Alert archive / Iowa / Severe Thunderstorm Warnings in 2003

Severe Thunderstorm Warning 74, NWS Des Moines, IA

May 10, 2003Black Hawk County, Iowa

NWS Des Moines, IA issued this severe thunderstorm warning at May 10, 2003, 6:33 PM CDT for Black Hawk County, Iowa. It was in force for 27 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: May 10, 2003, 6:33 PM CDT (23:33 UTC)
Expired: May 10, 2003, 7:00 PM CDT
In force: 27 min
Issued by: NWS Des Moines, IA
Area: Counties, with a storm outline in the text

County Black Hawk County, IA

The radar

The Des Moines radar (KDMX), 140 km from the middle of the area, began a volume at 23:33 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 12:00Z, 11.6 hours before the alert went out and 180 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: 1102 m above ground
0-6 km bulk shear: 51 kt
0-1 km storm-relative helicity: 139 m²/s²
0-3 km storm-relative helicity: 225 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.5

Open this sounding in Storm Lab

The text

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

682 
WUUS53 KDMX 102333
SVRDMX
IAC013-110000-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
634 PM CDT SAT MAY 10 2003

THE NATIONAL WEATHER SERVICE IN DES MOINES HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  BLACK HAWK COUNTY IN NORTHEAST IOWA
  THIS INCLUDES THE CITY OF WATERLOO

* UNTIL 700 PM CDT

* AT 628 PM...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM 5 MILES SOUTHEAST OF HUDSON...OR ABOUT 7 MILES
  SOUTH OF WATERLOO...MOVING NORTHEAST AT 60 MPH.

* THE SEVERE THUNDERSTORM WILL BE...

  NEAR DUNKERTON AROUND 645 PM.

DAMAGING HAIL UP TO TWO INCHES IN DIAMETER IS LIKELY IN THE WARNED
AREA.

LARGE HAIL CAN CAUSE SERIOUS INJURY AND EXTENSIVE PROPERTY DAMAGE.
SEEK SAFETY IN A STURDY BUILDING...AND STAY AWAY FROM WINDOWS.

A TORNADO WATCH REMAINS IN EFFECT UNTIL 1000 PM SATURDAY EVENING FOR
EASTERN IOWA.

LAT...LON 4237 9254 4236 9209 4263 9211 4265 9248

FORSTER

$$

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 10, 3:59 PM CDT, 2 hours 34 minutes earlier.

Area forecast discussion, May 10, 3:59 PM CDT, 2 hours 34 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
2578PM CDT SAT MAY 10 2003

SVRL SGFNT THINGS TO CONSIDER TDA FM SVR WX TO HIGH WND POTENTIAL.
STLT IMAGERY SHOWS LG WV TROF THRU HIGH PLAINS WITH SHRT WV/SHEAR
AXIS FM KS/NE INTO MO VLY.  20Z SFC ANLYS PLACES LOW/TRIPLE POINT
JUST N KMKC METRO AREA WITH OLD OUTFLOW BNDRY TO JUST S KSTL METRO
AND ASSOCD WRMFNT INTO IA ALG KLWD-KCWI LN.  ELEVATED INSTABLITY
AXIS INTO S CNTRL IA WITH MLCAPES AOA 1000 J/KG HEADING INTO SERN IA
AS WRM SECTOR SURGES NWD.  DEEP LAYER SHEAR STG WITH VARIOUS
SUPERCELL/TORNADO SCREAMING...BUT MAINLY S ACRS MO AT THIS
POINT.  PRIMARY WARM SECTOR LOOKS TO BE ASSOCD WITH OUTFLOW BNDRY
WITH EXTRAPOLATION OF CURRENT FEATURES GOING ACRS SERN IA AND OUT OF
FA ARND 23Z.  FAVORED AREA FOR TORNADIC SUPERCELLS WOULD APPR TO BE
ALG AND SE OF KLWD-KPEA-JUST S KALO LN.  MAY SEE HAIL POTENTIAL IN
ELEVATED CONVECTION IN DEFORMATION ZN TOO.  HGT FALL CNTR AND STG
KINEMATIC FORCING CROSSES SRN 2/3RD OF FA THIS EVE.  SYS SHOULD BE
FAST MOVG ENOUGH THAT RAINS MAY BE LCLLY HVY BUT BRIEF ENOUGH TO NOT
AGGREVATE FLOODING SITUATION MUCH.  WL GO WITH CATEGORICAL WORDING
NWRN THIRD...CHCS SW...AND LIKELY CNTRL TO SE.  PCPN SHOULD DMSH
OVNGT TO CHC CATEGORY NERN PTNS.

NEXT QUESTION WL BE WNDS LATE TNGT AND SUN.  SFC LOW SHOULD QUICKLY
LIFT INTO KLSE VCNTY TWRD 06Z.  STG HGT FALL CNTR SHOULD DEEPING SFC
LOW WITH PRODUCE SGFNT ISALLOBARIC COUPLET AS DEPICTED BY MDLS.
THIS AND FOLLOWING PRES RISE CNTR SHOULD EXIT FA BY 12Z...WITH
SCNDRY ISALLOBARIC MAX INTO NERN SXNS TMRW.  PRES GRADIENT QUITE
IMPRESSIVE SO HAVE ISSUED WND ADVY LATE TNGT AND SUN FOR NRN 2 TO 3
TIERS OF COUNTIES.  TEMP WISE GENERALLY FOLLOWED COMPROMISE OF
GUIDANCE WHICH IS FAIRLY CLOSE.

PRIMARY QUESTIONS FOR NEXT WEEK WL BE POPS WITH MIDWEEK SYS...AND
WHETHER TO ADD MENTION AGN LATE IN WEEK.  RECENT GFS RUNS STRONGEST
WITH SYS ARND WED...EURO MDLS WEAKEST AND CANADIAN A COMPROMISE.
GFS SLOWEST WITH EURO/CANADIAN SOLUTIONS A BIT FASTER.  HWVR 12Z GFS
AND GFS ENSEMBLES ARE LEANING IN DIRECTION OF CANADIAN/EURO MDLS.
SEE NO REASON TO ALTER NCEP THINKING OF FOLLOWING ECMWF...SPCLLY
ARND MIDWEEK...WITH INFLUENCE OF 12Z GFS AND ENSEMBLES IN LATER PDS
TOO.  THUS WL KEEP CHCS GOING TUE NGT WRN PTNS...AND FA WIDE WED.
TWRD FRI AND SAT...ECMWF MUCH STGR AND FARTHER N WITH SRN PLAINS
SYS.  HWVR WL SIDE WITH SUGGESTIONS FM GFS/CANADIAN ENSEMBLES AND
SURROUNDING OFFICES KEEPING FCST DRY ATTM.  DO NOT HAVE THE BEST
CONFIDENCE IN 00Z MOS EITHER SO HAVE NOT CHGD GOING TEMPS MUCH.

.DSM...WND ADVY OVNGT AND SUN NRN PTNS
       IAZ004>007-015>017-024>028

SMALL

Hazardous weather outlook, May 10, 11:50 AM CDT, 6 hours 43 minutes before

IAZ004>007-015>017-023>028-033>039-044>050-057>062-070>075-081>086-
092>097-111100-

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE DES MOINES IA
1150 AM CDT SAT MAY 10 2003

...MORE SEVERE WEATHER POSSIBLE THIS AFTERNOON AND EARLY EVENING...

THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL IOWA.

.DAY ONE...THIS AFTERNOON AND TONIGHT

A SURFACE LOW WILL TRACK THROUGH SOUTHEAST IOWA...AND DRAW VERY
MOIST...UNSTABLE AIR INTO THE SOUTHERN PART OF THE STATE THIS
AFTERNOON INTO THE EARLY EVENING HOURS. SUPERCELL THUNDERSTORMS WITH
SEVERE WEATHER ARE POSSIBLE FROM AROUND 3 PM TO 9 PM.  THE AREA IN
HIGH RISK FOR SEEING SEVERE WEATHER LIES SOUTHEAST OF A LINE FROM
EDDYVILLE TO CLIO.  LARGE HAIL...DAMAGING WIND AND TORNADOES ARE
POSSIBLE IN THIS AREA.  THERE IS A MODERATE RISK OF SEVERE STORMS
SOUTHEAST OF A LINE FROM BROOKLYN TO LAMONI. LARGE HAIL...DAMAGING
WIND AND ISOLATED TORNADOES ARE POSSIBLE IN THIS AREA. IN
ADDITION...RAINFALL AMOUNTS OF A QUARTER TO ONE HALF INCH ARE
POSSIBLE OVER CENTRAL IOWA THROUGH TONIGHT...WITH ISOLATED TOTALS
BETWEEN 1 AND 2 INCHES. LOCALLY HEAVY RAIN WILL HAVE AN AFFECT ON
AREA RIVERS DURING THE COMING WEEK...BUT THE RISK FOR FLASH FLOODING
IS LOW FOR TODAY AND TONIGHT.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY

EXPECT VERY WINDY CONDITIONS ON SUNDAY...WITH A SUSTAINED NORTHWEST
WIND AT 20 TO 30 MPH...AND GUSTS TO 45 MPH. PERIODS OF SHOWERS AND A
FEW THUNDERSTORMS ARE EXPECTED ACROSS PARTS OF CENTRAL IOWA TUESDAY
NIGHT INTO WEDNESDAY...AND AGAIN THURSDAY. NO SEVERE WEATHER IS
ANTICIPATED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS LIKELY THIS AFTERNOON INTO EARLY
EVENING...MAINLY ALONG AND SOUTHEAST OF A LINE FROM BROOKLYN TO
LAMONI.
&&

MORE INFORMATION CAN BE OBTAINED AT WWW.CRH.NOAA.GOV/DMX (ALL LOWER
CASE).

FAB

In the hours before

Local storm report, May 10, 5:50 PM CDT, 43 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DES MOINES IA
0550 PM CDT SAT MAY 10 2003

TIME(CDT)  .....CITY LOCATION.....STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0540 PM    5 NNE MOULTON             IA   1.00 IN HAIL
05/10/03   DAVIS                          FROM NWS SPOTTER

SMALL

Local storm report, May 10, 5:52 PM CDT, 41 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DES MOINES IA
0552 PM CDT SAT MAY 10 2003

TIME(CDT)  .....CITY LOCATION.....STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0540 PM    6 S SULLY                 IA   2.75 IN HAIL
05/10/03   MAHASKA                        KCCI TV.

BF

Local storm report, May 10, 5:53 PM CDT, 40 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DES MOINES IA
0553 PM CDT SAT MAY 10 2003

TIME(CDT)  .....CITY LOCATION.....STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0540 PM    GRINNELL                  IA   2.00 IN HAIL
05/10/03   POWESHIEK                      TRAINED SPOTTER.

BF

Local storm report, May 10, 6:12 PM CDT, 21 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DES MOINES IA
0612 PM CDT SAT MAY 10 2003

TIME(CDT)  .....CITY LOCATION.....STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0530 PM    7 SE KNOXVILLE            IA   FX TORNADO
05/10/03   MARION                         F SCALE RATING UNKNOWN.
                                          SOUTHWEST OF ATTICA. LAW
                                          ENFORCEMENT.

0530 PM    8 SE KNOXVILLE            IA   FX TORNADO
05/10/03   MARION                         F SCALE RATING UNKNOWN. 3W
                                          ATTICA. LAW ENFORCEMENT.

BF

Local storm report, May 10, 6:16 PM CDT, 17 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DES MOINES IA
0616 PM CDT SAT MAY 10 2003

TIME(CDT)  .....CITY LOCATION.....STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0545 PM    GRINNELL                  IA   2.75 IN HAIL
05/10/03   POWESHIEK                      TRAINED SPOTTER.

0547 PM    GRINNELL                  IA   1.75 IN HAIL
05/10/03   POWESHIEK                      TRAINED SPOTTER.

0542 PM    GRINNELL                  IA   1.75 IN HAIL
05/10/03   POWESHIEK                      TRAINED SPOTTER.

BF

Local storm report, May 10, 6:19 PM CDT, 14 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DES MOINES IA
0619 PM CDT SAT MAY 10 2003

TIME(CDT)  .....CITY LOCATION.....STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0540 PM    GRINNELL                  IA   1.75 IN HAIL
05/10/03   POWESHIEK                      TRAINED SPOTTER.

0530 PM    10 SE KNOXVILLE           IA   FX TORNADO
05/10/03   MARION                         F SCALE RATING UNKNOWN.
                                          REPORTED BY EMERGENCY
                                          MANAGER. 3E OF ATTICA.

BF

The office that day

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

Issued	Product	Office	Counties	Lasted
May 10, 3:54 PM CDT	Severe Thunderstorm Warning	DMX	Cerro Gordo	36 min
May 10, 4:25 PM CDT	Severe Thunderstorm Warning	DMX	Wayne	50 min
May 10, 4:42 PM CDT	Severe Thunderstorm Warning	DMX	Appanoose	48 min
May 10, 4:46 PM CDT	Tornado Warning	DMX	Appanoose, Wayne	44 min
May 10, 4:48 PM CDT	Severe Thunderstorm Warning	DMX	Poweshiek, Tama	27 min
May 10, 5:11 PM CDT	Severe Thunderstorm Warning	DMX	Marion, Wapello	34 min
May 10, 5:17 PM CDT	Tornado Warning	DMX	Marion	28 min
May 10, 5:29 PM CDT	Tornado Warning	DMX	Appanoose, Davis	46 min
May 10, 5:31 PM CDT	Severe Thunderstorm Warning	DMX	Jasper, Poweshiek	29 min
May 10, 5:43 PM CDT	Tornado Warning	DMX	Mahaska	32 min
May 10, 5:49 PM CDT	Tornado Warning	DMX	Poweshiek	26 min
May 10, 5:57 PM CDT	Severe Thunderstorm Warning	DMX	Tama	33 min
May 10, 5:58 PM CDT	Tornado Warning	DMX	Davis	47 min
May 10, 6:07 PM CDT	Tornado Warning	DMX	Wapello	38 min
May 10, 6:12 PM CDT	Tornado Warning	DMX	Appanoose, Davis	33 min
May 10, 6:14 PM CDT	Tornado Warning	DMX	Poweshiek	31 min
May 10, 6:22 PM CDT	Tornado Warning	DMX	Tama	23 min
May 10, 6:44 PM CDT	Tornado Warning	DMX	Davis	46 min
May 10, 6:52 PM CDT	Severe Thunderstorm Warning	DMX	Bremer	23 min
May 10, 6:54 PM CDT	Tornado Warning	DMX	Bremer	36 min

Nearby

Severe Thunderstorm Warnings in Iowa, 2003 Every severe thunderstorm warning in 2003

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.