Alert archive / Colorado / Severe Thunderstorm Warnings in 1990

Severe Thunderstorm Warning 40, NWS Denver/Boulder, CO

July 27, 1990Weld County, Colorado

NWS Denver/Boulder, CO issued this severe thunderstorm warning at Jul 27, 1990, 6:34 PM MDT for Weld County, Colorado. It was in force for 41 min.

The area

The counties it named.

The facts

Issued
Jul 27, 1990, 6:34 PM MDT (00:34 UTC)
Expired
Jul 27, 1990, 7:15 PM MDT
In force
41 min
Issued by
NWS Denver/Boulder, CO
Area
Whole counties

County 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 00:00Z, 0.6 hours before the alert went out and 125 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 00:00Z on 1990-07-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Denver, CO at 00:00Z on 1990-07-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -71 square meters per square second.193958Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
3328 m above ground
0-6 km bulk shear
26 kt
0-1 km storm-relative helicity
-71 m²/s²
0-3 km storm-relative helicity
-83 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 280038
SVRDEN
COC123-280115-

BULLETIN...IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE DENVER CO
634 PM MDT FRI JUL 27 1990

THE NATIONAL WEATHER SERVICE HAS ISSUED A SEVERE THUNDERSTORM
WARNING EFFECTIVE UNTIL 715 PM  MDT FOR PEOPLE IN THE
FOLLOWING COUNTIES OF NORTHEAST COLORADO:

     SOUTH CENTRAL WELD

INCLUDING THE FOLLOWING TOWNS/CITIES:

     EVANS..GARDEN CITY..GILCREST..GREELEY..KERSEY..AND LA SALLE


AT 0634 PM MDT NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
A SEVERE THUNDERSTORM 2 MILES SOUTH OF LA SALLE...OR ABOUT 7
MILES SOUTH OF GREELEY.

THE STORM WAS MOVING EAST AT 15 TO 20 MPH AND WILL BE AFFECTING 
THE TOWN OF KERSEY WITHIN THE NEXT 10 TO 15 MINUTES.

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 361-0663.  DO NOT CALL THIS NUMBER FOR INFORMATION.

HEITKAMP

LAT...LON 4014 10417 4024 10476 4044 10476 4048 10416

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 27, 3:12 PM MDT, 3 hours 22 minutes before
COZ011-012-272230-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE  DENVER CO
315 PM MDT FRIDAY JULY 27 1990

...THUNDERSTORMS DEVELOPING EAST OF DENVER...

AT 310 PM MDT NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A LINE
OF THUNDERSTORMS DEVELOPING IN NORTHEASTERN COLORADO.  THE LINE EXTENDED
FROM JUST SOUTHWEST OF FORT MORGAN IN MORGAN COUNTY...THROUGH CENTRAL
ADAMS AND ARAPAHOE COUNTY...AND PAST CASTLE ROCK INTO SOUTHWESTERN
DOUGLAS COUNTY.

THE STRONGEST STORMS WERE IN ADAMS COUNTY NEAR STRASBURG...ABOUT 30
MILES EAST OF DENVER.  THE STORMS WERE MOVING TOWARD THE EAST AT ABOUT
15 MPH.

THESE STORMS MAY PRODUCE HEAVY RAIN...HAIL...DANGEROUS LIGHTNING...AND
STRONGx WINDS UNTIL AT LEAST 430 PM MDT.  PERSONS ALONG AND JUST TO THE
EAST OF THE LINE SHOULD SEEK SHELTER IF THUNDERSTORMS APPROACH.

MARKKANEN
Special weather statement, Jul 27, 6:05 PM MDT, 29 minutes before
COZ011-012-280030-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE  DENVER CO
600 PM MDT FRIDAY JULY 27 1990

...THUNDERSTORMS CONTINUING TO DEVELOP IN PORTIONS OF NORTHEAST
COLORADO...

AT 555 PM MDT NATIONAL WEATHER SERVICE DOPPLER RADAR SHOWED AN AREA
OF DEVELOPING THUNDERSTORMS IN PORTIONS OF NORTHEAST COLORADO.  THE
AREA OF THUNDERSTORMS WERE ALONG A LINE FROM FORT COLLINS IN SOUTHEAST
LARIMER COUNTY TO FORT LUPTON...25 MILES NORTHEAST OF DOWNTOWN DENVER
...IN SOUTHERN WELD COUNTY.  THE STRONGEST STROM WAS LOCATED 7 MILES
SOUTHEAST OF FORT COLLINS.

PEOPLE IN SOUTHEAST LARIMER...NORTHCENTRAL ADAMS...AND WELD COUNTIES
SHOULD BE ON THE LOOKOUT FOR THESE STORMS AS THEY ARE CAPABLE OF
PRODUCING HEAVY RAIN...HAIL...DEADLY LIGHTNING...AND STRONG GUSTY
WINDS.  IF THREATENING WEATHER APPROACHES YOUR AREA GO INSIDE YOUR
SHELTER AND WAIT FOR THE STORMS TO PASS.

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.