Alert archive / Iowa / Severe Thunderstorm Warnings in 2001

Severe Thunderstorm Warning 121, NWS Des Moines, IA

May 10, 2001Poweshiek County, Iowa

NWS Des Moines, IA issued this severe thunderstorm warning at May 10, 2001, 7:20 PM CDT for Poweshiek County, Iowa. It was in force for 40 min. 1 report came from inside the area while it was in force.

The area

The outline the Iowa Environmental Mesonet reconstructed for it; the warning itself named whole counties, with what was reported inside it.

The facts

Issued: May 10, 2001, 7:20 PM CDT (00:20 UTC)
Expired: May 10, 2001, 8:00 PM CDT
In force: 40 min
Issued by: NWS Des Moines, IA
Area: Whole counties; the outline is the Mesonet’s reconstruction

County Poweshiek County, IA

What was reported inside it

Time	Report	Where	Remark
May 10, 8:04 PM CDT	Hail 0.75	Oskaloosa, IA

NCEI Storm Data entries that began inside the alert's area while it was in force. Before 2003 the local storm report archive is thin, so this is the record of what happened rather than what was phoned in.

The watch it was issued in

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

Issued	Product	Office	Lasted
May 10, 4:15 PM CDT	Severe Thunderstorm Watch	SPC	6 hr

The nearest sounding before it

Davenport, (KDVN), launched 00:00Z, 0.3 hours before the alert went out and 172 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: 794 J/kg
Mixed-layer CIN: -45 J/kg
Mixed-layer LCL: 1445 m above ground
0-6 km bulk shear: 33 kt
0-1 km storm-relative helicity: 58 m²/s²
0-3 km storm-relative helicity: 142 m²/s²
Significant tornado parameter: 0.1
Supercell composite: 2.4

Open this sounding in Storm Lab

The text

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

000 
WUUS53 KDMX 110021
SVRDSM
IAC157-110100-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
720 PM CDT THU MAY 10 2001

THE NATIONAL WEATHER SERVICE IN DES MOINES HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  POWESHIEK COUNTY IN CENTRAL IOWA

* UNTIL 800 PM CDT

* AT 719 PM...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A LINE
  OF SEVERE THUNDERSTORMS FROM 11 MILES NORTHEAST OF BROOKLYN TO 20
  MILES SOUTHWEST OF GRINNELL...OR FROM 33 MILES WEST OF CEDAR RAPIDS
  TO 34 MILES EAST OF DES MOINES...MOVING SOUTHEAST AT 20 MPH.

* SEVERE THUNDERSTORMS WILL BE...
  NEAR BROOKLYN AROUND 730 PM
  NEAR MONTEZUMA AROUND 750 PM

HAIL UP TO THE SIZE OF QUARTERS IS LIKELY IN THE WARNED AREA.

VERY STRONG WINDS UP TO 60 MPH ARE LIKELY IN THE WARNED AREA.

SEEK A STURDY SHELTER SUCH AS A BASEMENT OR INTERIOR ROOM.

REMEMBER...SEVERE THUNDERSTORMS CAN PRODUCE TORNADOES WITH LITTLE OR
NO ADVANCE WARNING.


LAT...LON 4176 9275 4151 9276 4151 9231 4185 9230

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 May 10, 3:30 PM CDT, 3 hours 50 minutes earlier.

Area forecast discussion, May 10, 3:30 PM CDT, 3 hours 50 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
330 PM CDT THU MAY 10 2001

IN THE SHORT TERM...EAST TO WEST OUTFLOW BOUNDARY ALONG HIGHWAY 20
NOW BEGINNING TO LIGHT UP WHILE ADDITIONAL DEVELOPMENT EXPECTED
FURTHER WEST ALONG COLD FRONT. ATMOSPHERE OVER SOUTHWEST IOWA SHOULD
HAVE WARMED ENOUGH TO ELIMINATE WEAK CAP SHOWN ON 18Z OMA SOUNDING.
LCL HAVE LOWERED CONSIDERABLY FROM YESTERDAY...THROUGH THEY STILL
REMAIN FAIRLY HIGH AT AROUND 5.5K FT. SURFACE WINDS IN WARM SECTOR
HAVE VEERED SO IT APPEARS MAIN THREAT FROM STORMS WILL CONTINUE TO
BE HAIL/WIND. SOME ROTATING STORMS MAY BE A LITTLE MORE LIKELY ALONG
THE OUTFLOW BOUNDARY TO THE NORTH OR NEAR OUTFLOW/FRONTAL
INTERSECTION. AS SHORT WAVE TROUGH MOVES THROUGH CWA THIS EVENING...
CONVECTION SHOULD BE SHUNTED OFF INTO N MO AND SE IA BY OR AROUND
MIDNIGHT.

MOST OF THE FRONTAL CONVECTION SHOULD BE S OF THE CWA FRIDAY SO WILL
MAINTAIN A DRY FORECAST.

MODELS SHOWING SOME POSSIBILITY OF WARM AIR ADVECTION SHOWERS/STORMS
SATURDAY. WILL HOLD OFF ON ADDITION OF POPS ACROSS THE NORTH FOR NOW
AND LET ANOTHER MODEL RUN OR TWO PASS TO GET A BETTER HANDLE ON
THAT. HAVE LEFT EXTENDEDQ UNCHANGED.

MOS TEMPS LOOK PRETTY GOOD AND ARE IN LINE WITH CURRENT FORECASTS.

.DSM...NONE

JAW

The office that day

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

Issued	Product	Office	Counties	Lasted
May 10, 7:08 PM CDT	Severe Thunderstorm Warning	DMX	Dallas, Polk	32 min
May 10, 7:29 PM CDT	Severe Thunderstorm Warning	DMX	Madison, Warren	41 min
May 10, 7:33 PM CDT	Severe Thunderstorm Warning	DMX	Jasper	42 min
May 10, 7:59 PM CDT	Severe Thunderstorm Warning	DMX	Poweshiek	41 min
May 10, 8:01 PM CDT	Severe Thunderstorm Warning	DMX	Madison, Warren	39 min
May 10, 8:10 PM CDT	Tornado Warning	DMX	Marion	30 min
May 10, 8:23 PM CDT	Severe Thunderstorm Warning	DMX	Clarke, Lucas	42 min
May 10, 8:26 PM CDT	Severe Thunderstorm Warning	DMX	Taylor	19 min
May 10, 8:35 PM CDT	Severe Thunderstorm Warning	DMX	Mahaska	40 min
May 10, 8:42 PM CDT	Severe Thunderstorm Warning	DMX	Warren	18 min
May 10, 9:06 PM CDT	Severe Thunderstorm Warning	DMX	Clarke	19 min
May 10, 9:10 PM CDT	Severe Thunderstorm Warning	DMX	Wapello	40 min
May 10, 9:16 PM CDT	Severe Thunderstorm Warning	DMX	Lucas	39 min

Nearby

Severe Thunderstorm Warnings in Iowa, 2001 Every severe thunderstorm warning in 2001

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive.