Alert archive / North Dakota / Severe Thunderstorm Warnings in 2002

Severe Thunderstorm Warning 203, NWS Grand Forks, ND

August 11, 2002Cass County, Traill County, North Dakota

NWS Grand Forks, ND issued this severe thunderstorm warning at Aug 11, 2002, 6:29 PM CDT for Cass County, Traill County, North Dakota. It was in force for 56 min. 1 report came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued
Aug 11, 2002, 6:29 PM CDT (23:29 UTC)
Expired
Aug 11, 2002, 7:25 PM CDT
In force
56 min
Issued by
NWS Grand Forks, ND
Area
Counties, with a storm outline in the text

Counties Cass County, ND, Traill County, ND

What was reported inside it

TimeReportWhereRemark
Aug 11, 7:10 PM CDTThunderstorm Wind 52 EArgusville, ND

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.

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 11, 1:55 PM CDTSevere Thunderstorm WatchSPC5 hr

The nearest sounding before it

Bismarck Municip, ND (KBIS), launched 12:00Z, 11.5 hours before the alert went out and 263 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, Bismarck Municip, ND at 12:00Z on 2002-08-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 194 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, Bismarck Municip, ND at 12:00Z on 2002-08-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 423 square meters per square second.193958Sfc1 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
194 J/kg
Mixed-layer CIN
-368 J/kg
Mixed-layer LCL
1960 m above ground
0-6 km bulk shear
39 kt
0-1 km storm-relative helicity
423 m²/s²
0-3 km storm-relative helicity
466 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.

612 
WUUS53 KFGF 112329
SVRFAR
NDC017-097-120025-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS
625 PM CDT SUN AUG 11 2002

THE NATIONAL WEATHER SERVICE IN GRAND FORKS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...

  NORTHERN CASS COUNTY IN SOUTHEAST NORTH DAKOTA AND   
  TRAILL COUNTY IN SOUTHEAST NORTH DAKOTA.

* UNTIL 725 PM CDT.

* AT 619 PM...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED THE
  LEADING EDGE OF SEVERE THUNDERSTORMS ALONG A LINE EXTENDING FROM 43
  MILES NORTH OF VALLEY CITY TO 20 MILES EAST OF VALLEY CITY...      
  MOVEMENT WAS TO THE EAST AT 50 MPH.  WINDS IN EXCESS OF 70 MPH 
  WILL BE LIKELY...ESPECIALLY IN TRAIL COUNTY. 

* SEVERE THUNDERSTORMS WILL BE NEAR...

  PAGE AT 630 PM...
  GALESBURG AT 640 PM...
  CLIFFORD AT 640 PM...
  MAYVILLE AT 655 PM AND
  HILLSBORO AT 710 PM.

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

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 700 PM SUNDAY
EVENING FOR NORTHWEST MINNESOTA AND EASTERN NORTH DAKOTA.

LAT...LON 4757 9732 4719 9745 4720 9764 4679 9758
          4690 9685 4765 9702


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 11, 3:15 PM CDT, 3 hours 14 minutes earlier.

Area forecast discussion, Aug 11, 3:15 PM CDT, 3 hours 14 minutes before
FORECAST DISCUSSION FOR EASTERN NORTH DAKOTA AND NORTHWEST MINNESOTA
NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS ND
315 PM CDT SUN AUG 11 2002

...FCST CHALLENGE IS SEVERE WEATHER THREAT THROUGH THIS EVENING...

ANALYSIS/NEAR TERM...DISCUSSION IS ABBREVIATED DUE TO SEVERE WEATHER
THREAT. SUPERCELL TSTMS DEVELOPING QUICKLY AHEAD OF A DEEPENING LOW
PRESSURE SYSTEM IN SCNTRL ND...IN AREA OF LOW LVL MOISTURE
CONVERGENCE. STRENGTHENING 500MB (50KT PLUS) JET STREAK NOW ROUNDING
THE BASE OF THE 500MB TROF IN SOUTHWEST MT WILL PROVIDE INCREASING
DYNAMIC SUPPORT FOR STRONG TSTM DEVELOPMENT AND ORGANIZATION THROUGH
THE LATE AFTERNOON AND EVENING HOURS. SWOMCD PROJECTS POSSIBLE
SQUALL LINE DEVELOPMENT...LATE AFTERNOON IN ERN ND THEN EARLY
EVENING INTO WRN MN. SEVERE WATCH IN EFFECT ACROSS ERN ND ATTM. WILL
POSSIBLY NEED ADDN WATCH INTO WRN MN BY EARLY EVENING AS LINE
DEVELOPS.

MONDAY AND TUESDAY...COLD POOL ALOFT SHIFTS ACROSS THE NRN PLAINS ON
MONDAY WITH SHOWERS EXPECTED TO REDEVLOP BY MID AFTERNOON. UPPER LVL
TROUGH THEN ANCHORS OVR THE NRN PLAINS THROUGH THE MIDWEEK PERIOD
KEEPING AREA UNDER SEASONABLY COOLER FLOW NEXT WEAK IMPULSE INTO THE
AREA LATE AFTERNOON TUESDAY. SOME DRYING POSSIBLE BY LATE WEK PERIOD
THOUGH TEMPS REMAIN BELOW SEASONAL NORMALS.

.FGF...SEVERE THUNDERSTORM WATCH FOR EASTERN ND THIS EVENING.

GUST

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 11, 4:54 PM CDTSevere Thunderstorm WarningFGFEddy51 min
Aug 11, 5:08 PM CDTSevere Thunderstorm WarningFGFBenson, Nelson, Ramsey37 min
Aug 11, 5:44 PM CDTSevere Thunderstorm WarningFGFBarnes61 min
Aug 11, 5:47 PM CDTSevere Thunderstorm WarningFGFNelson, Ramsey, Walsh43 min
Aug 11, 5:54 PM CDTSevere Thunderstorm WarningFGFGriggs, Steele51 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; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive.