Area Forecast Discussion
Issued by NWS Salt Lake City, UT

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FXUS65 KSLC 261143
AFDSLC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
543 AM MDT TUE APR 26 2016

.SYNOPSIS...AN UPPER LOW WILL CONTINUE TO MOVE SLOWLY EAST AND OUT
OF UTAH LATE THIS AFTERNOON THROUGH THIS EVENING. ANOTHER SYSTEM
IS EXPECTED FOR THE LATTER HALF OF THE WEEK...AND A THIRD FOR THE
UPCOMING WEEKEND.

&&

.SHORT TERM (THRU 12Z FRIDAY)...THE UPPER LOW IS CENTERED ROUGHLY
OVER THE UT-CO BORDER EARLY THIS MORNING WITH WRAP AROUND PRECIP
SPREADING WWD THRU WY AND INTO NRN UT AND WRN UT. ALTHO RADAR
ECHOES ARE PRETTY SPARSE LIGHT RAIN IS BEING REPORTED FROM MOST
AREAS UP AND DOWN THE I-15 CORRIDOR FROM SLC SOUTH TO ALMOST CEDAR
CITY.

EXPECT THIS TO CONTINUE THROUGH ABOUT MID AFTERNOON THEN GRADUALLY
TAPER OFF AS THE LOW MOVES OFF INTO ERN CO AND UPSTREAM SHORT WAVE
RIDGING STARTS TO SPREAD INTO THE CWA.

THE NEXT PAC TROF IS FORECAST TO BEGIN SPREADING SHOWERY PRECIP
INTO THE CWA WED AFTN THAT BECOMES FAIRLY WIDESPREAD WED NIGHT
THRU THU AS THIS NEXT UPPER LOW TRACKS EAST ALONG THE UT AZ
BORDER.

MODELS ARE ALSO ADVERTISING A MODEST CANYON WIND EPISODE FOR THE
WASATCH FRONT THU MORNING WITH 8 TO 10 MB SURFACE PRESSURE
GRADIENT RIW-SLC AND EASTERLY FLOW ALOFT AROUND THE N SIDE OF THE
UPPER LOW. THESE FACTORS WOULD BE SUFFICIENT TO ALLOW WINDS TO
REACH ADVISORY LEVELS IF MODELS ARE CORRECT.

SCATTERED PRECIP PERSISTS THU NIGHT AS THE LOW CENTER MOVES EAST
INTO SWRN CO.

.LONG TERM (AFTER 12Z FRIDAY)...THE MEAN LONG WAVE TROUGH WILL
CONTINUE TO ENCOMPASS THE INTERMOUNTAIN REGION THROUGH MUCH OF THE
EXTENDED PERIOD. AS THE SLOW MOVING UPPER LOW EMBEDDED WITHIN THIS
PATTERN GRADUALLY PULLS EAST AND DOWNSTREAM OF THE AREA FRIDAY A
GENERAL DECREASE IN PRECIP POTENTIAL IS EXPECTED THROUGH THE
DAY...THOUGH THE SOUTHEAST WILL HOLD ONTO THE BEST POTENTIAL THROUGH
MIDDAY WHERE CONVERGENT MID LEVEL FLOW SHOULD CONTINUE TO AID LIFT.

WEAK SHORT WAVE RIDGING ADVERTISED IN GLOBALS DOES LOOK TO LIMIT
CONVECTIVE POTENTIAL SOME FRIDAY AFTERNOON...BUT INFLUENCE OF THE
NEXT UPSTREAM TROUGH LOOKS TO INCREASE LARGE SCALE LIFT ONCE AGAIN
COME SATURDAY. LATEST 06Z GFS SHOWING SIGNS OF TRENDING TOWARDS THE
EC AND ITS SLIGHTLY MORE AMPLIFIED SOLUTION ALLOWING MORE NOTABLE
CURVATURE AND A NET TIGHTENING OF THE H7 THERMAL GRADIENT OVERHEAD AS
THE SHORT WAVE DEEPENS AND TRENDS TO FORM A CLOSED MID LEVEL
CIRCULATION DURING THE DAY. SET UP APPEARS CONDITIONALLY UNSTABLE
ONCE AGAIN...WITH LIFT LIKELY FOCUSED ALONG SAID THERMAL GRADIENT
AND AREAS OF CONVERGENT MID LEVEL FLOW. NOT OVERLY CONFIDENT WHERE
THIS WILL OCCUR AS OF YET SO MAINTAINED SLIGHT CHANCE/CHANCE POPS
MOST ALL AREAS OUTSIDE OF THE EXTREME SOUTH. MORE DETAILS TO FALL
OUT AS MODEL TO MODEL AND RUN TO RUN CONSISTENCY INCREASES.

PATTERN THEREAFTER SHIFTS THE MEAN LONG WAVE TROUGH EAST ALLOWING
BUILDING HEIGHTS...DRYING CONDITIONS AND NET STABILIZATION EARLY
NEXT WEEK. TIMING AND EVOLUTION OF THIS REMAINS DEPENDENT ON THE
MEAN AMPLIFICATION OF THE PREVIOUS TROUGH HOWEVER. FAIR CONFIDENCE
IN THE OVERALL EVOLUTION OF THE LONG WAVE PATTERN ATTM.

&&

.AVIATION...LOW CIGS AND PERIODIC SHOWERS ARE THE MAIN OPERATIONAL
WEATHER CONCERN FOR THE KSLC TERMINAL INTO EARLY AFTERNOON.
EXPECTING CIGS TO BOUNCE BETWEEN 2000-4000FT AGL DURING THIS
TIME...WITH A 30 PERCENT CHANCE OF VIS LOWERING TO MVFR LEVELS AT
TIMES THROUGH 18/19Z DURING HEAVIER SHOWER PERIODS. CIGS ARE
EXPECTED TO LIFT THIS AFTERNOON AND LARGELY REMAIN OVER 6000FT
AGL...THOUGH MOUNTAIN OBSCURATION WILL LIKELY CONTINUE INTO EARLY
EVENING.

&&

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

$$

SHORT TERM...WILENSKY
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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