Area Forecast Discussion
Issued by NWS Salt Lake City, UT

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FXUS65 KSLC 230341
AFDSLC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
941 PM MDT TUE JUL 22 2014

.SYNOPSIS...MOISTURE WILL INCREASE FROM THE SOUTH TONIGHT AND
WEDNESDAY THEN LINGER OVER SOUTHERN UTAH THROUGH THE WEEKEND. THE
NORTH WILL DRY BACK OUT OVER THE WEEKEND.

&&

.DISCUSSION...A DRY SOUTHERLY FLOW REMAINS OVER THE AREA THIS
EVENING. CLOUDS AT THE LEADING EDGE OF THE MOISTURE SURGE COMING
UP FROM THE SOUTH HAVE REACHED SERN UT AND RADAR IS SHOWING A FEW
LIGHT ECHOES. HOWEVER THE DEWPOINTS ARE STILL IN THE 30S ACROSS
THIS AREA SO SUSPECT LITTLE IF ANY RAIN IS REACHING THE GROUND AT
THIS TIME. THIS COULD CHANGE LATER TONIGHT AS THE MOISTURE DEEPENS
WITH AN INCREASING CHANCE OF RAIN LATER TONIGHT THRU WED. THIS
MOISTURE WILL SPREAD NORTH OVER THE NEXT 24 HOURS TO ALL BUT THE
FAR NWRN CWA BRINGING A CHANCE OF SHOWERS AND THUNDERSTORMS. THESE
COULD BE DRY WITH GUSTY WINDS AT FIRST BUT THE LOWER LEVELS SHOULD
MOISTEN UP THRU THE DAY.

THE HIGH TO OUR SOUTHEAST IS STILL FORECAST TO FLATTEN THU INTO
FRI AS A TROF PASSES TO OUR NORTH. THIS SENDS A DRIER WEST-SWLY
FLOW INTO THE NRN CWA BUT MOISTURE WILL NOT CLEAR FROM THE
SOUTHEAST. THIS PATTERN OF DRY NORTH AND MOIST SOUTH STAYS MORE OR
LESS IN PLACE THRU THE WEEKEND AS THE HIGH CENTER MIGRATES WWD
ACROSS AZ AND EVENTUALLY OVER NRN UT BY SUN. THIS WILL KEEP THE
THREAT OF CONVECTION GOING OVER THE SOUTH AND IT WILL BE HOT AND
DRY OVER THE NORTH.

UPDATED EARLIER TO RAISE POPS FOR SERN UT AFTER MIDNIGHT TONIGHT.
NO OTHER CHANGES PLANNED.

&&

.AVIATION...VFR CONDITIONS UNDER CLEAR SKIES WILL PREVAIL AT THE
KSLC TERMINAL THROUGH THE NIGHT. NORTH WINDS WILL SHIFT TO
SOUTHERLY AROUND 04Z.

&&

.FIRE WEATHER...THERE ARE TWO MAIN FIRE WEATHER CONCERNS OVER
THE NEXT FEW DAYS. THE FIRST IS GUSTY WINDS AND LOW RELATIVE
HUMIDITY...AND THE SECOND IS THE POTENTIAL FOR DRY THUNDERSTORMS
ACROSS PORTIONS OF SOUTHERN AND WESTERN UTAH TOMORROW AFTERNOON.

AS FAR AS WINDS...GUSTY SOUTHWESTERLY WINDS WILL DEVELOP AGAIN
TOMORROW AFTERNOON ACROSS NORTHWESTERN UTAH. THESE
WINDS...COMBINED WITH LOW HUMIDITY...WILL COMBINE TO CREATE
HAZARDOUS FIRE WEATHER CONDITIONS...AND SO THE RED FLAG WARNING
FOR WINDS AND LOW RH HAS BEEN EXTENDED THROUGH TOMORROW EVENING
FOR ZONE 478...THE NORTHWEST CORNER OF UTAH.

AS FAR AS LIGHTNING GOES...MOISTURE WILL SPREAD INTO SOUTHERN
UTAH OVERNIGHT TONIGHT...AND CONTINUE NORTHWARD INTO CENTRAL UTAH
THROUGH LATE TOMORROW MORNING. THIS MOISTURE WILL RESULT IN
SHOWERS AND THUNDERSTORMS ACROSS THE HIGHER TERRAIN TOMORROW
AFTERNOON. ACROSS SOUTHEASTERN UTAH WHERE THE MOISTURE IS
DEEPEST...MOST STORMS WILL BE ACCOMPANIED BY WETTING RAIN.
HOWEVER...ACROSS PORTIONS OF SOUTHERN AND CENTRAL UTAH NORTHWARD
THROUGH WESTERN UTAH TO ABOUT I-80...MOISTURE WILL BE LARGELY
CONFINED TO THE MID AND UPPER LEVELS...INCREASING THE THREAT FOR
DRY LIGHTNING. DRY LIGHTNING IS CHALLENGING TO FORECAST...AND SO
THERE IS THE POSSIBILITY THAT MOST OF THE STORMS ACROSS SOUTHWEST
AND CENTRAL UTAH WILL ALSO BE ACCOMPANIED BY WETTING RAIN.
HOWEVER...FEEL THAT THE THREAT FOR DRY LIGHTNING IS HIGH ENOUGH TO
WARRANT A RED FLAG WARNING AND IT WILL REMAIN IN EFFECT FOR
PORTIONS OF SOUTHWEST AND CENTRAL UTAH AND HAVE EXPANDED THIS INTO
THE NORTHWEST AS WELL TO COVER SOUTHERN PORTIONS OF ZONE 478.

A SHALLOW FRONT WILL MOVE INTO NORTHWEST UTAH THURSDAY
MORNING...ADVANCING INTO CENTRAL UTAH BY LATE AFTERNOON. THIS IS A
WEAK FRONT...AND THE MAIN IMPACT WILL BE A SHIFT OF SURFACE WINDS
TO THE NORTH WITH THE FRONT. WINDS WILL REMAIN ELEVATED ACROSS
SOUTHERN AND EASTERN UTAH THURSDAY AND FRIDAY...BUT AT THIS TIME
IT APPEARS THAT SPEEDS WILL REMAIN JUST BELOW CRITICAL LEVELS.

&&

.SLC WATCHES/WARNINGS/ADVISORIES...
UT...RED FLAG WARNING FROM NOON TO 10 PM MDT WEDNESDAY FOR UTZ488-489-
     492-493-495-496.

     RED FLAG WARNING UNTIL 10 PM MDT WEDNESDAY FOR UTZ478.

     RED FLAG WARNING UNTIL 10 PM MDT THIS EVENING FOR UTZ492-495.

WY...NONE.
&&

$$

WILENSKY

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)


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