Severe Thunderstorm Warning 15, NWS La Crosse, WI

Issued

Apr 18, 2002, 4:01 AM CDT (09:01 UTC)

Expired

Apr 18, 2002, 4:45 AM CDT

In force

44 min

Issued by

NWS La Crosse, WI

Area

Counties, with a storm outline in the text

County Allamakee County, 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.

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.

000 
WUUS53 KARX 180901
SVRLSE
IAC005-180945-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE LA CROSSE WI
401 AM CDT THU APR 18 2002

THE NATIONAL WEATHER SERVICE IN LA CROSSE HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  ALLAMAKEE COUNTY IN NORTHEAST IOWA

* UNTIL 445 AM CDT

* AT 401 AM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM 6 MILES SOUTH OF WAUKON...MOVING NORTHEAST AT
  30 MPH.

* THE SEVERE THUNDERSTORM IS EXPECTED TO BE...
  NEAR ROSSVILLE AT 410 AM CDT...
  NEAR HARPERS FERRY...AND LANSING AT 425 AM CDT...

LARGE DESTRUCTIVE HAIL IS THE MAIN THREAT WITH THESE STORMS. FOR YOUR
PROTECTION...SEEK SHELTER IN A STURDY BUILDING AND STAY AWAY FROM
WINDOWS.

LAT...LON 4330 9162 4308 9161 4309 9118 4330 9108
          4342 9124

MW

NWS La Crosse, WI wrote its last area forecast discussion before this severe thunderstorm warning went out at Apr 18, 3:10 AM CDT, 51 minutes earlier.

AREA FORECAST DISCUSSION...CORRECTION AND RETRANSMISSION
NATIONAL WEATHER SERVICE LA CROSSE WI
310 AM CDT THU APR 18 2002

FORECAST CONCERNS FOR THIS PACKAGE INCLUDE PRECIPITATION CHANCES AND
SEVERE WEATHER THREAT TODAY...THEN CLOUDS AND TEMPERATURES THROUGH
SATURDAY.

07Z SURFACE ANALYSIS SHOWS STRONG LOW PRESSURE ACROSS SOUTH CENTRAL
SOUTH DAKOTA. WARM FRONT EXTENDING EASTWARD ACROSS IOWA. AREA RADARS
SHOWING SCATTERED CONVECTION TO THE NORTH OF THE FRONT ACROSS
MINNESOTA...NORTHERN IOWA AND WISCONSIN...MAINLY PRODUCING HAIL.

00Z MODELS IN DECENT AGREEMENT. THEY HAVE BACKED OFF A LITTLE WITH
THE MOVEMENT OF THE FRONT THROUGH THE AREA TODAY AND TONIGHT. AGAIN
WILL FOLLOW ETA FOR THE DETAILS.

CONVECTION TO CONTINUE TO BE SEVERE THIS MORNING AS WARM FRONT HEADS
NORTHWARD. STRONG MOISTURE TRANSPORT ON 60 KNOT 850 MB JET WILL
WEAKEN LATER THIS MORNING AND THUS CONVECTION WILL BE ON THE WANE AS
WELL. SURFACE LOW THEN PULLS TO NEAR THE TWIN CITIES BY MIDDAY AND
INTO NORTHEAST WISCONSIN BY EVENING. ASSOCIATED COLD FRONT PULLS
INTO THE FORECAST AREA...WITH MUCH OF THE EASTERN TWO THIRDS
REMAINING IN THE WARM SECTOR. CAPES OF 2000-3000 J/KG ALONG WITH
STEEP LAPSE RATES AND GOOD DIRECTIONAL SHEAR WILL RE-IGNITE MORE
CONVECTION WITH IT MOVING EASTWARD OUT OF THE AREA THIS EVENING.

STRONG COLD ADVECTION BEHIND FRONT LATER TONIGHT WILL BRING AN
END TO OUR SUMMER LIKE WEATHER. COLD ADVECTION CONTINUES RIGHT INTO
SATURDAY. TIME HEIGHT CROSS SECTIONS OF RELATIVE HUMIDITY INDICATE
SOME CLOUDS TO BE AROUND THE AREA THROUGH THE EARLY PART OF THE
WEEKEND. WILL KEEP PARTLY CLOUDY WORDING. AVN INDICATES A SMALL
CHANCE OF SHOWERS ON FRIDAY ACROSS THE FAR SOUTHERN ZONES...BUT
WILL KEEP DRY FORECAST GOING FOR NOW.

AS FOR TEMPERATURES...HAVE TRENDED TOWARD THE WARM MAV NUMBERS
TODAY. FOR FRIDAY AND SATURDAY WENT ABOVE GUIDANCE VALUES...BUT
COOLER THAN CURRENT FORECAST INDICATES. A LOT WILL DEPEND ON
AMOUNTS OF SUN.

.LSE...NONE.

RABERDING

Severe Thunderstorm Warnings in Iowa, 2002Every severe thunderstorm warning in 2002

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.