Alert archive / Colorado / Severe Thunderstorm Warnings in 1998
Severe Thunderstorm Warning 129, NWS Denver/Boulder, CO
NWS Denver/Boulder, CO issued this severe thunderstorm warning at Jul 21, 1998, 6:36 PM MDT for Logan County, Colorado. It was in force for 39 min. 4 reports 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
- Jul 21, 1998, 6:36 PM MDT (00:36 UTC)
- Expired
- Jul 21, 1998, 7:15 PM MDT
- In force
- 39 min
- Issued by
- NWS Denver/Boulder, CO
- Area
- Whole counties
County Logan County, CO
The radar
The Cheyenne radar (KCYS), 150 km from the middle of the area, began a volume at 00:37 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, 6:41 PM MDT | Hail 2.5 | Sterling, CO | |
| Jul 21, 6:50 PM MDT | Hail 2.5 | Sterling, CO | |
| Jul 21, 7:05 PM MDT | Hail 0.75 | Sterling, CO | |
| Jul 21, 7:05 PM MDT | Thunderstorm Wind 61 | Sterling, 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 96 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
- 116 J/kg
- Mixed-layer CIN
- -226 J/kg
- Mixed-layer LCL
- 2387 m above ground
- 0-6 km bulk shear
- 25 kt
- 0-1 km storm-relative helicity
- -12 m²/s²
- 0-3 km storm-relative helicity
- 132 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.6
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, Jul 21, 1:30 PM MDT, 5 hours 6 minutes before
COZ033>035-212015- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE DENVER CO 130 PM MDT TUE JUL 21 1998 ...THUNDERSTORMS INTENSIFYING IN SOUTH CENTRAL LARIMER... NORTHWESTERN BOULDER AND EXTREME NORTHEASTERN GRAND COUNTIES OF COLORADO AT 125 PM MDT NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A LINE OF SCATTERED THUNDERSTORMS FROM ESTES PARK SOUTH TO WARD. THESE THUNDERSTORMS WILL PRODUCE VERY HEAVY RAIN...HAIL...GUSTY WINDS AND DANGEROUS LIGHTNING. THE THUNDERSTORMS WERE MOVING SOUTHEAST AT 10 MPH. PERSONS IN OR NEAR ALLENSPARK...BRAINARD LAKE...DRAKE...ESTES PARK... GLEN HAVEN...GOLD HILL...JAMESTOWN...LONG'S PEAK...MEEKER PARK...MT AUDUBON...PEACEFUL VALLEY...RAYMOND AND WARD SHOULD BE ON THE LOOKOUT FOR THREATENING WEATHER AND MOVE TO A PLACE OF SAFETY IF BAD WEATHER APPROACHES. HEAVY RAINS MAY FLOOD LOW LYING AREAS. AVOID THESE AREAS AND DO NOT CROSS FLOODED ROADS AS THEY MAY BE WASHED OUT. WATER LEVELS OF SMALL STREAMS AND RIVERS MAY ALSO RISE...THEREFORE SEEK HIGHER GROUND IF THREATENED BY FLOOD WATERS. KLEYLA
Special weather statement, Jul 21, 1:30 PM MDT, 5 hours 6 minutes before
COZ033>035-212015- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE DENVER CO 130 PM MDT TUE JUL 21 1998 ...THUNDERSTORMS INTENSIFYING IN SOUTH CENTRAL LARIMER... NORTHWESTERN BOULDER AND EXTREME NORTHEASTERN GRAND COUNTIES OF COLORADO AT 125 PM MDT NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A LINE OF SCATTERED THUNDERSTORMS FROM ESTES PARK SOUTH TO WARD. THESE THUNDERSTORMS WILL PRODUCE VERY HEAVY RAIN...HAIL...GUSTY WINDS AND DANGEROUS LIGHTNING. THE THUNDERSTORMS WERE MOVING SOUTHEAST AT 10 MPH. PERSONS IN OR NEAR ALLENSPARK...BRAINARD LAKE...DRAKE...ESTES PARK... GLEN HAVEN...GOLD HILL...JAMESTOWN...LONG'S PEAK...MEEKER PARK...MT AUDUBON...PEACEFUL VALLEY...RAYMOND AND WARD SHOULD BE ON THE LOOKOUT FOR THREATENING WEATHER AND MOVE TO A PLACE OF SAFETY IF BAD WEATHER APPROACHES. HEAVY RAINS MAY FLOOD LOW LYING AREAS. AVOID THESE AREAS AND DO NOT CROSS FLOODED ROADS AS THEY MAY BE WASHED OUT. WATER LEVELS OF SMALL STREAMS AND RIVERS MAY ALSO RISE...THEREFORE SEEK HIGHER GROUND IF THREATENED BY FLOOD WATERS. KLEYLA
Special weather statement, Jul 21, 2:10 PM MDT, 4 hours 26 minutes before
COZ033>035-038-212045- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE DENVER CO 210 PM MDT TUE JUL 21 1998 ...SCATTERED THUNDERSTORMS CONTINUE OVER PORTIONS OF LARIMER... WESTERN BOULDER AND NORTHEASTERN GRAND COUNTIES OF COLORADO EARLY THIS AFTERNOON... AT 200 PM MDT NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED SCATTERED THUNDERSTORMS CAPABLE OF PRODUCING HEAVY RAIN UP TO 1 INCH PER HOUR...SMALL HAIL...GUSTY WINDS AND DANGEROUS LIGHTNING OVER PORTIONS OF LARIMER...WESTERN BOULDER AND NORTHEASTERN GRAND COUNTIES. THE THUNDERSTORMS WERE MOVING SLOWLY SOUTHEAST AT 5 TO 10 MPH. PERSONS IN OR NEAR ALLENSPARK...BELLVUE...BRAINARD LAKE...BUCKHORN MOUNTAIN...DRAKE...ESTES PARK...GLEN HAVEN...GRAND LAKE...LIVERMORE...LONGS PEAK...MEEKER PARK...MISHOWAKA...MT AUDUBON...PEACEFUL VALLEY...PINGREE PARK...POUDRE PARK...RAYMOND...RUSTIC...TEDS PLACE...TRAIL RIDGE AND WARD SHOULD BE ON THE LOOKOUT FOR THREATENING WEATHER AND MOVE TO A PLACE OF SAFETY IF BAD WEATHER APPROACHES. HEAVY RAINS MAY FLOOD LOW LYING AREAS. AVOID THESE AREAS AND DO NOT CROSS FLOODED ROADS AS THEY MAY BE WASHED OUT. WATER LEVELS OF SMALL STREAMS AND RIVERS MAY ALSO RISE...THEREFORE SEEK HIGHER GROUND IF THREATENED BY FLOOD WATERS. KLEYLA
Special weather statement, Jul 21, 3:10 PM MDT, 3 hours 26 minutes before
COZ035-038-212145- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE DENVER CO 310 PM MDT TUE JUL 21 1998 ...THUNDERSTORMS CONTINUE IN EASTERN LARIMER AND EXTREME WEST CENTRAL WELD COUNTIES OF COLORADO THIS AFTERNOON... AT 305 PM MDT NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED SCATTERED THUNDERSTORMS FROM WEST OF CARR EXTENDING SOUTH TO 10 MILES NORTHWEST OF LOVELAND. THE STRONGEST THUNDERSTORM WAS LOCATED 2 MILES NORTH OF TEDS PLACE...OR ABOUT 9 MILES NORTHWEST OF FORT COLLINS. THESE THUNDERSTORMS WILL PRODUCE RAINFALL UP TO 1 INCH PER HOUR... SMALL HAIL...GUSTY WINDS AND DANGEROUS LIGHTNING. THE THUNDERSTORMS WERE MOVING SLOWLY EAST AT 5 TO 10 MPH. PERSONS IN OR NEAR FORT COLLINS...BELLVUE...BUCKHORN MOUNTAIN... DRAKE...GLEN HAVEN...HARMONY...LIVERMORE...MASONVILLE...MISHOWAKA... POUDRE PARK...TEDS PLACE...TIMNATH AND WELLINGTON SHOULD BE ON THE LOOKOUT FOR THREATENING WEATHER AND MOVE TO A PLACE OF SAFETY IF BAD WEATHER APPROACHES. HEAVY RAINS MAY BRIEFLY FLOOD LOW LYING AREAS SUCH AS DITCHES AND UNDERPASSES. AVOID THESE AREAS AND DO NOT CROSS FLOODED ROADS AS THEY MAY BE WASHED OUT. WATER LEVELS OF SMALL STREAMS AND RIVERS MAY ALSO RISE...THEREFORE SEEK HIGHER GROUND IF THREATENED BY FLOOD WATERS. KLEYLA
Special weather statement, Jul 21, 3:10 PM MDT, 3 hours 26 minutes before
COZ035-038-212145- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE DENVER CO 310 PM MDT TUE JUL 21 1998 ...THUNDERSTORMS CONTINUE IN EASTERN LARIMER AND EXTREME WEST CENTRAL WELD COUNTIES OF COLORADO THIS AFTERNOON... AT 305 PM MDT NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED SCATTERED THUNDERSTORMS FROM WEST OF CARR EXTENDING SOUTH TO 10 MILES NORTHWEST OF LOVELAND. THE STRONGEST THUNDERSTORM WAS LOCATED 2 MILES NORTH OF TEDS PLACE...OR ABOUT 9 MILES NORTHWEST OF FORT COLLINS. THESE THUNDERSTORMS WILL PRODUCE RAINFALL UP TO 1 INCH PER HOUR... SMALL HAIL...GUSTY WINDS AND DANGEROUS LIGHTNING. THE THUNDERSTORMS WERE MOVING SLOWLY EAST AT 5 TO 10 MPH. PERSONS IN OR NEAR FORT COLLINS...BELLVUE...BUCKHORN MOUNTAIN... DRAKE...GLEN HAVEN...HARMONY...LIVERMORE...MASONVILLE...MISHOWAKA... POUDRE PARK...TEDS PLACE...TIMNATH AND WELLINGTON SHOULD BE ON THE LOOKOUT FOR THREATENING WEATHER AND MOVE TO A PLACE OF SAFETY IF BAD WEATHER APPROACHES. HEAVY RAINS MAY BRIEFLY FLOOD LOW LYING AREAS SUCH AS DITCHES AND UNDERPASSES. AVOID THESE AREAS AND DO NOT CROSS FLOODED ROADS AS THEY MAY BE WASHED OUT. WATER LEVELS OF SMALL STREAMS AND RIVERS MAY ALSO RISE...THEREFORE SEEK HIGHER GROUND IF THREATENED BY FLOOD WATERS. KLEYLA
The office that day
Everything else NWS Denver/Boulder, CO issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 21, 6:03 PM MDT | Severe Thunderstorm Warning | BOU | Logan | 42 min |
| Jul 21, 6:22 PM MDT | Severe Thunderstorm Warning | BOU | Morgan, Washington | 38 min |
| Jul 21, 6:35 PM MDT | Severe Thunderstorm Warning | BOU | Logan | 40 min |
| Jul 21, 6:58 PM MDT | Severe Thunderstorm Warning | BOU | Washington | 47 min |
| Jul 21, 7:16 PM MDT | Severe Thunderstorm Warning | BOU | Logan | 44 min |
| Jul 21, 7:57 PM MDT | Flash Flood Warning | BOU | Logan | 3 hr |
Nearby
Severe Thunderstorm Warnings in Colorado, 1998Every severe thunderstorm warning in 1998
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.