Alert archive / Colorado / Severe Thunderstorm Warnings in 1990
Severe Thunderstorm Warning 5, NWS Denver/Boulder, CO
NWS Denver/Boulder, CO issued this severe thunderstorm warning at May 20, 1990, 5:15 PM MDT for Adams County, Arapahoe County, Colorado. It was in force for 30 min. 1 report 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
- May 20, 1990, 5:15 PM MDT (23:15 UTC)
- Expired
- May 20, 1990, 5:45 PM MDT
- In force
- 30 min
- Issued by
- NWS Denver/Boulder, CO
- Area
- Whole counties
Counties Adams County, CO, Arapahoe County, CO
The radar
The WSR-88D network and its archive begin in 1991, so there is no radar volume for this alert.
What was reported inside it
| Time | Report | Where | Remark |
|---|---|---|---|
| May 20, 5:19 PM MDT | Hail 1 | Arapahoe, 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. Storm Data before 1996 records only tornadoes, thunderstorm wind and hail.
The nearest sounding before it
Denver, CO (KDEN), launched 12:00Z, 11.3 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.
- Mixed-layer CAPE
- 85 J/kg
- Mixed-layer CIN
- -310 J/kg
- Mixed-layer LCL
- 1475 m above ground
- 0-6 km bulk shear
- 20 kt
- 0-1 km storm-relative helicity
- 4 m²/s²
- 0-3 km storm-relative helicity
- -12 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 202318
SVRDEN
COC005-001-202345-
BULLETIN...IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE DENVER CO
515 PM MDT SUN MAY 20 1990
THE NATIONAL WEATHER SERVICE HAS ISSUED A SEVERE THUNDERSTORM
WARNING EFFECTIVE UNTIL 545 PM MDT FOR PEOPLE IN THE
FOLLOWING COUNTIES OF NORTHEAST COLORADO:
WESTERN ARAPAHOE
EXTREME SOUTHWESTERN ADAMS
INCLUDING THE FOLLOWING TOWNS/CITIES:
EASTERN AURORA...WATKINS
AT 515 PM MDT RADAR INDICATED A SEVERE THUNDERSTORM 7 MILES
WEST OF WATKINS..WHICH IS 14 MILES EAST OF DENVER. THE STORM WAS MOVING
TO THE SOUTHEAST AT ABOUT 25 MPH. PERSONS IN EASTERN AURORA SHOULD BE
PREPARED FOR THE SEVERE WEATHER AND TAKE COVER IF THREATENING WEATHER
APPROCHES. BUCKLEY FIELD IN EAST AURORA REPORTED 1 INCH DIAMETER HAIL.
ADDITIONALLY SOME REPORTS OF FUNNEL CLOUDS HAVE BEEN RECEIVED IN THE
VICINITY OF BUCKLEY ROAD AND MISSISSIPPI AVENUE.
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.
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.
TO REPORT SEVERE WEATHER HAVE THE NEAREST LAW ENFORCEMENT
AGENCY RELAY YOUR REPORT TO THE N:ATIONAL WEATHER SERVICE OFFICE
IN DENVER..OR CALL YOUR REPORT TO THE NATIONAL WEATHER SERVICE
AT 361-0663. DO NOT CALL THIS NUMBER FOR INFORMATION.
T.H./E.T.
LAT..LON 3961 10456 3964 10481 3977 10480 3977 10453What 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, May 20, 2:04 PM MDT, 3 hours 11 minutes before
COZ011-192100- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE OFFICE DENVER CO 2PM MDT SUN MAY 20 1990 ...THUNDERSTORMS RAPIDLY DEVELOPING NORTH AND WEST OF FORT COLLINS... THUNDERSTORMS IN NORTHERN LARIMER COUNTY WERE RAPIDLY DEVELOPING SHORTLY BEFORE 200 THIS AFTERNOON. THESE STORMS WERE LOCATED JUST WEST AND NORTH OF FORT COLLINS AND MOVING TO THE EAST AT ABOUT 20 MPH. HAIL...STRONG GUSTY WINDS...AND BRIEF HEAVY RAINS ARE POSSIBLE AS THESE STORMS MOVE THROUGH NORTHERN AND EASTERN LARIMER COUNTY. RESIDENTS OF FORT COLLINS...LAPORT...WELLINGTON AND SURROUNDING AREAS SHOULD HEAD FOR COVER IF THREATENED BY SEVERE WEATHER. REPORT ANY SEVERE WEATHER TO YOUR LOCAL LAW ENFORECEMENT AGENCY. RTG
Special weather statement, May 20, 2:26 PM MDT, 2 hours 49 minutes before
COZ011-192200- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE OFFICE DENVER CO 230PM MDT SUNDAY MAY 20 1990 ...PEA SIZE HAIL IN WELLINGTON COLORADO... THUNDERSTORMS HAVE DEVELOPED IN LARIMER COUNTY THIS AFTERNOON. ONE OF THE THUNDERSTORMS PRODUCED PEA SIZE HAIL 5 MILES WEST NORTHWEST OF THE TOWN OF WELLINGTON COLORADO WHICH IS BY I-25 ABOUT 10 MILES NORTHEAST OF FORT COLLINS. THUNDER AND LIGHT RAIN WAS ALSO BEING REPORTED AT FORT COLLINS AT 220PM MDT. THE THUNDERSTORMS ARE MOVING TO THE EAST ABOUT 20 MPH. HAIL...STRONG GUSTY WINDS...AND BRIEF HEAVY RAINS ARE POSSIBLE AS THESE STORMS MOVE THROUGH NORTHERN AND EASTERN LARIMER COUNTY AND INTO WELD COUNTY BY 3PM MDT. RESIDENTS OF FORT COLLINS...LAPORT...WELLINGTON AND SURROUNDING AREAS SHOULD HEAD FOR COVER IF THREATENED BY SEVERE WEATHER. REPORT ANY SEVERE WEATHER TO YOUR LOCAL LAW ENFORECEMENT AGENCY. END...GCF...WSFO DENVER
Special weather statement, May 20, 3:25 PM MDT, 1 hour 50 minutes before
COZ011-192200- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE OFFICE DENVER CO 315 PM MDT SUNDAY MAY 20 1990 ...HALF INCH HAIL NEAR LAKE LOVELAND... THUNDERSTORMS CONTINUE IN EXTREME SOUTHEAST LARIMER AND EXTREME WESTERN WELD COUNTIES. THE STORMS WERE LOCATED BETWEEN THE TOWNS OF LOVELAND AND PLATTEVILLE AND MOVING TOWARDS THE EAST AT 15 TO 20 MPH. AT 313 PM MDT HALF INCH DIAMETER HAIL WAS REPORTED JUST TO SOUTHWEST OF LAKE LOVELAND AND BEGINNING TO COVER THE GROUND. HAIL...STRONG GUSTY WINDS...AND BRIEF HEAVY RAINS ARE POSSIBLE WITH THESE STORMS AS THEY CONTINUE TO MOVE INTO WESTERN WELD COUNTY. RESIDENTS OF PLATTEVILLE AND LOVELAND AND NEARBY AREAS SHOULD BE ON THE LOOKOUXT FOR THESE STORMS AND SEEK SHELTER IF THREATENING WEATHER APPROACHES. REPORT ANY SEVERE WEATHER TO YOUR LOCAL LAW ENFORECEMENT AGENCY. END...TAH...WSFO DENVER
Special weather statement, May 20, 4:19 PM MDT, 56 minutes before
COZ011-192300- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE OFFICE DENVER CO 415 PM MDT SUNDAY MAY 20 1990 ...THUNDERSTORMS CONTINUE OVER NORTHEAST COLORADO... THUNDERSTORMS CONTINUE TO RUMBLE IN NORTHEASTERN COLORADO THIS AFTERNOON. THE STRONGEST THUNDERSTORMS ARE IN AN AREA OF SOUTHWEST WELD...NORTHWEST ADAMS AND EXTREME EASTERN BOULDER COUNTIES. ALL THE CELLS ARE MOVING EAST ABOUT 15 TO 20 MPH. THE THUNDERSTORMS WILL BE REACHING THE TOWNS OF BRIGHTON...PLATTEVILLE AND KEENESBURG AS WELL AS THE NORTHERN AREAS OF NORTHGLENN BY 5PM MDT. PEA SIZE HAIL WAS REPORTED IN THE TOWNS OF LAFAYETTE AND NORTHERN SECTION OF BOULDER AT 4PM MDT. HAIL...STRONG GUSTY WINDS...AND BRIEF HEAVY RAINS ARE POSSIBLE WITH THESE STORMS. PEOPLE IN SOUTHERN WELD AND NORTHERN ADAMS COUNTIES SHOULD BE ALERT FOR THESE STORMS AND MOVE INDOORS IF THREATENING WEATHER APPROACHES. REPORT ANY SEVERE WEATHER TO YOUR LOCAL LAW ENFORCEMENT AGENCY. END...GCF...WSFO DENVER
Special weather statement, May 20, 4:53 PM MDT, 22 minutes before
COZ011-192330- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE OFFICE DENVER CO 455 PM MDT SUNDAY MAY 20 1990 ...STRONG THUNDERSTORM MOVING INTO THE DENVER METRO AREA... AT 450 PM MDT RADAR INDICATED A STRONG THUNDERSTORM ABOUT 5 MILES NORTH OF STAPLETON AIRPORT. THIS STORM IS MOVING SOUTHEAST AT 10 TO 20 MPH AND WILL BE MOVING INTO MONTEBELLO AND NORTHERN AURORA BY 530 PM MDT. HAIL...STRONG GUSTY WINDS...AND BRIEF HEAVY RAINS ARE POSSIBLE WITH THIS STORM. PEOPLE IN NORTHERN AURORA AND MONTBELLO SHOULD BE ON THE LOOKOUT FOR THIS STORM. MOTORISTS SHOULD ALSO EXERCISE CAUTION IF THIS STORM IS ENCOUNTERED. REPORT ANY SEVERE WEATHER TO YOUR LOCAL LAW ENFORCEMENT AGENCY. END...TAH...WSFO DENVER
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; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive.