Severe Thunderstorm Warning 18, NWS Salt Lake City, UT

UTAH AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
335 PM MDT THU AUG 14 2003

.SYNOPSIS...A MOIST AND UNSTABLE AIRMASS WILL BE OVER THE AREA
TONIGHT THROUGH THE WEEKEND.

.DISCUSSION...CONVECTION SO FAR TODAY HAS BEEN LIMITED TO THE HIGHER
TERRAIN AND MAINLY OVER THE NORTH. THE NORTHEAST FLOW ALOFT THAT
HAS SPREAD INTO THE SOUTHEAST HAS SUPPRESSED ACTIVITY BUT I STILL
EXPECT ISOLATED CELLS TO DEVELOP THIS EVENING AND LINGER WELL INTO
THE NIGHT. CONVECTION SHOULD ALSO PERSIST INTO TONIGHT OVER THE
MTNS AND WESTERN VALLEYS.

ALTHOUGH WE DEVELOP LOCAL HIGH PRESSURE AT THE SURFACE ALONG THE
WASATCH FRONT THIS EVE DUE TO THE PRECIP...THIS SHOULD WEAKEN ENOUGH
BY MORNING TO ALLOW SEVERAL MILLIBARS OF SYNOPTIC SCALE GRADIENT TO
DEVELOP BETWEEN CENTRAL WYO AND NRN UT AND COMBINE WITH 20-30 KT 700
MB EAST WINDS TO GENERATE A LOCAL CANYON WIND EVENT ALONG THE
NORTHERN AND CENTRAL WASATCH FRONT. DONT EXPECT AN ADVISORY LEVEL
EVENT BUT IT WILL BE LOCALLY WINDY. ALL SUPPORT ENDS BY FRIDAY
AFTERNOON AND WINDS SHOULD TOO.

EXPECT THE EAST TO BE MORE ACTIVE TOMORROW ONCE THE FLOW VEERS
AROUND TO SOUTHERLY AFTER THE INVERTED TROF PASSES WITH THIS
ACTIVITY SPREADING INTO THE REMAINDER OF THE AREA BY LATE IN THE
DAY. THE MOIST AIRMASS WILL BE IN PLACE AND WITH THE WEAK TROF OVER
WESTERN UT...IT SHOULD STAY QUITE ACTIVE ON SAT. THIS BECOMES A
CYCLONIC SHEAR AXIS SUN THEN LATEST GFS REFORMS A LOW ALONG THE
SOUTHERN UT BORDER MON AND THIS GRADUALLY DRIFTS NORTHWARD THROUGH
THE STATE. MOISTURE WILL STILL BE AVAILABLE THROUGH THIS PERIOD SO
WILL KEEP CHANCE POPS GOING THROUGH TUE. SUPPOSEDLY WE WILL START TO
DRY AGAIN WED THROUGH THE END OF THE WEEK SO HAVE TRENDED DOWN
POPS BUT DONT HAVE A LOT OF CONFIDENCE IN THIS SOLUTION.

SLC 5445  CDC 5555  WILENSKY

.SLC...NONE.

IDZ024-025-UTZ001>021-WYZ021-151300-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
700 AM MDT THU AUG 14 2003

THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE WESTERN TWO-THIRDS OF
UTAH...EXTREME SOUTHEAST IDAHO AND EXTREME SOUTHWEST WYOMING

.DAY ONE... TODAY

DEEP MOISTURE AND LIGHT WINDS WILL ALLOW SLOW MOVING THUNDERSTORMS
TO PRODUCE LOCAL HEAVY RAIN OVER MUCH OF SOUTHERN AND CENTRAL UTAH
TODAY.  THE GREATEST RISK APPEARS TO BE EAST OF HIGHWAY 89 AND SOUTH
OF PRICE.

.DAYS TWO THROUGH SEVEN... FRIDAY THROUGH WEDNESDAY

A VERY MOIST AND UNSTABLE AIRMASS WILL REMAIN OVER THE AREA AT LEAST
THROUGH THE WEEKEND. THUNDERSTORMS DEVELOPING IN THIS AIRMASS WILL
BE ABLE TO PRODUCE HEAVY RAIN AND MAY BE MOVING SLOWLY ENOUGH AT
TIMES TO PRODUCE FLASH FLOODING...ESPECIALLY IN DRAINAGES THAT ARE
PREDOMINANTLY ROCKY AND IN AREAS WHERE FIRES HAVE REMOVED MOST OF
THE VEGETATION.

.SPOTTER INFORMATION STATEMENT...

WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER
CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURE.

WCJIN-WYSW