Alert archive / Iowa / Severe Thunderstorm Warnings in 2008

Severe Thunderstorm Warning 455, NWS Des Moines, IA

July 27, 20084 counties in Iowa

NWS Des Moines, IA issued this severe thunderstorm warning at Jul 27, 2008, 5:28 PM CDT for 4 counties in Iowa. It was in force for 47 min. 5 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: Jul 27, 2008, 5:28 PM CDT (22:28 UTC)
Expired: Jul 27, 2008, 6:15 PM CDT
In force: 47 min
Issued by: NWS Des Moines, IA
Area: Storm-based polygon

Counties Jasper County, IA, Mahaska County, IA, Marion County, IA, Poweshiek County, IA

The radar

The Des Moines radar (KDMX), 101 km from the middle of the area, began a volume at 22:29 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
Jul 27, 5:29 PM CDT	TSTM WND GST 62	Montezuma, IA
Jul 27, 5:30 PM CDT	TSTM WND GST 66	Montezuma, IA
Jul 27, 5:31 PM CDT	TSTM WND GST 65	Montezuma, IA
Jul 27, 5:31 PM CDT	TSTM WND GST 66	Montezuma, IA
Jul 27, 5:31 PM CDT	NON-TSTM WND GST 65	Montezuma, 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 4 storm reports to this severe thunderstorm warning; the first came 1 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
Jul 27, 2:29 PM CDT	Severe Thunderstorm Watch	SPC	8 hr

The nearest sounding before it

Davenport, (KDVN), launched 12:00Z, 10.5 hours before the alert went out and 167 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: 1405 m above ground
0-6 km bulk shear: 42 kt
0-1 km storm-relative helicity: -26 m²/s²
0-3 km storm-relative helicity: 155 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 272228
SVRDMX
IAC099-123-125-157-272315-
/O.NEW.KDMX.SV.W.0455.080727T2228Z-080727T2315Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
528 PM CDT SUN JUL 27 2008

THE NATIONAL WEATHER SERVICE IN DES MOINES HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  JASPER COUNTY IN CENTRAL IOWA...
  POWESHIEK COUNTY IN CENTRAL IOWA...
  NORTHERN MAHASKA COUNTY IN SOUTH CENTRAL IOWA...
  NORTHEASTERN MARION COUNTY IN SOUTH CENTRAL IOWA...

* UNTIL 615 PM CDT.

* AT 525 PM CDT...TRAINED WEATHER SPOTTERS REPORTED A SEVERE
  THUNDERSTORM CAPABLE OF PRODUCING NICKEL SIZE HAIL...AND
  DESTRUCTIVE WINDS IN EXCESS OF 70 MPH.  THIS STORM WAS LOCATED NEAR
  SULLY...OR 36 MILES EAST OF DES MOINES...AND MOVING EAST AT 32 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  SULLY BY 530 PM CDT...
  LYNNVILLE BY 535 PM CDT...
  SEARSBORO BY 545 PM CDT...
  NEW SHARON BY 555 PM CDT...
  8 MILES SOUTH OF MONTEZUMA BY 600 PM CDT...
  BARNES CITY BY 610 PM CDT...

THIS INCLUDES INTERSTATE 80 BETWEEN MILE MARKERS 154 AND 204.

GO TO A BASEMENT OR SMALL INTERIOR ROOM. EXTENSIVE DAMAGE IS LIKELY.
EVACUATE MOBILE HOMES...AND SEEK SHELTER IN A STURDY BUILDING. SEVERE
STRAIGHT LINE WINDS CAN SOUND LIKE A TORNADO...AND PRODUCE SIMILAR
DAMAGE.

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

THIS STORM HAS A HISTORY OF PRODUCING WIDESPREAD WIND DAMAGE ACROSS 
THE AREA. 

LAT...LON 4150 9231 4150 9241 4135 9242 4143 9301
      4172 9330 4186 9266 4186 9230 4178 9230
      4178 9229 4163 9229
TIME...MOT...LOC 2228Z 286DEG 28KT 4154 9289

$$

LEE

1 follow-up statement

000 
WWUS53 KDMX 272251
SVSDMX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
550 PM CDT SUN JUL 27 2008

IAC099-123-125-157-272315-
/O.CON.KDMX.SV.W.0455.000000T0000Z-080727T2315Z/
JASPER IA-POWESHIEK IA-MAHASKA IA-MARION IA-
550 PM CDT SUN JUL 27 2008

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 615 PM CDT
FOR NORTHEASTERN MARION...NORTHERN MAHASKA...POWESHIEK AND
SOUTHEASTERN JASPER COUNTIES...

AT 547 PM CDT...TRAINED WEATHER SPOTTERS REPORTED A SEVERE
THUNDERSTORM CAPABLE OF PRODUCING NICKEL SIZE HAIL...AND DESTRUCTIVE
WINDS IN EXCESS OF 70 MPH.  THIS STORM WAS LOCATED NEAR NEW SHARON...
OR 28 MILES NORTHWEST OF SIGOURNEY...MOVING EAST AT 32 MPH.

THE SEVERE THUNDERSTORM WILL BE NEAR...
  NEW SHARON BY 555 PM CDT...
  8 MILES SOUTH OF MONTEZUMA BY 600 PM CDT...
  BARNES CITY BY 610 PM CDT...

THIS INCLUDES INTERSTATE 80 BETWEEN MILE MARKERS 189 AND 204.

FOR YOUR PROTECTION GO TO THE BASEMENT OR AN INTERIOR ROOM ON THE
LOWEST FLOOR OF YOUR HOME OR BUSINESS. THIS STORM HAS THE POTENTIAL
TO CAUSE SERIOUS INJURY AND SIGNIFICANT DAMAGE TO PROPERTY.

THIS STORM HAS A HISTORY OF PRODUCING WIDESPREAD WIND DAMAGE ACROSS 
THE WARNED AREA.

AT 530 PM...THUNDERSTORM WIND GUSTS OF 66 MPH WERE MEASURED AT 
MONTEZUMA. 

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

LAT...LON 4150 9231 4150 9241 4135 9242 4143 9301
      4155 9295 4160 9261 4186 9262 4186 9230
      4167 9229
TIME...MOT...LOC 2250Z 286DEG 28KT 4149 9267

$$

LEE

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 Jul 27, 3:28 PM CDT, 2 hours earlier.

Area forecast discussion, Jul 27, 3:28 PM CDT, 2 hours before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
328 PM CDT SUN JUL 27 2008

.DISCUSSION...
WILL KEEP DISCUSSION BRIEF TODAY WITH ONGOING ACTIVE WEATHER. STRONG
TO SEVERE STORMS CURRENTLY FIRING ALONG CONVECTIVE OUTFLOW IN
NORTHERN IOWA AND WILL KEEP PROGRESSING SOUTHWARD INTO CENTRAL AND
SOUTHERN IOWA THROUGH LATE AFTERNOON/EVENING. SEVERE THUNDERSTORM
WATCH CONTINUES FOR MOST OF THE CWA UNTIL 10 PM. ALREADY GETTING
SIGNIFICANT STRAIGHT LINE WIND REPORTS...CAN/T RULE OUT ISOLATED TOR
THREAT INVOF BOUNDARY FOR THE NEXT SEVERAL HOURS. SOME QUESTION
ABOUT CONVECTIVE EVOLUTION BEYOND THE FIRST SHOT...AS THE GFS/ECMWF
BOTH SUGGESTING ADDITIONAL MCS POTENTIAL ESPECIALLY EASTERN HALF
LATE TONIGHT. WILL HAVE TO WATCH HEAVY RAIN THREAT CLOSELY AS
CONVECTION MOVES INTO SOUTHERN IOWA...AREAS THAT CANNOT TAKE MUCH
ADDITIONAL RAIN BEFORE FLASH FLOODING OCCURS. NO FLASH FLOOD WATCH
PLANNED AT THIS TIME WITH UNCERTAINTY ABOUT AMOUNTS/LOCATION...BUT
MAY HAVE TO ISSUE LATER ONCE EVENT SHOWS ITS HAND.

BEYOND THE OVERNIGHT...SIGNIFICANT HEAVY RAIN/SVR WEATHER AGAIN
EXPECTED MONDAY NIGHT INTO TUESDAY AS DOLLY MOISTURE REMNANTS BEGIN
TO IMPACT THE REGION. ACTIVE WEATHER LIKELY TO CONTINUE LATE
WEDNESDAY INTO THURSDAY WITH NEXT SHORT WAVE TOPPING THE RIDGE
FOLLOWED BY UPPER RIDGING AND MAINLY DRY AND HOT WEATHER FROM FRIDAY
THROUGH SUNDAY.

&&

.AVIATION...27/18Z
CURRENT CONVECTIVE COMPLEX OVER NRN IA WILL CONTINUE MOVING ESE
EARLY THIS AFTERNOON. THE FORECAST BEYOND THE NEXT FEW HOURS IS
STILL UNCERTAIN AS FAR AS EXACTLY WHERE ADDITIONAL STORMS WILL
DEVELOP. THUNDERSTORMS MAY DEVELOP DURING PEAK HEATING ALONG AND
SOUTH OF HWY 30...AND/OR REDEVELOP ACROSS NRN IA OVERNIGHT...OR
BOTH. THIS UNCERTAINTY IN TIMING...AS WELL AS LOCATION...HAS LEAD TO
NO MENTION OF THUNDER BEYOND DEALING WITH STORMS THAT ARE ONGOING.
HAVE INCLUDED CB WORDING AFTER 00Z WITH FURTHER DETAILS ADDED ONCE
TIMING AND LOCATION BECOMES MORE CLEAR RATHER THAN ADDING THUNDER
FOR PROLONGED PERIODS WITH LOW CONFIDENCE.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...SEVERE THUNDERSTORM WATCH IN
EFFECT UNTIL 10 PM FOR ENTIRE CWA EXCEPT NORTHERN 2 TIERS OF
COUNTIES.

&&

AVIATION...MOYER
PUBLIC...KINNEY

Hazardous weather outlook, Jul 27, 4:25 PM CDT, 1 hour 3 minutes before

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE DES MOINES IA
425 PM CDT SUN JUL 27 2008

IAZ023>028-033>039-044>050-057>062-070>075-081>086-092>097-281100-
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-WARREN-MARION-MAHASKA-ADAMS-UNION-
CLARKE-LUCAS-MONROE-WAPELLO-TAYLOR-RINGGOLD-DECATUR-WAYNE-
APPANOOSE-DAVIS-
425 PM CDT SUN JUL 27 2008

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

.DAY ONE...TONIGHT

SCATTERED TO WIDESPREAD THUNDERSTORMS WILL CONTINUE THIS EVENING
AND OVERNIGHT. THE MAIN THREATS WILL BE DAMAGING STRAIGHT LINE
WINDS TO 90 MPH...AND QUARTER SIZE HAIL. AN ISOLATED TORNADO IS
NOT OUT OF THE QUESTION THROUGH EARLY EVENING. LOCALLY HEAVY
RAINFALL COULD LEAD TO FLASH FLOODING...ESPECIALLY OVER SOUTHERN
IOWA...WHERE HEAVY RAIN FELL RECENTLY.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY

THERE ARE VARIABLE CHANCES FOR THUNDERSTORMS THROUGHOUT MANY OF
THE NEXT 7 DAYS. AT THIS TIME THE GREATER CHANCES FOR
THUNDERSTORMS LOOK TO BE LATE MONDAY NIGHT...AND AGAIN TUESDAY.
CURRENTLY THE AREA IS IN A SLIGHT RISK FOR SEVERE WEATHER AGAIN
MONDAY NIGHT....WITH THE CHANCES FOR SEVERE WEATHER UNCERTAIN AT
THIS TIME FOR THE REMAINDER OF THE WEEK.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE NEEDED THIS EVENING AND OVERNIGHT.

IAZ004>007-015>017-281100-
EMMET-KOSSUTH-WINNEBAGO-WORTH-PALO ALTO-HANCOCK-CERRO GORDO-
425 PM CDT SUN JUL 27 2008

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTHERN IOWA.

.DAY ONE...TONIGHT

SCATTERED THUNDERSTORMS ARE POSSIBLE WITH AN ISOLATED SEVERE STORM
NOT OUT OF THE QUESTION. THE MAIN THREAT WOULD BE STRAIGHT LINE
WINDS TO 60 MPH AND QUARTER SIZE HAIL.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY

THERE ARE VARIABLE CHANCES FOR THUNDERSTORMS THROUGHOUT MANY OF
THE NEXT 7 DAYS. AT THIS TIME THE GREATER CHANCES FOR
THUNDERSTORMS LOOK TO BE LATE MONDAY NIGHT...AND AGAIN TUESDAY.
CURRENTLY THE AREA IS IN A SLIGHT RISK FOR SEVERE WEATHER AGAIN
MONDAY NIGHT....WITH THE CHANCES FOR SEVERE WEATHER UNCERTAIN AT
THIS TIME FOR THE REMAINDER OF THE WEEK.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE NEEDED ON AN ISOLATED BASIS TONIGHT.

ALBRECHT/KINNEY

In the hours before

Local storm report, Jul 27, 5:05 PM CDT, 23 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DES MOINES IA
505 PM CDT SUN JUL 27 2008

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

0423 PM     TSTM WND DMG     8 SW BOONE AIRPORT      41.97N 93.96W
07/27/2008                   BOONE              IA   TRAINED SPOTTER

            15 INCH DIAMETER TREES DOWN.

&&

BF

Local storm report, Jul 27, 5:07 PM CDT, 21 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DES MOINES IA
507 PM CDT SUN JUL 27 2008

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

0445 PM     TSTM WND DMG     1 W PLEASANT HILL       41.59N 93.53W
07/27/2008                   POLK               IA   TRAINED SPOTTER

            LARGE TREE LIMBS UP TO 18 INCHES IN DIAMETER DOWN.

&&

BMOYER

Local storm report, Jul 27, 5:08 PM CDT, 20 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DES MOINES IA
508 PM CDT SUN JUL 27 2008

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

0429 PM     TSTM WND DMG     MADRID                  41.88N 93.82W
07/27/2008                   BOONE              IA   LAW ENFORCEMENT

            STRUCTURAL DAMAGE NEAR INTERSECTION OF 320TH AND
            VIOLET...310TH AND UNICORN.

&&

BF

Local storm report, Jul 27, 5:09 PM CDT, 19 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DES MOINES IA
509 PM CDT SUN JUL 27 2008

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

0445 PM     TORNADO          6 NE ANKENY             41.79N 93.54W
07/27/2008                   POLK               IA   TRAINED SPOTTER

            NUMEROUS TREES DOWN. HOUSE DAMAGE WITH PART OF HOUSE IN
            THE TREES. SEVERAL SIGNS BLOWN DOWN.

&&

MS JUL 08

Local storm report, Jul 27, 5:11 PM CDT, 17 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DES MOINES IA
511 PM CDT SUN JUL 27 2008

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

0455 PM     TSTM WND DMG     ELKHART                 41.79N 93.51W
07/27/2008                   POLK               IA   LAW ENFORCEMENT

            8-12 INCH DIAMETER TREES DOWN WEST OF ELKHART ON NE 126TH
            AVE.

&&

BF

Local storm report, Jul 27, 5:23 PM CDT, 5 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DES MOINES IA
523 PM CDT SUN JUL 27 2008

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

0445 PM     TSTM WND GST     DES MOINES              41.58N 93.62W
07/27/2008  E70 MPH          POLK               IA   FIRE DEPT/RESCUE

            15 TO 20 INCH DIAMETER TREES DOWN

&&

MS JUL 08

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 27, 12:18 PM CDT	Severe Thunderstorm Warning	DMX	Palo Alto	42 min
Jul 27, 1:59 PM CDT	Severe Thunderstorm Warning	DMX	Cerro Gordo, Franklin	46 min
Jul 27, 2:12 PM CDT	Severe Thunderstorm Warning	DMX	Butler	48 min
Jul 27, 2:49 PM CDT	Severe Thunderstorm Warning	DMX	Calhoun, Humboldt, Pocahontas, Webster	41 min
Jul 27, 3:28 PM CDT	Severe Thunderstorm Warning	DMX	Boone, Greene, Hamilton, Story, Webster	47 min
Jul 27, 3:46 PM CDT	Severe Thunderstorm Warning	DMX	Grundy, Hardin, Marshall, Tama	44 min
Jul 27, 4:07 PM CDT	Severe Thunderstorm Warning	DMX	Boone, Dallas, Polk, Story	38 min
Jul 27, 4:11 PM CDT	Tornado Warning	DMX	Boone, Polk, Story	34 min
Jul 27, 4:30 PM CDT	Severe Thunderstorm Warning	DMX	Boone, Dallas, Jasper, Marion, Polk, Story and 1 more	45 min
Jul 27, 4:31 PM CDT	Severe Thunderstorm Warning	DMX	Clarke, Madison, Union, Warren	44 min
Jul 27, 4:43 PM CDT	Tornado Warning	DMX	Jasper, Polk	32 min
Jul 27, 4:50 PM CDT	Severe Thunderstorm Warning	DMX	Jasper, Mahaska, Marion, Polk, Poweshiek	40 min
Jul 27, 4:57 PM CDT	Severe Thunderstorm Warning	DMX	Clarke, Lucas, Warren	48 min
Jul 27, 5:09 PM CDT	Tornado Warning	DMX	Jasper, Mahaska, Marion, Poweshiek	36 min
Jul 27, 5:13 PM CDT	Severe Thunderstorm Warning	DMX	Clarke, Jasper, Lucas, Mahaska, Marion, Monroe and 2 more	47 min
Jul 27, 5:14 PM CDT	Severe Thunderstorm Warning	DMX	Boone, Dallas, Greene, Webster	46 min
Jul 27, 5:17 PM CDT	Severe Thunderstorm Warning	DMX	Jasper	13 min
Jul 27, 5:52 PM CDT	Severe Thunderstorm Warning	DMX	Appanoose, Davis, Lucas, Mahaska, Marion, Monroe and 1 more	38 min
Jul 27, 5:54 PM CDT	Tornado Warning	DMX	Appanoose, Davis, Monroe, Wapello	36 min
Jul 27, 5:55 PM CDT	Severe Thunderstorm Warning	DMX	Appanoose, Decatur, Lucas, Wayne	50 min
Jul 27, 5:58 PM CDT	Severe Thunderstorm Warning	DMX	Boone, Dallas, Polk, Story	47 min
Jul 27, 6:27 PM CDT	Severe Thunderstorm Warning	DMX	Appanoose, Davis, Monroe, Wapello	48 min
Jul 27, 6:30 PM CDT	Tornado Warning	DMX	Davis	15 min
Jul 27, 6:38 PM CDT	Tornado Warning	DMX	Wayne	23 min
Jul 27, 6:43 PM CDT	Flash Flood Warning	DMX	Wayne	3 hr

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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.