Alert archive / Colorado / Severe Thunderstorm Warnings in 1987
Severe Thunderstorm Warning 3, NWS Denver/Boulder, CO
NWS Denver/Boulder, CO issued this severe thunderstorm warning at May 17, 1987, 6:08 PM MDT for Washington County, Colorado. It was in force for 67 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 17, 1987, 6:08 PM MDT (00:08 UTC)
- Expired
- May 17, 1987, 7:15 PM MDT
- In force
- 67 min
- Issued by
- NWS Denver/Boulder, CO
- Area
- Whole counties
County Washington 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 17, 6:18 PM MDT | Thunderstorm Wind 75 | Washington, 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 00:00Z, 0.1 hours before the alert went out and 11 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
- 8 J/kg
- Mixed-layer CIN
- -199 J/kg
- Mixed-layer LCL
- 1516 m above ground
- 0-6 km bulk shear
- 28 kt
- 0-1 km storm-relative helicity
- 56 m²/s²
- 0-3 km storm-relative helicity
- 126 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 180008 SVRDEN COC121-180115- BULLETIN - IMMEDIATE BROADCAST REQUESTED SEVERE THUNDERSTORM WARNING NATIONAL WEATHER SERVICE DENVER CO 608 PM MDT SUN MAY 17 1987 THE NATIONAL WEATHER SERVICE HAS ISSUED A SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL 715 PM MDT FOR PEOPLE IN THE FOLLOWING COUNTY OF NORTHEAST COLORADO...NORTHERN WASHINGTON THIS WARNING INCLUDES THE FOLLOWING TOWNS AND CITIES...AKRON.. PLATNER..OTIS AT 600PM MDT RADAR INDICATED A SEVERE THUNDERSTORM 5 MILES NORTHEAST OF AKRON OR ABOUT 30 MILES SOUTH OF STERLING. MOVEMENT WAS TO THE EAST AT 15 MPH. LARGE HAIL..STRONG GUSTY WINDS..AND HEAVY RAINFALL ARE POSSIBLE WITH THIS STORM. IF YOU ARE IN AN AREA THREATENED BY THE STORM..GO TO A REINFORCED SHELTER AND PREPARE FOR DAMAGING WIND...LARGE HAIL...VERY HEAVY RAIN AND LIGHTNING. THIS SLOW MOVING THUNDERSTORM MAY CAUSE FLOODING OF SMALL STREAMS AND UNDERPASSES. DULONG
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, May 17, 1:24 PM MDT, 4 hours 44 minutes before
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE DENVER CO 125 PM MDT SUN MAY 17 1987 ...THUNDERSTORMS CONTINUE ALONG NORTHEAST COLORADO FOOTHILLS... STRONG THUNDERSTORMS ARE CONTINUING ALONG THE FOOTHILLS IN NORTHEAST COLORADO WITH THE STRONGEST CELLS LOCATED JUST NORTHEAST OF FORT COLLINS AND NORTH OF GOLDEN. HEAVY RAIN..HAIL..STRONG WINDS AND LIGHTNING CAN BE ANTICIPATED WITH THESE STORMS. AN OBSERVER IN FORT COLLINS REPORTED THAT ONE-HALF INCH HAIL FELL IN THAT CITY AROUND ONE OCLOCK THIS AFTERNOON WITH PEA-SIZE HAIL FALLING IN AND AROUND LONGMONT EARLIER THIS AFTERNOON. THE HEAVY RAIN WITH THESE STORMS CAN PRODUCE PONDING OF WATER IN LOW- LYING AREAS SUCH AS UNDERPASSES ALONG WITH MINOR FLOODING OF SMALL STREAMS. THALER
Special weather statement, May 17, 2:22 PM MDT, 3 hours 46 minutes before
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE DENVER CO 223 PM MDT SUN MAY 17 1987 ...THUNDERSTORMS CONTINUE ALONG NORTHEAST COLORADO FOOTHILLS... STRONG THUNDERSTORMS ARE CONTINUING IN AND ALONG THE FOOTHILLS IN NORTHEAST COLORADO. A LINE EXTENDS FROM NORTHWEST WELD COUNTY..20 MILES NORTHEAST OF FORT COLLINS THROUGH SOUTHWEST WELD COUNTY TO 10 MILES NORTHEAST OF DENVER IN ADAMS COUNTY THROUGH WESTERN ARAPAHOE COUNTY AND NORTHWEST DOUGLAS COUNTY INTO SOUTHERN JEFFERSON COUNTY 30 MILES SOUTHWEST OF DENVER. A VERY STRONG THUNDERSTORM WAS LOCATED ABOUT 30 MILES SOUTH OF DENVER IN SOUTH CENTRAL DOUGLAS COUNTY. THE THUNDERSTORMS ARE MOVING TO THE NORTH EAST AROUND 10 MPH. STRONG WI NDS..HAIL..LIGHTNING AND HEAVY RAIN CAN ACCOMPANY THE THUNDER- STORMS. THE HEAVY RAIN WITH THESE STORMS CAN PRODUCE PONDING OF WATER IN LOW-LYING AREAS SUCH AS UNDERSPASSES ALONG WITH MINOR FLOODING OF SMALL STREAMS. BALINT
Special weather statement, May 17, 3:41 PM MDT, 2 hours 27 minutes before
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE DENVER CO 340 PM MDT SUN MAY 17 1987 ...THUNDERSTORMS IN NORTHEAST COLORADO... A LINE OF VERY STRONG THUNDERSTORMS EXTENDS FROM THE WYOMING COLORADO BORDER NEAR HEREFORD IN NORTHERN WELD COUNTY SOUTH TO JUST EAST OF THE DENVER METROPOLITAN AREA. THIS LINE IS MOVING TO THE EAST AT 10 TO 15 MPH. AT 330PM MDT THE STRONGEST STORM WAS LOCATED ABOUT 15 MILES WEST NORTHWEST OF GOODRICH COLORADO WHICH IS LOCATED 60 MILES NORTHEAST OF DENVER. ALL PERSONS IN EASTERN WELD..WESTERN MORGAN..CENTRAL ADAMS AND WESTERN AND CENTRAL ARAPAHOE COUNTIES SHOULD BE ALERT FOR HAIL..STRONG GUSTY WINDS..FREQUENT LIGHTNING..AND LOCALLY HEAVY RAIN. UNTIL 500 PM MDT THIS EVENING. THE HEAVY RAIN WITH THESE STORMS MAY PRODUCE PONDING OF WATER IN LOW-LYING AREAS AND MINOR FLOODING OF SMALL STREAMS. GARD...WSFO DENVER
Special weather statement, May 17, 4:46 PM MDT, 1 hour 22 minutes before
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE DENVER CO 445 PM MDT SUN MAY 17 1987 ...LINE OF VERY STRONG THUNDERSTORMS CONTINUES TO MOVE EAST THROUGH NORTHEAST AND EAST CENTRAL COLORADO... A LINE OF VERY STRONG THUNDERSTORMS EXTENDS FROM THE WYOMING COLORADO BORDER NEAR HEREFORD IN NORTHERN WELD COUNTY SOUTH TO BYERS IN ARAPAHOE COUNTY AND TO ELIZABETH IN ELBERT COUNTY. OTHER SCATTERED THUNDERSTORMS LINGER WEST OF THIS LINE TOWARDS THE FOOTHILLS..WHERE ACTIVITY IS SLOWLY DECREASING. THERE HAVE BEEN NUMEROUS REPORTS OF FUNNEL CLOUDS AND HAIL FROM THE HEAVIER STORMS THIS AFTERNOON. IT APPEARS THAT THE LINE OF STRONG THUNDERSTORMS WILL MOVE INTO LOGAN..WASHINGTON AND EASTERN PARTS OF ADAMS AND ARAPAHOE COUNTIES DURING THE NEXT COUPLE OF HOURS. PERSONS IN THESE AREAS SHOULD BE ALERT FOR HAIL..STRONG GUSTY WINDS..FREQUENT LIGHTNING..AND LOCALLY HEAVY RAIN. RADAR INDICATES THAT THINGS SHOULD QUIET DOWN ALONG THE FRONT RANGE THE REST OF THIS AFTERNOON AND EARLY EVENING..WITH MOST OF THE ENERGY CONCENTRATED TO THE EAST ALONG THE LINE. DULONG
Special weather statement, May 17, 5:57 PM MDT, 11 minutes before
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE DENVER CO 550 PM MDT SUN MAY 17 1987 ...SHOWERS AND THUNDERSTORMS CONTINUE TO SPREAD THROUGH NORTHEAST COLORADO... THE LINE OF VERY HEAVY THUNDERSTORMS IS BREAKING UP BUT SHOWERS AND THUNDERSTORMS CONTINUE TO BE WIDESPREAD ACROSS MUCH OF NORTHEAST COLORADO. THIS ACTIVITY CONTINUES TO SPREAD SLOWLY EASTWARD AS WELL. ONE VERY HEAVY THUNDERSTORM IS NEAR AKRON IN NORTHERN WASHINGTON COUNTY. THIS STORM IS MOVING EASTWARD 15 MILES AN HOUR AND MAY PRODUCE GUSTY WINDS..HAIL..FREQUENT LIGHTNING..OR HEAVY DOWNPOURS OVER NORTHEASTERN WASHINGTON DURING THE NEXT HOUR. THE SHOWERS AND THUNDERSTORMS SHOULD DECREASE IN COVERAGE AND INTENSITY DURING THE NEXT FEW HOURS AS DARKNESS SETS IN. DULONG
Special weather statement, May 17, 6:01 PM MDT, 7 minutes before
SPECIAL WEATHER STATEMENT CORRECTED NATIONAL WEATHER SERVICE DENVER CO 555 PM MDT SUN MAY 17 1987 ...SHOWERS AND THUNDERSTORMS CONTINUE TO SPREAD THROUGH NORTHEAST COLORADO... THE LINE OF VERY HEAVY THUNDERSTORMS IS BREAKING UP BUT SHOWERS AND THUNDERSTORMS CONTINUE TO BE WIDESPREAD ACROSS MUCH OF NORTHEAST COLORADO. THIS ACTIVITY CONTINUES TO SPREAD SLOWLY EASTWARD TOWARDS THE BORDER AREAS AS WELL. ONE VERY HEAVY THUNDERSTORM IS NEAR AKRON IN NORTHERN WASHINGTON COUNTY. THIS STORM IS MOVING EASTWARD 15 MILES AN HOUR AND MAY PRODUCE GUSTY WINDS..HAIL..FREQUENT LIGHTNING..OR HEAVY DOWNPOURS OVER NORTHEASTERN WASHINGTON COUNTY DURING THE NEXT HOUR. THE SHOWERS AND THUNDERSTORMS SHOULD DECREASE IN COVERAGE AND INTENSITY DURING THE NEXT FEW HOURS AS DARKNESS SETS IN. DULONG
Nearby
Severe Thunderstorm Warnings in Colorado, 1987Every severe thunderstorm warning in 1987
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.