Alert archive / Colorado / Severe Thunderstorm Warnings in 1991
Severe Thunderstorm Warning 85, NWS Denver/Boulder, CO
NWS Denver/Boulder, CO issued this severe thunderstorm warning at Jun 9, 1991, 5:59 PM MDT for Arapahoe County, Denver County, Colorado. It was in force for 61 min. 1 report 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 9, 1991, 5:59 PM MDT (23:59 UTC)
- Expired
- Jun 9, 1991, 7:00 PM MDT
- In force
- 61 min
- Issued by
- NWS Denver/Boulder, CO
- Area
- Whole counties
Counties Arapahoe County, CO, Denver County, CO
What was reported inside it
| Time | Report | Where | Remark |
|---|---|---|---|
| Jun 9, 6:00 PM MDT | Hail 1 | Arapahoe, 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 12:00Z, 12.0 hours before the alert went out and 119 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
- 2 J/kg
- Mixed-layer CIN
- -512 J/kg
- Mixed-layer LCL
- 2648 m above ground
- 0-6 km bulk shear
- 20 kt
- 0-1 km storm-relative helicity
- 71 m²/s²
- 0-3 km storm-relative helicity
- 63 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, Jun 9, 3:05 PM MDT, 2 hours 54 minutes before
COZ011-012-013-014-092200- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE DENVER CO 305 PM MDT SUN JUN 9 1991 ...TORNADO WATCH FOR MOST OF NORTHEAST COLORADO TIL 900 PM MDT... AT 305 PM MDT RADAR WAS SHOWING A STRONG THUNDERSTORM OVER NORTHERN LARIMER COUNTY ABOUT 30 MILES NORTH OF FORT COLLINS. THIS STORM WAS MOVING TO THE EAST-SOUTHEAST AT 25 MPH AND WILL CROSS EXTREME NORTHEAST LARIMER COUNTY BY 400 PM. A FEW OTHER THUNDERSTORMS WERE DEVELOPING OVER EASTERN LARIMER AND WESTERN WELD COUNTY...AND SOUTHERN PARTS OF DOUGLAS AND ARAPAHOE COUNTIES. THESE STORMS WERE MOVING EAST AT 25 MPH. A TORNADO WATCH IS IN EFFECT UNTIL 900 PM FOR MOST OF NORTHEAST COLORADO. IN THE DENVER METRO AREA...THIS IS TO THE EAST OF SHERIDAN BOULEVARD. LISTEN TO NOAA WEATHER RADIO...OR LOCAL RADIO AND T.V....FOR UPDATES OR WARNINGS THIS AFTERNOON AND EVENING. MCQUEEN
Special weather statement, Jun 9, 4:42 PM MDT, 1 hour 17 minutes before
COZ0-012-10000- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE DENVER CO 440 PM MDT SUN JUN 9 1991 ...THUNDERSTORMS MOVING THROUGH EASTERN ARAPAHOE COUNTY... AT 435 PM MDT NATIONAL WEATHER SERVICE DOPPLER RADAR SHOWED THUNDERSTORMS MOVING THROUGH EXTREME EASTERN ARAPAHOE COUNTY. THE STRONGEST STORM WAS ABOUT 5 MILES SOUTHEAST OF BYERS...OR 45 MILES EAST OF DENVER. THUNDERSTORMS WERE ALSO DEVELOPING OVER SOUTHEASTERN ADAMS AND WESTERN WASHINGTON COUNTIES. ALL OF THE STORMS WERE MOVING NORTHEAST AT 15 MPH. PEOPLE IN EASTERN ARAPAHOE...EASTERN ADAMS AND WESTERN WASHINGTON COUNTIES...INCLUDING THE TOWNS OF DEER TRAIL AND LAST CHANCE SHOULD BE ALERT FOR BRIEF HEAVY RAIN...GUSTY WINDS AND POSSIBLE HAIL UNTIL AT LEAST 530 PM MDT. MOTORISTS ALONG INTERSTATE 70 EAST OF BYERS...AND STATE HIGHWAY 36 NEAR LAST CHANCE SHOULD ALSO BE ALERT FOR CHANGING WEATHER CONDITIONS. A TORNADO WATCH REMAINS IN EFFECT FOR MUCH OF NORTHEASTERN ]COLORADO UNTIL 9PM MDT TONIGHT. CONTINUE TO MONITOR THE LOCAL MEDIA AS WELL AS NOAA WEATHER RADIO FOR FURTHER STATEMENTS AND POSSIBLE WARNINGS. LESZCYNSKI
Special weather statement, Jun 9, 4:48 PM MDT, 1 hour 11 minutes before
COZ011-012-013-014-092200- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE DENVER CO 449 PM MDT SUN JUN 9 1991 ...STRONG THUNDERSTORMS MAY DEVELOP OVER THE METRO AREA WITHIN THE NEXT HOUR... AT 449 PM NATIONAL WEATHER SERVICE DOPPLER RADAR WAS SHOWING SIGNS THAT STRONG THUNDERSTORMS MAY BUILD RAPIDLY OVER THE DENVER AREA BETWEEN ABOUT 500 AND 545 PM. TWO LOW LEVEL BOUNDARIES FROM EARLIER THUNDERSTORM ACTIVITY WILL COLLIDE FROM THE SOUTHWEST METRO AREA... TO AROUND THE NEW AIRPORT SITE BY ABOUT 515 PM...AND COULD VERY LIKELY CAUSE THESE THUNDERSTORMS TO DEVELOP. A TORNADO WATCH REMAINS IN EFFECT FOR MOST OF NORTHEAST COLORADO... INCLUDING THE DENVER METRO AREA EAST OF SHERIDAN BgOULEVARD...TIL 900 PM. KEEP LISTENING FOR UPDATES OR POSSIBLE WARNINGS. MCQUEEN
The office that day
Everything else NWS Denver/Boulder, CO issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 8, 6:30 PM MDT | Severe Thunderstorm Warning | BOU | Logan, Phillips | 45 min |
| Jun 9, 3:35 PM MDT | Severe Thunderstorm Warning | BOU | Weld | 55 min |
| Jun 9, 3:51 PM MDT | Tornado Warning | BOU | Weld | 39 min |
| Jun 9, 4:30 PM MDT | Tornado Warning | BOU | Weld | 45 min |
| Jun 9, 5:10 PM MDT | Severe Thunderstorm Warning | BOU | Adams, Arapahoe | 35 min |
| Jun 9, 5:12 PM MDT | Severe Thunderstorm Warning | BOU | Adams, Denver, Jefferson | 48 min |
| Jun 9, 5:16 PM MDT | Tornado Warning | BOU | Weld | 59 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.