Area Forecast Discussion
Issued by NWS Salt Lake City, UT

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FXUS65 KSLC 171643
AFDSLC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
1043 AM MDT THU APR 17 2014

.SYNOPSIS...HIGH PRESSURE WILL SPREAD ACROSS THE REGION THROUGH
TONIGHT. THE NEXT WEAKENING STORM SYSTEM WILL CROSS THE REGION
LATE FRIDAY THROUGH SATURDAY. A STRONGER STORM WILL IMPACT THE
AREA MIDWEEK OF NEXT WEEK.


&&

.DISCUSSION...HEIGHTS CONTINUE TO BUILD PER LATEST 500MB ANALYSIS
AS SHORT WAVE RIDGING TRANSITIONS OVERHEAD. MODELS INDICATE STRONG
WARM ADVECTION OVER THE NEXT 12 TO 18 HOURS AS SUCH...THIS AS FLOW
ALOFT BACKS TO THE SOUTHWEST AND INCREASES. 12Z KSLC RAOB
INDICATED A H7 TEMP OF -2 C BUT BY DAYS END EXPECTING THIS TO
CLIMB TO +5 C LOCALLY AND AROUND +8 C ACROSS THE SOUTH. BOTTOM
LINE FOR TODAY...CLEAR AND STABLE WITH AFTERNOON HIGHS SOME 10 OR
MORE DEGREES WARMER THAN YESTERDAY. NO SHORT TERM UPDATES MADE OR
PLANNED.

RIDGE TRANSITION AND OVERHEAD AMPLAFICATION IS A DIRECT RESULT OF
A SPLITTING TROUGH NOTED IN MORNING WATER VAPOR JUST OFF THE
PACIFIC COAST. THE MORE PROGRESSIVE NORTHERN BRANCH OF THIS SPLIT
WILL TRACK THROUGH THE NORTHERN ROCKIES LATE TONIGHT THROUGH
TOMORROW MORNING FORMING AND THEN SAGGING A WEAK COLD FRONT INTO
FAR NORTHERN UTAH THROUGH THAT TIME. DOWNSTREAM PROPAGATION OF
THE UPPER SUPPORT OF THIS WAVE WILL STALL THE FRONT OVER THE NORTH
FOR THE DAYTIME HOURS WHILST THE SOUTHERN BRANCH BEGINS TO CLOSE
OFF OVER SOCAL LIFTING NORTHEAST SPREADING MOISTURE INTO THE
SOUTH. SPC SHORT RANGE ENSEMBLES INDICATE THE BEST
INSTABILITY...ON THE ORDER OF 100-200 J/KG MUCAPE...WILL OCCUR
ALONG THE STALLED FRONTAL BOUNDARY OVER THE NORTH BUT SOME
POSITIVE VALUES EXIST OVER THE SOUTH AS WELL OWING TO SOME
CONVECTIVE POTENTIAL OVER THE HIGHER TERRAIN THERE. SHORT TERM
FORECAST PROBLEM OF THE DAY WILL BE TO FOCUS ON FINE TUNING
TOMORROWS FRONTAL LOCATION AND TIMING AS THIS WILL HAVE EFFECT ON
BOTH TEMPS AND FOCUS OF PRECIP.

MODELS CONTINUE TO INDICATE A WEAK DEFORMATION FORMING OVER
CENTRAL UTAH SATURDAY AS THE SOUTHERN BRANCH CLOSED FEATURE
BECOMES AN OPEN WAVE LIFTING NORTHEAST THROUGH THE 4-CORNERS.
EXPECT AREAL EXTENT OF PRECIP WILL BE GREATEST BENEATH THIS
DEFORMATION AS IT FORMS OVER CENTRAL UTAH THEN TRANSITIONS
EAST...BUT CONVECTION STILL APPEARS SCATTERED AT BEST AND
GENERALLY QUITE SHALLOW.

LONG RANGE WILL CONTINUE TO FOCUS ON A A MORE SIGNIFICANT STORM
THAT LOOKS TO BRING STRONG WINDS...MUCH COLDER TEMPERATURES AND
PRECIP TO THE REGION DURING THE MIDDLE OF NEXT WEEK.

&&

.AVIATION...SOUTHERLY WINDS WILL CONTINUE AT THE SLC TERMINAL
THROUGH THE MORNING AND INTO THE EARLY AFTERNOON. SURFACE WINDS
ARE EXPECTED TO SWITCH TO THE NORTHWEST BETWEEN 20-22Z IN THE 6 TO
9 KNOT RANGE...BUT A 30 PERCENT EXISTS THAT WINDS WILL REMAIN FROM
THE SOUTH THROUGH THE DAY.

&&

.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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