Alert archive / North Dakota / Severe Thunderstorm Warnings in 2002

Severe Thunderstorm Warning 146, NWS Grand Forks, ND

July 31, 2002Sargent County, North Dakota

NWS Grand Forks, ND issued this severe thunderstorm warning at Jul 31, 2002, 3:36 AM CDT for Sargent County, North Dakota. 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 outline as issued.

The facts

Issued
Jul 31, 2002, 3:36 AM CDT (08:36 UTC)
Expired
Jul 31, 2002, 4:15 AM CDT
In force
39 min
Issued by
NWS Grand Forks, ND
Area
Counties, with a storm outline in the text

County Sargent County, ND

The radar

The Aberdeen radar (KABR), 89 km from the middle of the area, began a volume at 08:40 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 nearest sounding before it

Aberdeen, SD (KABR), launched 00:00Z, 8.6 hours before the alert went out and 142 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 2002-07-31Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1470 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 2002-07-31The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 112 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
1470 J/kg
Mixed-layer CIN
-209 J/kg
Mixed-layer LCL
1589 m above ground
0-6 km bulk shear
53 kt
0-1 km storm-relative helicity
112 m²/s²
0-3 km storm-relative helicity
202 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.3

Open this sounding in Storm Lab

The text

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

323 
WUUS53 KFGF 310836
SVRFAR
NDC081-310915-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS
336 AM CDT WED JUL 31 2002

THE NATIONAL WEATHER SERVICE IN GRAND FORKS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...

  SOUTHERN SARGENT COUNTY IN SOUTHEAST NORTH DAKOTA.

* UNTIL 415 AM CDT.

* AT 331 AM...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM 10 MILES SOUTHWEST OF STRAUBVILLE...OR ABOUT 68
  MILES SOUTH OF VALLEY CITY...MOVEMENT WAS TO THE EAST AT 40 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...

  STRAUBVILLE AT 340 AM...
  BRAMPTON AT 350 AM...
  FORMAN AT 400 AM AND
  RUTLAND AT 410 AM.

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

LAT...LON 4615 9798 4596 9798 4595 9728 4619 9730


04

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 Jul 31, 3:15 AM CDT, 21 minutes earlier.

Area forecast discussion, Jul 31, 3:15 AM CDT, 21 minutes before
FORECAST DISCUSSION FOR EASTERN NORTH DAKOTA AND NORTHWEST MINNESOTA
NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS ND
315 AM CDT WED JUL 31 2002

FORECAST CHALLENGE CONCERNS EARLY TSRA THREAT AND TEMPERATURES.

MODELS IN FAIR AGREEMENT THROUGH PERIOD ALTHOUGH PREFERRED SFC
FEATURES FROM ETA EARLY.

MAIN CONCERN TODAY WILL THREAT FOR MAINLY AFTERNOON AND EVENING
SEVERE TSRA. SFC LOW PRESSURE STILL FAIRLY UNORGANIZED EARLY THIS
MORNING HOWEVER FEATURE GAINS BETTER DEFINITION AND SHIFTS EAST TO
WESTERN FA BY MID AFTERNOON AND ACROSS FORECAST AREA DURING LATE
AFTERNOON EARLY EVENING HOURS. IN THE NEAR TERM SEVERAL CLUSTERS OF
TSRA FROM KMVX/KBIS 88S WILL PROPAGATE EAST THROUGH FA EARLY THIS
AM BEFORE GRADUALLY DIMINISHING. WILL LIKELY SEE A BREAK FROM LATE
AM INTO MID AFTERNOON. CONVECTIVE DEBRIS CLOUDS WILL HAVE SOME
IMPACT ON TEMPS HOWEVER DO EXPECT A GOOD DOSE OF AFTERNOON SOLAR TO
AID IN DESTABILIZATION. AS SFC LOW BECOMES BETTER DEFINED INCREASING
SOUTHERLY FLOW WILL PROVIDE GOOD LOW LEVEL MOISTURE FLUX INTO AREA.
AT THIS TIME FAVORED AREA FOR INITIATION OF AFTERNOON CONVECTION
LOOKS TO BE ACROSS THE NORTH WITH LESS CAPPING AND ON NOSE OF UPPER
JET. AS SIGNIFICANT SHORTWAVE APPROACHES REGION GOOD MID LEVEL
COOLING WILL PUT WHOLE AREA UNDER GUN AS CAP ERODES WITH EXCEPTION
OF FAR NW BEHIND FRONT. SVR THREAT WILL SHIFT EAST OF RIVER THIS
EVENING AND BASED ON FROPA SHOULD EXIT FA BY MIDNIGHT.

STRONG COLD ADVECTION DIVES FROM NW TO SE ACROSS FA OVERNIGHT. WE
SHOULD THEN SEE MUCH COOLER TEMPERATURES BUT RAIN FREE CONDITIONS AS
SFC AND MID LEVEL RIDGING TAKES CONTROL. RETURN FLOW SETS UP AHEAD
OF NEXT WAVE LATE FRIDAY WITH OUR NEXT CHANCE OF PCPN STILL ON TRACK
FOR FRIDAY NIGHT/SAT. NO CHANGES PLANNED TO EXTENDED.

.FGF...NONE.
VOELKER

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 31, 4:13 AM CDTSevere Thunderstorm WarningFGFRichland, Sargent47 min
Jul 31, 4:59 AM CDTSevere Thunderstorm WarningFGFRichland31 min
Jul 31, 6:13 PM CDTTornado WarningFGFBenson32 min
Jul 31, 6:18 PM CDTTornado WarningFGFRamsey42 min
Jul 31, 6:46 PM CDTSevere Thunderstorm WarningFGFBenson44 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.