER THIS WEEK.

IAZ004>007-015>017-023>026-033>037-044>048-081-092-231100-
EMMET-KOSSUTH-WINNEBAGO-WORTH-PALO ALTO-HANCOCK-CERRO GORDO-
POCAHONTAS-HUMBOLDT-WRIGHT-FRANKLIN-SAC-CALHOUN-WEBSTER-HAMILTON-
HARDIN-CRAWFORD-CARROLL-GREENE-BOONE-STORY-ADAMS-TAYLOR-
547 AM CDT TUE APR 22 2008

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL AND
NORTHERN IOWA.

.DAY ONE...TODAY AND TONIGHT

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

THUNDERSTORMS RETURN TO THE FORECAST LATE WEDNESDAY NIGHT THROUGH
EARLY FRIDAY. A FEW OF THE STORMS MAY BE SEVERE WITH LARGE HAIL
AND DAMAGING WINDS...ESPECIALLY THURSDAY NIGHT.

.SPOTTER INFORMATION STATEMENT...

A FEW PERIODS OF SPOTTER ACTIVATION MAY BE NEEDED LATE WEDNESDAY
NIGHT INTO EARLY FRIDAY.

IAZ057>060-070>072-082-093-231100-
AUDUBON-GUTHRIE-DALLAS-POLK-CASS-ADAIR-MADISON-UNION-RINGGOLD-
547 AM CDT TUE APR 22 2008

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL AND
SOUTHWEST IOWA.

.DAY ONE...TODAY AND TONIGHT

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

ADDITIONAL THUNDERSTORMS ARE IN THE FORECAST FROM LATE WEDNESDAY
NIGHT THROUGH EARLY FRIDAY. SOME OF THESE STORMS MAY BE
SEVERE...ESPECIALLY THURSDAY NIGHT. MODERATE TO LOCALLY HEAVY
RAINS MAY ALSO OCCUR AND WITH CURRENT SOIL CONDITIONS SO
MOIST...ADDITIONAL FLOODING OF STREAMS AND RIVERS MAY DEVELOP.

.SPOTTER INFORMATION STATEMENT...

A FEW PERIODS OF SPOTTER ACTIVATION MAY BE NEEDED LATER THIS WEEK.

SMALL

In the hours before

Local storm report, Apr 22, 1:27 AM CDT, 4 hours 24 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DES MOINES IA
127 AM CDT TUE APR 22 2008

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0126 AM     HAIL             3 E ATLANTIC AIRPORT    41.41N 95.00W
04/22/2008  E1.00 INCH       CASS               IA   BROADCAST MEDIA

            PENNY TO QUARTER SIZED HAIL COMING DOWN IN BUCKETS AND
            ACCUMULATING. FROM KJAN RADIO IN ATLANTIC.

&&

SMALL

Local storm report, Apr 22, 1:33 AM CDT, 4 hours 18 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DES MOINES IA
133 AM CDT TUE APR 22 2008

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0125 AM     HAIL             5 NNE ATLANTIC          41.46N 94.97W
04/22/2008  E1.00 INCH       CASS               IA   TRAINED SPOTTER

            HAIL NEARLY COVERING THE GROUND. LASTED FOR SEVERAL
            MINUTES.

&&

SMALL

Local storm report, Apr 22, 1:39 AM CDT, 4 hours 12 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DES MOINES IA
139 AM CDT TUE APR 22 2008

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0135 AM     HAIL             1 S BRAYTON             41.52N 94.93W
04/22/2008  E0.75 INCH       AUDUBON            IA   TRAINED SPOTTER

            DIME TO PENNY HAIL COVERING THE GROUND.

&&

MRUSSELL

Local storm report, Apr 22, 3:24 AM CDT, 2 hours 27 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DES MOINES IA
324 AM CDT TUE APR 22 2008

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0229 AM     HAIL             1 W ANITA               41.44N 94.78W
04/22/2008  E0.25 INCH       CASS               IA   LAW ENFORCEMENT

0307 AM     HAIL             7 N BOONE AIRPORT       42.15N 93.82W
04/22/2008  E0.75 INCH       BOONE              IA   TRAINED SPOTTER

&&

MRUSSELL

Local storm report, Apr 22, 3:26 AM CDT, 2 hours 25 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DES MOINES IA
326 AM CDT TUE APR 22 2008

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0326 AM     HAIL             BEDFORD                 40.67N 94.72W
04/22/2008  E0.88 INCH       TAYLOR             IA   EMERGENCY MNGR

&&

MRUSSELL

Local storm report, Apr 22, 3:40 AM CDT, 2 hours 11 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DES MOINES IA
340 AM CDT TUE APR 22 2008

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0325 AM     HAIL             1 SE CLIVE              41.59N 93.75W
04/22/2008  E0.88 INCH       POLK               IA   BROADCAST MEDIA

            NICKEL SIZED HAIL AT I235 AND VALLEY WEST DRIVE. PEOPLE
            PULLING OVER. FROM KCCI TV.

&&

SMALL

The office that day

Everything else NWS Des Moines, IA issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Apr 22, 1:12 AM CDT	Severe Thunderstorm Warning	DMX	Cass	33 min
Apr 22, 1:31 AM CDT	Severe Thunderstorm Warning	DMX	Audubon, Cass	29 min
Apr 22, 1:47 AM CDT	Severe Thunderstorm Warning	DMX	Audubon, Guthrie	28 min
Apr 22, 3:36 AM CDT	Severe Thunderstorm Warning	DMX	Hardin, Marshall, Story	39 min
Apr 22, 3:39 AM CDT	Severe Thunderstorm Warning	DMX	Polk	36 min
Apr 22, 4:15 AM CDT	Severe Thunderstorm Warning	DMX	Dallas, Madison, Polk, Warren	45 min
Apr 22, 4:50 AM CDT	Severe Thunderstorm Warning	DMX	Jasper, Polk	28 min
Apr 22, 5:04 AM CDT	Severe Thunderstorm Warning	DMX	Clarke, Lucas, Warren	41 min
Apr 22, 5:25 AM CDT	Severe Thunderstorm Warning	DMX	Clarke, Lucas, Marion	35 min

Nearby

Severe Thunderstorm Warnings in Iowa, 2008 Every severe thunderstorm warning in 2008

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.