Alert archive / Colorado / Severe Thunderstorm Warnings in 1997
Severe Thunderstorm Warning 68, NWS Denver/Boulder, CO
NWS Denver/Boulder, CO issued this severe thunderstorm warning at Jun 21, 1997, 6:34 PM MDT for Larimer County, Weld County, Colorado. It was in force for 41 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
- Jun 21, 1997, 6:34 PM MDT (00:34 UTC)
- Expired
- Jun 21, 1997, 7:15 PM MDT
- In force
- 41 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), 77 km from the middle of the area, began a volume at 00:34 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 |
|---|---|---|---|
| Jun 21, 6:53 PM MDT | Hail 1.5 | Windsor, 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, 0.6 hours before the alert went out and 151 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
- 687 J/kg
- Mixed-layer CIN
- -122 J/kg
- Mixed-layer LCL
- 2509 m above ground
- 0-6 km bulk shear
- 34 kt
- 0-1 km storm-relative helicity
- 51 m²/s²
- 0-3 km storm-relative helicity
- 135 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 3.2
The text
As transmitted, in the capitals the NWS used until 2016.
760
WUUS1 KDEN 220035 RRA
SVRDEN
COC069-123-220115-
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE DENVER CO
634 PM MDT SAT JUN 21 1997
THE NATIONAL WEATHER SERVICE IN DENVER HAS ISSUED A SEVERE
THUNDERSTORM WARNING EFFECTIVE UNTIL 715 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...EATON...JOHNSTOWN...LOVELAND...LUCERNE...SEVERANCE...
TIMNATH AND WINDSOR
AT 626 PM MDT NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM 4 MILES SOUTHEAST OF LOVELAND...OR ABOUT 14 MILES
SOUTH OF FORT COLLINS.
THE STORM WAS MOVING NORTHEAST AT 15 MILES PER HOUR.
VERY LARGE HAIL IS POSSIBLE WITH THIS SEVERE THUNDERSTORM. IF YOU ARE
IN THE PATH OF THE STORM...PUT YOUR CAR IN A GARAGE AND MOVE TO A
SUBSTANTIAL SHELTER.
INTENSE LIGHTNING IS OCCURRING WITH THIS STORM. IF OUTDOORS...STAY
AWAY FROM ISOLATED HIGH OBJECTS SUCH AS TREES. MOVE INDOORS IF
POSSIBLE. WHEN INDOORS...STAY AWAY FROM WINDOWS AND DOORS AND AVOID
USING TELEPHONES UNLESS IT IS AN EMERGENCY. TRY TO UNPLUG UNNECESSARY
ELECTRICAL APPLIANCES BEFORE THE THUNDERSTORM APPROACHES.
REPORT SEVERE WEATHER TO THE NEAREST LAW ENFORCEMENT AGENCY. THEY
WILL RELAY YOUR REPORT TO THE NATIONAL WEATHER SERVICE FORECAST
OFFICE IN DENVER.
GARD...WSFO DENVER
LAT...LON 4047 10459 4027 10497 4040 10513 4067 10488What 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 21, 4:28 PM MDT, 2 hours 6 minutes before
COZ036-040-041-212330- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE DENVER CO 428 PM MDT SAT JUN 21 1997 ...THUNDERSTORMS PRODUCING LOCALLY HEAVY RAIN OVER HIGHER TERRAIN IN NORTHEASTERN PARK...SOUTHERN JEFFERSON AND WESTERN DOUGLAS COUNTIES... AT 420 PM MDT NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED AN AREA OF THUNDERSTORMS OVER NORTHEAST PARK...SOUTHERN JEFFERSON... WESTERN DOUGLAS COUNTIES. THE STRONGEST THUNDERSTORM WAS 6 MILES SOUTHEAST OF BUFFALO CREEK...OR ABOUT 32 MILES SOUTHWEST OF DENVER. THESE STORMS WERE MOVING SOUTHEAST AT 20 MILES AN HOUR. DOPPLER RADAR HAS ESTIMATED FROM 0.25 TO 0.50 INCH OF RAIN IN THE PAST HOUR FROM THUNDERSTORMS MOVING ACROSS SOUTHERN JEFFERSON COUNTY. POOLING OF WATER ON ROADWAYS AND MINOR RISES IN WATER LEVELS IN DITCHES AND SMALL CREEKS MAY OCCUR. PERSONS IN OR NEAR BUFFALO CREEK...CHEESMAN RESERVOIR...DECKERS... DEVILS HEAD...HARRIS PARK...PINE...SHAWNEE...SOUTH PLATTE... SPRUCEWOOD AND WELLINGTON LAKE SHOULD BE ON THE LOOKOUT FOR THUNDERSTORMS THE NEXT COUPLE OF HOURS CAPABLE OF LOCALLY HEAVY RAIN...STRONG GUSTY WINDS AND DEADLY LIGHTNING. BE PREPARED TO MOVE TO A PLACE OF SAFETY IF THREATENING WEATHER APPROACHES. BAKER
Special weather statement, Jun 21, 4:30 PM MDT, 2 hours 4 minutes before
COZ036-040-041-212330- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE DENVER CO 428 PM MDT SAT JUN 21 1997 ...THUNDERSTORMS PRODUCING LOCALLY HEAVY RAIN OVER HIGHER TERRAIN IN NORTHEASTERN PARK...SOUTHERN JEFFERSON AND WESTERN DOUGLAS COUNTIES... AT 420 PM MDT NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED AN AREA OF THUNDERSTORMS OVER NORTHEAST PARK...SOUTHERN JEFFERSON... WESTERN DOUGLAS COUNTIES. THE STRONGEST THUNDERSTORM WAS 6 MILES SOUTHEAST OF BUFFALO CREEK...OR ABOUT 32 MILES SOUTHWEST OF DENVER. THESE STORMS WERE MOVING SOUTHEAST AT 20 MILES AN HOUR. DOPPLER RADAR HAS ESTIMATED FROM 0.25 TO 0.50 INCH OF RAIN IN THE PAST HOUR FROM THUNDERSTORMS MOVING ACROSS SOUTHERN JEFFERSON COUNTY. POOLING OF WATER ON ROADWAYS AND MINOR RISES IN WATER LEVELS IN DITCHES AND SMALL CREEKS MAY OCCUR. PERSONS IN OR NEAR BUFFALO CREEK...CHEESMAN RESERVOIR...DECKERS... DEVIL'S HEAD...HARRIS PARK...PINE...SHAWNEE...SOUTH PLATTE... SPRUCEWOOD AND WELLINGTON LAKE SHOULD BE ON THE LOOKOUT FOR THUNDERSTORMS THE NEXT COUPLE OF HOURS CAPABLE OF LOCALLY HEAVY RAIN...STRONG GUSTY WINDS AND DEADLY LIGHTNING. BE PREPARED TO MOVE TO A PLACE OF SAFETY IF THREATENING WEATHER APPROACHES. BAKER
The office that day
Everything else NWS Denver/Boulder, CO issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 21, 6:02 PM MDT | Severe Thunderstorm Warning | BOU | Boulder | 28 min |
| Jun 21, 6:37 PM MDT | Severe Thunderstorm Warning | BOU | Park | 33 min |
| Jun 21, 7:14 PM MDT | Severe Thunderstorm Warning | BOU | Weld | 46 min |
| Jun 21, 8:38 PM MDT | Severe Thunderstorm Warning | BOU | Park | 52 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.