Alert archive / North Dakota / Severe Thunderstorm Warnings in 1991
Severe Thunderstorm Warning 4, NWS Bismarck, ND
NWS Bismarck, ND issued this severe thunderstorm warning at May 12, 1991, 6:12 PM CDT for Emmons County, North Dakota. It was in force for 33 min.
The area
The counties it named.
The facts
- Issued
- May 12, 1991, 6:12 PM CDT (23:12 UTC)
- Expired
- May 12, 1991, 6:45 PM CDT
- In force
- 33 min
- Issued by
- NWS Bismarck, ND
- Area
- Whole counties
County Emmons County, ND
The nearest sounding before it
Bismarck Municip, ND (KBIS), launched 12:00Z, 11.2 hours before the alert went out and 64 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
- 1247 J/kg
- Mixed-layer CIN
- -145 J/kg
- Mixed-layer LCL
- 1013 m above ground
- 0-6 km bulk shear
- 32 kt
- 0-1 km storm-relative helicity
- 187 m²/s²
- 0-3 km storm-relative helicity
- 213 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
The text of this product is not in the archive. The NWS text archive before 2002 is incomplete.
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.
In the hours before
Special weather statement, May 12, 2:44 PM CDT, 3 hours 28 minutes before
NDZ001>003-005-122030- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE WILLISTON ND 240 PM CDT SUN MAY 12 1991 ...TORNADO WATCH IN EFFECT UNTIL 900 PM CDT FOR MOUNTRAIL COUNTY IN NORTHWEST NORTH DAKOTA... AT 235 PM CDT...NATIONAL WEATHER SERVICE RADAR IN WILLISTON INDICATED STRONG THUNDERSTORMS 45 MILES NORTHEAST OF WILLISTON...ALONG THE MOUNTRAIL/WILLIAMS COUNTY BORDER. THESE THUNDERSTORMS WERE MOVING TO THE NORTH AT 40 MILES AN HOUR. THESE THUNDERSTORMS WILL PRODUCE DEADLY LIGHTNING STRIKES...GUSTY WINDS ...AND HEAVY DOWNPOURS. RADAR AT 235 PM CDT WAS NOT SHOWING ANY SEVERE WEATHER BUT REMEMBER... THUNDERSTORMS CAN AND SOMETIMES DO PRODUCE TORNADOES. OTHER THUNDERSTORMS WEREr DEVELOPING OVER MCKENZIE AND WILLIAMS COUNTIES. IF THESE THUNDERSTORMS MOVE INTO YOUR AREA...SEEK SHELTER IMMEDIATELY. MARTIN
Special weather statement, May 12, 3:00 PM CDT, 3 hours 12 minutes before
NDZ001>018-122200- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE BISMARCK ND 255 PM CDT SUN MAY 12 1991 ...TORNADO WATCH IN EFFECT FOR CENTRAL NORTH DAKOTA UNTIL 9PM CDT... VERY UNSTABLE AIR HAS SPAWNED A THREAT OF SEVERE THUNDERSTORMS AND TORNADOS OVER CENTRAL NORTH DAKOTA THIS AFTERNOON AND EVENING. AT 255 PM CDT...RADARS SHOWED A BAND OF SCATTERED THUNDERSTORMS ABOUT 30 MILES WIDE EXTENDING FROM THE SOUTH DAKOTA BORDER SOUTH OF BISMARCK ACROSS EASTERN LAKE SAKAKAWEA TO JUST SOUTHWEST OF MINOT. SOME OF THE STORMS CONTAINED BRIEF HEAVY RAIN AND POSSIBLE HAIL. THEY WERE MOVING NORTH ABOUT 30 MPH. A COLD FRONT JUST WEST OF THIS BAND WILL MOVE EAST ACROSS CENTRAL NORTH DAKOTA THIS AFTERNOON AND EVENING. IT WILL INCREASE THE RISK OF SEVERE WEATHER. PERSONS IN CENTRAL NORTH DAKOTA SHOULD STAY ALERT FOR POSSIBLE FUTURE WARNINGS. LM
Special weather statement, May 12, 3:42 PM CDT, 2 hours 30 minutes before
NDZ001>003-005-122140- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE WILLISTON ND 340 PM CDT SUN MAY 12 1991 ...TORNADO WATCH IN EFFECT UNTIL 900 PM CDT FOR MOUNTRAIL COUNTY IN NORTHWEST NORTH DAKOTA... AT 335 PM CDT...STRONG THUNDERSTORMS WERE OCCURRING 90 MILES NORTHEAST OF WILLISTON...BETWEEN THE TOWNS OF AMBROSE AND COLUMBUS NORTH DAKOTA. OTHER THUNDERSTORMS WERE SCATTERED ACROSS THE AREA. THUNDERSTORMS WERE MOVING TO THE NORTHWEST AT 35 MILES AN HOUR. THESE THUNDERSTORMS MAY PRODUCE DEADLY LIGHTNING STRIKES...HAIL...GUSTY WINDS...AND HEAVY RAIN. NATIONAL WEATHER SERVICE RADAR AT 335 PM WAS NOT SHOWING ANY SEVERE WEATHER BUT REMEMBER...THUNDERSTORMS ARE CAPABLE OF PRODUCING TORNADOES. IF THUNDERSTORMS MOVE INTO YOUR AREA...SEEK SHELTER AS SOON AS POSSIBLE ...DO NOT DELAY. MARTIN
Special weather statement, May 12, 4:24 PM CDT, 1 hour 48 minutes before
NDZ001>018-122300- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE BISMARCK ND 410 PM CDT SUN MAY 12 1991 ...TORNADO WATCH IN EFFECT FOR CENTRAL NORTH DAKOTA UNTIL 9PM CDT... AT 415 PM CDT...RADARS SHOWED STRONG THUNDERSTORMS IN SOUTH CENTRAL NORTH DAKOTA IN THE COUNTIES OF BURLEIGH...MORTON AND SIOUX. ONE VERY STRONG STORM PASSED OVER BISMARCK AT 4 PM CDT DROPPING MUCH MARBLE SIZE HAIL AND A FEW HAIL STONES UP TO ONE INCH. IN NORTH CENTRAL NORTH DAKOTA...A SEVERE THUNDERSTORM WARNING CONTINUES IN EFFECT FOR MCHENRY COUNTY UNTIL 445 PM CDT. RADARS AT 415 PM CDT INDICATED A SEVERE THUNDERSTORM IN SOUTHWEST MCHENRY COUNTY MOVING NORTH 30 MPH. IN NEAIGHBORING NORTHEAST WARD COUNTY...MINOT AIR BASE REPORTED HAIL ONE HALF INCH IN DIAMETER. < PERSONS THROUGHOUT CENTRAL NORTH DAKOTA SHOULD REMAIN ALERT FOR FUTURE WARNINGS. LM
Special weather statement, May 12, 4:48 PM CDT, 1 hour 24 minutes before
NDZ001>003-005-122140- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE WILLISTON ND 445 PM CDT SUN MAY 12 1991 ...TORNADO WATCH IN EFFECT UNTIL 900 PM CDT FOR MOUNTRAIL COUNTY IN NORTHWEST NORTH DAKOTA... AT 440 PM CDT...STRONG THUNDERSTORMS CONTINUED TO DEVELOP OVER NORTHWEST NORTH DAKOTA. THE STRONGEST THUNDERSTORMS WERE LOCATED 35 MILES NORTHEAST OF WILLISTON IN NORTHEAST WILLIAMS COUNTY. THUNDERSTORMS WERE MOVING TO THE NORTHWEST AT 35 MILES AN HOUR. THESE THUNDERSTORMS MAY PRODUCE DEADLY LIGHTNING STRIKES...HAIL...GUSTY WINDS...AND HEAVY RAIN. NATIONAL WEATHER SERVICE RADAR AT 440 PM WAS NOT SHOWING ANY SEVERE WEATHER BUT REMEMBER...THUNDERSTORMS ARE CAPABLE OF PRODUCING TOR<NADOES. IF THUNDERSTORMS MOVE INTO YOUR AREA...SEEK SHELTER IMMEDIATELY...DO NOT DELAY. MARTIN
Special weather statement, May 12, 5:40 PM CDT, 32 minutes before
NDZ001>003-005-122340- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE WILLISTON ND 540 PM CDT SUN MAY 12 1991 ...TORNADO WATCH IN EFFECT UNTIL 900 PM CDT FOR MOUNTRAIL COUNTY IN NORTHWEST NORTH DAKOTA... AT 540 PM CDT...STRONG THUNDERSTORMS CONTINUED TO DEVELOP OVER NORTHWEST NORTH DAKOTA. THE STRONGEST THUNDERSTORMS WERE LOCATED 55 MILES NORTH OF WILLISTON IN EAST CENTRAL DIVIDE COUNTY...10 MILES NORTH TO THE TOWN OF AMBROSE. ANOTHER STRONG THUNDERSTORM WAS LOCATED 50 MILES SOUTHEAST OF WILLISTON...OR 25 MILES SOUTH OF WATFORD CITY. THESE THUNDERSTORMS WERE MOVING TO THE NORTH AT 35 MILES AN HOUR AND ARE CAPABLE OF PRODUCING DEADLY LIGHTNING STRIKES...SMALL HAIL...GUSTY WINDS...AND HEAVY RAIN. NATIONAL WEATHER SERVICE RADAR AT 540 PM WAS NOT SHOWING ANY SEVERE WEATHER IN THE TORNADO WATCH AREA IN MOUNTRAIL COUNTY. IF THESE STORMS MOVE INTO YOUR AREA...MOVE TO A SAVE SHELTER. RICHMOND
The office that day
Everything else NWS Bismarck, ND issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 12, 3:43 PM CDT | Severe Thunderstorm Warning | BIS | McHenry | 62 min |
| May 12, 4:28 PM CDT | Severe Thunderstorm Warning | BIS | Burleigh | 47 min |
| May 12, 5:19 PM CDT | Severe Thunderstorm Warning | BIS | Benson | 41 min |
| May 12, 6:05 PM CDT | Tornado Warning | BIS | Benson | 40 min |
| May 12, 6:23 PM CDT | Severe Thunderstorm Warning | BIS | Logan | 37 min |
Nearby
Severe Thunderstorm Warnings in North Dakota, 1991Every severe thunderstorm warning in 1991
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.