Area Forecast Discussion
Issued by NWS Salt Lake City, UT

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000
FXUS65 KSLC 180422
AFDSLC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
922 PM MST MON NOV 17 2014

.SYNOPSIS...A STRONG UPPER LEVEL RIDGE OVER THE WEST COAST STATES
THIS EVENING WILL SHIFT EAST INTO THE GREAT BASIN FOR THE MIDWEEK
PERIOD. A SERIES OF WEAKENING WEATHER DISTURBANCES WILL MOVE EAST
ACROSS THE REGION LATE IN THE WEEK.

&&

.SHORT TERM (UNTIL 00Z FRIDAY)...THE STRONG HIGH-AMPLITUDE UPPER
RIDGE MOVING INTO THE WEST COAST STATES THIS EVENING WILL CONTINUE
EAST INTO THE WESTERN GREAT BASIN TUESDAY. SOLID WARMING ALOFT
ASSOCIATED WITH THE ADVANCING RIDGE WILL STRENGTHEN VALLEY
INVERSIONS AND MAINTAIN VERY STABLE CONDITIONS HEADING INTO
MIDWEEK. TEMPERATURES WILL CONTINUE ON A WARMING TREND ACROSS THE
FORECAST AREA...WITH THE HIGHER ELEVATIONS ABOVE THE INVERSIONS
LIKELY TO SEE THE GREATEST DAY-TO-DAY CHANGE. THE NORTHERN AND
CENTRAL VALLEYS MAY STRUGGLE A BIT TUESDAY AS RESIDUAL COLD AIR
FROM THE WEEKEND ARCTIC AIR MASS CONTINUES TO SLOWLY MODIFY.

THE UPPER LOW CURRENTLY CENTERED NEAR 38/137 WILL BE THE FIRST...
BUT NOT VERY PROMISING FEATURE...TO BRING PRECIP TO THE AREA LATE
IN THE WEEK. THIS UPPER LOW IS PROGGED TO WEAKEN AND BECOME AN
OPEN WAVE AS IT REACHES THE NORTHERN CALIFORNIA COAST EARLY
WEDNESDAY. FROM THERE THIS FEATURE WILL WEAKEN FURTHER AS IT
CRASHES INTO THE BACK OF THE STILL FORMIDABLE RIDGE OVER THE GREAT
BASIN. THE LATEST VERSIONS OF THE GFS AND ECMWF DIFFER ON THE
STRENGTH OF THE UNDERCUTTING WESTERLIES...WITH THE GFS THE MORE
AGGRESSIVE OF THE TWO. AT THIS POINT THE DIFFERENCE BETWEEN THE
TWO MODELS IS NEGLIGIBLE...WITH BOTH OFFERING UP PLENTY OF CLOUD
COVER AND MINIMAL LIGHT PRECIP FOCUSED ON THE SOUTHERN HALF OF
THE STATE. A SECOND TRAILING SHORTWAVE WILL LIFT NORTHEAST INTO
THE NORTHERN ROCKIES EARLY THURSDAY WITH A THREAT OF LIGHT PRECIP
FOR THE NORTHERN UTAH DURING THE DAY.

&&

.LONG TERM (AFTER 00Z FRIDAY)...THE NEXT WEAK STORM SYSTEM IS ON
TRACK TO CROSS THE GREAT BASIN THURSDAY NIGHT INTO FRIDAY. THIS
SYSTEM WILL BECOME INCREASINGLY SPLIT...AND GFS AND EC BOTH NOW
AGREE ON A MORE SOUTHERLY TRACK. THE CORE OF THIS SYSTEM IS PROGGED
TO MOVE ACROSS NORTHERN ARIZONA...SO THE BEST CHANCE OF
PRECIPITATION IN THE FORECAST AREA WILL REMAIN PRIMARILY DOWN SOUTH.
WITH THE UNSETTLED AIRMASS IN PLACE...MIXING WILL BE IMPROVED...
WITH SNOW LEVELS HOVERING NEAR 6000FT.

A MORE POTENT STORM CAN BE EXPECTED ON SATURDAY AS A STRONG JET WITH
160KT CORE AT 250MB APPROACHES UTAH. AHEAD OF THIS STORM...MOISTURE
IS PROGGED TO INCREASE OVER UTAH WITH PRECIPITATION DEVELOPING BY
SATURDAY MORNING IN WARM ADVECTION. BY NOW THE AIRMASS WILL HAVE
BEEN FAIRLY WELL MIXED SO THIS WILL MAINLY BE A VALLEY RAIN/MOUNTAIN
SNOW EVENT. THE ASSOCIATED COLD FRONT WILL CROSS THE AREA LATE
SATURDAY AFTERNOON THROUGH SATURDAY EVENING...WITH SNOW LEVELS THEN
FALLING TO THE VALLEY FLOORS BY EARLY SUNDAY MORNING. THIS COULD BE
A FAIRLY WIDESPREAD EVENT...BUT THE BULK OF THE PRECIPITATION LOOKS
TO IMPACT NORTHERN AND CENTRAL UTAH. A MEAN TROUGH WILL REMAIN IN
PLACE THROUGH THE REMAINDER OF THE WEEKEND...WITH UTAH REMAINING
UNSETTLED UNDER A COLD AND MOIST NORTHWESTERLY FLOW. ANOTHER IMPULSE
EMBEDDED IN THE TROUGH LOOKS TO MOVE THROUGH ON SUNDAY WHICH COULD
BRING A RENEWED BURST OF SNOW TO THE AREA.

&&

.AVIATION...NO OPERATIONAL WEATHER CONCERNS AT SLC TERMINAL THROUGH
THE TAF PERIOD. LIGHT AND VARIABLE WINDS AT 04Z WILL TRANSITION TO
A LIGHT SOUTHEAST WIND BETWEEN 04Z-05Z.

&&

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

$$

SHORT TERM...CONGER
LONG TERM...CHENG
AVIATION...STRUTHWOLF

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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