Alert archive / Iowa / Severe Thunderstorm Warnings in 2007

Severe Thunderstorm Warning 336, NWS Des Moines, IA

August 28, 2007Polk County, Story County, Iowa

NWS Des Moines, IA issued this severe thunderstorm warning at Aug 28, 2007, 7:56 PM CDT for Polk County, Story County, Iowa. It was in force for 49 min. 3 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued: Aug 28, 2007, 7:56 PM CDT (00:56 UTC)
Expired: Aug 28, 2007, 8:45 PM CDT
In force: 49 min
Issued by: NWS Des Moines, IA
Area: Counties, with a storm outline in the text

Counties Polk County, IA, Story County, IA

The radar

The Des Moines radar (KDMX), 24 km from the middle of the area, began a volume at 00:59 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.

What was reported inside it

Time	Report	Where	Remark
Aug 28, 8:00 PM CDT	TSTM WND DMG	1 W Kelley, IA	SEMI TRUCK BLOWN OFF ROAD ON E-57
Aug 28, 8:10 PM CDT	TSTM WND DMG	Ames, IA	AMES POLICE REPORTS SEVERAL LARGE TREES DOWN ALONG COUNTRY CLUB BLVD. 1 POWER POLE DOWN. OTHER DAMAGE NEAR THE CORNER OF STATE AND MORTENSON ROADS.
Aug 28, 8:20 PM CDT	TSTM WND GST 60	4 Nw Ames, IA

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

Did it verify

Verified. The Iowa Environmental Mesonet's Cow matched 3 storm reports to this severe thunderstorm warning; the first came 4 minutes after it went out.

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 watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
Aug 28, 5:30 PM CDT	Severe Thunderstorm Watch	SPC	5 hr

The nearest sounding before it

Davenport, (KDVN), launched 00:00Z, 0.9 hours before the alert went out and 258 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: 1395 J/kg
Mixed-layer CIN: -72 J/kg
Mixed-layer LCL: 1610 m above ground
0-6 km bulk shear: 20 kt
0-1 km storm-relative helicity: 65 m²/s²
0-3 km storm-relative helicity: 78 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 1.6

Open this sounding in Storm Lab

The text

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

000 
WUUS53 KDMX 290055
SVRDMX
IAC153-169-290145-
/O.NEW.KDMX.SV.W.0336.070829T0056Z-070829T0145Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
756 PM CDT TUE AUG 28 2007

THE NATIONAL WEATHER SERVICE IN DES MOINES HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTHERN POLK COUNTY IN CENTRAL IOWA...
  STORY COUNTY IN CENTRAL IOWA...

* UNTIL 845 PM CDT.

* AT 754 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING DAMAGING WINDS IN EXCESS
  OF 60 MPH.  THIS STORM WAS LOCATED 10 MILES SOUTHWEST OF AMES...OR
  ABOUT 28 MILES NORTH OF DES MOINES...AND MOVING EAST AT 50 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  AMES AND HUXLEY BY 805 PM CDT...
  NEVADA BY 815 PM CDT...

THIS INCLUDES INTERSTATE 35 BETWEEN MILE MARKERS 95 AND 121.

PREPARE FOR DAMAGING WINDS...FALLING TREES AND FLYING DEBRIS. MOVE
INDOORS AND STAY AWAY FROM WINDOWS. IF YOU LIVE IN A MOBILE HOME...
SEEK SHELTER IN A STURDY BUILDING.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 1000 PM CDT
TUESDAY EVENING FOR NORTHWESTERN IOWA.

LAT...LON 4186 9382 4185 9371 4208 9371 4212 9370
      4220 9324 4186 9333 4186 9334 4175 9335
      4175 9381
TIME...MOT...LOC 0056Z 263DEG 47KT 4196 9376

$$

JUNGBLUTH

2 follow-up statements

000 
WWUS53 KDMX 290123
SVSDMX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
822 PM CDT TUE AUG 28 2007

IAC153-290132-
/O.CAN.KDMX.SV.W.0336.000000T0000Z-070829T0145Z/
POLK IA-
822 PM CDT TUE AUG 28 2007

...THE SEVERE THUNDERSTORM WARNING FOR NORTHERN POLK COUNTY IS
CANCELLED...

AT 820 PM 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.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 1000 PM CDT
TUESDAY EVENING FOR NORTHWESTERN IOWA.

LAT...LON 4212 9370 4220 9325 4219 9324 4186 9333
      4186 9360 4208 9371
TIME...MOT...LOC 0122Z 262DEG 44KT 4214 9351 4188 9342

$$

IAC169-290145-
/O.CON.KDMX.SV.W.0336.000000T0000Z-070829T0145Z/
STORY IA-
822 PM CDT TUE AUG 28 2007

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 845 PM CDT
FOR STORY COUNTY...

AT 820 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A LINE OF SEVERE THUNDERSTORMS CAPABLE OF PRODUCING DAMAGING
WINDS IN EXCESS OF 60 MPH.  THESE STORMS WERE LOCATED ALONG A LINE
EXTENDING FROM 6 MILES EAST OF GILBERT TO MAXWELL...OR ALONG A LINE
EXTENDING FROM 39 MILES NORTH OF DES MOINES TO 22 MILES NORTHEAST OF
DES MOINES...MOVING EAST AT 50 MPH.

SEVERE THUNDERSTORMS WILL BE NEAR...
  MCCALLSBURG AND COLO BY 830 PM CDT...
  ZEARING BY 835 PM CDT...

WINDS WITH THIS STORM HAVE APPROACHED 50 MPH NEAR AMES. 

THIS INCLUDES INTERSTATE 35 BETWEEN MILE MARKERS 103 AND 121.

PREPARE FOR DAMAGING WINDS...FALLING TREES AND FLYING DEBRIS. MOVE
INDOORS AND STAY AWAY FROM WINDOWS. IF YOU LIVE IN A MOBILE HOME...
SEEK SHELTER IN A STURDY BUILDING.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 1000 PM CDT
TUESDAY EVENING FOR NORTHWESTERN IOWA.

LAT...LON 4212 9370 4220 9325 4219 9324 4186 9333
      4186 9360 4208 9371
TIME...MOT...LOC 0122Z 262DEG 44KT 4214 9351 4188 9342

$$

JUNGBLUTH

000 
WWUS53 KDMX 290151
SVSDMX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
852 PM CDT TUE AUG 28 2007

IAC169-290202-
/O.EXP.KDMX.SV.W.0336.000000T0000Z-070829T0145Z/
STORY IA-
852 PM CDT TUE AUG 28 2007

...THE SEVERE THUNDERSTORM WARNING FOR STORY COUNTY EXPIRES AT 845 PM
CDT...

AT 849 PM CDT...WEATHER SERVICE DOPPLER RADAR INDICATED THAT THE
THUNDERSTORMS WHICH PROMPTED THE WARNING HAVE MOVED OUT OF THE AREA.
THEREFORE...THE SEVERE THUNDERSTORM WARNING HAS BEEN 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.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 1000 PM CDT
TUESDAY EVENING FOR NORTHEAST IOWA.

LAT...LON 4212 9370 4220 9325 4219 9324 4186 9333
      4186 9360 4208 9371
TIME...MOT...LOC 0123Z 262DEG 44KT 4214 9349 4188 9340

$$

JUNGBLUTH

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 Aug 28, 3:30 PM CDT, 4 hours 26 minutes earlier.

Area forecast discussion, Aug 28, 3:30 PM CDT, 4 hours 26 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
330 PM CDT TUE AUG 28 2007

.DISCUSSION...
CDFNT MAKING SLOW PROGRESS ACROSS THE STATE WITH CUR PSN FM NEAR
KMCW-ONAWA LINE.  WL SEE AREAL COVERAGE OF TSRA INC OVR NGT WITH
SLOW PROGRESS SEWD IN AREA.  CONT FFA TNGT WITH BEST CHC OVR THE NW
HLF OF THE STATE.  LINGERING PCPN IN THE AM BUT AMOUNTS NOT ALL THAT
GREAT.  TEMPS A GOOD 15 DEG COOLER WITH CLOUDS AND CAA.  WX PRETTY
NIL AFT PSG OF THIS SYS.  HIGH PRES RDG WL HOLD OVR THE CENTRAL U.S.
FOR THE END OF THE WK INTO THE WKND.  TEMPS WILL COOL TO NEAR NORMAL
WITH GRADUAL WARMING THRU THE WKND.

&&

.AVIATION...28/18Z
SLOW MOVING COLD FRONT IN EXTREME NORTHWEST IOWA WITH ISOLATED
THUNDERSTORM DEVELOPMENT ALONG THE FRONT.  MUCH OF THE DAY
CONDITIONS WILL REMAIN VFR EXCEPT IN FAR NORTHERN IOWA NEAR BOUNDARY
WHERE IFR CEILINGS AND VSBYS IN THUNDERSTORMS.  FRONT WILL BE SLOW
TO REACH CENTRAL IOWA AND SOUTHERN IOWA BY MORNING WITH LOW IFR
CEILINGS BEHIND COLD FRONT.  STORMS FOR CENTRAL AND SOUTHERN IOWA
NOT EXPECTED UNTIL WELL AFTER 06Z.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...FLASH FLOOD WATCH TONIGHT
IAZ016-017-023>028-033>039-044>050-057>062-070>072.

&&

Hazardous weather outlook, Aug 28, 7:50 PM CDT, 6 minutes before

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE DES MOINES IA
750 PM CDT TUE AUG 28 2007

IAZ004>007-015-300100-
EMMET-KOSSUTH-WINNEBAGO-WORTH-PALO ALTO-
750 PM CDT TUE AUG 28 2007

THIS HAZARDOUS WEATHER OUTLOOK IS FOR A PORTION OF CENTRAL IOWA
MAINLY ALONG AND NORTH OF HIGHWAY 9.

.DAY ONE...TONIGHT

SCATTERED NON SEVERE THUNDERSTORMS ARE EXPECTED THROUGH MIDNIGHT.
LOCALLY HEAVY RAINFALL IS EXPECTED WITH STRONGER THUNDERSTORMS.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.

IAZ016-017-023>028-033>039-044>050-057>062-070>072-300100-
HANCOCK-CERRO GORDO-POCAHONTAS-HUMBOLDT-WRIGHT-FRANKLIN-BUTLER-
BREMER-SAC-CALHOUN-WEBSTER-HAMILTON-HARDIN-GRUNDY-BLACK HAWK-
CRAWFORD-CARROLL-GREENE-BOONE-STORY-MARSHALL-TAMA-AUDUBON-GUTHRIE-
DALLAS-POLK-JASPER-POWESHIEK-CASS-ADAIR-MADISON-
750 PM CDT TUE AUG 28 2007

THIS HAZARDOUS WEATHER OUTLOOK IS FOR A PORTION OF CENTRAL IOWA
MAINLY BETWEEN HIGHWAY 20 AND INTERSTATE 80.

.DAY ONE...TONIGHT

SCATTERED THUNDERSTORMS WILL MOVE ACROSS THE AREA TONIGHT. A FEW
STORMS THROUGH MIDNIGHT WILL BE CAPABLE OF PRODUCING 65 MPH WIND
GUSTS AND HEAVY RAINFALL. AN ISOLATED TORNADO CANNOT BE RULED
OUT. WIDESPREAD 1 TO 3 INCH RAINFALL AMOUNTS ARE EXPECTED.
LOCALLY HIGHER AMOUNTS OF 3 TO 4 INCHES ARE POSSIBLE.

A FLASH FLOOD WATCH IS IN EFFECT FOR THE AREA. PLEASE REFER TO
THE NATIONAL WEATHER SERVICE WEBSITE AT WEATHER.GOV/DESMOINES.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

SCATTERED NON SEVERE THUNDERSTORMS ARE POSSIBLE WEDNESDAY MORNING.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS LIKELY THROUGH MIDNIGHT. RAINFALL REPORTS
WOULD BE GREATLY APPRECIATED TONIGHT AND WEDNESDAY MORNING.

IAZ073>075-081>086-092>097-300100-
WARREN-MARION-MAHASKA-ADAMS-UNION-CLARKE-LUCAS-MONROE-WAPELLO-
TAYLOR-RINGGOLD-DECATUR-WAYNE-APPANOOSE-DAVIS-
750 PM CDT TUE AUG 28 2007

THIS HAZARDOUS WEATHER OUTLOOK IS FOR A PORTION OF CENTRAL IOWA
MAINLY SOUTH OF INTERSTATE 80.

.DAY ONE...TONIGHT

SCATTERED THUNDERSTORMS ARE EXPECTED TONIGHT. AN ISOLATED SEVERE
STORM IS POSSIBLE WITH 65 MPH WIND GUSTS BEING THE MAIN THREAT.
BRIEF LOCALLY HEAVY RAINFALL IS ALSO POSSIBLE WITH STRONGER STORMS.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

SCATTERED NON SEVERE THUNDERSTORMS ARE POSSIBLE ON WEDNESDAY.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.

FAB

In the hours before

Local storm report, Aug 28, 6:54 PM CDT, 1 hour 2 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DES MOINES IA
654 PM CDT TUE AUG 28 2007

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

0651 PM     FLASH FLOOD      EAGLE GROVE             42.67N 93.90W
08/28/2007                   WRIGHT             IA   LAW ENFORCEMENT

            IN AND AROUND EAGLE GROVE STREET FLOODING AND WATER
            RUNNING OVER HIGHWAYS.

&&

GFORSTER

Local storm report, Aug 28, 7:05 PM CDT, 51 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DES MOINES IA
705 PM CDT TUE AUG 28 2007

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

0658 PM     TORNADO          2 N DEDHAM              41.94N 94.82W
08/28/2007                   CARROLL            IA   LAW ENFORCEMENT

            TOUCHED DOWN BETWEEN WILLEY AND DEDHAM

&&

GFORSTER

Local storm report, Aug 28, 7:14 PM CDT, 42 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DES MOINES IA
714 PM CDT TUE AUG 28 2007

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

0644 PM     TSTM WND GST     TEMPLETON               41.92N 94.94W
08/28/2007  M68 MPH          CARROLL            IA   TRAINED SPOTTER

            50 YEAR OLD LARGE TREE DOWN...ALONG WITH SEVERAL OTHER
            LIMBS COVERING ROADS IN THE TOWN OF TEMPLETON.

&&

PODRAZIK

Local storm report, Aug 28, 7:17 PM CDT, 39 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DES MOINES IA
717 PM CDT TUE AUG 28 2007

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

0702 PM     TSTM WND DMG     AUDUBON                 41.72N 94.93W
08/28/2007                   AUDUBON            IA   LAW ENFORCEMENT

            A FEW LARGE TREES DOWN AND SEVERAL 5 TO 10 INCH DIAMETER
            LIMBS DOWN IN AUDOBON.

&&

PODRAZIK

Local storm report, Aug 28, 7:34 PM CDT, 22 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DES MOINES IA
734 PM CDT TUE AUG 28 2007

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

0721 PM     TORNADO          2 S JEFFERSON           41.99N 94.38W
08/28/2007                   GREENE             IA   LAW ENFORCEMENT

            TORNADO REPORTED ON THE GROUND BETWEEN JEFFERSON AND
            COOPER NEAR E57.

&&

STEACHOU

Local storm report, Aug 28, 7:56 PM CDT, 0 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DES MOINES IA
756 PM CDT TUE AUG 28 2007

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

0655 PM     TSTM WND DMG     GLIDDEN                 42.06N 94.73W
08/28/2007                   CARROLL            IA   EMERGENCY MNGR

            TREES DOWN IN TOWN...ONE ON FIRE.

0700 PM     TSTM WND DMG     2 N COON RAPIDS         41.90N 94.68W
08/28/2007                   CARROLL            IA   EMERGENCY MNGR

            BARN BLEW OVER

&&

STEACHOU

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 28, 7:12 PM CDT	Severe Thunderstorm Warning	DMX	Dallas, Guthrie	55 min
Aug 28, 7:25 PM CDT	Tornado Warning	DMX	Boone, Greene	40 min
Aug 28, 8:35 PM CDT	Severe Thunderstorm Warning	DMX	Marshall	43 min

Nearby

Severe Thunderstorm Warnings in Iowa, 2007 Every severe thunderstorm warning in 2007

Sources

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