Area Forecast Discussion
Issued by NWS Salt Lake City, UT

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000
FXUS65 KSLC 301030
AFDSLC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
430 AM MDT SAT AUG 30 2014

.SYNOPSIS...A COLD FRONT WILL PUSH THROUGH NORTHERN UTAH THIS
AFTERNOON...THEN CONTINUE ACROSS SOUTHERN UTAH DURING THE DAY
SUNDAY. THE PARENT STORM SYSTEM WILL BRUSH NORTHERN UTAH LATE
TONIGHT INTO SUNDAY MORNING. A MORE STABLE AIRMASS WILL RETURN
FOR THE EARLY TO MIDDLE PART OF NEXT WEEK.


&&

.SHORT TERM (THROUGH 00Z WEDNESDAY)...AN UPPER TROUGH CURRENTLY
CROSSING THE PACIFIC NORTHWEST WILL PUSH A SURFACE COLD FRONT
THROUGH NORTHERN UT THIS AFTERNOON...BEFORE THE MID LEVEL TROUGH
AXIS CROSSES NORTHERN UT LATE TONIGHT THROUGH SUNDAY
MORNING...PUSHING THE FRONTAL BOUNDARY SOUTHWARD THROUGH CENTRAL
AND SOUTHERN UT. AHEAD OF THIS FRONT MID AND HIGH LEVEL MOISTURE
CONTINUE TO STREAM ACROSS PORTIONS OF NORTHERN AND CENTRAL
UT...AND THIS WILL REMAIN THE CASE THROUGH THE MORNING HOURS.
MEANWHILE AHEAD OF THE APPROACHING FRONT SOUTHERLY SURFACE WINDS
ARE EXPECTED TO INCREASE AND BECOME GUSTY THROUGH THE MORNING
HOURS.

AS THE FRONT SLOWLY PUSHES ACROSS NORTHERN UT THIS
AFTERNOON...INSTABILITY BASED ON THE SREF IS EXPECTED TO REMAIN
MINIMAL...AND LARGELY CONFINED TO AREAS NORTH OF I-80. THIS IS
ALSO WHERE MOST MODELS CONFINE ANY QPF THIS AFTERNOON...AND THUS
HAVE LARGELY RESTRICTED POPS TO THESE AREAS...WITH AN ADDITIONAL
CHANCE ACROSS THE SOUTHERN WASATCH/WESTERN UINTAS.

THE BEST CHANCE FOR PRECIPITATION WILL COME OVERNIGHT INTO EARLY
SUNDAY MORNING AS THE MAIN MID LEVEL TROUGH AXIS CROSSES NORTHERN
UT. AGAIN THE GREATEST THREAT FOR PRECIPITATION...WITH AMOUNTS
LARGELY REMAINING BELOW 0.10...WILL COME ACROSS AREAS NORTH OF
I-80...AND SHOULD WIND DOWN BY LATE SUNDAY MORNING. WITH THE
PASSAGE OF THE COLD FRONT TEMPERATURES ARE EXPECTED TO ONLY REACH
THE LOW TO MID 70S SUNDAY ACROSS THE NORTHERN VALLEYS...WITH
ROUGHLY 5 DEGREES OF COOLING EXPECTED ACROSS CENTRAL/SOUTHERN UT
FROM SATURDAYS FORECAST HIGHS.

IN THE WAKE OF THIS TROUGH A GRADUAL INCREASE IN MID LEVEL HEIGHTS
WILL RESULT IN A WARMING TREND DURING THE EARLY PORTION OF NEXT
WEEK...AND WITH NO APPRECIABLE MOISTURE TO SPEAK OF HAVE
MAINTAINED A DRY FORECAST FOR LATE SUNDAY THROUGH TUESDAY.

&&

.LONG TERM (AFTER 00Z WEDNESDAY)...THE RIDGE AXIS WILL SLIDE BY TO
OUR EAST WEDNESDAY ALLOWING FOR A WARM SOUTHWEST FLOW TO PREVAIL
ACROSS THE ENTIRE DISTRICT WEDNESDAY AFTERNOON THROUGH FRIDAY. THIS
SHOULD BE A MAINLY DRY AND WARM FLOW BUT SUBTLE DISTURBANCES RIDING
NORTHEAST IN THIS FLOW COULD SET OFF SOME ISOLATED SHOWERS OVER THE
HIGHER TERRAIN SOUTH OF I-80 THURSDAY AND FRIDAY. THE EC TRIES TO
BRING A LITTLE DEEPER MOISTURE UP ACROSS THE SOUTHERN AND EASTERN
HALF OF THE REGION THURSDAY BUT HAVE OPTED TO LEAN TOWARD THE GFS
AND ITS ENSEMBLE MEMBERS WHICH KEEPS THE FLOW A LITTLE MORE
SOUTHWESTERLY RATHER THAN THE SOUTH SOUTHWEST FLOW THE EC FORECASTS
WHICH TAPS THE DEEPER MOISTURE. BOTTOM LINE HAVE GONE WITH ISOLATED
MOUNTAIN SHOWERS VERSES SCATTERED SHOWERS AT THIS TIME.

&&

.AVIATION...SOUTH WINDS WILL INCREASE AT THE SLC TERMINAL THIS
MORNING WITH GUSTS OVER 30 MPH POSSIBLE BY MID MORNING. THE WINDS
SHOULD SHIFT TO WEST NORTHWEST AT 15 TO 20 MPH AFTER ABOUT 20-21Z
THIS AFTERNOON AS A COLD FRONT MOVES THROUGH. THERE IS LESS THAN A
15 PERCENT CHANCE OF RAIN OCCURRING AT THE TERMINAL BUT GUSTY
ERRATIC WINDS ARE POSSIBLE WITH THE FRONT. VFR CONDITIONS WILL
PREVAIL THROUGH THE TAF PERIOD.

&&

.FIRE WEATHER...A COLD FRONT WILL MOVE ACROSS THE NORTHERN PORTIONS
OF THE STATE THIS AFTERNOON. SOUTH WINDS WILL INCREASE AHEAD OF THIS
FRONT OVER WESTERN VALLEYS WITH CRITICAL FIRE WEATHER CONDITIONS
OVER SOME AREAS DUE TO RELATIVE HUMIDITY LEVELS BELOW 15 PERCENT.
HOWEVER...FUELS REMAIN MOIST DUE TO RECENT RAINS SO POTENTIAL FOR
LARGE FIRES WILL ALSO REMAIN LOW. ISOLATED SHOWERS AND THUNDERSTORMS
WILL ACCOMPANY THE COLD FRONT THIS AFTERNOON. THE CORE OF THE STORM
SYSTEM WILL MOVE ACROSS NORTHERN UTAH BETWEEN MIDNIGHT AND NOON
SUNDAY RESULTING IN SCATTERED SHOWERS AND THUNDERSTORMS. THE SOUTH
WILL REMAIN DRY. A RIDGE WILL BUILD BACK FOR NEXT WEEK WITH WARM AND
DRY CONDITIONS PREVAILING ALONG WITH LOW RELATIVE HUMIDITIES THROUGH
AT LEAST THURSDAY.

&&

.SLC WATCHES/WARNINGS/ADVISORIES...
UT...NONE.
WY...NONE.
&&

$$

SEAMAN/STRUTHWOLF

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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