Area Forecast Discussion
Issued by NWS Salt Lake City, UT

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FXUS65 KSLC 272242
AFDSLC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
442 PM MDT WED APR 27 2016

.SYNOPSIS...THE PACIFIC STORM SYSTEM ALONG THE NORTHERN
CALIFORNIA COAST WILL CONTINUE SOUTHEAST INTO THE GREAT BASIN
TONIGHT...THEN TRACK SLOWLY EAST ALONG THE UTAH ARIZONA BORDER
THROUGH FRIDAY. A SECOND STORM SYSTEM WILL SETTLE INTO THE GREAT
BASIN SATURDAY AND LINGER OVER THE REGION INTO EARLY NEXT WEEK.

&&

.SHORT TERM (UNTIL 00Z SUNDAY)...THE UPPER LOW CURRENTLY ALONG THE
NORTHERN CALIFORNIA COAST WILL CONTINUE ON A SOUTHEAST TRACK IN
EXTREME SOUTHERN NEVADA OVERNIGHT. AHEAD OF THIS LOW A VORTICITY
LOBE OVER EXTREME SOUTHWEST UTAH WILL LIFT NORTH ACROSS THE
WESTERN PORTION OF UTAH OVERNIGHT. AN EXPANDING AREA OF CONVECTIVE
PRECIP WILL DEVELOP ALONG THIS FEATURE ACROSS WESTERN UTAH THIS
EVENING...THEN GRADUALLY WIND DOWN OVER SOUTHWEST UTAH LATE
TONIGHT.

ANY BREAK IN PRECIP WILL BE SHORT-LIVED ACROSS SOUTHERN UTAH AS
THE CENTER OF THE UPPER LOW TAKES A POSITION ACROSS EXTREME
SOUTHERN NEVADA EARLY THURSDAY. THIS LOW WILL TAKE A SLOW EASTWARD
TRACK ALONG THE UTAH/ARIZONA BORDER DURING THE DAY. GOOD DYNAMIC
LIFT EAST AND NORTH OF THE LOW CENTER ALONG WITH AN AMBIENT AIR
MASS THAT SHOULD STILL BE SUFFICIENT MOIST AND UNSTABLE WILL
PRODUCE WIDESPREAD PRECIP ACROSS MAINLY THE SOUTHERN HALF OF UTAH
DURING THE DAY.

PRECIP SHOULD LINGER INTO THE EVENING...WITH MOST OF THE REMAINING
ACTIVITY IN THE NORTH AND WEST FLANK OF THE EXITING UPPER LOW.
NORTHERN UTAH/SOUTHWEST WYOMING WILL COME UNDER AN INCREASINGLY
STRONG EASTERLY FLOW ALOFT AS THE UPPER LOW APPROACHES THE FOUR
CORNERS REGION LATE TONIGHT. A STRENGTHENING NORTHEAST SURFACE
GRADIENT OVER WESTERN WYOMING SUPPORTED BY THE EASTERLY FLOW ALOFT
WILL CREATE GUSTY EAST WINDS OVER SOUTHWEST WYOMING...AND SPILLING
INTO FAR NORTHERN UTAH. THE SITUATION WILL BE FAVORABLE FOR CANYON
WINDS THROUGH THE CACHE VALLEY AND NORTHERN WASATCH FRONT.
EXPECTED SPEEDS FOR THE MOST PART WILL BE BELOW ADVISORY LEVELS...
SO NO HIGHLIGHTS ARE ANTICIPATED AT THIS TIME.

A SHORTWAVE RIDGE MOVING INTO UTAH FRIDAY NIGHT WILL GIVE WAY TO A
SECOND STORM SYSTEM ENTERING THE WESTERN GREAT BASIN LATE FRIDAY
NIGHT. THIS SECOND SYSTEM WILL TAKE A MORE NORTH-TO-SOUTH TRACK
THROUGH THE WESTERN GREAT BASIN...WITH THE ASSOCIATED PRECIP
REACHING INTO EXTREME WESTERN UTAH. WIDESPREAD PRECIP WILL LIKELY
HOLD OFF UNTIL THIS FEATURE SETTLES INTO EXTREME SOUTHERN NEVADA
AD SOUTHWEST UTAH DURING THE DAY SATURDAY. LARGE-SCALE SYNOPTIC
LIFT ALONG WITH ABUNDANT MOISTURE SHOULD BRING ABOUT ANOTHER ROUND
OF PRECIP TO MUCH OF SOUTHERN/CENTRAL/EASTERN UTAH BY SATURDAY
AFTERNOON.

.LONG TERM (AFTER 00Z SUNDAY)...IN THE ACTIVE SERIES OF UPPER LEVEL
TROUGH SYSTEMS...THE NEXT CUT OFF LOW SLIDES DOWN NEVADA AND SETTLES
ON THE TRI-STATE AREA (NEVADA/CALIFORNIA/ARIZONA) LATE SATURDAY.
EXTENDED FORECAST MODELS ARE IN AGREEMENT ON THE TRACK OF THIS CUT
OFF LOW TO MOVE EAST ACROSS NORTHERN ARIZONA/SOUTHERN UTAH THROUGH
THE WEEKEND. WITH THE FAR SOUTH TRACK OF THIS CUT OFF SYSTEM...THE
SURFACE PRESSURE GRADIENT FROM WYOMING INTO UTAH BECOMES COMPRESSED
AND THE 700 MB WINDS BECOME BREEZY FOR SUNDAY. ONE ITEM TO KEEP AN
EYE ON AS WE NEAR THE WEEKEND WILL BE AN EASTERLY WIND EVENT.

PRECIPITATION LOOKS TO BE FOCUSED ON THE CENTRAL AND SOUTHERN
PORTIONS OF UTAH THROUGH THE WEEKEND DUE IN PART TO THE SOUTHERN
PLACEMENT OF THE TROUGH. BY THE END OF THE WEEKEND...THE TROUGH
BECOMES AN OPEN WAVE AS DEPICTED ON THE GLOBAL FORECAST MODELS WITH
RIDGING BUILDING IN FROM THE WEST. A STEADY RISE IN 500 MB HEIGHTS
THROUGH LATE TUESDAY SHOULD ALLOW TEMPERATURES ENOUGH OF A WARMING
BIAS TO WARM TO ABOVE NORMAL FOR THIS TIME OF YEAR. IN THE FAR
EXTENDED IT APPEARS ANOTHER DEEP TROUGH WILL MAKE AN APPEARANCE
THROUGH THE GREAT BASIN BY LATE NEXT WEEK.

&&

.AVIATION...FOR THE KSLC TERMINAL...WINDS ARE STRUGGLING TO
SWITCH TO THE NORTH LIKELY DUE TO SHOWERS AND CONVECTION SOUTHWEST
OF THE SALT LAKE VALLEY. A 30 PERCENT CHANCE OF WINDS SWITCHING TO
THE NORTH FOR THE REMAINDER OF THIS AFTERNOON/EVENING. CONVECTION IS
EXPECTED THIS EVENING AGAIN AND TO PERSIST OFF AND ON THROUGH THE
OVERNIGHT HOURS.

&&


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

$$

SHORT TERM...CONGER
LONG TERM/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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