Alert archive / Iowa / Severe Thunderstorm Warnings in 2007

Severe Thunderstorm Warning 123, NWS Des Moines, IA

May 29, 2007Dallas County, Iowa

NWS Des Moines, IA issued this severe thunderstorm warning at May 29, 2007, 5:59 PM CDT for Dallas County, Iowa. It was in force for 46 min. 1 report 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: May 29, 2007, 5:59 PM CDT (22:59 UTC)
Expired: May 29, 2007, 6:45 PM CDT
In force: 46 min
Issued by: NWS Des Moines, IA
Area: Counties, with a storm outline in the text

County Dallas County, IA

The radar

The Des Moines radar (KDMX), 38 km from the middle of the area, began a volume at 23:01 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
May 29, 6:01 PM CDT	HAIL 0.88	2 Wnw Redfield, IA	ALSO WITH STRONG WINDS. MANY SMALL BRANCHES AND LEAVES DOWN.

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

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

Omaha, NE (KOAX), launched 12:00Z, 11.0 hours before the alert went out and 187 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: 38 J/kg
Mixed-layer CIN: -134 J/kg
Mixed-layer LCL: 743 m above ground
0-6 km bulk shear: 20 kt
0-1 km storm-relative helicity: 148 m²/s²
0-3 km storm-relative helicity: 119 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 292258
SVRDMX
IAC049-292345-
/O.NEW.KDMX.SV.W.0123.070529T2259Z-070529T2345Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
559 PM CDT TUE MAY 29 2007

THE NATIONAL WEATHER SERVICE IN DES MOINES HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  WESTERN DALLAS COUNTY IN CENTRAL IOWA...

* UNTIL 645 PM CDT

* AT 557 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING NICKEL SIZE HAIL...AND
  DAMAGING WINDS IN EXCESS OF 60 MPH.  THIS STORM WAS LOCATED 20
  MILES SOUTH OF PERRY...OR ABOUT 32 MILES WEST OF DES MOINES...AND
  MOVING NORTH AT 25 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  PERRY BY 640 PM CDT...

LAT...LON 4186 9408 4185 9404 4150 9411 4151 9425
      4160 9425 4160 9429 4184 9429 4185 9428

$$

VACHALEK

2 follow-up statements

000 
WWUS53 KDMX 292320
SVSDMX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
620 PM CDT TUE MAY 29 2007

IAC049-292345-
/O.CON.KDMX.SV.W.0123.000000T0000Z-070529T2345Z/
DALLAS IA-
620 PM CDT TUE MAY 29 2007

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 645 PM CDT
FOR WESTERN DALLAS COUNTY...

AT 619 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO 
INDICATE A SEVERE THUNDERSTORM CAPABLE OF PRODUCING DAMAGING WINDS 
TO 60 MPH.  THIS STORM WAS LOCATED NEAR DAWSON...OR ABOUT 33 MILES 
NORTHWEST OF DES MOINES...MOVING NORTH AT 30 MPH.

THE SEVERE THUNDERSTORM WILL BE NEAR...
  DAWSON AND PERRY BY 630 PM CDT...

LAT...LON 4186 9408 4185 9404 4150 9411 4151 9425
      4160 9425 4160 9429 4184 9429 4185 9428

$$

000 
WWUS53 KDMX 292342
SVSDMX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
642 PM CDT TUE MAY 29 2007

IAC049-292352-
/O.EXP.KDMX.SV.W.0123.000000T0000Z-070529T2345Z/
DALLAS IA-
642 PM CDT TUE MAY 29 2007

...THE SEVERE THUNDERSTORM WARNING FOR WESTERN DALLAS COUNTY EXPIRES
AT 645 PM CDT...

LAT...LON 4186 9408 4185 9404 4150 9411 4151 9425
      4160 9425 4160 9429 4184 9429 4185 9428

$$

VACHALEK

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 May 29, 3:32 PM CDT, 2 hours 27 minutes earlier.

Area forecast discussion, May 29, 3:32 PM CDT, 2 hours 27 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
332 PM CDT TUE MAY 29 2007

.DISCUSSION...
WEAK SHEAR ENVIRONMENT WITH NO CAP ALLOWING TSRA TO DVLP OVR THE
CWA THIS AFTN. STORMS LKLY TO CONT UNTIL SNST WITH ISOLATED HAIL
LIKELY. OVR NGT HRS SHOULD BE QUIET WITH NEXT ROUND DVLPG DURING
THE DAY WED. WILL GO WITH A FLOOD WATCH FOR MUCH OF THE CWA WEST
OF I-35 AS ANTICEDENT CONDS QUITE WET AND IT WONT TAKE A WHOLE
LOT TO GET CREEKS AND STREAMS OUT OF THEIR BANKS. SYS SHOULD SHUNT
OFF WITH WX QUIETER UNTIL FRI NGT WHEN NEXT S/WV ROUNDS THE UPPER
TROF. ONCE THAT OCCURS IT SHOULD DRY OUT FOR A FEW DAYS BUT CANT
RULE OUT AN ISOLD TSRA HERE AND THERE WITH THE UPR LOW IN THE
VCNTY FOR THE NEXT SEVERAL DAYS. MODEL INCONSISTENCIES ABOUND AND
WILL CONT TO BE A PROBLEM, ESPECIALLY IN THE LONGER TERM.
INFLUENCE OF POTENTIAL MJO DVLPMT CREATING DIFFICULTIES IN
MODELING, HOWEVER THAT DISCUSSION IS WELL BEYOND SCOPE OF THIS PRODUCT.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...
FLOOD WATCH FROM WEDNESDAY AFTERNOON THROUGH LATE WEDNESDAY
NIGHT FOR ADAIR-ADAMS-AUDUBON-BOONE-CALHOUN-CARROLL-CASS-CERRO
GORDO-CLARKE-CRAWFORD-DALLAS-DECATUR-FRANKLIN-GREENE-GUTHRIE-
HAMILTON-HANCOCK-HARDIN-HUMBOLDT-KOSSUTH-MADISON-POLK-RINGGOLD-
STORY-TAYLOR-UNION-WARREN-WEBSTER-WINNEBAGO-WORTH-WRIGHT.

&&

Hazardous weather outlook, May 29, 3:41 PM CDT, 2 hours 18 minutes before

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE DES MOINES IA
341 PM CDT TUE MAY 29 2007

IAZ005>007-016-017-024>026-034>037-044>048-057>060-070>073-
081>083-092>094-301100-
KOSSUTH-WINNEBAGO-WORTH-HANCOCK-CERRO GORDO-HUMBOLDT-WRIGHT-
FRANKLIN-CALHOUN-WEBSTER-HAMILTON-HARDIN-CRAWFORD-CARROLL-GREENE-
BOONE-STORY-AUDUBON-GUTHRIE-DALLAS-POLK-CASS-ADAIR-MADISON-WARREN-
ADAMS-UNION-CLARKE-TAYLOR-RINGGOLD-DECATUR-
341 PM CDT TUE MAY 29 2007

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL
IOWA...ALONG AND WEST OF INTERSTATE 35.

.DAY ONE...TONIGHT

SCATTERED THUNDERSTORMS WILL CONTINUE THROUGH SUNSET THEN QUICKLY
DIMINISH. A FEW STORMS COULD PRODUCE SMALL HAIL BUT NO SEVERE
WEATHER IS EXPECTED. SCATTERED NON-SEVERE THUNDERSTORMS ARE
POSSIBLE AGAIN OVERNIGHT.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

THUNDERSTORMS ARE EXPECTED TO BECOME MORE WIDESPREAD BY WEDNESDAY
AFTERNOON...AND WILL BE ACTIVE ACROSS CENTRAL IOWA UNTIL THURSDAY
MORNING. POTENTIAL FOR SEVERE WEATHER IS LOW. HOWEVER...PLENTIFUL
MOISTURE AND SLOW MOVEMENT WILL PRODUCE AREAS OF HEAVY
RAINFALL... EXCEEDING 1 TO 2 INCHES IN A FEW HOURS IN SOME
LOCATIONS...WITH ISOLATED HIGHER AMOUNTS. RENEWED RIVER FLOODING OR
COUNTY WIDE FLOODING IS POSSIBLE...ESPECIALLY ACROSS AREAS ALONG
AND WEST OF INTERSTATE 35. THUNDERSTORMS ARE AGAIN POSSIBLE ON
FRIDAY...BEFORE A DRIER SPELL SETS IN.

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

.SPOTTER INFORMATION STATEMENT...

THE POTENTIAL FOR SPOTTER ACTIVATION DUE TO SEVERE WEATHER IS
LOW...BUT REPORTS OF HEAVY RAIN AND FLOODING MAY BE NEEDED.

IAZ027-028-038-039-049-050-061-062-074-075-084>086-095>097-301100-
BUTLER-BREMER-GRUNDY-BLACK HAWK-MARSHALL-TAMA-JASPER-POWESHIEK-
MARION-MAHASKA-LUCAS-MONROE-WAPELLO-WAYNE-APPANOOSE-DAVIS-
341 PM CDT TUE MAY 29 2007

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL
IOWA...EAST OF INTERSTATE 35.

.DAY ONE...TONIGHT

SCATTERED THUNDERSTORMS WILL CONTINUE THROUGH SUNSET THEN QUICKLY
DIMINISH. A FEW STORMS COULD PRODUCE SMALL HAIL BUT NO SEVERE
WEATHER IS EXPECTED. SCATTERED NON-SEVERE THUNDERSTORMS ARE
POSSIBLE AGAIN OVERNIGHT.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

THUNDERSTORMS ARE EXPECTED TO BECOME MORE WIDESPREAD BY WEDNESDAY
AFTERNOON...AND WILL BE ACTIVE ACROSS CENTRAL IOWA UNTIL THURSDAY
MORNING. POTENTIAL FOR SEVERE WEATHER IS MINIMAL. HOWEVER...MANY
LOCATIONS EAST OF INTERSTATE 35 CAN EXPECT RAINFALL AMOUNTS OF ONE
HALF TO ONE INCH...AND LOCALLY HIGHER.  THUNDERSTORMS ARE AGAIN
POSSIBLE ON FRIDAY...BEFORE A DRIER SPELL SETS IN.

.SPOTTER INFORMATION STATEMENT...

THE POTENTIAL FOR SPOTTER ACTIVATION DUE TO SEVERE WEATHER IS
LOW...BUT REPORTS OF HEAVY RAIN AND FLOODING MAY BE NEEDED.

IAZ004-015-023-033-301100-
EMMET-PALO ALTO-POCAHONTAS-SAC-
341 PM CDT TUE MAY 29 2007

THIS HAZARDOUS WEATHER OUTLOOK IS FOR A SMALL PORTION OF NORTHWEST
IOWA...FROM ESTHERVILLE...TO POCAHONTAS AND SAC CITY.

.DAY ONE...TONIGHT

SCATTERED THUNDERSTORMS WILL CONTINUE THROUGH SUNSET THEN QUICKLY
DIMINISH. A FEW STORMS COULD PRODUCE SMALL HAIL BUT NO SEVERE
WEATHER IS EXPECTED. SCATTERED NON-SEVERE THUNDERSTORMS ARE
POSSIBLE AGAIN OVERNIGHT.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

THUNDERSTORMS ARE EXPECTED TO BECOME MORE WIDESPREAD BY WEDNESDAY
MORNING...AND WILL BE ACTIVE ACROSS CENTRAL IOWA UNTIL THURSDAY
MORNING. POTENTIAL FOR SEVERE WEATHER IS MINIMAL. HOWEVER...MANY
LOCATIONS OVER NORTHWEST IOWA CAN EXPECT RAINFALL AMOUNTS OF ONE HALF
TO ONE INCH...AND LOCALLY HIGHER. THUNDERSTORMS ARE AGAIN POSSIBLE
ON FRIDAY...BEFORE A DRIER SPELL SETS IN.

.SPOTTER INFORMATION STATEMENT...

THE POTENTIAL FOR SPOTTER ACTIVATION DUE TO SEVERE WEATHER IS
LOW...BUT REPORTS OF HEAVY RAIN AND FLOODING MAY BE NEEDED.

JUNGBLUTH/KINNEY

The office that day

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

Issued	Product	Office	Counties	Lasted
May 29, 12:55 PM CDT	Severe Thunderstorm Warning	DMX	Story	16 min
May 29, 3:42 PM CDT	Flood Watch	DMX	Adair, Adams, Audubon, Boone, Calhoun, Carroll and 25 more	30 hr
May 29, 5:13 PM CDT	Severe Thunderstorm Warning	DMX	Adair	32 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.