Area Forecast Discussion
Issued by NWS Salt Lake City, UT

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FXUS65 KSLC 221639
AFDSLC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
1039 AM MDT FRI APR 22 2016

.SYNOPSIS...A PACIFIC STORM SYSTEM WILL REACH THE WEST COAST
TODAY...THEN ADVANCE EAST INTO UTAH BY EARLY SATURDAY. THIS STORM
SYSTEM WILL IMPACT THE AREA LATE TONIGHT THROUGH SATURDAY. A
SECOND STORM SYSTEM WILL IMPACT THE AREA EARLY NEXT WEEK.

&&

.SHORT TERM...

SATELLITE IMAGERY THIS MORNING SHOWS A LARGE UPPER-LEVEL LOW MOVING
ONSHORE INTO NORTHERN CALIFORNIA...WITH PLENTY OF HIGH CLOUDS
STREAMING OUT IN ADVANCE OF THE LOW INTO THE GREAT BASIN. AT THE
SURFACE...BREEZY SOUTH WINDS HAVE ALREADY DEVELOPED...GUSTING
AROUND 30MPH THIS MORNING FOR MANY LOCATIONS IN THE WEST DESERTS.
THESE WINDS ARE EXPECTED TO INCREASE TODAY AS MIXING BRINGS DOWN
SOME STRONG 700MB WINDS IN ADVANCE OF THE UPPER-LEVEL LOW. SEVERAL
FORECAST ENSEMBLE PRODUCTS ARE SHOWING A MODEST WIND SIGNAL ALONG
I-80 FROM AROUND TOOELE TO WENDOVER...AND FURTHER SOUTH FROM DELTA
VICINITY TO THE NEVADA BORDER. AS A RESULT...HAVE INCREASED THE
WIND FORECAST A LITTLE AND ADDED AREAS OF BLOWING DUST TO THE WEST
DESERTS OF UTAH AND UP TO THE WASATCH FRONT. SOME AREAS MAY BE
CLOSE TO WARNING-LEVEL WINDS THIS AFTERNOON...BUT THINKING IT WILL
NOT BE WIDESPREAD. NEVERTHELESS...WILL NEED TO KEEP A CLOSE EYE ON
THAT THIS AFTERNOON AS WE MIX OUT.

SPEAKING OF MIXING OUT...HIGH TEMPERATURES TODAY LOOK TO BE QUITE
WARM AGAIN. ONLY LIMITING FACTOR COULD BE THE HIGH CLOUDS WHICH
WILL PERSIST THROUGH THE DAY FOR MUCH OF THE AREA

A COLD FRONT WILL SWEEP ACROSS THE STATE LATE TONIGHT...AROUND
3-6AM FOR THE WESTERN HALF OF UTAH AND 6AM TO NOON FOR THE REST OF
THE STATE AND SOUTHWESTERN WYOMING. MAIN HAZARDS LOOK TO BE
WINDS...A FEW THUNDERSTORMS WITH THE FRONT PASSAGE...AND SNOW IN
THE MOUNTAINS (MAINLY ABOVE 6500 FEET). SOME FLAKES ARE POSSIBLE
IN THE WASATCH FRONT BENCHES...BUT SHOULD NOT BE AN IMPACT.

.PREVIOUS DISCUSSION...ISSUED 452 AM MDT...

STRONG LOW-LEVEL COLD ADVECTION WILL SUPPORT THE COLD FRONT AS IT
MOVES THROUGH NORTHERN UTAH LATE TONIGHT/EARLY SATURDAY. LOOKING
AT A WINDOW FOR WIDESPREAD AND LOCALLY HEAVY CONVECTIVE AS THE
UPPER LOW CROSSES NORTHERN UTAH SATURDAY MORNING THROUGH EARLY
AFTERNOON. TEMPS WILL COOL SUFFICIENTLY FOR ACCUMULATING MOUNTAIN
SNOWS...WITH THE VALLEYS REMAINING AS RAIN...WITH BRIEF PERIODS OF
RAIN/SNOW MIXED DURING THE HEAVIER CONVECTIVE PRECIP.

INSTABILITY SHOWERS WILL LINGER THROUGH THE AFTERNOON/EARLY
EVENING...WITH CENTRAL UTAH SEE AN INCREASE IN ACTIVITY AS THE
COLD POOL ALOFT MOVES THROUGH THE AREA. A TRAILING VORTICITY LOBE
ROTATING AROUND THE EXITING UPPER LOW WILL BRING ONE LAST SHOT OF
ORGANIZED PRECIP TO THE FAR NORTHERN ZONES SATURDAY EVENING. TEMPS
ALOFT MAY BE A BIT MORE SUPPORTIVE FOR SNOW IN THE HIGHER
VALLEYS...THOUGH WITH INTENSITIES NOT ALL THAT STRONG WOULD
SUSPECT THAT THE PRECIP TYPE WILL REMAIN MORE AS RAIN THAN SNOW
THROUGH THIS LAST ORGANIZED EVENT.

A SHORTWAVE RIDGE CROSSES THROUGH UTAH SUNDAY SHOULD LIMIT ANY
PRECIP TO LIGHT SHOWERS OVER THE NORTHERN MOUNTAINS DURING THE
DAY. THE NEXT PACIFIC TROUGH DROPPING SOUTHEAST INTO THE PACIFIC
NORTHWEST SUNDAY NIGHT WILL EJECT A SHORTWAVE OUT AHEAD THROUGH
THE GREAT BASIN SUNDAY NIGHT. THIS FEATURE WILL LIFT NORTHEAST
THROUGH WESTERN.NORTHERN UTAH LATE SUNDAY NIGHT. HAVE BROUGHT AN
INCREASING CHANCE FOR SHOWERS BACK INTO THE FAR WESTERN ZONES LATE
SUNDAY EVENING AND THROUGH THE BALANCE OF THE OVERNIGHT HOURS.

.LONG TERM (AFTER 12Z MONDAY)...THE NEXT STORM SYSTEM IN THE SERIES
IS PROGGED TO CONSOLIDATE OVER THE CALIFORNIA COAST MONDAY MORNING
BEFORE TRACKING EAST INTO THE FORECAST AREA MONDAY AFTERNOON THROUGH
TUESDAY. GLOBAL MODELS ALL INDICATING A BROAD CLOSED LOW THAT WILL
BRING A GOOD AMOUNT OF MOISTURE AND A REINFORCING SHOT OF COLD AIR
AS IT MOVES THROUGH. SNOW LEVELS SHOULD STAY ABOVE VALLEY FLOORS BUT
MOUNTAIN ACCUMULATIONS COULD BE POTENTIALLY SIGNIFICANT...PARTICULARLY
OVER NORTHERN UTAH.

THE PROGRESSIVE PATTERN IS THEN EXPECTED TO CONTINUE THROUGH THE
MIDDLE TO LATTER PART OF THE UPCOMING WEEK. BRIEF RIDGING SHOULD
MOVE OVER UTAH AND SOUTHWEST WYOMING MONDAY...THOUGH LINGERING
MOISTURE COULD KEEP SOME SHOWERS AROUND OVER NORTHERN UTAH. ANOTHER
LOW IS THEN EXPECTED TO SLIDE DOWN THE CALIFORNIA COAST WEDNESDAY
AFTERNOON/EVENING BEFORE TRACKING THROUGH THE GREAT BASIN THURSDAY
THROUGH THE WEEKEND. THERE REMAINS SOME DISAGREEMENT AMONG THE
GLOBAL MODELS WITH RESPECT TO THE TIMING AND TRACK OF THIS SYSTEM.
LATEST EC MOVES THE CENTER OF THE LOW OVER SOUTHERN ARIZONA FRIDAY
BEFORE TRACKING IT NORTHEASTWARD INTO NEW MEXICO AND COLORADO ON
SATURDAY. THIS TRACK WOULD KEEP THE BRUNT OF THE MOISTURE SOUTH OF
THE AREA AND WOULD ALSO RESULT IN WARMER TEMPERATURES COMPARED TO
THE GFS. THE LATEST GFS TRACKS THE LOW ALONG THE UT/AZ BORDER LATE
FRIDAY THROUGH SATURDAY...BRINGING A MORE SIGNIFICANT FRONT WITH IT
AS IT PASSES. THOUGH THE BEST MOISTURE WOULD BE OVER SOUTHERN UTAH
IN THIS SOLUTION...IT KEEPS THE POSSIBILITY OF PRECIP OVER NORTHERN
AND CENTRAL UTAH AS WELL. HAVE SHIFTED THE FOCUS OF POPS TO SOUTHERN
UTAH FOR THE END OF THE FORECAST PERIOD...BUT CONFIDENCE REMAINS LOW
IN THE SPECIFICS OF PRECIPITATION BY DAY 7.

&&

.AVIATION...THE SLC TERMINAL WILL SEE VFR CONDITIONS THROUGHOUT THE
DAY WITH SOME HIGH CLOUDS. SOUTHERLY WINDS WILL PREVAIL AND CONTINUE
TO INCREASE DURING THE DAY...BECOMING GUSTY LATE THIS MORNING AND
LASTING THROUGH THIS EVENING INTO SATURDAY WITH FRONTAL PASSAGE
EXPECTED BEFORE 12Z SATURDAY.

&&

.SLC WATCHES/WARNINGS/ADVISORIES...
UT...WIND ADVISORY UNTIL 10 PM MDT THIS EVENING FOR UTZ003-005-015-
     016.

WY...NONE.
&&

$$

PUBLIC...VAN CLEAVE
AVIATION...DEWEY

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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