Alert archive / North Dakota / Severe Thunderstorm Warnings in 2002
Severe Thunderstorm Warning 171, NWS Grand Forks, ND
NWS Grand Forks, ND issued this severe thunderstorm warning at Aug 1, 2002, 2:11 AM CDT for Cass County, North Dakota. It was in force for 49 min. 2 reports 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 1, 2002, 2:11 AM CDT (07:11 UTC)
- Expired
- Aug 1, 2002, 3:00 AM CDT
- In force
- 49 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), 61 km from the middle of the area, began a volume at 07:14 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
| Time | Report | Where | Remark |
|---|---|---|---|
| Aug 1, 2:30 AM CDT | Hail 1 | Mapleton, ND | |
| Aug 1, 2:40 AM CDT | Hail 0.75 | West Fargo, 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
Aberdeen, SD (KABR), launched 00:00Z, 7.2 hours before the alert went out and 245 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.
- Mixed-layer CAPE
- 3338 J/kg
- Mixed-layer CIN
- -198 J/kg
- Mixed-layer LCL
- 1589 m above ground
- 0-6 km bulk shear
- 46 kt
- 0-1 km storm-relative helicity
- 160 m²/s²
- 0-3 km storm-relative helicity
- 235 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 6.8
The text
As transmitted, in the capitals the NWS used until 2016.
970 WUUS53 KFGF 010711 SVRFAR NDC017-010800- BULLETIN - EAS ACTIVATION REQUESTED SEVERE THUNDERSTORM WARNING NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS 211 AM CDT THU AUG 1 2002 THE NATIONAL WEATHER SERVICE IN GRAND FORKS HAS ISSUED A * SEVERE THUNDERSTORM WARNING FOR... CASS COUNTY IN SOUTHEAST NORTH DAKOTA. * UNTIL 300 AM CDT. * AT 209 AM...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A SEVERE THUNDERSTORM 6 MILES SOUTHWEST OF BUFFALO...OR ABOUT 19 MILES EAST OF VALLEY CITY...MOVEMENT WAS TO THE EAST AT 60 MPH. * THE SEVERE THUNDERSTORM WILL BE NEAR... BUFFALO AT 210 AM... EMBDEN AT 215 AM... WHEATLAND AT 220 AM AND CASSELTON AT 225 AM. DAMAGING WINDS...LARGE HAIL...DEADLY LIGHTNING AND TORNADOES ARE ALL POSSIBLE IN SEVERE THUNDERSTORMS. SEEK SHELTER IN A REINFORCED BUILDING IMMEDIATELY. LAT...LON 4715 9768 4669 9766 4668 9682 4722 9687 HOPPES 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, 8:55 PM CDT, 5 hours 16 minutes earlier.
Area forecast discussion, Jul 31, 8:55 PM CDT, 5 hours 16 minutes before
FORECAST DISCUSSION FOR EASTERN NORTH DAKOTA AND NORTHWEST MINNESOTA NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS ND 855 PM CDT WED JUL 31 2002 FORECAST CHALLENGE FOR TONIGHT IS SEVERE WEATHER. KMVX HAS NUMEROUS SEVERE STORMS MOVING THROUGH E ND INTO NW MN. WITH COLD FRONT EXTENDING THROUGH ND ALONG A LANGDON TO BAKER TO BISMARCK LINE... STILL HAVE A LONG TIME TO GO BEFORE EXPECT SEVERE TO BE OUT OF AREA. WITH WATCH OVER DEVILS LAKE AREA EXPECTED TO EXPIRE AT 9 PM...AND LINE OF SEVERE CLOSE TO EXIT THAT AREA...TIMING FOR WATCH EXPIRATION LOOKS GOOD. REMAINDER OF AREA STILL UNDER SEVERE THUNDERSTORM WATCH UNTIL 1 AM...WITH LOADED GUN SOUNDINGS...STRONG SURFACE BOUNDARY... JET SUPPORT...DARKENING ON WATER VAPOR STARTING TO SHOW UP...ETC ...SO WATCH FOR REMAINDER OF AREA UNTIL 1 AM STILL LOOKS GOOD. CONSEQUENTLY...CURRENT FORECAST WELL IN HAND. WILL ONLY NEED TO MAKE MINOR CHANGES. .FGF...NONE. NG
In the hours before
Local storm report, Jul 31, 11:43 PM CDT, 2 hours 28 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GRAND FORKS, ND
1143 PM CDT WED JUL 31 2002
TIME(CDT) .....CITY LOCATION.....STATE ...EVENT/REMARKS...
....COUNTY LOCATION....
0735 PM LANKIN ND FLOOD
07/31/02 WALSH STREET FLOODING DUE TO
HEAVY RAINS
0737 PM LANKIN ND 70 MPH TSTORM WIND
07/31/02 WALSH
0740 PM DEVILS LAKE ND .75 INCH HAIL
07/31/02 RAMSEY FUNNEL CLOUD REPORTED BY
COOPERATIVE OBSERVER
0805 PM LANKIN ND 1.00 INCH HAIL
07/31/02 WALSH WIND DAMAGE
0902 PM GRAFTON ND FLOOD
07/31/02 WALSH STREET FLOODING DUE TO
HEAVY RAINS
MELocal storm report, Jul 31, 11:43 PM CDT, 2 hours 28 minutes before
PRELIMINARY LOCAL STORM REPORT...CORRECTED
NATIONAL WEATHER SERVICE GRAND FORKS, ND
1143 PM CDT WED JUL 31 2002
...CORRECTED TIME OF SECOND REPORT...
TIME(CDT) .....CITY LOCATION.....STATE ...EVENT/REMARKS...
....COUNTY LOCATION....
0735 PM LANKIN ND FLOOD
07/31/02 WALSH STREET FLOODING DUE TO
HEAVY RAINS
0757 PM LANKIN ND 70 MPH TSTORM WIND
07/31/02 WALSH
0740 PM DEVILS LAKE ND .75 INCH HAIL
07/31/02 RAMSEY FUNNEL CLOUD REPORTED BY
COOPERATIVE OBSERVER
0805 PM LANKIN ND 1.00 INCH HAIL
07/31/02 WALSH WIND DAMAGE
0902 PM GRAFTON ND FLOOD
07/31/02 WALSH STREET FLOODING DUE TO
HEAVY RAINS
METhe office that day
Everything else NWS Grand Forks, ND issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 31, 7:03 PM CDT | Severe Thunderstorm Warning | FGF | Ramsey | 42 min |
| Jul 31, 7:19 PM CDT | Severe Thunderstorm Warning | FGF | Cavalier | 41 min |
| Jul 31, 7:33 PM CDT | Severe Thunderstorm Warning | FGF | Benson | 42 min |
| Jul 31, 7:36 PM CDT | Tornado Warning | FGF | Ramsey | 39 min |
| Jul 31, 7:40 PM CDT | Severe Thunderstorm Warning | FGF | Walsh | 50 min |
| Jul 31, 8:06 PM CDT | Severe Thunderstorm Warning | FGF | Grand Forks | 54 min |
| Jul 31, 8:24 PM CDT | Severe Thunderstorm Warning | FGF | Nelson | 51 min |
| Jul 31, 8:26 PM CDT | Severe Thunderstorm Warning | FGF | Walsh | 49 min |
| Jul 31, 11:41 PM CDT | Severe Thunderstorm Warning | FGF | Eddy | 49 min |
| Aug 1, 12:09 AM CDT | Severe Thunderstorm Warning | FGF | Griggs | 51 min |
| Aug 1, 12:40 AM CDT | Severe Thunderstorm Warning | FGF | Barnes, Steele, Traill | 50 min |
| Aug 1, 12:53 AM CDT | Severe Thunderstorm Warning | FGF | Cass | 37 min |
| Aug 1, 1:33 AM CDT | Severe Thunderstorm Warning | FGF | Cass | 42 min |
| Aug 1, 1:37 AM CDT | Severe Thunderstorm Warning | FGF | Barnes | 23 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.