Area Forecast Discussion
Issued by NWS Salt Lake City, UT

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FXUS65 KSLC 021645
AFDSLC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
1045 AM MDT TUE JUN 2 2015

.SYNOPSIS...A COLD FRONT WILL REMAIN STALLED ACROSS CENTRAL UTAH
TODAY. ANOTHER WEAK PACIFIC STORM SYSTEM WILL GRAZE NORTHERN UTAH
WEDNESDAY AND WEDNESDAY NIGHT. A CLOSED LOW OFF THE CALIFORNIA
COAST WILL BEGIN TO SEND MOISTURE NORTH INTO UTAH ON FRIDAY.

&&

.DISCUSSION...MORNING WATER VAPOR AND H5 ANALYSIS PLACE A
PROGRESSIVE SHORT WAVE OVER SOUTHWESTERN IDAHO MOVING NORTHEAST.
SURFACE ANALYSIS PLACES A WEAK FRONTAL BOUNDARY JUST SOUTH OF
KSLC WHICH WILL GRADUALLY MOVE SOUTH TODAY IN RESPONSE TO WAVE
PASSAGE TO THE NORTH. NOT MUCH TO NOTE WITH EITHER OF THESE
FEATURES AS THE MID LEVELS HAVE CONTINUE TO DRY AND ANY
EARLY FORCING/INSTABILITY WILL HAVE LITTLE TO WORK WITH...BUT
WILL MAINTAIN SOME ISOLATED TERRAIN BASED POPS ACROSS THE FAR NW
AND NE DUE TO STEEP MID LEVEL LAPSE RATES AND JUST ENOUGH MOISTURE
FOR SOME CU DEVELOPMENT THIS AFTERNOON.

SENSIBLY AREAS NORTH OF THE FRONTAL BOUNDARY WILL TEND TO RUN
ABOUT 10 DEGREES COOLER THAN YESTERDAY...BUT VERY WARM AND BREEZY
CONDITIONS WILL REMAIN ACROSS THE SOUTHERN HALF OF THE AREA. ONLY
MADE MINIMAL UPDATES TO SKY COVER ACROSS THE NORTH...OTHERWISE NO
OTHER UPDATES WERE MADE OR ARE PLANNED.

TROUGH OFF THE PACNW COAST WILL BEGIN TO RELOAD AND DEEPEN
TOMORROW PLACING THE EXIT REGION OF THE UPPER JET OVER NORTHERN
UTAH...ENHANCED CURVATURE DRIVING WEAK HEIGHT FALLS ACROSS THE
NW AS THE FORMER TROUGH WEAKENS AND TRANSITIONS INTO THE NORTHERN
ROCKIES STATES. ADDITIONALLY THE NEXT PROGRESSIVE SHORT WAVE OFF
SHORE AND CURRENTLY NEAR 135W/35N IS EXPECTED TO PASS SW-NE
THROUGH THE AREA DURING THE LATE AFTERNOON AND EVENING. BUFR
SOUNDINGS AND SREF IN AGREEMENT REGARDING MODERATE INSTABILITY
DEVELOPING IN THE FAR NORTH /UP TO 1500 J PER KG/ WITH MODERATELY
STRONG SOUTHWEST FLOW ALOFT AIDING DEEP LAYER EFFECTIVE SHEAR ON
THE ORDER OF 30-40 KTS. THOUGH PWAT WILL REMAIN TO BE AN
INHIBITING FACTOR...EXPECTING AREAL COVERAGE OF STORMS TO
INCREASE...SOME STRONG WITH GUSTY WINDS THE MOST LIKELY IMPACT
ALONG THE UT/ID BORDER REGION AND ACROSS SW WYOMING. AREAS SOUTH
OF ROUGHLY OGDEN/KSLC SHOULD SEE MINIMAL ACTIVITY HOWEVER.

WET WEATHER REMAINS ON TAP FRI THROUGH THE WEEKEND AS THE
AFOREMENTIONED PACNW LOW DEEPENS FURTHER AND CLOSES OFF OVER SOCAL.
MODELS REMAIN IN AT LEAST DECENT AGREEMENT THAT A STRONG MOISTURE
TAP FROM THE TROPICAL EASTERN PACIFIC WILL SURGE INTO THE AREA
DURING THAT TIME. MORE ON THIS AFTER FULL SUITE OF 12Z GUIDANCE
HAS BEEN ANALYZED.

&&

.AVIATION...OPERATIONAL WEATHER CONCERNS WILL REMAIN MINIMAL AT
THE KSLC TERMINAL THROUGH THE VALID TAF PERIOD. LIGHT NORTHWEST
WINDS WILL GRADUALLY INCREASE TO ABOVE 8 KNOTS BY 17Z AND REMAIN
IN PLACE THROUGH THIS EVENING. VFR CONDITIONS WILL BE MAINTAINED
UNDER LARGELY CLEAR SKIES.

&&

.FIRE WEATHER...A WEAK UPPER LEVEL TROUGH IS SITUATED
ALONG THE WEST COAST WITH AN UPPER LEVEL RIDGE OVER THE CENTRAL
AND SOUTHERN PLAINS. THIS LARGE SCALE PATTERN WILL KEEP THE
DISTRICT UNDER WARM AND RELATIVELY DRY FLOW THROUGH THURSDAY. THE
FRONTAL BOUNDARY THAT MOVED THROUGH NORTHERN UTAH ON MONDAY
EVENING HAS STALLED ACROSS CENTRAL UTAH. SOUTH OF THE STALLED
BOUNDARY MANY AREAS WILL EXPERIENCE GUSTY WINDS THIS AFTERNOON.
MINIMUM RH VALUES WILL ALSO BE QUITE LOW ACROSS SOUTHERN UTAH
THIS AFTERNOON. TEMPERATURES WILL BE ABOUT 10 DEGREES COOLER
ACROSS NORTHERN UTAH TODAY WITH LIGHT NORTH OR TERRAIN DRIVEN
WINDS. AN UPPER LEVEL LOW THEN MOVES DOWN THE CALIFORNIA COAST ON
FRIDAY BEFORE DRIFTING SLOWLY ACROSS THE GREAT BASIN FOR THE
WEEKEND. THIS UPPER LEVEL LOW TAPS INTO DEEPER SUB-TROPICAL
MOISTURE BRINGING INCREASED COVERAGE OF SHOWERS AND THUNDERSTORMS
AND TO THE AREA FOR THE WEEKEND.

&&

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

$$

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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