Severe Thunderstorm Warning 69, NWS Salt Lake City, UT

UTAH AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
955 AM MDT TUE AUG 21 2001

SYNOPSIS...A MOIST AND UNSTABLE AIR MASS OVER UTAH WILL BE OVER UTAH
TODAY.  THIS WILL COMBINE WITH AN UPPER LEVEL TROUGH MOVING EAST
ACROSS THE GREAT BASIN WILL PRODUCE WIDESPREAD SHOWERS AND
THUNDERSTORMS THIS AFTERNOON AND EVENING.  SOME OF THE THUNDERSTORMS
COULD BE STRONG.  DRIER AND MORE STABLE AIR WILL SPREAD ACROSS THE
STATE WEDNESDAY.

DISCUSSION...TODAY SHAPING UP TO BE VERY ACTIVE.  MODELS WILL BE
UNDERDONE ON BOUNDARY LEVEL MOISTURE...ESPECIALLY OVER THE NORTHWEST
WHERE WIDESPREAD RAIN FELL LAST EVENING.  THE TROF OVER NV SLOWLY
MOVING EAST ACROSS THE AREA THIS AFTERNOON/EVENING WILL PROVIDE
PLENTY OF DYNAMIC HELP.  ALTHOUGH THE JET AHEAD OF THE TROF IS
RELATIVELY WEAK THE ETA IS STILL PRODUCING LARGE AREAS OF FAIRLY
STRONG DIVERGENCE AT JET LEVEL.  THAT IS WHAT DROVE LAST EVENINGS
STORMS OVER NORTHWEST UT AND NO REASON NOT TO EXPECT SOME SORT OF
REPEAT TODAY.  CLOUDINESS IN THE WEST MAY INHIBIT THINGS A BIT BUT
PROBABLY NOT ENOUGH TO PREVENT GOOD CONVECTION.  STORM PREDICTION
CENTER HAS A SLIGHT CHANCE OF SEVERE STORMS OVER MUCH OF THE
FORECAST AREA AND NO ARGUMENT WITH THAT.  HOWEVER I MIGHT LEAN A
LITTLE MORE TOWARD SOME LARGE HAIL AS WELL AS THE THREAT OF STRONG
WINDS.  HISTORICALLY THIS TYPE OF PATTERN AT THIS TIME OF YEAR
PRODUCES STRONG STORMS INCLUDING LARGE HAIL.

WILL BE DOING A COMPLETE UPDATE OF THE ZONES TO GO TO LIKELY OR
HIGHER PROBABILITIES THROUGHOUT THE AREA TODAY AND INCLUDE THE RISK
OF HAIL AS WELL AS STRONG WINDS IN MOST ZONES.

SLC 651 CDC 641 SANDERS

.SLC...NONE.

IDZ024-025-UTZ001>021-WYZ021-211900-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
934 AM MDT TUE AUG 21 2001

...STRONG THUNDERSTORMS POSSIBLE TODAY...

STRONG THUNDERSTORMS ARE POSSIBLE OVER UTAH...EXTREME SOUTHEAST
IDAHO AND EXTREME SOUTHWEST WYOMING TODAY. SOME THUNDERSTORMS MAY
HAVE LARGE HAIL AND STRONG GUSTY WINDS ALONG WITH LOCAL HEAVY RAIN
AND FREQUENT LIGHTNING.

A COMBINATION OF AN UPPER LEVEL TROUGH AND ABUNDANT LOW LEVEL
MOISTURE WILL MAKE TODAY ONE OF THE STORMIER DAYS OF THE SUMMER.
PERSONS PLANNING OUTDOOR ACTIVITY SHOULD HAVE A PLAN TO SEEK
SHELTER IF SEVERE WEATHER APPROACHES AND STAY TUNED TO NOAA WEATHER
RADIO OR LOCAL MEDIA FOR FURTHER INFORMATION.