High Wind in Utah, May 7, 2002

UTAH AREA FORECAST DISCUSSION...CORRECTION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
300 PM MDT TUE MAY 7 2002

.SYNOPSIS...A COLD FRONT WILL MOVE SOUTH ACROSS THE STATE TONIGHT
WITH THE BULK OF THE MOISTURE WITH THE FRONT REMAINING OVER THE
NORTH. COLD...MOSTLY DRY HIGH PRESSURE WILL BE OVER THE AREA
WEDNESDAY.

.DISCUSSION...DEEP AND UNSEASONABLY COLD UPPER LOW SWEEPING THROUGH
IDAHO THIS AFTERNOON.  ASSOCIATED COLD FRONT STILL HOLDING BACK OVER
EXTREME NORTHWEST UTAH AT DISCUSSION TIME WITH VERY TIGHT NW TO SE
PRESSURE GRADIENT AND MUCH COLDER AIR POISED TO PUSH THROUGH THE
FORECAST AREA TONIGHT.  MAIN UPPER COLD CORE SLIDES BY TO OUR NORTH
ACROSS MONTANA AND WYOMING...MEANWHILE COLDER AIR AT LOW LEVELS
MOVES THROUGH THE AREA TONIGHT AND WEDNESDAY.  BIGGEST FORECAST
PROBLEM IS WINDS AND TO SOME EXTENT TEMPERATURES.  NO DOUBT SFC
TEMPERATURES WILL BE MUCH BELOW NORMAL TONIGHT ACROSS THE NORTH AND
OVER MOST OF THE AREA WEDNESDAY.  ETA QUITE A BIT COLDER THAN THE
AVN BEHIND THE FRONT FOR WEDNESDAY ALTHOUGH BOTH ARE SIGNIFICANTLY
BELOW NORMAL....EVEN WITH MAY SUN.  MODELS FORECAST TIGHT PRESSURE
GRADIENT ALONG AND EITHER SIDE OF THE FRONT AS IT MOVES THROUGH SO
ADVISORY LEVEL WINDS A STRONG POSSIBILITY BEHIND THE FRONT
ESPECIALLY NW AND WEST CENT UTAH AND USUAL SPOTS THROUGH SOUTHERN
WASATCH FRONT.  SYSTEM WONT BE A BIG PRECIP PRODUCER GIVEN BETTER
DYNAMICS WILL BE TO THE NORTH.  BEST CHANCE OF PRECIP APPEARS TO BE
AS THE FRONT MOVES THROUGH AFTER 00Z...THOUGH STILL A QUESTION OF
WHETHER ITLL MAKE IT THROUGH SOON ENOUGH TO TAKE ADVANTAGE OF SOME
WEAK INSTABILITY.  AVN DEVELOPS SFC LOW IN WESTERN ARIZONA BY 12Z
WEDNESDAY...JUST AS THE FRONT MOVES INTO SOUTHERN UTAH.  AS A RESULT
AVN GENERATES RELATIVELY HIGH POPS FOR SOUTHWEST UTAH TOMORROW AM.
ETA ALSO DEVELOPS A SFC LOW...THOUGH NOT AS DEEP AS THE AVN AND
KEEPING IT MUCH DRIER.  WILL SIDE WITH THE ETA IN THIS CASE AND KEEP
AREA DRY WEDNESDAY.  COLDER...BUT DRY.

BEYOND WEDNESDAY...RIDGING AND WARM ADVECTION QUICKLY BUILD IN FOR
THURSDAY TO BRING MAX TEMPS BACK TO NEAR NORMAL.  YET ANOTHER SYSTEM
DIVES OUT OF BC AND IS CENTERED OVER SEA THURSDAY EVE.  OUR UPPER
FLOW MOISTENS UP WITH MINOR RIPPLES JUST TO OR WEST AS EARLY AS
THURSDAY NIGHT.  FRIDAY SHOULD WARM UP IN THE SOUTH AND COOL DOWN
SLIGHTLY IN THE NORTH.  BY 12Z SATURDAY TROF AXIS IN THE AVN SITS
ACROSS THE FORECAST AREA.  AVN HAS BEEN CONSISTENT IN TIMING WITH
SLIGHT DIFFERENCES IN INTENSITY OVER PREVIOUS RUNS.  ITS ALSO
SLIGHTLY FASTER THAN THE MRF...EC AND UK...WHICH CHOOSE TO HANG A
MORE AMPLIFIED SYSTEM JUST TO OUR WEST.  LATTER SOLUTION AGREES MORE
WITH MRF ENSEMBLES...KEEPING SOME PRECIPITATION INTO SATURDAY.  WILL
ADD MENTION FOR SATURDAY...ESPECIALLY NORTHERN CENTRAL AREAS
THINKING WELL AT LEAST HAVE ACTIVITY EARLY SAT.  QUICK RECOVERY IN
STORE FOR SUNDAY AND MONDAY...THEN THE SERIES OF BC WAVES SWEEPING
THROUGH PAC NW CONTINUES FOR TUESDAY THOUGH RIGHT NOW MODELS SLIDE
IT BY OUR NORTH.  LOOKING AT THE MRF 5-WAVE OUT TO TEN DAYS...THE
HEMISPHERIC PATTERN CHANGES VERY LITTLE.  IF SO...WELL CONTINUE TO
SEE THESE DIVING SYSTEMS OUT OF BC FOR COOLING...FOLLOWED BY WARMING
ON A REGULAR CYCLE...AS IN SPRINGTIME.  MODEL RELIABILITY IN
EXTENDED LIKELY TO BE LOW AS WELL.

SLC 3100  CDC 2100  JACKSON

.SLC...RED FLAG WARNING FOR SOUTHERN UT TODAY THROUGH THIS EVENING.
       HIGH WIND ADVISORY SALT FLATS...SOUTHERN WASATCH FRONT AND
       WEST CENTRAL UTAH THIS EVENING TO MIDNIGHT...UTZ004-005-015.