Alert archive / North Dakota / Severe Thunderstorm Warnings in 2002

Severe Thunderstorm Warning 309, NWS Grand Forks, ND

August 30, 2002Grand Forks County, Walsh County, North Dakota

NWS Grand Forks, ND issued this severe thunderstorm warning at Aug 30, 2002, 10:45 PM CDT for Grand Forks County, Walsh County, North Dakota. It was in force for 45 min. 2 reports came from inside the area while it was in force.

The area

The counties it named, with what was reported inside it.

The facts

Issued
Aug 30, 2002, 10:45 PM CDT (03:45 UTC)
Expired
Aug 30, 2002, 11:30 PM CDT
In force
45 min
Issued by
NWS Grand Forks, ND
Area
Counties, with a storm outline in the text

Counties Grand Forks County, ND, Walsh County, ND

The radar

The Fargo/Grand Forks radar (KMVX), 71 km from the middle of the area, began a volume at 03:47 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.

What was reported inside it

TimeReportWhereRemark
Aug 30, 10:50 PM CDTHail 0.75Forest River, ND
Aug 30, 10:50 PM CDTHail 0.88Johnstown, 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 nearest sounding before it

Bismarck Municip, ND (KBIS), launched 00:00Z, 3.8 hours before the alert went out and 279 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 00:00Z on 2002-08-31Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1932 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 00:00Z on 2002-08-31The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 111 square meters per square second.1939Sfc1 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
1932 J/kg
Mixed-layer CIN
-38 J/kg
Mixed-layer LCL
1185 m above ground
0-6 km bulk shear
21 kt
0-1 km storm-relative helicity
111 m²/s²
0-3 km storm-relative helicity
212 m²/s²
Significant tornado parameter
0.0
Supercell composite
3.3

Open this sounding in Storm Lab

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 30, 8:45 PM CDT, 2 hours earlier.

Area forecast discussion, Aug 30, 8:45 PM CDT, 2 hours before
FORECAST DISCUSSION FOR EASTERN NORTH DAKOTA AND NORTHWEST MINNESOTA
NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS ND
845 PM CDT FRI AUG 30 2002

MODELS APPEAR TO HAVE A NICE HANDLE ON THE LOW (925-850MB) LEVEL JET
CURRENTLY THOUGH MAYBE 10 KNOTS LOW. KMVX RADAR SHOWS 45-55 KNOTS AT
3-4 KFT AND SEEMS TO FIT THE MODELS DEPICTION THAT THE JET MAX IS
OVER EASTCENTRAL ND AND READY TO FEED SEVERE THUNDERSTORMS MOVING
NORTHEAST TOWARD DVL. NORTHERN COUNTIES TO BE UNDER GREATEST THREAT
OF HEAVY RAIN/SEVERE STORMS TONIGHT...UNFORTUNATELY THE AREA LEAST
ABLE TO HANDLE IT DUE TO ALREADY SATURATED SOILS. NOSE OF THETA-E
RIDGE IS ALSO FEEDING THOSE STORMS WHICH WILL ROTATE INTO NORTHEAST
ND AND STAY PRETTY MUCH ALL NIGHT. REST OF REGION MAY NOT HAVE MORE
THAN SCATTERED THUNDER TONIGHT BUT WILL LEAVE ZONES ALONE FOR NOW AS
THUNDERTORMS WEST OF ABR MAY GROW IN NUMBER IN HIGH MOISTURE. SOME
OF THE MODELS ALSO SUGGEST RESPECTABLE LOW LEVEL MOIST CONVERGENCE
OVER MUCH OF THE REGION TONIGHT.

.FGF...FLOOD WATCH ALL ZONES FOR TONIGHT AND SATURDAY.
GV

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 30, 11:33 PM CDTFlash Flood WarningFGFPolk8 hr
Aug 31, 2:19 AM CDTSevere Thunderstorm WarningFGFNorman, Polk41 min
Aug 31, 3:24 AM CDTSevere Thunderstorm WarningFGFNorman51 min
Aug 31, 7:21 AM CDTSevere Thunderstorm WarningFGFBeltrami39 min
Aug 30, 10:00 PM CDTSevere Thunderstorm WarningFGFGrand Forks, Nelson45 min
Aug 31, 12:51 AM CDTSevere Thunderstorm WarningFGFGrand Forks24 min
Aug 31, 1:53 AM CDTSevere Thunderstorm WarningFGFTraill37 min
Aug 31, 6:37 PM CDTSevere Thunderstorm WarningFGFCavalier, Towner38 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; radar from the NEXRAD Level II archive.