Alert archive / Colorado / Severe Thunderstorm Warnings in 1997
Severe Thunderstorm Warning 105, NWS Denver/Boulder, CO
NWS Denver/Boulder, CO issued this severe thunderstorm warning at Jul 21, 1997, 5:27 PM MDT for Weld County, Colorado. It was in force for 48 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
- Jul 21, 1997, 5:27 PM MDT (23:27 UTC)
- Expired
- Jul 21, 1997, 6:15 PM MDT
- In force
- 48 min
- Issued by
- NWS Denver/Boulder, CO
- Area
- Whole counties; the outline is the Mesonet’s reconstruction
County Weld County, CO
The radar
The Cheyenne radar (KCYS), 84 km from the middle of the area, began a volume at 23:31 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 |
|---|---|---|---|
| Jul 21, 5:50 PM MDT | Hail 0.75 | New Raymer, CO | Large hail and strong thunderstorms winds estimated to 50 mph shredded wheat fields. |
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 12:00Z, 11.5 hours before the alert went out and 130 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
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 2335 m above ground
- 0-6 km bulk shear
- 22 kt
- 0-1 km storm-relative helicity
- 17 m²/s²
- 0-3 km storm-relative helicity
- 45 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 212329 RRA
SVRDEN
COC123-220015-
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE DENVER CO
527 PM MDT MON JUL 21 1997
THE NATIONAL WEATHER SERVICE IN DENVER HAS ISSUED A SEVERE
THUNDERSTORM WARNING EFFECTIVE UNTIL 615 PM MDT FOR PEOPLE IN THE
FOLLOWING COUNTIES...
IN NORTHEAST COLORADO
NORTHEASTERN WELD
INCLUDING THE FOLLOWING LOCATIONS
PAWNEE BUTTES
AT 527 PM MDT NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM 12 MILES NORTH OF PAWNEE BUTTES...OR ABOUT 45
MILES NORTHWEST OF STERLING.
THE STORM WAS MOVING SOUTHEAST AT 10 MILES PER HOUR AND WILL BE MOVING
INTO THE PAWNEE BUTTES AREA BY 605 PM.
VERY LARGE HAIL AND STRONG GUSTY WINDS UP TO 60 MPH ARE 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. STAY AWAY
FROM WINDOWS.
REPORT SEVERE WEATHER TO THE NEAREST LAW ENFORCEMENT AGENCY. THEY
WILL RELAY YOUR REPORT TO THE NATIONAL WEATHER SERVICE FORECAST
OFFICE IN DENVER.
BARJENBRUCH
LAT...LON 4099 10373 4081 10368 4081 10400 4100 10404
4101 10392What 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, Jul 21, 11:30 AM MDT, 5 hours 57 minutes before
COZ030-032>050-220600- SIGNIFICANT WEATHER OUTLOOK FOR NORTHEAST AND NORTH CENTRAL COLORADO NATIONAL WEATHER SERVICE DENVER CO 1130 AM MDT MON JUL 21 1997 THIS OUTLOOK PERTAINS TO THE FOLLOWING COLORADO COUNTIES ADAMS ARAPAHOE BOULDER CLEAR CREEK DENVER DOUGLAS ELBERT GILPIN GRAND JACKSON JEFFERSON LARIMER LINCOLN LOGAN MORGAN PARK PHILLIPS SEDGWICK SUMMIT WASHINGTON WELD SYNOPSIS: HIGH SURFACE PRESSURE OVER NEBRASKA AND SOUTH DAKOTA AND A SURFACE LOW OVER WESTERN COLORADO IS CAUSING LOW LEVEL MOISTURE TO MOVE INTO NORTHEAST COLORADO FROM OUT OF THE NEBRASKA PANHANDLE TODAY. WINDS AT HIGHER ELEVATIONS ARE OUT OF THE WEST AND FAIRLY WEAK...WITH A BIT STRONGER FLOW OVER SOUTHERN WYOMING. CLEAR SKIES THIS MORNING HAVE ALSO ALLOWED FOR GOOD SURFACE HEATING THROUGH THE MORNING HOURS. WARM AFTERNOON TEMPERATURES AND INCREASING LOW LEVEL MOISTURE WILL COMBINE FOR A CHANCE OF AFTERNOON AND EVENING THUNDERSTORMS ON THE PLAINS...MAINLY NORTHEAST OF DENVER. TEMPERATURES ALOFT ARE WARM ENOUGH THAT THE THREAT OF LARGE HAIL WITH THUNDERSTORMS SHOULD BE MINIMAL. HOWEVER...HEAVY RAINS WILL BE POSSIBLE SINCE THUNDERSTORMS WILL BE SLOW MOVING AND THE RELATIVELY HIGH MOISTURE CONTENT. THE BEST CHANCE OF THUNDERSTORMS PRODUCING HEAVY RAINS APPEARS TO BE TO THE NORTHEAST OF A GREELY TO LAST CHANCE LINE. SPOTTER ACTIVATION IS NOT EXPECTED TODAY...BUT RESIDENTS ON THE NORTHEAST COLORADO PLAINS SHOULD REMAIN ALERT TO DEVELOPING WEATHER SITUATIONS AND KEEP IN MIND THE THREAT OF HEAVY RAINS CAUSING LOCALIZED FLOODING. DANKERS
Special weather statement, Jul 21, 11:32 AM MDT, 5 hours 55 minutes before
COZ030-032>050-220600- SIGNIFICANT WEATHER OUTLOOK FOR NORTHEAST AND NORTH CENTRAL COLORADO NATIONAL WEATHER SERVICE DENVER CO 1130 AM MDT MON JUL 21 1997 THIS OUTLOOK PERTAINS TO THE FOLLOWING COLORADO COUNTIES ADAMS ARAPAHOE BOULDER CLEAR CREEK DENVER DOUGLAS ELBERT GILPIN GRAND JACKSON JEFFERSON LARIMER LINCOLN LOGAN MORGAN PARK PHILLIPS SEDGWICK SUMMIT WASHINGTON WELD SYNOPSIS: HIGH SURFACE PRESSURE OVER NEBRASKA AND SOUTH DAKOTA AND A SURFACE LOW OVER WESTERN COLORADO IS CAUSING LOW LEVEL MOISTURE TO MOVE INTO NORTHEAST COLORADO FROM OUT OF THE NEBRASKA PANHANDLE TODAY. WINDS AT HIGHER ELEVATIONS ARE OUT OF THE WEST AND FAIRLY WEAK...WITH A BIT STRONGER FLOW OVER SOUTHERN WYOMING. CLEAR SKIES THIS MORNING HAVE ALSO ALLOWED FOR GOOD SURFACE HEATING THROUGH THE MORNING HOURS. WARM AFTERNOON TEMPERATURES AND INCREASING LOW LEVEL MOISTURE WILL COMBINE FOR A CHANCE OF AFTERNOON AND EVENING THUNDERSTORMS ON THE PLAINS...MAINLY NORTHEAST OF DENVER. TEMPERATURES ALOFT ARE WARM ENOUGH THAT THE THREAT OF LARGE HAIL WITH THUNDERSTORMS SHOULD BE MINIMAL. HOWEVER...HEAVY RAINS WILL BE POSSIBLE SINCE THUNDERSTORMS WILL BE SLOW MOVING AND THE RELATIVELY HIGH MOISTURE CONTENT. THE BEST CHANCE OF THUNDERSTORMS PRODUCING HEAVY RAINS APPEARS TO BE TO THE NORTHEAST OF A GREELY TO LAST CHANCE LINE. SPOTTER ACTIVATION IS NOT EXPECTED TODAY...BUT RESIDENTS ON THE NORTHEAST COLORADO PLAINS SHOULD REMAIN ALERT TO DEVELOPING WEATHER SITUATIONS AND KEEP IN MIND THE THREAT OF HEAVY RAINS CAUSING LOCALIZED FLOODING. DANKERS
Special weather statement, Jul 21, 1:25 PM MDT, 4 hours 2 minutes before
COZ049-212000- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE DENVER CO 125 PM MDT MON JUL 21 1997 ...THUNDERSTORM WITH HEAVY RAIN IN CENTRAL WASHINGTON COUNTY... AT 123 PM MDT NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A THUNDERSTORM JUST WEST OF ELBA...OR ABOUT 16 MILES SOUTH OF AKRON. THIS STORM WAS PRODUCING TORRENTIAL RAIN...SMALL HAIL...AND GUSTY WINDS UP TO 50 MPH. THE STORM WAS NEARLY STATIONARY...AND WILL PRODUCE 1 TO 2 INCHES OF RAIN IN 30 MINUTES OR LESS. HEAVY RAINS MAY FLOOD LOW LYING AREAS. DO NOT DRIVE ACROSS FLOODED ROADS. WATER LEVELS OF SMALL STREAMS AND RIVERS MAY ALSO RISE...THEREFORE SEEK HIGHER GROUND IF THREATENED BY FLOOD WATERS. BARJENBRUCH
Special weather statement, Jul 21, 1:26 PM MDT, 4 hours 1 minute before
COZ049-212000- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE DENVER CO 125 PM MDT MON JUL 21 1997 ...THUNDERSTORM WITH HEAVY RAIN IN CENTRAL WASHINGTON COUNTY... AT 123 PM MDT NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A THUNDERSTORM JUST WEST OF ELBA...OR ABOUT 16 MILES SOUTH OF AKRON. THIS STORM WAS PRODUCING TORRENTIAL RAIN...SMALL HAIL...AND GUSTY WINDS UP TO 50 MPH. THE STORM WAS NEARLY STATIONARY...AND WILL PRODUCE 1 TO 2 INCHES OF RAIN IN 30 MINUTES OR LESS. HEAVY RAINS MAY FLOOD LOW LYING AREAS. DO NOT DRIVE ACROSS FLOODED ROADS. WATER LEVELS OF SMALL STREAMS AND RIVERS MAY ALSO RISE...THEREFORE SEEK HIGHER GROUND IF THREATENED BY FLOOD WATERS. BARJENBRUCH
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.