Severe Thunderstorm Warning 67, NWS Salt Lake City, UT

UTAH AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UTAH
305 PM MDT THU SEP 16 1999

SYNOPSIS...AN UPPER LEVEL FRONT ACROSS SOUTHERN UTAH WILL MOVE INTO
COLORADO LATER TONIGHT.  A WEAK UPPER LEVEL FRONT WILL BRUSH BY
NORTHERN UTAH LATE FRIDAY.  THE AIRMASS OVER UTAH WILL REMAIN SEMI
MOIST IN THE SOUTH...AND MOSTLY DRY IN THE NORTH...BUT REMAIN
UNSTABLE DURING THE AFTERNOON AND EVENING HOURS.

DISCUSSION...SHORTWAVE MOVING ACROSS SOUTHERN UTAH THIS AFTERNOON
WILL BE EAST OF CWFA BY MIDNIGHT TAKING WITH IT THE ORGANIZED
CONVECTION.  SEVERAL STRONG CELLS THIS AFTERNOON RESULTED IN SVRS
AND FFWS.  UNSTABLE PROFILE HAS LIFTED MINIMALLY MOIST AIRMASS IN
THE NORTH WITH RESULT BEING ISOLATED CELLS.  WILL KEEP MENTION OF
EVENING CONVECTION IN MOST ZONES WITH HIGHEST POPS EASTERN ZONES.
NEXT UPSTREAM WAVE NOW NEAR VANCOUVER ISLAND IS PROGGED BY ETA AT
300 TO BE A GLANCING BLOW TO NORTHERN UT LATE FRIDAY...WHILE NGM
SPLITS AND DAMPENS IT OUT IN SRN ID...AND AVN A BIT SLOWER WITH
WEAKENING TREND.  AIRMASS IS DRY IN THE NORTH...SO EVEN WITH A
GLANCING BLOW DONT EXPECT MUCH AND WILL ONLY GO LOW POPS IN
NORTHERN ZONES.  PROFILE STILL UNSTABLE IN THE AFTERNOONS ACROSS
CWFA...THUS GARDEN VARIETY CONVECTION EXPECTED OVER SOUTH AND HIGHER
TERRAIN. DIFFICULT TO FIND SIGNIFICANT WEATHER MAKER FROM SATURDAY
INTO EARLY NEXT WEEK.  MODELS KEEP MAIN ENERGY INTO CANADA AND
EASTERN U.S. WITH WEAK FLOW OVER THE WEST UNDER A REX TYPE BLOCK.
MODELS ALSO SHOW CIRCULATION SOUTH OF BAJA WHICH WOULD BE BEST
SOURCE OF MOISTURE IF FAVORABLE FLOW WOULD DEVELOP.  WILL CONTINUE
TREND OF PREVIOUS EXTENDED.  MRF AND NOGAPS PROG A COLD FRONT INTO
CWFA BY WED.  LONGER RANGE HAS FLIP-FLOPPED BUT DIDNT CHECK THE
SPAGHETTI CHARTS SO CANT SAY IF LATEST FLIP WAS A POSSIBLE EARLIER
SOLUTION.

SLC 3---  CDC 3333 BURCH

.SLC...NONE.