Alert archive / Utah / Severe Thunderstorm Warnings in 1987
Severe Thunderstorm Warning 8, NWS Salt Lake City, UT
NWS Salt Lake City, UT issued this severe thunderstorm warning at Jul 21, 1987, 5:36 PM MDT for Emery County, Grand County, Utah. It was in force for 54 min.
The area
The counties it named.
The facts
- Issued
- Jul 21, 1987, 5:36 PM MDT (23:36 UTC)
- Expired
- Jul 21, 1987, 6:30 PM MDT
- In force
- 54 min
- Issued by
- NWS Salt Lake City, UT
- Area
- Whole counties
Counties Emery County, UT, Grand County, UT
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
Grand Junction, CO (KGJT), launched 12:00Z, 11.6 hours before the alert went out and 142 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
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 1898 m above ground
- 0-6 km bulk shear
- 38 kt
- 0-1 km storm-relative helicity
- 88 m²/s²
- 0-3 km storm-relative helicity
- 248 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 KSLC 212336
SVRSLC
UTC015-019-220030-
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
536 PM MDT TUE JUL 21 1987
THE NATIONAL WEATHER SERVICE HAS ISSUED A SEVERE THUNDERSTORM WARNING
EFFECTIVE UNTIL 630 PM MDT FOR PEOPLE IN THE FOLLOWING COUNTIES...
IN EAST CENTRAL UTAH
...EASTERN EMERY...WESTERN GRAND
A VERY HEAVY THUNDERSHOWER WAS INDICATED BY RADAR IN SOUTHEAST EMERY
COUNTY MOVING RAPIDLY TO THE NORTHEAST. THE STORM WAS ABOUT 15 MILES
SOUTHWEST OF GREEN RIVER AT 530 PM MDT.
THIS IS A DANGEROUS STORM. IF YOU ARE IN ITS PATH YOU SHOULD
PREPARE FOR DAMAGING WIND IN EXCESS OF 55 MPH...LARGE HAIL...AND
DEADLY LIGHTNING. PEOPLE OUTSIDE SHOULD MOVE TO A SHELTER...
PREFERABLY INSIDE A STRONG BUILDING BUT STAY AWAY FROM WINDOWS.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 21, 4:35 PM MDT, 1 hour 1 minute before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SALT LAKE CITY
430 PM MDT TUE JUL 21 1987
...STILL SCATTERED THUNDERSTORMS OVER THE STATE...
SCATTERED THUNDERSTORMS WILL CONTINUE OVER UTAH THIS EVENING. A FEW
OF THE CELLS STILL ARE PRODUCING LOCAL HEAVY RAIN..STRONG WINDS AND
HAIL. ANOTHER HIT THE PROVO/OREM AREA ABOUT 315 PM WITH 1/2 INCH
HAIL. SNOWBIRD HAS HAD WIND GUSTS TO 40 MPH WITH THUNDERSTORMS AND SMALL
HAIL. A SMALL ROCKSLIDE WAS REPORTED TO HAVE CLOSED THE ROAD UP
LITTLE COTTONWOOD CANYON. ONE INCH DIAMETER HAIL HIT KAMAS BETWEEN
2 AND 3 PM AND GUNNISON AND CENTERFIELD IN THE SEVIER VALLEY WERE HARD
HIT WITH GOLFBALL SIZED HAIL AT 330 PM WHILE MANTI AND EPHRIAM HAD
CHERRY SIZED HAIL A FEW MINUTES LATER. TREES AND POWER LINES WERE
REPORTED DOWN ALONG WITH MUD SLIDES AROUND HOYTSVILLE IN WEST SUMMIT
COUNTY FROM EARLIER THUNDERSTORMS. 1.50 INCHES OF RAIN FELL AT
CROYDON IN 2 HOURS AND 1 INCH AT KAMAS IN A FEW MINUTES. COALVILLE
ESTIMATED HAIL JUST SMALLER THAN A BASEBALL AROUND 130 PM.
BESIDES ALL THE THUNDERSTORM ACTIVITY...STRONG GUSTY SOUTH WINDS
ARE BLOWING IN THE SOUTHWEST DESERT AREAS. MILFORD REPORTS A
GUSTS TO 47 MPH AND MANY OTHER STATIONS GUSTS TO BETWEEN 30 AND 40 MPH.
THESE WINDS SHOULD DECREASE SLOWLY DURING THE EVENING.
THE THUNDERSTORMS ARE EXPECTED TO DECREASE BY ABOUT MIDNIGHT AS
SOMEWHAT DRIER AIR MOVES IN OVER THE STATE FROM THE SOUTHWEST. THE
FORECAST FOR WEDNESDAY IS FOR WIDE^LY SCATTERED THUNDERSTORMS MAINLY
NEAR THE NORTHERN MOUNTAINS... MUCH LESS ACTIVITY THEN TODAY.
FURTHER STATEMENTS WILL BE ISSUED AS NECESSARY.
DJ...2225ZThe office that day
Everything else NWS Salt Lake City, UT issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 21, 12:50 PM MDT | Severe Thunderstorm Warning | SLC | Davis, Salt Lake | 40 min |
| Jul 21, 12:50 PM MDT | Severe Thunderstorm Warning | SLC | Summit | 40 min |
| Jul 21, 1:38 PM MDT | Severe Thunderstorm Warning | SLC | Utah, Wasatch | 52 min |
Nearby
Severe Thunderstorm Warnings in Utah, 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; the sounding from the Mesonet's radiosonde archive.