Alert archive / Colorado / Severe Thunderstorm Warnings in 1997
Severe Thunderstorm Warning 129, NWS Denver/Boulder, CO
NWS Denver/Boulder, CO issued this severe thunderstorm warning at Aug 16, 1997, 8:31 PM MDT for Larimer County, Weld County, Colorado. It was in force for 44 min. 1 report came from inside the area while it was in force.
The area
The outline the Iowa Environmental Mesonet reconstructed for it; the warning itself named whole counties, with what was reported inside it.
The facts
- Issued
- Aug 16, 1997, 8:31 PM MDT (02:31 UTC)
- Expired
- Aug 16, 1997, 9:15 PM MDT
- In force
- 44 min
- Issued by
- NWS Denver/Boulder, CO
- Area
- Whole counties; the outline is the Mesonet’s reconstruction
Counties Larimer County, CO, Weld County, CO
The radar
The Cheyenne radar (KCYS), 75 km from the middle of the area, began a volume at 02:32 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 16, 9:18 PM MDT | Hail 0.75 | Greeley, 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.
The nearest sounding before it
Denver, CO (KDNR), launched 00:00Z, 2.5 hours before the alert went out and 142 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
- 1611 J/kg
- Mixed-layer CIN
- -16 J/kg
- Mixed-layer LCL
- 1576 m above ground
- 0-6 km bulk shear
- 14 kt
- 0-1 km storm-relative helicity
- 11 m²/s²
- 0-3 km storm-relative helicity
- -15 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
000
TTAA00 KDEN 170232 RRA
SVRDEN
COC069-123-170315-
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE DENVER CO
831 PM MDT SAT AUG 16 1997
THE NATIONAL WEATHER SERVICE IN DENVER HAS ISSUED A SEVERE
THUNDERSTORM WARNING EFFECTIVE UNTIL 915 PM MDT FOR PEOPLE IN THE
FOLLOWING COUNTIES...
IN NORTHEAST COLORADO
WEST CENTRAL WELD
IN NORTH CENTRAL COLORADO
SOUTHEASTERN LARIMER
INCLUDING THE FOLLOWING LOCATIONS
GREELEY...AULT...EATON...EVANS...GALETON...GILL...JOHNSTOWN...
KERSEY...LA SALLE...LUCERNE...MILLIKEN...SEVERANCE AND WINDSOR
AT 831 PM MDT NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM 5 MILES SOUTH OF WINDSOR...OR ABOUT 9 MILES WEST
OF GREELEY.
THE STORM WAS MOVING EAST AT 15 MILES PER HOUR.
IF SEVERE WEATHER APPROACHES YOUR AREA...GO INSIDE A STURDY SHELTER
AWAY FROM CREEK BEDS AND OTHER FLOOD-PRONE AREAS. REMEMBER...A SEVERE
THUNDERSTORM CAN PRODUCE LARGE DAMAGING HAIL...DAMAGING WINDS OVER 60
MPH...DEADLY LIGHTNING...AND VERY HEAVY RAIN. FLOODING OVER CREEKS
...STREAMS AND LOW LYING AREAS IS ALOS POSSIBLE. DO NOT DRIVE
THROUGH FLOODED ROADWAYS.
REPORT SEVERE WEATHER TO THE NEAREST LAW ENFORCEMENT, AGENCY. THEY
WILL RELAY YOUR REPORT TO THE NATIONAL WEATHER SERVICE FORECAST
OFFICE IN DENVER.
LAT...LON 4062 10451 4030 10455 4033 10498 4054 10494
FMCWhat 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, Aug 16, 4:35 PM MDT, 3 hours 56 minutes before
COZ035-036-038-039-040-043-162330- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE DENVER CO 435 PM MDT SAT AUG 16 1997 ...SCATTERED THUNDERSTORMS DEVELOPING IN THE FOOTHILLS LATE THIS AFTERNOON... AT 430 PM MDT NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A STRONG THUNDERSTORM 4 MILES EAST OF BOULDER...OR ABOUT 24 MILES NORTHWEST OF DENVER. THE STORM WAS MOVING SOUTHEAST AT 15 MILES PER HOUR. PERSONS IN OR NEAR ARVADA...BOULDER...BROOMFIELD...LONGMONT... ELDORADO SPRINGS...ERIE...JAMESTOWN...LAFAYETTE...LOUISVILLE...NIWOT ...ROCKY FLATS AND SUPERIOR SHOULD BE ON THE LOOKOUT FOR THREATENING WEATHER AND MOVE TO A PLACE OF SAFETY IF BAD WEATHER APPROACHES. DANGEROUS LIGHTNING...SMALL HAIL...LOCALLY HEAVY RAIN...AND GUSTY WINDS WILL OCCUR WITH THIS STORM. RADAR INDICATED THIS STORM HAD PRODUCED UP TO 1 INCH OF RAINFALL IN THE LAST HOUR. ELSEWHERE SCATTERED THUNDERSTORMS WILL CONTINUE TO DEVELOP OVER THE FOOTHILLS LATE THIS AFTERNOON AND DRIFT INTO THE URBAN CORRIDOR. HEAVY RAINS MAY FLOOD LOW LYING AREAS SUCH AS DITCHES AND UNDERPASSES. AVOID THESE AREAS AND DO NOT CROSS FLOODED ROADS. WATER LEVELS OF SMALL STREAMS AND RIVERS MAY ALSO RISE...THEREFORE SEEK HIGHER GROUND IF THREATENED BY FLOOD WATERS. FMC
Special weather statement, Aug 16, 4:37 PM MDT, 3 hours 54 minutes before
COZ035-036-038-039-040-043-162330- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE DENVER CO 435 PM MDT SAT AUG 16 1997 ...SCATTERED THUNDERSTORMS DEVELOPING IN THE FOOTHILLS LATE THIS AFTERNOON... AT 430 PM MDT NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A STRONG THUNDERSTORM 4 MILES EAST OF BOULDER...OR ABOUT 24 MILES NORTHWEST OF DENVER. THE STORM WAS MOVING SOUTHEAST AT 15 MILES PER HOUR. PERSONS IN OR NEAR ARVADA...BOULDER...BROOMFIELD...LONGMONT... ELDORADO SPRINGS...ERIE...JAMESTOWN...LAFAYETTE...LOUISVILLE...NIWOT ...ROCKY FLATS AND SUPERIOR SHOULD BE ON THE LOOKOUT FOR THREATENING WEATHER AND MOVE TO A PLACE OF SAFETY IF BAD WEATHER APPROACHES. DANGEROUS LIGHTNING...SMALL HAIL...LOCALLY HEAVY RAIN...AND GUSTY WINDS WILL OCCUR WITH THIS STORM. RADAR INDICATED THIS STORM HAD PRODUCED UP TO 1 INCH OF RAINFALL IN THE LAST HOUR. ELSEWHERE SCATTERED THUNDERSTORMS WILL CONTINUE TO DEVELOP OVER THE FOOTHILLS LATE THIS AFTERNOON AND DRIFT INTO THE URBAN CORRIDOR. HEAVY RAINS MAY FLOOD LOW LYING AREAS SUCH AS DITCHES AND UNDERPASSES. AVOID THESE AREAS AND DO NOT CROSS FLOODED ROADS. WATER LEVELS OF SMALL STREAMS AND RIVERS MAY ALSO RISE...ZTHEREFORE SEEK HIGHER GROUND IF THREATENED BY FLOOD WATERS. FMC
The office that day
Everything else NWS Denver/Boulder, CO issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 16, 6:00 PM MDT | Severe Thunderstorm Warning | BOU | Arapahoe, Denver, Douglas, Jefferson | 45 min |
| Aug 16, 6:51 PM MDT | Severe Thunderstorm Warning | BOU | Adams, Morgan, Washington | 39 min |
| Aug 16, 7:28 PM MDT | Tornado Warning | BOU | Adams | 32 min |
| Aug 16, 7:38 PM MDT | Severe Thunderstorm Warning | BOU | Weld | 22 min |
| Aug 16, 7:48 PM MDT | Severe Thunderstorm Warning | BOU | Washington | 27 min |
| Aug 16, 7:59 PM MDT | Severe Thunderstorm Warning | BOU | Weld | 46 min |
| Aug 16, 8:17 PM MDT | Severe Thunderstorm Warning | BOU | Lincoln, Washington | 28 min |
| Aug 16, 8:40 PM MDT | Severe Thunderstorm Warning | BOU | Logan, Weld | 30 min |
| Aug 16, 9:10 PM MDT | Severe Thunderstorm Warning | BOU | Weld | 50 min |
| Aug 16, 9:34 PM MDT | Severe Thunderstorm Warning | BOU | Boulder, Larimer | 31 min |
Nearby
Severe Thunderstorm Warnings in Colorado, 1997Every severe thunderstorm warning in 1997
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.