Alert archive / Colorado / Tornado Warnings in 1991
Tornado Warning 8, NWS Denver/Boulder, CO
NWS Denver/Boulder, CO issued this tornado warning at May 23, 1991, 3:51 PM MDT for 4 counties in Colorado. It was in force for 39 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
- May 23, 1991, 3:51 PM MDT (21:51 UTC)
- Expired
- May 23, 1991, 4:30 PM MDT
- In force
- 39 min
- Issued by
- NWS Denver/Boulder, CO
- Area
- Whole counties
Counties Adams County, CO, Arapahoe County, CO, Denver County, CO, Douglas County, CO
What was reported inside it
| Time | Report | Where | Remark |
|---|---|---|---|
| May 23, 4:15 PM MDT | Hail 1.75 | 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
Fort Carson/Butt, CO (KFCS), launched 12:00Z, 9.9 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
- 13 J/kg
- Mixed-layer CIN
- -154 J/kg
- Mixed-layer LCL
- 1187 m above ground
- 0-6 km bulk shear
- 33 kt
- 0-1 km storm-relative helicity
- 50 m²/s²
- 0-3 km storm-relative helicity
- 71 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 tornado 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 23, 10:56 AM MDT, 4 hours 55 minutes before
COZALL-232100- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE DENVER CO 1055 AM MDT THU MAY 23 1991 ...ANOTHER ROUND OF STRONG THUNDERSTORMS LIKELY TODAY... AN APPROACHING UPPER LEVEL LOW AND PLENTY OF LOW LEVEL MOISTURE HAVE SET UP CONDITIONS FOR ANOTHER AFTERNOON AND EVENING OF STRONG THUNDERSTORMS OVER MUCH OF COLORADO. THE BEST CHANCE OF SEVERE STORMS IS OVER EASTERN COLORADO WHERE LARGE HAIL...STRONG WINDS...AND HEAVY RAIN ARE POSSIBLE WITH SOME OF THE STORMS. STRONG STORMS WITH A CHANCE OF HAIL...GUSTY WINDS...AND BRIEF HEAVY RAIN ARE ALSO A POSSIBILITY OVER THE WEST AND NORTHERN AND CENTRAL MOUNTAINS. LATE THIS MORNING THUNDERSTORMS HAD ALREADY FORMED OVER NORTHWESTERN COLORADO AND WERE DEVELOPING OVER THE NORTHERN AND CENTRAL MOUNTAINS. THUNDERSTORM DEVELOPMENT OVER OTHER PARTS OF THE STATE WILL BEGIN BY EARLY THIS AFTERNOON. PEOPLE IN COLORADO...ESPECIALLY IN THE EAST... SHOULD BE ALERT FOR POSSIBLE SEVERE THUwNDERSTORMS THIS AFTERNOON. CONTINUE TO LISTEN TO NOAA WEATHER RADIO AND OTHER MEDIA OUTLETS FOR LATER STATEMENTS. SZOKE/GARD
Special weather statement, May 23, 12:47 PM MDT, 3 hours 4 minutes before
COZALL-231930- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE DENVER CO 1245 PM MDT THU MAY 23 1991 ...STRONG THUNDERSTORMS IN CENTRAL JEFFERSON COUNTY... AT 1245 PM NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED STRONG THUNDERSTORMS IN JEFFERSON COUNTY. ONE STORM WAS LOCATED NEAR EVERGREEN AND THE SECOND STORM TO THE SOUTHWEST NEAR CONIFER. SMALL HAIL IS OCCURRING WITH THESE STORMS WITH ONE QUARTER TO UP TO ONE HALF INCH DIAMETER HAIL REPORTED IN EVERGREEN. THE STORMS ARE MOVING TO THE NORTH NORTHEAST AT ABOUT 15 MPH. A TORNADO WATCH HAS BEEN ISSUED FOR MUCH OF EASTERN COLORADO INCLUDING THE DENVER AREA UNTIL 8 PM THIS EVENING. PEOPLE SHOULD CONTINUE TO BE ALERT FOR DEVExLOPING THUNDERSTORMS THAT MAY PRODUCE SEVERE WEATHER INCLUDING POSSIBLE TORNDADOES THIS AFTERNOON AND EVENING. CONTINUE TO LISTEN TO NOAA WEATHER RADIO AND OTHER MEDIA OUTLETS FOR LATER STATEMENTS. SZOKE/GARD
Special weather statement, May 23, 1:07 PM MDT, 2 hours 44 minutes before
COZ011-012-231945- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE DENVER CO 105 PM MDT THU MAY 23 1991 ...STRONG THUNDERSTORMS IN NORTHERN DOUGLAS COUNTY... AT 100 PM MDT NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED STRONG THUNDERSTORMS IN NORTHERN DOUGLAS COUNTY. THE STRONGEST STORM WAS LOCATED 3 MILES SOUTHEAST OF PARKER...OR 20 MILES SOUTHEAST OF DOWNTOWN DENVER. THESE STORMS WERE MOVING NORTH-NORTHEAST AT 20 TO 30 MPH AND WILL BE AFFECTING THE TOWNS OF PARKER AND OTHER SURROUNDING AREAS OF NORTHEAST DOUGLAS AND SOUTHWEST ARAPAHOE COUNTIES BY 115 PM MDT. HAIL...HEAVY RAIN...FREQUENT LIGHTING...AND STRONG WINDS ARE POSSIBLE WITH THESE STORMS. THEREFORE...PERSONS IN THE ABOVE MENTIONED AREAS SHOULD BE ON THE LOOKOUT FOR THESE STORMS AND SEEK SHELTER IF THREATENING WEATHER APPROACHES. PERSONS SHOULD CONTINUE TO MONTIOR NOAA WEATHER RADIO...TELEVISION... OR COMMERCIAL RADIO FOR LATER STATMENTS AND/OR WARNINGS. A TORNADO WATCH IS IN EFFECT FOR MUCH OF EASTERN COLORADO INCLUDING THE DENVER METRO AREA UNTIL 800 PM THIS EVENING. HEITKAMP
The office that day
Everything else NWS Denver/Boulder, CO issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 22, 6:12 PM MDT | Tornado Warning | BOU | Douglas | 33 min |
| May 22, 6:37 PM MDT | Severe Thunderstorm Warning | BOU | Weld | 68 min |
| May 22, 6:45 PM MDT | Tornado Warning | BOU | Arapahoe, Denver | 45 min |
| May 22, 6:45 PM MDT | Tornado Warning | BOU | Douglas | 45 min |
| May 22, 7:23 PM MDT | Severe Thunderstorm Warning | BOU | Morgan, Weld | 67 min |
| May 22, 7:29 PM MDT | Tornado Warning | BOU | Morgan | 46 min |
| May 23, 1:25 PM MDT | Severe Thunderstorm Warning | BOU | Arapahoe | 35 min |
| May 23, 1:26 PM MDT | Severe Thunderstorm Warning | BOU | Jefferson | 64 min |
| May 23, 1:58 PM MDT | Severe Thunderstorm Warning | BOU | Adams, Denver, Jefferson | 62 min |
| May 23, 2:01 PM MDT | Severe Thunderstorm Warning | BOU | Arapahoe | 29 min |
| May 23, 2:30 PM MDT | Severe Thunderstorm Warning | BOU | Arapahoe | 45 min |
| May 23, 3:06 PM MDT | Tornado Warning | BOU | Adams, Arapahoe | 39 min |
| May 23, 3:33 PM MDT | Severe Thunderstorm Warning | BOU | Arapahoe, Denver, Douglas | 57 min |
| May 23, 3:45 PM MDT | Tornado Warning | BOU | Adams, Arapahoe | 30 min |
| May 23, 4:17 PM MDT | Severe Thunderstorm Warning | BOU | Adams, Arapahoe, Washington | 43 min |
| May 23, 4:25 PM MDT | Severe Thunderstorm Warning | BOU | Arapahoe | 65 min |
| May 23, 5:00 PM MDT | Severe Thunderstorm Warning | BOU | Arapahoe, Washington | 60 min |
Nearby
Tornado Warnings in Colorado, 1991Every tornado warning in 1991Tornadoes 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.