Alert archive / Iowa / Severe Thunderstorm Warnings in 2001

Severe Thunderstorm Warning 318, NWS Des Moines, IA

August 3, 2001Greene County, Iowa

NWS Des Moines, IA issued this severe thunderstorm warning at Aug 3, 2001, 7:01 AM CDT for Greene County, Iowa. It was in force for 39 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued: Aug 3, 2001, 7:01 AM CDT (12:01 UTC)
Expired: Aug 3, 2001, 7:40 AM CDT
In force: 39 min
Issued by: NWS Des Moines, IA
Area: Whole counties; the outline is the Mesonet’s reconstruction

County Greene County, IA

The nearest sounding before it

Davenport, (KDVN), launched 12:00Z, 0.0 hours before the alert went out and 326 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: 1095 J/kg
Mixed-layer CIN: -74 J/kg
Mixed-layer LCL: 622 m above ground
0-6 km bulk shear: 19 kt
0-1 km storm-relative helicity: 13 m²/s²
0-3 km storm-relative helicity: 121 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

The text of this product is not in the archive. The NWS text archive before 2002 is incomplete.

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 3, 3:05 AM CDT, 3 hours 56 minutes earlier.

Area forecast discussion, Aug 3, 3:05 AM CDT, 3 hours 56 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
305 AM CDT FRI AUG 3 2001

WL KEEP SCTD/ISOLLD TSMT IN ERY TDA AS MID DECK HINT OF THINGS TO
DVLP.  INSTABILITY ALOFT GREAT AS ARE OTHER NUMBERS.  MODELS ETA AND
RUC HAVE PICKED UP ON THIS AND PCPN ATTM COMING OUT OF SD INTO NW
IA.  XPCT PCPN TO DVLP ALG CONVERGENT LN NW-SE THIS MRNG.  TNGT
NOTHING THERE DYNAMCIALLY SO WILL DROP MENTION OF POPS.  OTHERWISE
FCST REMAINS MUCH OF THE AS RIDGE IN PLACE AND SW FLO RETURNS.  GUID
TEMPS CLOSE WITH MINOR ADJSTMNTS FOR CLDS.

.DSM...NONE

FORSTER

In the hours before

Special weather statement, Aug 3, 5:30 AM CDT, 1 hour 31 minutes before

CENTRAL IOWA THUNDERSTORM OUTLOOK
NATIONAL WEATHER SERVICE DES MOINES IA
530 AM CDT FRI AUG 3 2001

DESPITE A LARGE DOME OF HIGH PRESSURE OVER THE CENTRAL U.S. ISOLATED
TO SCATTERED THUNDERSTORMS ARE EXPECTED TO DEVELOP IN THE STATE FROM
EARLY THIS MORNING TO EARLY AFTERNOON.  WITH PLENTY OF MOISTURE
AVAILABLE LOCALLY HEAVY RAINS ARE LIKELY.

IAZ004>007-015>017-023>028-033>039-044>050-057>062-070>075-081>086-
092>097-032300-
ADAIR-ADAMS-APPANOOSE-AUDUBON-BLACK
HAWK-BOONE-BREMER-BUTLER-CALHOUN-CARROLL-CASS-CERRO
GORDO-CLARKE-CRAWFORD-DALLAS-DAVIS-DECATUR-EMMET-FRANKLIN-GREENE-
GRUNDY-GUTHRIE-HAMILTON-HANCOCK-HARDIN-HUMBOLDT-JASPER-KOSSUTH-LUCAS-
MADISON-MAHASKA-MARION-MARSHALL-MONROE-PALO
ALTO-POCAHONTAS-POLK-POWESHIEK-RINGGOLD-SAC-STORY-TAMA-TAYLOR-UNION-
WAPELLO-WARREN-WAYNE-WEBSTER-WINNEBAGO-WORTH-WRIGHT-
INCLUDING THE CITIES OF...ALGONA...AMES...ATLANTIC...BOONE...
CARROLL...CENTERVILLE...CHARITON...CRESTON...DENISON...DES MOINES...
ESTHERVILLE...FORT DODGE...GRINNELL...INDIANOLA...IOWA FALLS...
KNOXVILLE...LAMONI...MARSHALLTOWN...MASON CITY...NEWTON...
OSKALOOSA...OTTUMWA...PELLA...PERRY...WATERLOO...WAVERLY AND WEBSTER
CITY
520 AM CDT FRI AUG 3 2001

* EVENT TIMING...THROUGH NOON.

* THREAT CATEGORIES...
     TORNADO..........NONE
     DAMAGING WINDS...LOW
     LARGE HAIL.......NONE
     FLASH FLOODING...HIGH

* SPOTTER ACTIVATION OUTLOOK...LOW

* LOCALLY HEAVY RAINS COULD PRODUCE FLASH FLOODING IN SOME AREAS
WITH RAINFALL RATES OF ONE TO TWO INCHES PER HOUR.

-------------------------------------------------------------------

THREAT KEY:
    TORNADO.......... ANY TORNADO OCCURRENCE
    DAMAGING WINDS... WINDS >= 58 MPH
    LARGE HAIL....... HAIL >= 3/4 INCH DIAMETER
    FLASH FLOODING... FLOODING CAUSED BY HEAVY RAINS WITHIN 6 HOURS
                      OF RAIN EVENT. POSES THREAT TO LIFE OR
                      PROPERTY.

THREAT CATEGORY KEY:  PROBABILITY OF THREAT OCCURRING WITHIN 25
                      MILES OF POINT WITHIN FORECAST AREA
    NONE....... NOT EXPECTED.  LESS THAN 5% ( 2% FOR TORNADOES)
    LOW........ 5-15% (2-15% FOR TORNADOES)
    MODERATE... 25-35%
    HIGH....... 45% OR GREATER

SPOTTER ACTIVATION OUTLOOK KEY:
    NOT EXPECTED
    LOW........ ACTIVATION POSSIBLE BUT NOT LIKELY
    MODERATE... POSSIBILITIES ABOUT 50-50
    HIGH....... ACTIVATION LIKELY

FOR MORE INFORMATION ON PROBABILISTIC SEVERE WEATHER OUTLOOKS...GO
TO THE STORM PREDICTION CENTER WEBSITE AT
WWW.SPC.NOAA.GOV/PRODUCTS/OUTLOOK/PROBINFO.HTML .

FORSTER

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 3, 5:02 AM CDT	Flash Flood Warning	DMX	Davis	4 hr
Aug 3, 5:49 AM CDT	Flash Flood Warning	DMX	Calhoun, Pocahontas, Sac	6 hr
Aug 3, 6:06 AM CDT	Flash Flood Warning	DMX	Wapello	3 hr
Aug 3, 8:50 AM CDT	Flash Flood Warning	DMX	Appanoose, Davis, Monroe, Wapello	4 hr

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; the sounding from the Mesonet's radiosonde archive.