Alert archive / Colorado / Severe Thunderstorm Warnings in 1990

Severe Thunderstorm Warning 49, NWS Denver/Boulder, CO

September 1, 1990Morgan County, Weld County, Colorado

NWS Denver/Boulder, CO issued this severe thunderstorm warning at Sep 1, 1990, 5:49 PM MDT for Morgan County, Weld County, Colorado. It was in force for 41 min.

The area

The counties it named.

The facts

Issued
Sep 1, 1990, 5:49 PM MDT (23:49 UTC)
Expired
Sep 1, 1990, 6:30 PM MDT
In force
41 min
Issued by
NWS Denver/Boulder, CO
Area
Whole counties

Counties Morgan 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, 11.8 hours before the alert went out and 95 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.

Skew-T log-pSkew-T log-p diagram, Denver, CO at 12:00Z on 1990-09-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 14 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Denver, CO at 12:00Z on 1990-09-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -9 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
14 J/kg
Mixed-layer CIN
-269 J/kg
Mixed-layer LCL
1981 m above ground
0-6 km bulk shear
17 kt
0-1 km storm-relative helicity
-9 m²/s²
0-3 km storm-relative helicity
104 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

000 
TTAA00 KDEN 012352
SVRDEN
COC087-123-020030-

BULLETIN...IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE DENVER CO
549 PM MDT SAT SEP 01 1990

THE NATIONAL WEATHER SERVICE HAS ISSUED A SEVERE THUNDERSTORM
WARNING EFFECTIVE UNTIL 630 PM  MDT FOR PEOPLE IN THE
FOLLOWING COUNTIES OF NORTHEAST COLORADO:

     NORTHWESTERN MORGAN
     EAST CENTRAL WELD

INCLUDING THE FOLLOWING TOWNS/CITIES:

     BRIGGSDALE..KEOTA..NEW RAYMER..AND STONEHAM


AT 549 PM MDT NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
A SEVERE THUNDERSTORM 10 MILES SOUTH OF BRIGGSDALE...OR ABOUT 19
MILES EAST OF GREELEY.

THE STORM WAS MOVING NORTHEAST AT 20 TO 25 MPH AND WILL AFFECT THE
TOWN OF KEOTA BY 605 PM MDT.

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.

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 361-06d63.  DO NOT CALL THIS NUMBER FOR INFORMATION.

HEITKAMP

LAT...LON 4053 10357 4032 10423 4051 10448 4090 10396

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, Sep 1, 3:13 PM MDT, 2 hours 36 minutes before
COZ011-010445-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE  DENVER CO
315PM MDT SAT SEP 1 1990

...LINE OF THUNDERSTORMS FORMING SOUTHEAST OF DENVER...

AT 3PM A LINE OF THUNDERSTORMS WAS FORMING SOUTHEAST OF DENVER FROM
NORTHEAST DOUGLAS COUNTY TO NORTH CENTRAL ARAPAHOE COUNTY. THE STRONGEST
OF THESE CELLS WAS NEAR THE TOWN OF PARKER. THESE STORMS CONTAIN
CONSIDERABLE LIGHTNING AND GUSTY WINDS. BRIEF HEAVY RAIN AND SMALL HAIL
MAY ALSO BE PRESENT. MOVEMENT ON THESE STORMS WAS TOWARD THE NORTHEAST
AT 10 TO 20 MILES PER HOUR. PESONS IN NORTHEASTERN
DOUGLAS...NORTHWESTERN
ELBERT AND EASTERN APAPAHOE COUNTIES SHOULD BE ON
THE LOOKOUT FOR INCLEMENT WEATHER FOR THE NEXT HOUR.
LET
Special weather statement, Sep 1, 3:53 PM MDT, 1 hour 56 minutes before
COZ011-012-012230-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE  DENVER CO
350 PM MDT SAT SEP 1 1990

...STRONG THUNDERSTORMS IN PORTIONS OF NORTHEAST COLORADO...

AT 345 PM MDT NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED STRONG
THUNDERSTORMS ALONG A LINE FROM EXTREME NORTHEAST DOUGLAS COUNTY THROUGH
CENTRAL ARAPAHOE AND INTO CENTRAL ADAMS COUNTY.  THE STRONGEST STORM WAS
LOCATED 5 MILES SOUTHEAST OF WATKINS...OR 20 MILES EAST OF DOWNTOWN
DENVER.  ALL OF THE THUNDERSTORMS WERE MOVING NORTHEAST AT 15 TO 25 MPH
AND WILL BE AFFECTING PERSONS IN CENTRAL ARAPAHOE AND CENTRAL ADAMS
COUNTIES.

PEOPLE IN THE TOWNS OF MANILA AND BENNETT SHOULD BE ON THE LOOKOUT
FOR THESE STORMS AS THEY ARE CAPABLE OF PRODUCING BRIEF HEAVY RAIN
...DEADLY LIGHTNING...HAIL...AND POSSIBLY A FEW FUNNEL CLOUDS.  IF
THREATENING WEATHER APPROACHES SEEK SHELTER IMMEDIATELY AND WAIT FOR
THE STORM TO PASS.  LOCALIZED STREET FLOODING IS ALSO A POSSIBILITY
WITH THESE STORMS SO MOTORISTS SHOULD AVOID ROADS COVERED BY WATER.

HEITKAMP
Special weather statement, Sep 1, 4:39 PM MDT, 1 hour 10 minutes before
COZ011-012-012315-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE  DENVER CO
440 PM MDT SAT SEP 1 1990

...STRONG THUNDERSTORM IN PORTIONS OF SOUTHEAST WELD COUNTY...

AT 435 PM MDT NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED STRONG
THUNDERSTORMS IN SOUTHEAST WELD COUNTY.  THE STRONGEST THUNDERSTORM WAS
LOCATED 6 MILES NORTHEAST OF KEENESBURG...OR 40 MILES NORTHEAST OF
DOWNTOWN DENVER.  THE THUNDERSTORM WAS MOVING NORTHEAST AT 15 TO 25 MPH
AND WILL BE AFFECTING PEOPLE IN THE TOWN OF ROGGEN AND ALSO MOTORISTS
TRAVELING ALONG STATE HIGHWAY 6 BETWEEN ROGGEN AND WIGGINS BY 445 PM
MDT.

PEOPLE IN THE THE ABOVE MENTIONED AREAS SHOULD BE ON THE LOOKOUT FOR
THIS STORM AS IT IS CAPABLE OF PRODUCING BRIEF HEAVY RAIN...DEADLY
LIGHTNING...HAIL...AND POSSIBLY A FEW FUNNEL CLOUDS.  IF THREATENING
WEATHER APPROACHES SEEK SHELTER IMMEDIATELY AND WAIT FOR THE STORM TO
PASS.  LOCALIZED STREET FLOODING IS ALSO A POSSIBILITY WITH THIS STORM
SO MOTORISTS SHOULD AVOID ROADS COVERED BY WATER.

HEITKAMP

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.