Alert archive / North Dakota / Severe Thunderstorm Warnings in 2002

Severe Thunderstorm Warning 329, NWS Grand Forks, ND

August 31, 2002Cass County, North Dakota

NWS Grand Forks, ND issued this severe thunderstorm warning at Aug 31, 2002, 10:52 PM CDT for Cass County, North Dakota. It was in force for 53 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
Aug 31, 2002, 10:52 PM CDT (03:52 UTC)
Expired
Aug 31, 2002, 11:45 PM CDT
In force
53 min
Issued by
NWS Grand Forks, ND
Area
Counties, with a storm outline in the text

County Cass County, ND

The radar

The Fargo/Grand Forks radar (KMVX), 57 km from the middle of the area, began a volume at 03:54 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 watch it was issued in

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

IssuedProductOfficeLasted
Aug 31, 9:55 PM CDTSevere Thunderstorm WatchSPC6 hr

The nearest sounding before it

Aberdeen, SD (KABR), launched 00:00Z, 3.9 hours before the alert went out and 248 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-pSkew-T log-p diagram, Aberdeen, SD at 00:00Z on 2002-09-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 3369 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Aberdeen, SD at 00:00Z on 2002-09-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 130 square meters per square second.19395878Sfc1 km3 km6 km9 kmRMLM
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
3369 J/kg
Mixed-layer CIN
-54 J/kg
Mixed-layer LCL
1554 m above ground
0-6 km bulk shear
32 kt
0-1 km storm-relative helicity
130 m²/s²
0-3 km storm-relative helicity
161 m²/s²
Significant tornado parameter
0.7
Supercell composite
4.4

Open this sounding in Storm Lab

The text

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

441 
WUUS53 KFGF 010352
SVRFAR
NDC017-010445-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS
1051 PM CDT SAT AUG 31 2002

THE NATIONAL WEATHER SERVICE IN GRAND FORKS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...

 CASS COUNTY IN SOUTHEAST NORTH DAKOTA.

* UNTIL 1145 PM CDT.

* AT 1049 PM...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM 12 MILES WEST OF BUFFALO...OR ABOUT 10 MILES   
  EAST OF VALLEY CITY...MOVEMENT WAS TO THE NORTHEAST AT 30 MPH.  
  THIS STORM HAS PRODUCED BASEBALL SIZE HAIL IN THE VALLEY CITY      
  AREA. 

* THE SEVERE THUNDERSTORM WILL BE NEAR...

  BUFFALO AT 1110 PM...
  AYR AT 1120 PM...
  ABSARAKA AT 1125 PM AND
  ERIE AT 1130 PM.

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

A SEVERE THUNDERSTORM WATCH ALSO REMAINS IN EFFECT UNTIL 400 AM 
SUNDAY MORNING FOR NORTHWESTERN MINNESOTA AND EASTERN NORTH DAKOTA. 

LAT...LON 4706 9768 4677 9766 4697 9687 4723 9700


06

NNNN

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 Grand Forks, ND wrote its last area forecast discussion before this severe thunderstorm warning went out at Aug 31, 8:45 PM CDT, 2 hours 7 minutes earlier.

Area forecast discussion, Aug 31, 8:45 PM CDT, 2 hours 7 minutes before
FORECAST DISCUSSION FOR EASTERN NORTH DAKOTA AND NORTHWEST MINNESOTA
NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS ND
845 PM CDT SAT AUG 31 2002

SEVERE THUNDERSTORMS ARE CONFINED SO FAR TO EXTREME NORTHERN RED
RIVER VALLEY BUT TRAINING THUNDERSTORMS ARE APPROACHING ON SEVERAL
FRONTS AT WEST/SOUTHWEST SIDE OF CWA. BELIEVE THE AVN WAS MOST
CORRECT IN PLACEMENT OF HEAVIEST RAIN TONIGHT BUT FLOOD WATCH IN
EFFECT THROUGHOUT REGION IS STILL VALID WITH SATURATED SOILS IN
ABUNDANCE. WILL LEAVE ZONES BASICALLY ALONE BUT WILL ADD EMPHASIS
ON FLOOD POTENTIAL AS NONE WAS INCLUDED EARLIER.

.FGF...FLASH FLOOD WATCH ENTIRE CWA TONIGHT.
       SEVERE THUNDERSTORM WATCH TIL MIDNIGHT NORTH HALF EXCEPT LAKE
       OF THE WOODS AND BELTRAMI COUNTIES.
GV

The office that day

Everything else NWS Grand Forks, ND issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 31, 7:13 PM CDTSevere Thunderstorm WarningFGFCavalier47 min
Aug 31, 7:22 PM CDTFlash Flood WarningFGFCavalier4 hr
Aug 31, 7:45 PM CDTSevere Thunderstorm WarningFGFPembina45 min
Aug 31, 7:56 PM CDTSevere Thunderstorm WarningFGFCavalier34 min
Aug 31, 8:32 PM CDTSevere Thunderstorm WarningFGFCavalier43 min
Aug 31, 8:42 PM CDTTornado WarningFGFCavalier33 min
Aug 31, 8:53 PM CDTSevere Thunderstorm WarningFGFPembina52 min
Aug 31, 9:00 PM CDTSevere Thunderstorm WarningFGFBenson, Towner45 min
Aug 31, 9:11 PM CDTSevere Thunderstorm WarningFGFCavalier49 min
Aug 31, 9:43 PM CDTSevere Thunderstorm WarningFGFBenson, Ramsey, Towner62 min
Aug 31, 9:47 PM CDTSevere Thunderstorm WarningFGFPembina43 min
Aug 31, 10:02 PM CDTSevere Thunderstorm WarningFGFCavalier43 min
Aug 31, 10:07 PM CDTFlash Flood WarningFGFCavalier, Pembina3 hr
Aug 31, 10:20 PM CDTSevere Thunderstorm WarningFGFBarnes, Griggs55 min
Aug 31, 10:30 PM CDTSevere Thunderstorm WarningFGFPembina45 min
Aug 31, 10:45 PM CDTSevere Thunderstorm WarningFGFCavalier45 min
Aug 31, 11:15 PM CDTSevere Thunderstorm WarningFGFBarnes30 min
Aug 31, 11:18 PM CDTSevere Thunderstorm WarningFGFPembina42 min
Sep 1, 12:28 AM CDTSevere Thunderstorm WarningFGFSargent47 min
Sep 1, 1:19 AM CDTSevere Thunderstorm WarningFGFRichland41 min

Nearby

Severe Thunderstorm Warnings in North Dakota, 2002Every severe thunderstorm warning in 2002

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.