Area Forecast Discussion
Issued by NWS Salt Lake City, UT

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000
FXUS65 KSLC 262215
AFDSLC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
415 PM MDT WED AUG 26 2015

.SYNOPSIS...A LOW PRESSURE SYSTEM WILL SLOWLY TRANSLATE NORTHEAST
OF THE AREA TONIGHT. HIGH PRESSURE WILL RETURN FOR THE LATTER
HALF OF THE WEEK INTO THE UPCOMING WEEKEND.

&&

.DISCUSSION...THE MID LEVEL CIRCULATION OF A LOW EMBEDDED WITHIN
DEEPLY MOIST SOUTHWESTERLY FLOW HAS SLOWLY TRANSLATED NORTHEAST
INTO NORTH CENTRAL UTAH TODAY. THE ASSOCIATED TROUGH AXIS EXTENDS
SOUTH ROUGHLY FROM KSLC TO KPUC TO KPGA AND IS SLOWLY TRANSLATING
EAST-NORTHEAST AS WELL. SUBSIDENCE IN LEE OF THIS AXIS CAN BE
NOTED ACROSS THE MUCH OF THE WESTERN HALF OF THE STATE AS
CONVECTION HAS BECOME QUITE SUPPRESSED...THOUGH A MODEST
INSTABILITY AXIS EXISTS FROM SOUTHWEST UTAH NORTHWEST INTO NEVADA
WHERE SCATTERED CONVECTION IS REFORMING AIDED BY MODEST DIFFERENTIAL
HEATING WHERE CLOUDS HAVE THINNED. THOUGH THE BULK OF ONGOING
PRECIPITATION EAST OF THE AXIS REMAINS ON THE LIGHT AND SHOWERY
SIDE...THE ADDED FORCING ALONG ITS SOUTHERN TAIL BENEATH WEAK
DEFORMATION ALOFT HAS SPARKED MULTI CELLULAR CONVECTION FROM LAKE
POWELL SOUTH INTO NORTHERN ARIZONA...SOME STRONG. HANGING ONTO TO
ONE LAST AREAL FLOOD WARNING ACROSS THE SOUTHEAST BET EXPECT THIS
TO EXPIRE ON TIME IN A LITTLE OVER AN HOURS TIME. CONTINUED
NORTHEAST PROGRESSION OF THE LOW AND ITS AXIS WILL ALLOW FOR A NET
DECREASING TREND IN COVERAGE THIS EVENING AND OVERNIGHT FOR ALL
AREAS OUTSIDE OF THE EAST.

OVER THE NEXT 24 HOURS THE MID LEVELS WILL BEGIN TO DRY AS HIGH
PRESSURE REBOUNDS AND EXPANDS NORTHEAST WITH ITS AXIS STRETCHING FROM
THE DESERT SOUTHWEST INTO CENTRAL NEVADA. LACK OF SUBSTANTIAL
BOUNDARY LAYER FLOW WILL LIMIT MUCH DRYING OF THE LOW LEVELS
HOWEVER...AND EXPECT ISOLATED TO WIDELY SCATTERED CONVECTION TO
REDEVELOP TOMORROW AFTERNOON WITH FOCUS OVER AND NEAR THE
TERRAIN. UPDRAFTS WILL HAVE TO OVERCOME INCREASED LARGE SCALE
SUBSIDENCE DUE TO THE BUILDING RIDGE. TEMPS WILL REBOUND AS SUCH
ALLOWING A NET WARMING TREND ALL AREAS.

AS THE DEEP UPPER LOW CURRENTLY OFF THE PACNW STATES OPENS AND
LIFTS NORTHEAST TOMORROW THROUGH FRIDAY...THE AFOREMENTIONED RIDGE
AXIS WILL SHIFT OVERHEAD THEN EAST OF THE AREA ALLOWING A DRYING
SOUTHWESTERLY FLOW TO SPREAD ACROSS THE EASTERN GREAT BASIN
STATES. A SERIES OF PROGRESSIVE SHORT WAVES WILL CONTINUE TO
RELOAD THE PACNW THROUGH THROUGH THE WEEKEND SUPPRESSING THE HIGH
SOUTH AND EAST AS THEY LIFT INLAND...THIS LIMITING ANY ISOLATED
CONVECTIVE THREATS TO NAMELY AREAS CLOSEST TO THE UPPER JET AS IT
SHIFTS INTO NORTHWESTERN UTAH EARLY NEXT WEEK. THE AFOREMENTIONED
WARMING TREND WILL CONTINUE THROUGH SATURDAY BEFORE WEAK MID LEVEL
CAA ADVECTION LOWERS THEM BACK TO NEAR NORMAL VALUES FOR EARLY
NEXT WEEK.

&&

.AVIATION...ERRATIC WINDS WILL CONTINUE AT THE SLC TERMINAL INTO THE
EVENING. EXPECT WINDS TO EVENTUALLY BECOME MAINLY SOUTHERLY AFTER 23Z
AND REMAIN SO THROUGH THE NIGHT. A FEW SHOWERS WILL REMAIN
POSSIBLE...THOUGH THE THREAT OF THUNDERSTORMS IS LOW.

&&

.FIRE WEATHER...A WEAK STORM SYSTEM INTERACTING WITH MONSOON
MOISTURE IS RESULTING IN WIDESPREAD SHOWERS AND ISOLATED
THUNDERSTORMS ACROSS UTAH TODAY. COVERAGE OF PRECIPITATION WILL
DIMINISH THIS EVENING. AN UPPER LEVEL RIDGE BUILDS OVER THE REGION
BEGINNING ON THURSDAY WHICH WILL BRING A WARMING AND DRYING TREND
TO THE AREA. LINGERING MOISTURE WILL RESULT IN A SLIGHT CHANCE OF
SHOWERS AND THUNDERSTORMS ON THURSDAY AFTERNOON AND EVENING ACROSS
NEARLY ALL OF SOUTHERN UTAH AND THE MOUNTAINS OF NORTHERN UTAH.
WINDS ON THURSDAY ARE EXPECTED TO BE PRIMARILY TERRAIN DRIVEN. A
STORM SYSTEM WILL MOVE INTO THE PACIFIC NORTHWEST LATE IN THE WEEK
INTO THE WEEKEND AND THIS WILL RESULT IN THE DEVELOPMENT OF
STRONGER SOUTH WINDS ACROSS THE AREA BY SATURDAY.

&&

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

$$

MERRILL/KRUSE/GRAHAM


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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