Area Forecast Discussion
Issued by NWS Salt Lake City, UT

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000
FXUS65 KSLC 252132
AFDSLC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
332 PM MDT TUE AUG 25 2015

.SYNOPSIS...MOISTURE WILL SPREAD NORTHWARD ACROSS THE AREA AS AN
UPPER LEVEL DISTURBANCE MOVES ACROSS THE REGION TONIGHT THROUGH
WEDNESDAY. HIGH PRESSURE WILL RETURN FOR THE LATTER HALF OF THE
WEEK INTO THE UPCOMING WEEKEND.

&&

.SHORT TERM (THROUGH 06Z SATURDAY)...RIDGE OF HIGH PRESSURE IS
CENTERED EAST OF THE FORECAST AREA THIS AFTERNOON. THE SOUTHERLY
FLOW OVER THE AREA ON THE BACK SIDE OF THE RIDGE IS DRAWING
MONSOONAL MOISTURE NORTHWARD. SATELLITE DERIVED PWS SHOWING VALUES
IN EXCESS OF 1.0 INCH ACROSS THE VAST MAJORITY OF UTAH AND
SOUTHWEST WYOMING. WITH THIS MOISTURE IN PLACE...SOME SHOWERS AND
THUNDERSTORMS HAVE DEVELOPED OVER THE HIGHER TERRAIN WITH SOME
GUSTY WINDS REPORTED. SOME OF THIS ACTIVITY HAS DRIFTED INTO
NORTHERN UTAH VALLEYS SO HAVE RAISED POPS A BIT THERE FOR THE
EVENING PERIOD. TEMPERATURES ARE RUNNING SIMILAR TO YESTERDAY
ACROSS NORTHERN UTAH...ALMOST 10F ABOVE SEASONAL NORMS...WHILE
CLOUD COVER HAS COOLED TEMPERATURES BY A FEW DEGREES OVER SOUTHERN
UTAH COMPARED TO VALUES OBSERVED YESTERDAY.

A WAVE WILL MOVE NORTHWARD ACROSS THE FORECAST AREA TONIGHT AND
TOMORROW...BRINGING ADDITIONAL MOISTURE AND INSTABILITY. GFS PWS
INDICATE WIDESPREAD VALUES IN THE 1.3 TO 1.5 INCH RANGE ACROSS
MUCH OF UTAH AND SOUTHWEST WYOMING...OVER TWO STANDARD DEVIATIONS
ABOVE NORMAL FOR THIS TIME OF YEAR. THIS COMBINATION WILL ALLOW
FOR GOOD COVERAGE SHOWERS WITH A FEW THUNDERSTORMS OVERNIGHT AND
INTO TOMORROW. HOWEVER...THINK THAT CLOUD COVER WILL BE A LIMITING
FACTOR AS WELL AS THE TIME OF DAY FOR THE BEST ACTIVITY. FEEL THAT
MOST OF THE ACTIVITY WILL BE MORE STRATIFORM IN NATURE...THOUGH
HEAVY RAIN IS POSSIBLE WITH ANY OF THIS DEVELOPMENT. THE
PRECIPITATION AND CLOUD COVER WILL KEEP TEMPERATURES DOWN...WITH
MAXES RUNNING AT LEAST A FEW DEGREES BELOW CLIMO IN MOST
LOCATIONS.

BEHIND THE EXITING WAVE...HIGH PRESSURE IS PROGGED TO BUILD BACK
OVER THE FORECAST AREA FOR THURSDAY AND FRIDAY...RESULTING IN A
DRYING AND WARMING TREND. LINGERING MOISTURE WILL KEEP THE
POSSIBILITY OF ISOLATED CONVECTION OVER THE HIGHER TERRAIN
THURSDAY AND FRIDAY AFTERNOON. MAXES SHOULD RETURN TO VALUES NEAR
OR SLIGHTLY ABOVE SEASONAL NORMALS BY FRIDAY.

&&

.LONG TERM (AFTER 06Z SATURDAY)...MODELS REMAIN IN GOOD AGREEMENT
THROUGH THE EXTENDED PERIOD AND THUS DID NOT MAKE ANY SIGNIFICANT
CHANGES TO THE PREVIOUS FORECAST. UPPER LEVEL HIGH PRESSURE OVER THE
AREA ON SATURDAY BRINGING HOT AND MOSTLY DRY CONDITIONS OUTSIDE OF A
SLIGHT CHANCE OF THUNDERSTORMS OVER THE CENTRAL MOUNTAINS. RIDGE OF
HIGH PRESSURE SHIFTS EAST ON SUNDAY AS A LARGE TROUGH OF LOW
PRESSURE MOVES INTO THE PACIFIC NORTHWEST. THIS PERSISTENT TROUGH
REMAINS IN THE PACIFIC NORTHWEST THROUGH MUCH OF THE REST OF THE
EXTENDED PERIOD WITH NO MOVEMENT INLAND. THIS LEAVES SOUTHWEST FLOW
ALOFT SET UP OVER MUCH OF THE STATE.  THERE IS NOT MUCH MOISTURE
ASSOCIATED WITH THIS PATTERN SO DO NOT EXPECT MUCH IF ANY
PRECIPITATION THROUGH THE EXTENDED PERIOD. THIS PATTERN WILL
CONTINUE TO KEEP WARM TEMPERATURES ACROSS THE AREA BUT NOT AS HOT AS
WHAT A RIDGE OF HIGH PRESSURE WOULD BRING. BREEZY CONDITIONS CAN
ALSO EXPECTED DURING MUCH OF THE EXTENDED PERIOD AS WELL.

&&

.AVIATION...NORTHWEST WINDS WILL CONTINUE AT THE SLC TERMINAL
THROUGH 02-04Z. SHOWERS WILL CONTINUE TO DEVELOP THIS AFTERNOON
ACROSS PORTIONS OF NORTHERN UTAH...WITH A FEW THUNDERSTORMS
POSSIBLE. GUSTY AND ERRATIC WINDS WILL BE POSSIBLE NEAR ANY
SHOWERS/THUNDERSTORMS THROUGH THE EVENING.

EXPECT ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS LATER TONIGHT INTO
WEDNESDAY MORNING.

&&

.FIRE WEATHER...HIGH PRESSURE IS JUST EAST OF THE AREA...WITH
SOUTHWEST FLOW BRINGING IN MONSOONAL MOISTURE FROM THE SOUTH.
CONVECTION HAS DEVELOPED OVER THE HIGHER TERRAIN AGAIN THIS
AFTERNOON...WITH SOME GUSTY WINDS. THIS CONVECTION WILL TEND TO
DISSIPATE THIS EVENING. HOWEVER...A WEATHER DISTURBANCE MOVING
THROUGH THE DISTRICT TONIGHT AND TOMORROW WILL PROVIDE ADDITIONAL
MOISTURE AND INSTABILITY...RESULTING IN MORE WIDESPREAD SHOWERS
WITH EMBEDDED THUNDERSTORMS AND A GOOD CHANCE OF WETTING RAINS. A
DRIER AND MORE STABLE AIRMASS WILL MOVE IN BEHIND THE EXITING
SYSTEM AS HIGH PRESSURE REBUILDS INTO THE FIRST PART OF THE
WEEKEND.


&&

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

$$

SHORT TERM/FIRE WEATHER...TRAPHAGAN
LONG TERM...SOLUM
AVIATION...KRUSE

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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