Area Forecast Discussion
Issued by NWS Salt Lake City, UT

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000
FXUS65 KSLC 292118
AFDSLC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
318 PM MDT SAT AUG 29 2015

.SYNOPSIS...A PACIFIC NORTHWEST STORM SYSTEM WILL BRING A COLD
FRONT INTO NORTHERN AND CENTRAL UTAH SUNDAY AND SUNDAY NIGHT. A
DRIER WEST TO SOUTHWEST FLOW WILL THEN DEVELOP FOR THE EARLY PART
OF THE UPCOMING WEEK.

&&

.SHORT TERM(THROUGH 00Z WEDNESDAY)...UPPER LEVEL RIDGE OVER THE
GREAT BASIN THIS AFTERNOON AS AN UNSEASONABLY STRONG TROUGH MOVES
INTO THE PACIFIC NW. SOUTHWEST FLOW HAS INCREASED OVER UTAH TODAY
AHEAD OF THIS TROUGH RESULTING IN BREEZY CONDITIONS ACROSS THE
AREA. AN AXIS OF HIGHER PRECIPITABLE WATER VALUES HAS SPREAD NORTH
INTO WESTERN AND CENTRAL UTAH. RELATIVELY MODEST SBCAPE EXTENDS
NORTHWARD THROUGH WESTERN UTAH SUPPORTING ISOLATED CONVECTION.
ALTHOUGH THERE IS SOME STRONGER DEEP LAYER SHEAR ACROSS THE
NORTHWEST PORTION OF THE STATE DO NOT ANTICIPATE MUCH STORM
ORGANIZATION. WITH VIGOROUS FLOW ALOFT AND DEWPOINT DEPRESSIONS
OF GREATER THAN 40 DEGREES F ANTICIPATE THAT SOME SHOWERS AND
STORMS MAY PRODUCE STRONG WINDS.

AS THE TROUGH MOVES INLAND THE MOISTURE AXIS SHIFTS INTO EASTERN UTAH
ON SUNDAY WITH PRECIPITABLE WATER VALUES IN EXCESS OF .75". COLD
FRONT IS EXPECTED TO MOVE INTO NORTHWEST UT ON SUNDAY WITH SHOWERS
AND STORMS DEVELOPING ACROSS CENTRAL AND EASTERN UTAH FOR THE
AFTERNOON AND EVENING. AHEAD OF THE BOUNDARY EXPECT BREEZY
SOUTHWEST WINDS TO CONTINUE. TEMPERATURES ACROSS NW UT WILL BE
ABOUT 10 DEGREES F COOLER THAN TODAY WITH MAX TEMPS ACROSS THE
SOUTH DIPPING BY AROUND 5 DEGREES.

FRONT PUSHES INTO CENTRAL UT SUN NGT BEFORE STALLING OUT. THE
AIRMASS DRIES OUT BEHIND THE BOUNDARY...SO ONLY ANTICIPATE MINIMAL
TERRAIN DRIVEN CONVECTION IN THE MOST FAVORED LOCATIONS ON MONDAY.
SOUTH FLOW INCREASES AGAIN ON TUE AS ANOTHER TROUGH BEGINS TO MOVE
INTO THE PACIFIC NW. CORRESPONDING WITH THE INCREASED SOUTHERLY
FLOW IS A REBOUND IN TEMPERATURES FOR TUESDAY.

.LONG TERM (AFTER 00Z WEDNESDAY)...THE FORECAST AREA IS EXPECTED TO
REMAIN UNDER AN INCREASINGLY DRY SOUTHWEST FLOW FOR MUCH OF THE LONG
TERM FORECAST PERIOD ON THE BACK SIDE OF A RIDGE CENTERED ACROSS THE
CENTRAL UNITED STATES. THE FLOW IS PROGGED TO STEADILY INCREASE
DURING THE MIDDLE TO LATTER PART OF THE WORK WEEK AS A LARGE PACIFIC
NORTHWEST TROUGH MOVES ONSHORE AND APPROACHES THE FORECAST AREA.
GLOBAL MODELS EVENTUALLY BRING THE ASSOCIATED FRONT ACROSS NORTHERN
UTAH THURSDAY NIGHT AND FRIDAY AS THE SYSTEM GRAZES NORTHERN UTAH.
LATEST EC BRINGS THE SYSTEM A BIT FARTHER SOUTH THAN THE GFS AND
WOULD HAVE A LITTLE BIT MORE MOISTURE ASSOCIATED WITH IT.
STILL...BOTH SOLUTIONS ARE MOSTLY DRY BUT WOULD RESULT IN A SLOW
COOLING TREND IN TEMPERATURES THROUGH DAY 7...KEEPING TEMPERATURES
NEAR OR BELOW CLIMO.


&&

.AVIATION...GUSTY SOUTHERLY WINDS IN EXCESS OF 30 MPH AT TIMES ARE
EXPECTED TO REMAIN IN PLACE AT THE KSLC TERMINAL THROUGH MUCH OF
TODAY. ISOLATED TO WIDELY SCATTERED THUNDERSTORMS WILL CONTINUE TO
FORM OVER THE WESTERN DESERTS THIS AFTERNOON...AND WILL GRADUALLY
SPREAD EAST THIS EVENING. WITH THIS A 40 PERCENT CHANCE EXISTS THAT
GUSTY AND ERRATIC OUTFLOW WINDS WILL IMPACT THE TERMINAL...MOST
LIKELY BETWEEN 00-04Z. ADDITIONALLY...A 10 PERCENT CHANCE EXISTS
THAT A TS WILL IMPACT THE TERMINAL DURING THAT WINDOW.

&&

.FIRE WEATHER...AN UPPER LEVEL RIDGE IS SITUATED OVER THE GREAT
BASIN WITH AN UPPER LEVEL TROUGH MOVING INTO THE PACIFIC NORTHWEST
TODAY. THIS IS RESULTING IN GUSTY SOUTHWEST WINDS OVER THE AREA.
ANTICIPATE THAT ISOLATED CONVECTION WILL CONTINUE INTO THE EVENING
ACROSS WESTERN UT BEFORE DIMINISHING. THESE SHOWERS AND STORMS
WILL BE CAPABLE OF PRODUCING STRONG AND GUSTY WINDS. A COLD FRONT
MOVES INTO THE NORTHWEST PORTION OF THE STATE ON SUNDAY AND MOVES
INTO CENTRAL UT SUN NIGHT BEFORE STALLING OUT. AHEAD OF THIS FRONT
ANTICIPATE BREEZY SOUTHWEST WINDS ALTHOUGH MINIMUM RELATIVE
HUMIDITY VALUES WILL BE WELL ABOVE CRITICAL LEVELS. AHEAD OF THE
FRONT SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED ACROSS
CENTRAL AND EASTERN UTAH. WINDS DECREASE A BIT FOR MONDAY BEFORE
INCREASING AGAIN ON TUESDAY AS ANOTHER STORM SYSTEM MOVES INTO THE
PACIFIC NW. ANTICIPATE LOCALLY CRITICAL CONDITIONS ACROSS WEST
CENTRAL AND NW UTAH ON TUE AND WED.

&&

.SLC WATCHES/WARNINGS/ADVISORIES...
UT...NONE.
WY...RED FLAG WARNING UNTIL 9 PM MDT SUNDAY FOR WYZ277.

&&

$$

SHORT TERM...GRAHAM
LONG TERM...TRAPHAGAN
FIRE WEATHER...GRAHAM
AVIATION...MERRILL

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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