Alert archive / Colorado / Severe Thunderstorm Warnings in 1990
Severe Thunderstorm Warning 42, NWS Denver/Boulder, CO
NWS Denver/Boulder, CO issued this severe thunderstorm warning at Aug 11, 1990, 3:36 PM MDT for Adams County, Weld County, Colorado. It was in force for 39 min.
The area
The counties it named.
The facts
- Issued
- Aug 11, 1990, 3:36 PM MDT (21:36 UTC)
- Expired
- Aug 11, 1990, 4:15 PM MDT
- In force
- 39 min
- Issued by
- NWS Denver/Boulder, CO
- Area
- Whole counties
Counties Adams County, CO, Weld County, CO
The radar
The WSR-88D network and its archive begin in 1991, so there is no radar volume for this alert.
The nearest sounding before it
Denver, CO (KDEN), launched 12:00Z, 9.6 hours before the alert went out and 104 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
- 56 J/kg
- Mixed-layer CIN
- -258 J/kg
- Mixed-layer LCL
- 1249 m above ground
- 0-6 km bulk shear
- 14 kt
- 0-1 km storm-relative helicity
- -47 m²/s²
- 0-3 km storm-relative helicity
- 18 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 112138
SVRDEN
COC001-123-112215-
BULLETIN...IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE DENVER CO
336 PM MDT SAT AUG 11 1990
THE NATIONAL WEATHER SERVICE HAS ISSUED A SEVERE THUNDERSTORM
WARNING EFFECTIVE UNTIL 415 PM MDT FOR PEOPLE IN THE
FOLLOWING COUNTIES OF NORTHEAST COLORADO:
NORTH CENTRAL ADAMS
EXTREME SOUTH CENTRAL WELD
INCLUDING THE FOLLOWING TOWNS/CITIES:
PROSPECT VALLEY
AT 335 PM MDT RADAR INDICATED A SEVERE THUNDERSTORM 8 MILES SOUTHWEST
OF PROSPECT VALLEY ... OR ABOUT 33 MILES NORTHEAST OF DENVER.
THE STORM WAS MOVING TO THE NORTHEAST AT ABOUT 20 MPH.
IF SEVERE WEATHER APPROACHES YOUR AREA...GO TO A STURDY
SHELTER AWAY FROM CREEK BEDS AND OTHER FLOOD PRONE AREAS.
REMEMBER...A SEVERE THUNDERSTORM CAN PRODUCE LARGE DAMAGING
HAIL...DAMAGING WINDS OF OVER 60 MPH...DEADLY LIGHTNING...AND
HEAVY RAINS THAT CAN QUICKLY FLOOD A LOW LYING AREA.
INTENSE LIGHTNING IS REPORTED WITH THIS STORM. IF OUTDOORS...
STAY AWAY FROM HIGH OBJECTS. MOVE INDOORS IF POSSIBLE. WHEN
INDOORS...STAY AWAY FROM WINDOWS AND DOORS AND AVOID USING
TELEPHONES AND ELECTRICAL EQUIPMENT.
THESE STORMS CAN PRODUCE A TORNADO WITH LITTLE OR NO ADVANCE
WARNING...SO BE ON THE LOOKOUT AND BE PREPARED TO MOVE TO A
PLACE OF SAFETY IF ONE IS SPOTTED.
A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT FOR MOST OF NORTHEAST
COLORADO UNTIL 8 PM MDT SATURDAY EVENING.
TO REPORT SEVERE WEATHER HAVE THE NEAREST LAW ENFORCEMENT
AGENCY RELAY YOUR REPORT TO THE NATIONAL WEATHER SERVICE OFFICE
IN DENVER...OR CALL YOUR REPORT TO THE NATIONAL WEATHER SERVICE
AT 361-0663. DO NOT CALL THIS NUMBER FOR INFORMATION.
ET
LAT...LON 3989 10427 3988 10452 4008 10453 4007 10424What 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 11, 1:22 PM MDT, 2 hours 14 minutes before
COZ011-112030- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE DENVER CO 125 PM MDT SAT AUG 11 1990 ...STRONG THUNDERSTORMS DEVELOPING OVER THE NORTHEAST COLORADO FOOTHILLS NATIONAL WEATHER SERVICE DOPPLER RADAR AT 120 PM INDICATED STRONG THUNDERSTORMS DEVELOPING OVER THE NORTHEASTERN COLORADO FOOTHILLS. ONE STRONG STORM WAS LOCATED SOUTHEAST OF ESTES PARK WITH NEW STORMS FORMING NORTHWARD TO WEST OF CHEYENNE IN WYOMING. OTHER STRONG STORMS ARE LOCATED IN SOUTHERN JEFFERSON COUNTY NEAR DECKERS...DEVELOPING EASTWARDS INTO SOUTHWEST DOUGLAS COUNTY. THE STORMS ARE MOVING TO THE EAST AT 20 MPH. HEAVY RAIN...HAIL...STRONG GUSTY WINDS AND DANGEROUS LIGHTNING MAY ACCOMPANY THE STORMS. THUNDERSTORMS WILL CONTINUE TO DEVELOP OVER THE FOOTHILLS AND MOVE OVER THE FRONT RANGE FROM FORT COLLINS TO SOUTH OF DENVER IN THE NEXT COUPLE OF HOURS. THESE MAY BECOME SEVERE SO PERSONS SHOULD BE ALERT FOR CHANGING WEATHER CONDITIONS. STAY TUNED TO NOAA WEATHER RADIO AND MEDIA OUTLETS FOR FURTHER UPDATES. SZOKE/LOONEY
Special weather statement, Aug 11, 2:49 PM MDT, 47 minutes before
COZ011-112200- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE DENVER CO 248 PM MDT SAT AUG 11 1990 ...SEVERE THUNDERSTORM WATCH CONTINUES FOR MOST OF NORTHEAST COLORADO... THUNDERSTORMS CONTINUE TO DEVELOP OVER THE FOOTHILLS OF NORTHEAST COLORADO. AT 245 PM MDT SATURDAY AFTERNOON NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED THE STRONGEST STORM WEST OF BOULDER NEAR THE TOWNS OF SUGARLOAF AND GOLD HILL. THIS STORM IS CAPABLE OF PRODUCING HAIL...HEAVY RAIN AND DANGEROUS LIGHTNING. THE STORM IS ALSO ROTATING WHICH IS SOMETIMES THE PRECURSOR TO THE DEVELOPMENT OF FUNNEL CLOUDS AND TORNADOES. PERSONS IN SOUTH CENTRAL BOULDER COUNTY INCLUDING THE TOWN OF BOULDER SHOULD BE ON THE LOOKOUT FOR DANGEROUS WEATHER AND SEEK SAFE SHELTER IF THREATENING WEATHER IS OBSERVED. THE RAIN WITH THE STORM MAY BE SUFFICIENT TO CAUSE LOCAL FLOODING OF SMALL STREAMS AND ROADWAYS. A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT FOR MOST O9F NORTHEAST COLORADO UNTIL 8 PM MDT. ET
Special weather statement, Aug 11, 3:31 PM MDT, 5 minutes before
COZ011-012-112300- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE DENVER CO 330 PM MDT SAT AUG 11 1990 ...MORE THUNDERSTORMS DEVELOPING IN NORTHEAST COLORADO... A RAPIDLY DEVELOPING THUNDERSTORM WAS LOCATED ABOUT 20 MILES NORTHEAST OF DOWNTOWN DENVER IN CENTRAL ADAMS COUNTY AT 320 PM MDT. THE STORM WILL BE MOVING TO THE EAST AT ABOUT 15 MPH FOR THE NEXT HOUR. OTHER STORMS WERE BEGINNING TO DEVELOP IN NORTH CENTRAL ADAMS COUNTY SOUTH OF KEENESBURG. HEAVY RAIN...HAIL AND STRONG GUSTY WINDS WILL ACCOMPANY THESE STORMS AS WELL AS FREQUENT LIGHTNING. PERSONS IN NORTH CENTRAL ADAMS COUNTY AS WELL AS SOUTHEAST WELD COUNTY INCLUDING THE TOWNS OF SOUTH ROGGEN AND PROSPECT VALLEY SHOULD BE ON THE LOOKOUT FOR THREATENING WEATHER AND SEEK SAFE SHELTER IF BAD WEATHER APPROACHES. THE STORM IN BOULDER COUNTY WAS DISSIPATING AT 320. HALF INCH HAIL AND LOTS OF RAIN FELL FROM THE STORM AROUND BOULDER SINCE 245 PM. ALSO FREQUENT LIGHTNING OCCURRED WITH THE STORM. A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT FOR MOST OF NORTHEAST COLORADO UNTIL 8 PM MDT. ET
The office that day
Everything else NWS Denver/Boulder, CO issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 11, 4:32 PM MDT | Severe Thunderstorm Warning | BOU | Adams, Arapahoe, Denver, Jefferson | 28 min |
Nearby
Severe Thunderstorm Warnings in Colorado, 1990Every severe thunderstorm warning in 1990
Sources
The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive.