Area Forecast Discussion
Issued by NWS Salt Lake City, UT

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000
FXUS65 KSLC 221052
AFDSLC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
452 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 (UNTIL 12Z MONDAY)...THE UPPER LOW ADVANCING TOWARD
THE WEST COAST ALONG 40N WILL REACH THE COAST THIS MORNING. FROM
THERE THE LOW WILL MAINTAIN A RESIDUAL MID-LEVEL CIRCULATION AS IT
MOVES THROUGH GREAT BASIN...REACHING NORTHERN UTAH EARLY SATURDAY.

AHEAD OF THE UPPER LOW A WARM AND INCREASINGLY STRONG SOUTHERLY
FLOW ALOFT WILL EXIST THROUGH THIS EVENING. TEMPERATURES OVERNIGHT
HAVE REMAINED EXCEPTIONALLY WARM FOR LATE APRIL. THIS WARM START
COMBINED WITH GOOD MIXING THIS AFTERNOON WILL DRIVE HIGHS TO
LEVELS WELL ABOVE NORMAL THIS AFTERNOON. THE ONLY LIMITING FACTOR
WILL BE THE POTENTIAL FOR EXTENSIVE HIGH CLOUDS WHICH COULD SHAVE
A FEW DEGREES OFF THE MAXES. FORECAST FOR TODAY WILL PUT TEMPS
PLUS OR MINUS A DEGREE OR TWO FROM YESTERDAYS READINGS.

THE SURFACE COLD FRONT ASSOCIATED WITH THE UPPER LOW IS EXPECTED
TO INTENSIFY RAPIDLY ACROSS CENTRAL NEVADA THIS AFTERNOON.
INTENSIFICATION OF THE SURFACE FRONT ALONG WITH STRONG LOW-LEVEL
SOUTHERLY FLOW ALOFT WILL CREATE VERY STRONG SOUTH WINDS ACROSS
THE WESTERN VALLEYS THIS AFTERNOON AND EVENING. CURRENT SUITE OF
WIND ADVISORIES LOOK TO BE ON TRACK FOR NOW. DO HAVE SOME CONCERN
THAT A FEW GUSTS COULD SPIKE INTO HIGH WIND WARNING CRITERIA LATE
THIS AFTERNOON/EARLY EVENING...THOUGH SUSPECT THAT BULK OF THE
PEAK WIND GUSTS WILL REMAIN IN THE 45-55 MPH RANGE.

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 CONTINUE TO INCREASE
DURING THE DAY...BECOMING GUSTY BY LATE MORNING.

&&

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

WY...NONE.
&&

$$

SHORT TERM...CONGER
LONG TERM/AVIATION...TRAPHAGAN

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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