High Wind and Strong Wind in Utah, May 10, 2004

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
932 AM MDT MON MAY 10 2004

.SYNOPSIS...A WARM AND DRY SOUTHWEST FLOW ALOFT WILL INCREASE ACROSS
THE AREA TODAY. A STRONG COLD FRONT WILL CROSS MOST OF THE AREA
TONIGHT. COOL...UNSETTLED WEATHER WILL REMAIN OVER THE INTERMOUNTAIN
REGION THROUGH MOST OF THE WEEK.

&&

.DISCUSSION...SURFACE ANALYSIS DEPICTS A 997 MB LOW BETWEEN DESERT
ROCK AND ELY NEVADA. THIS A REFLECTION OF A SHORT WAVE TROF NOW
MOVING THROUGH THE NORTHERN SIERRA NEVADA. THIS SYSTEM WILL MOVE
INTO NORTHERN UTAH LATER TODAY AND INTO WESTERN WYOMING THIS
EVENING...DEEPENING TO 990 MB OR LOWER WITH TIME. THIS INITIAL COLD
FRONT WILL INCREASE WINDS SIGNIFICANTLY AND TIMED WITH PEAK HEATING
OF AFTERNOON AND CLOUDY COOLER AIR OVER NEVADA IT WILL BECOME VERY
WINDY OVER MOST OF WESTERN 2/3 OF THE FORECAST AREA. MODEL PROGGED
700 MB WINDS REACH AS HIGH AS 45K KNOTS FOR GOOD UPPER AIR SUPPORT
AND WINDY CONDITIONS OVER THE MOUNTAINS. THE INITIAL FRONT LOOKS
PRECIP FREE THOUGH HIGH BASED CONVECTION IS SUPPORTED IN MODEL
SOUNDINGS THAT WILL LIKELY JUST BE HIGH BASED SHOWERS AND
VIRGA...UNDER A LARGE AREA OF UPPER DIVERGENCE. THIS ACTIVITY COULD
FURTHER INCREASE WINDS OVER THE WESTERN DESERTS AND VALLEYS. MIXING
IS EXCELLENT TODAY SO WE SHOULD MIX THE 9C-11C 700 MB TEMPS FULLY
THOUGH COLD ADVECTION REACH NW UTAH BY LATE TODAY. INCREASING WIND
COMBINED WITH VERY LOW HUMIDITY IS ADDRESSED IN FIRE WEATHER
PRODUCTS FOR SOUTHERN UTAH TODAY. WIND ADDRESSED IN NPW HIGHLIGHTS.

COOLER AIR ADVECTS INTO THE REGION TONIGHT AS THE MEAN UPPER TROF
SETS UP OVER NEVADA AND SENDS SHORT WAVES IN CYCLONIC FLOW OVER
UTAH. THIS COOLING AND MOISTURE ADVECTION SLOWLY BRINGS THE AIR MASS
CLOSER TO SATURATION...AND SHOULD LEAD TO DEVELOPING SHOWERS
TONIGHT...COLD ENOUGH FOR LOWER MOUNTAIN SNOW AS 700 MB TEMPS DROP
TO NEAR -6C BY EARLY TUESDAY. MEAN FLOW TONIGHT VEERS TO THE WEST
AND WEAKENS SIGNIFICANTLY. THEN THIS FLOW VEERS MORE AND
BECOMES NORTHWEST ON TUESDAY...MORE NW ON THE ETA. FRONTAL BOUNDARY
SITS OVER SOUTH CENTRAL UTAH ON TUESDAY AND THE SURFACE MSL GRADIENT
TIGHTENS AGAIN...BRINGING WINDY CONDITIONS TO FAVORED W-NW FLOW LOW
LAND AREAS. SECONDARY SHORT WAVE ENERGY DIVING SOUTH ALONG THE PACNW
COAST AND INTO THE MEAN UPPER TROF ALONG WITH STEEP LAPSE RATES PER
SOUNDINGS WILL INCREASE SHOWER THREAT...ISOLATED THUNDERSTORMS AS
WELL AS THE MEAN UPPER TROF APPROACHES WESTERN UTAH IN THE LATE
AFTERNOON. GIVEN 700 MB TEMPS HOLDING NEAR -5 OR -6C THE HIGHS MAY
STRUGGLE TO REACH THE MID 50S AT SLC.

MEAN UPPER TROF SHIFTS INTO UTAH TUESDAY NIGHT AND SHOULD BE
ACCOMPANIED BY CONTINUED SHOWERS...SPREADING INTO THE EASTERN AND
PARTS OF SOUTHERN VALLEYS. 12Z ETA FOCUSES THE BEST LIFT ALONG THE
OLD FRONTAL BOUNDARY WHERE THE UPPER TROF MOVES ACROSS...AFFECTING
SOUTHEAST UTAH. 06Z GFS HAS THIS AREA SHIFTED INTO CENTRAL UTAH AND
INTO THE UINTA MOUNTAINS WHERE A ELONGATED 700 MB CONVERGENCE ZONES
IS SITUATED. TO THE NORTH INSTABILITY LINGERS IN LIGHT NORTHWEST
FLOW FOR CONTINUING SCATTERED SHOWERS. CONVECTIVE NATURE OF THE
PRECIP WILL MAKE FORECAST OF AMOUNTS DIFFICULT BUT LOCALLY HEAVY
RAINFALL SHOULD RESULT IN THE PATTERN...LOCALLY HEAVY SNOW IN THE
MOUNTAINS. WET SNOWFALL DOWN INTO THE BENCHES. WILL TRY TO IRON OUT
THE DETAILS OF TUESDAY NIGHT AND WEDNESDAY WHEN ALL 12Z RUNS ARE IN.

CURRENT FORECAST COVERS THE SHORT TERM WIND ISSUES. WILL NEED TO
UPDATE STATEMENTS NEAR NOON.

NW FLOW LINGERS ON THURSDAY FOR POSSIBLE SHOWERS IN THE NORTHERN
AREAS AND SLOW WARMING BY FRIDAY AS TROFFINESS REMAINS OVER THE
NORTHERN GREAT BASIN.

&&

.SLC WATCHES/WARNINGS/ADVISORIES...

UT...HIGH WIND WARNINGS/WIND ADVISORIES MOST MOUNTAINS AND WESTERN
     VALLEYS THIS AFTERNOON AND EVENING...SEE SLCNPWSLC.
  ...RED FLAG WARNING FOR WESTERN AND SOUTHWEST UTAH BELOW 5000
FEET.
ID...WIND ADVISORIES 18Z-03Z.
WY...HIGH WIND WATCH THIS EVENING.

&&

TARDY