Alert archive / Colorado / Severe Thunderstorm Warnings in 1998
Severe Thunderstorm Warning 147, NWS Denver/Boulder, CO
NWS Denver/Boulder, CO issued this severe thunderstorm warning at Aug 9, 1998, 3:02 PM MDT for Douglas County, Colorado. It was in force for 43 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 9, 1998, 3:02 PM MDT (21:02 UTC)
- Expired
- Aug 9, 1998, 3:45 PM MDT
- In force
- 43 min
- Issued by
- NWS Denver/Boulder, CO
- Area
- Whole counties; the outline is the Mesonet’s reconstruction
County Douglas County, CO
The radar
The Denver radar (KFTG), 71 km from the middle of the area, began a volume at 21:06 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 9, 3:15 PM MDT | Hail 0.75 | Castle Rock, 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 12:00Z, 9.0 hours before the alert went out and 168 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
- -340 J/kg
- Mixed-layer LCL
- 2304 m above ground
- 0-6 km bulk shear
- 14 kt
- 0-1 km storm-relative helicity
- 20 m²/s²
- 0-3 km storm-relative helicity
- 11 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
695
WUUS1 KDEN 092104 RRA
SVRDEN
COC035-092145-
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE DENVER CO
302 PM MDT SUN AUG 9 1998
THE NATIONAL WEATHER SERVICE IN DENVER HAS ISSUED A
* SEVERE THUNDERSTORM WARNING FOR...
SOUTHWESTERN DOUGLAS COUNTY IN NORTHEAST COLORADO
* UNTIL 345 PM MDT
* AT 254 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM 4 MILES SOUTHWEST OF PERRY PARK...OR ABOUT
25 MILES NORTHWEST OF COLORADO SPRINGS...MOVING SOUTHEAST AT 5 TO
10 MILES PER HOUR.
LOCATIONS IN THE WARNING INCLUDE...DEVILS HEAD...GREENLAND...
LARKSPUR AND PERRY PARK
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.
HEAVY RAINS MAY 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.
LAT...LON 3932 10518 3914 10514 3915 10476 3937 10486
KLEYLAWhat 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 9, 11:15 AM MDT, 3 hours 47 minutes before
COZ030-032>050-100600- SIGNIFICANT WEATHER OUTLOOK FOR NORTHEAST AND NORTH CENTRAL COLORADO NATIONAL WEATHER SERVICE DENVER CO 1115 AM MDT SUN AUG 09 1998 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: MONSOON MOISTURE AROUND WILL BE PLENTY OF FUEL FOR WIDELY SCATTERED THUNDERSTORMS THIS AFTERNOON AND SCATTERED THUNDERSTORMS THIS EVENING. A WEAK DISTURBANCE ALOFT WILL TRIGGER THE STORMS BUT WEAK STEERING WINDS WILL KEEP THE STORMS NEARLY STATIONARY ALLOWING RAIN TO FALL OVER AREAS FOR EXTENDED PERIODS OF TIME. THUS HEAVY RAIN IS POSSIBLE. A FEW OF THE STORMS MAY PRODUCE HAIL TOO. THE STORMS ARE NOT EXPECTED TO BE SEVERE SO SPOTTER ACTIVATION IS NOT ANTICIPATED. TA
Special weather statement, Aug 9, 11:15 AM MDT, 3 hours 47 minutes before
COZ030-032>050-100600- SIGNIFICANT WEATHER OUTLOOK FOR NORTHEAST AND NORTH CENTRAL COLORADO NATIONAL WEATHER SERVICE DENVER CO 1115 AM MDT SUN AUG 09 1998 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: MONSOON MOISTURE AROUND WILL BE PLENTY OF FUEL FOR WIDELY SCATTERED THUNDERSTORMS THIS AFTERNOON AND SCATTERED THUNDERSTORMS THIS EVENING. A WEAK DISTURBANCE ALOFT WILL TRIGGER THE STORMS BUT WEAK STEERING WINDS WILL KEEP THE STORMS NEARLY STATIONARY ALLOWING RAIN TO FALL OVER AREAS FOR EXTENDED PERIODS OF TIME. THUS HEAVY RAIN IS POSSIBLE. A FEW OF THE STORMS MAY PRODUCE HAIL TOO. THE STORMS ARE NOT EXPECTED TO BE SEVERE SO SPOTTER ACTIVATION IS NOT ANTICIPATED. TA
The office that day
Everything else NWS Denver/Boulder, CO issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 8, 6:20 PM MDT | Flash Flood Warning | BOU | Morgan | 85 min |
| Aug 8, 6:25 PM MDT | Severe Thunderstorm Warning | BOU | Morgan | 50 min |
| Aug 8, 7:12 PM MDT | Flash Flood Warning | BOU | Morgan | 93 min |
| Aug 8, 8:59 PM MDT | Severe Thunderstorm Warning | BOU | Adams, Arapahoe | 31 min |
| Aug 9, 3:35 AM MDT | Flash Flood Warning | BOU | Lincoln | 3 hr |
| Aug 9, 3:38 AM MDT | Flash Flood Warning | BOU | Lincoln | 3 hr |
| Aug 9, 3:32 PM MDT | Severe Thunderstorm Warning | BOU | Douglas, Elbert | 43 min |
| Aug 9, 3:38 PM MDT | Severe Thunderstorm Warning | BOU | Arapahoe, Elbert | 52 min |
| Aug 9, 3:48 PM MDT | Tornado Warning | BOU | Adams | 27 min |
| Aug 9, 3:57 PM MDT | Tornado Warning | BOU | Morgan, Weld | 48 min |
| Aug 9, 4:01 PM MDT | Severe Thunderstorm Warning | BOU | Washington | 44 min |
| Aug 9, 4:33 PM MDT | Flash Flood Warning | BOU | Adams, Morgan | 117 min |
| Aug 9, 4:43 PM MDT | Tornado Warning | BOU | Adams, Morgan, Weld | 32 min |
| Aug 9, 4:49 PM MDT | Flash Flood Warning | BOU | Washington | 86 min |
| Aug 9, 4:52 PM MDT | Severe Thunderstorm Warning | BOU | Lincoln, Washington | 38 min |
| Aug 9, 5:21 PM MDT | Flash Flood Warning | BOU | Lincoln, Washington | 99 min |
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.