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000
FXUS65 KSLC 131536
AFDSLC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
936 AM MDT THU JUN 13 2013

.SYNOPSIS...A WARM AND DRY SOUTHWEST FLOW WILL CONTINUE THROUGH THIS
AFTERNOON. A DRY BUT FAIRLY STRONG COLD FRONT WILL CROSS NORTHERN
AND CENTRAL UTAH THIS AFTERNOON AND EVENING. DRY AND MILD SOUTHWEST
FLOW WILL RETURN FOR THE WEEKEND AND EARLY NEXT WEEK.


&&

.DISCUSSION...A PACIFIC TROUGH IS MOVING INTO THE GREAT BASIN
TODAY...WITH MUCH OF UTAH AND SOUTHWEST WYOMING IN THE WARM
SECTOR AND SOUTHWESTERLY FLOW AHEAD OF THE TROUGH THIS MORNING.
ISOLATED SHOWERS AND THUNDERSTORMS DEVELOPED ACROSS THE NORTHERN
HALF OF THE FORECAST AREA EARLY THIS MORNING...AS A SHORTWAVE IN
THE SOUTHWESTERLY FLOW MOVED THROUGH THE REGION. MOST OF THESE
SHOWERS HAVE MOVED OUT OF THE CWA TO THE NORTH AND EAST AS OF
15Z. A BREAK IN CONVECTIVE ACTIVITY IS LIKELY THROUGH LATE MORNING
AND EARLY AFTERNOON...BUT ISOLATED THUNDERSTORMS WILL STILL BE
POSSIBLE THIS AFTERNOON WITH SOME LINGERING MOISTURE AND
INSTABILITY...PARTICULARLY ACROSS NORTHWEST UTAH.

THE COLD FRONT ASSOCIATED WITH THIS TROUGH HAS STALLED ACROSS FAR
NORTHWEST UTAH THIS MORNING...AND IS EXPECTED TO PUSH THROUGH MUCH
OF THE FORECAST AREA IN EARNEST THIS AFTERNOON AND EVENING. THIS
WILL BRING A SIGNIFICANTLY COOLER AIRMASS TO THE NORTHERN TWO-
THIRDS OF THE CWA BY FRIDAY MORNING...WITH HIGHS FRIDAY LIKELY TO
BE NEAR OR EVEN BELOW NORMAL IN MANY LOCATIONS.

ISSUED A QUICK UPDATE TO THE FORECAST THIS MORNING TO INCREASE
THE AREA WHERE THUNDERSTORMS ARE MENTIONED THIS
AFTERNOON...ACROSS PRIMARILY THE WEST DESERT AND FAR NORTHERN
UTAH. OTHERWISE...THE FORECAST LOOKS GOOD AND NO FURTHER UPDATES
ARE ANTICIPATED FOR THIS MORNING.

&&

.AVIATION...LIGHT WESTERLY SURFACE GRADIENT KEEPING STRONGER WINDS
AT BAY FOR A WHILE AT THE SLC TERMINAL THIS MORNING. EXPECTING GUSTY
SOUTH WINDS TO KICK IN BETWEEN 16-17Z. A COLD FRONT WILL SWITCH
WINDS TO NORTHWEST FLOW THIS AFTERNOON...THOUGH LOW CONFIDENCE ON
TIMING.CURRENT MODELS INFER THE SWITCH BETWEEN 19-21Z...WITH A 30
PERCENT CHANCE OF OCCURRING AS LATE AS 23Z.


&&

.FIRE WEATHER...THE COLD FRONT STRENGTHENING JUST TO THE WEST OF
NORTHWEST UTAH WILL ENTER THE STATE THIS AFTERNOON. THE RESULT OF
THE ADVANCING FRONT WILL BE TO MAINTAIN BREEZY...WARM AND VERY DRY
CONDITIONS ACROSS THE SOUTHERN AND CENTRAL FIRE DISTRICTS HEADING
INTO THE WEEKEND. FUELS ACROSS ALL OF THE SOUTHWEST FIRE ZONES HAVE
NOW REACHED CRITICAL LEVELS...SO RED FLAG WARNINGS HAVE BEEN ISSUED
TO COVER THE WINDS/LOW RH CONDITIONS EXPECTED THROUGH LATE THIS
EVENING.

CONVECTION DID FIRE UP AHEAD OF THE FRONT OVER THE NORTHERN THIRD OF
THE STATE OVERNIGHT THROUGH EARLY THIS MORNING. THIS ACTIVITY WILL
DECREASE A BIT LATER THIS MORNING...THEN LIKELY DEVELOP AGAIN ALONG
THE FRONTAL BOUNDARY AND OVER THE NORTHERN MOUNTAINS LATER THIS
AFTERNOON THROUGH ABOUT MID-EVENING. WETTING RAINS ARE NOT EXPECTED
WITH GUSTY WINDS THE PRIMARY ISSUE WITH ANY CONVECTION.

SIGNIFICANTLY COOLER TEMPS WILL TRAIL THE COLD FRONT THROUGH CENTRAL
UTAH FRIDAY. THIS FRONTAL BOUNDARY MAY STALL JUST NORTH OF THE
ARIZONA BORDER...WITH WINDS AND LOW HUMIDITIES ONCE AGAIN AN ISSUE
FOR THE EXTREME SOUTHERN FIRE ZONES. EXTENSIONS OF CURRENT FIRE
WEATHER HIGHLIGHTS MAY BECOME NECESSARY WITH THE AFTERNOON FORECAST
PACKAGE.

&&

.SLC WATCHES/WARNINGS/ADVISORIES...
UT...RED FLAG WARNING UNTIL 10 PM MDT THIS EVENING FOR UTZ498.

     RED FLAG WARNING UNTIL 10 PM MDT THIS EVENING BELOW 9000 FEET
     FOR UTZ496.

     RED FLAG WARNING UNTIL 10 PM MDT THIS EVENING BELOW 6000 FEET
     FOR UTZ495.

     RED FLAG WARNING UNTIL 10 PM MDT THIS EVENING FOR UTZ497.

WY...NONE.
&&

$$

PUBLIC...SCHOENING
FIRE WEATHER...CONGER
AVIATION...VERZELLA

FOR MORE INFORMATION FROM NOAA/S NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/SALTLAKECITY (ALL LOWER CASE)

FOR FREQUENTLY ASKED QUESTIONS ABOUT THE AREA FORECAST DISCUSSION
VISIT...
HTTP://WEATHER.GOV/SALTLAKECITY/GENERAL/AFD_FAQS.PHP (ALL LOWER CASE)