Area Forecast Discussion
Issued by NWS Salt Lake City, UT

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000
FXUS65 KSLC 030957
AFDSLC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
257 AM MST WED FEB 3 2016

.SYNOPSIS...A WEAK WEATHER DISTURBANCE WILL GRAZE NORTHERN UTAH
THIS MORNING. A SECOND SLIGHTLY STRONGER SYSTEM WILL ARRIVE
THURSDAY...FOLLOWED BY STRONG HIGH PRESSURE ALOFT FOR THE END OF
THE WEEK.

&&

.SHORT TERM (THROUGH 00Z SATURDAY)...
WATER VAPOR LOOP SHOWS A TRAILING SHORTWAVE MOVING INTO SOUTHWEST
WYOMING...WITH RIDGING ALONG THE WEST COAST. AMDAR 400-250MB WIND
OBSERVATIONS PLACE A 100-125KT CYCLONIC JET FROM THE PACIFIC
NORTHWEST INTO THE SOUTHWEST CONUS. GOES/HRRR/GPS/00Z SLC RAOB
INDICATE THE PRECIPITABLE WATER VALUE RANGES BETWEEN 0.03"-0.10"
MOUNTAINS...TO 0.15"-0.20" NORTHWEST UTAH VALLEYS.

TRAILING WAVE IS PROMOTING SNOW SHOWERS ACROSS NORTHERN UTAH AND
SOUTHWEST WYOMING. HAVE BUMPED POPS UP CONSIDERABLY ACROSS THESE
AREAS UNTIL THE PASSAGE MIDDAY. QPF WILL BE QUITE LIGHT...HOWEVER
SNOW RATIO WILL BE QUITE HIGH AS CLOUD LAYER IS SQUARELY IN THE
DENDRITIC SNOW GROWTH TEMPERATURE LAYER.

WITH THE PASSAGE OF THIS WAVE HEIGHTS WILL FINALLY RISE WITH A RIDGE
BUILDING IN FOR TONIGHT.

THERE IS STILL CONDISERABLE DIFFERENCE BETWEEN THE EUROPEAN WHICH
HAS FAVORED AN EARLIER SPLIT...AND GFS/CANADIAN WHICH CONTINUES TO
ADVERTISE A LATER SPLIT OVER THE ROCKIES OR EAST OF THE ROCKIES.
BOTH PARTIES HAVE BEEN QUITE STUBBORN IN THEIR DEDICATION TO
AFOREMENTIONED SOLUTIONS.

THE TAKE AWAY IS THERE IS LOWER THAN TYPICAL CONFIDENCE IN THE NEXT
SYSTEM CONSIDERING ITS ONLY 24 HOURS OUT. NEVERTHELESS...HAVE OPTED
TO RAISE POPS AS EVEN THE HARDER SPLIT SOLUTION OF THE EUROPEAN IS
DEPICTING ENOUGH CONSOLIDATION AS THE SYSTEM PROPAGATES OVER THE
FORECAST AREA.

THE THREAT FOR PRECIPITATION SHOULD END LATE THURSDAY NIGHT...AS
RIDGING BUILDS BACK IN FOR FRIDAY.

.LONG TERM (AFTER 00Z SATURDAY)...
GLOBAL MODELS CONTINUE TO STRUGGLE WITH THE DOWNSTREAM
AMPLIFICATION OF A SHORT WAVE TROUGH SATURDAY AS THE MEAN EASTERN
PACIFIC RIDGE AMPLIFIES ALONG THE WEST COAST. SENSIBLY...THE MORE
AMPLIFIED SOLUTIONS OF THE LATEST GFS/CANADIAN INDICATE A BETTER
CHANCE OF LIGHT SNOW SHOWER ACTIVITY ACROSS THE FAR NORTH DURING
THE DAY AS A SHALLOW COLD FRONT AND WEAK DYNAMIC FORCING MOVE INTO
THAT AREA. THE NOW MORE PROGRESSIVE EC INDICATES PRIMARILY A NET
COOLING TREND ACROSS THE FAR NORTH AND MINIMAL IF ANY CHANCE OF
PRECIP AS THE WAVE TRANSLATES NORTH THROUGH THE NORTHERN ROCKIES.
OPTING TO MESSAGE A SLIGHT CHANCE OF SNOW SHOWERS OVER THE FAR
NORTH DUE TO THE SHARPER SOLUTIONS OF THE GFS/CANADIAN...BUT NET
CONFIDENCE IN PATTERN EVOLUTION REMAINS ON THE LOW SIDE. THIS
ESPECIALLY HOLDS TRUE SINCE DIFFERENCES IN THE EVOLUTION OF THE
PRECEDING LATE WEEK TROUGH ALREADY EXIST.

THEREAFTER...ALL GUIDANCE CONTINUES TO SUPPORT DEVELOPMENT OF A
HIGHLY AMPLIFIED PATTERN ACROSS THE CONUS WITH RIDGING DOMINATING
THE WESTERN STATES. MAINTAINING A DRY FORECAST WITH A GRADUAL
WARMING TREND...THOUGH WEAK VALLEY INVERSION MAY LIMIT THIS A BIT.

&&

.AVIATION...CIGS AT THE KSLC TERMINAL ARE EXPECTED TO FLUCTUATE
BETWEEN 6000-7000FT AGL THROUGH MUCH OF THIS MORNING BEFORE
THINNING. SOUTHEAST SURFACE WINDS ARE EXPECTED TO SWITCH TO THE
NORTHWEST BETWEEN 19-20Z.

&&

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

$$

SHORT TERM...ROGOWSKI
LONG TERM/AVIATION...MERRILL

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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