Alert archive / Colorado / Severe Thunderstorm Warnings in 1991
Severe Thunderstorm Warning 95, NWS Denver/Boulder, CO
NWS Denver/Boulder, CO issued this severe thunderstorm warning at Jun 18, 1991, 6:29 PM MDT for Logan County, Phillips County, Sedgwick County, Colorado. It was in force for 31 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
- Jun 18, 1991, 6:29 PM MDT (00:29 UTC)
- Expired
- Jun 18, 1991, 7:00 PM MDT
- In force
- 31 min
- Issued by
- NWS Denver/Boulder, CO
- Area
- Whole counties
Counties Logan County, CO, Phillips County, CO, Sedgwick County, CO
What was reported inside it
| Time | Report | Where | Remark |
|---|---|---|---|
| Jun 18, 6:30 PM MDT | Thunderstorm Wind 67 | Logan, CO | |
| Jun 18, 6:32 PM MDT | Thunderstorm Wind 69 | Sedgwick, CO |
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. Storm Data before 1996 records only tornadoes, thunderstorm wind and hail.
The nearest sounding before it
Denver, CO (KDEN), launched 00:00Z, 0.5 hours before the alert went out and 109 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
- 691 J/kg
- Mixed-layer CIN
- -43 J/kg
- Mixed-layer LCL
- 2943 m above ground
- 0-6 km bulk shear
- 30 kt
- 0-1 km storm-relative helicity
- -22 m²/s²
- 0-3 km storm-relative helicity
- 59 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.2
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, Jun 18, 3:53 PM MDT, 2 hours 36 minutes before
COZ011-012-182250- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE DENVER CO 350 PM MDT TUE JUN 18 1991 ...THUNDERSTORMS WITH GUSTY WINDS EAST OF DENVER... AT 350 PM MDT NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A LINE OF THUNDERSTORMS EAST OF DENVER ACROSS PORTIONS OF CENTRAL AND WESTERN ADAMS AND ARAPAHOE COUNTIES. BRIEF STRONG WINDS AND LIGHTNING ARE THE PRIMARY THREAT WITH THESE STORMS AT THIS TIME. AT 330 PM A WIND GUST OF 46 MPH WAS RECORDED AT BRIGHTON IN NORTHWEST ADAMS COUNTY. THUNDERSTORMS WILL CONTINUE TO DEVELOP THIS AFTERNOON OVER NORTHEASTERN COLORADO WITH THE STRONGER STORMS EXPECTED EAST OF THE DENVER AREA. MONITOR LOCAL NEWS MEDIA OR NOAA WEATHER RADIO 0FOR FUTURE STATEMENTS AND BULLETINS. END...SZOKE/GCF...WSFO DENVER
Special weather statement, Jun 18, 4:30 PM MDT, 1 hour 59 minutes before
COZ011-012-182300- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE DENVER CO 430 PM MDT TUE JUN 18 1991 ...NEW THUNDERSTORMS IN SOUTHEASTERN WELD AND WESTERN MORGAN COUNTIES... AT 430 PM MDT NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED THAT NEW THUNDERSTORMS HAVE DEVELOPED IN SOUTHEASTERN WELD COUNTY FROM EAST OF KEENSBURG EASTWARD TO THE MORGAN COUNTY LINE. BRIEF STRONG WINDS...LIGHTNING...AND POSSIBLE HAIL WILL OCCUR WITH THESE STORMS. THE STORMS ARE MOVING TO THE EAST-NORTHEAST AT ABOUT 20 MPH. NEW STORMS WILL CONTINUE TO DEVELOP NEAR I-76 BETWEEN ROGGEN AND WIGGINS...AND ACROSS MUCH OF WESTERN MORGAN COUNTY. OTHER THUNDERSTORMS WITH FREQUENT LIGHTNING WERE FOUND IN SOUTHERN DOUGLAS COUNTY. ADDITIONAL THUNDERSTORM DEVELOPMENT CAN BE EXPECTED OVER NORTHEASTERN COLORADO INTO THIS EVENING AND SOME STORMS COULD BECOME STRONG...ESPECIALLY OVER THE EXTREME EASTERN PLAINS EAST OF DENVER. MONITOR LOCAL NEWS MEDIA OR NOAA WEATHER RADIO FOR FUTURE STATEMENTS AND BULLETINS. END...SZOKE/GCF...WSFO DENVER
Special weather statement, Jun 18, 5:15 PM MDT, 1 hour 14 minutes before
COZ011-012-190000- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE DENVER CO 515 PM MDT TUE JUN 18 1991 ...THUNDERSTORMS CONTINUE OVER PORTIONS OF NORTHEASTERN COLORADO... THUNDERSTORMS CONTINUED TO DEVELOP OVER PORTIONS OF THE NORTHEAST THIS EVENING. AT 515 PM MDT NATIONAL WEATHER SERVICE DOPPLER RADAR SHOWED TWO MAIN AREAS OF THUNDERSTORMS. ONE AREA WAS IN THE SOUTHEASTERN QUARTER OF DOUGLAS COUNTY WHILE THE OTHER AREA OF THUNDERSTORMS EXTENDED FROM SOUTHERN MORGAN COUNTY NORTHWARDS ACROSS FORT MORGAN INTO NORTHEASTERN WELD COUNTY. STRONG WINDS...LIGHTNING...AND POSSIBLE HAIL WILL ACCOMPANY THESE STORMS. ADDITIONAL THUNDERSTORMS WILL DEVELOP ACROSS PORTIONS OF NORTHEASTERN COLORADO INTO THIS EVENING AND SOME STORMS COULD BECOME STRONG...ESPECIALLY OVER THE EXTREME EASTERN PLAINS EAST OF DENVER. CONTINUE TO MONITOR LOCAL NEWS MEDIA OR NOAA WEATHER RADIO FOR FUTURE STATEMENTS AND BULLETINS. END...SZOKE/GCF...WSFO DENVER
The office that day
Everything else NWS Denver/Boulder, CO issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 18, 6:04 PM MDT | Severe Thunderstorm Warning | BOU | Logan | 26 min |
| Jun 18, 7:03 PM MDT | Tornado Warning | BOU | Logan, Phillips, Yuma | 27 min |
| Jun 19, 5:50 PM MDT | Severe Thunderstorm Warning | BOU | Morgan, Washington | 25 min |
Nearby
Severe Thunderstorm Warnings in Colorado, 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; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive.