Area Forecast Discussion
Issued by NWS Salt Lake City, UT

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000
FXUS65 KSLC 012137
AFDSLC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
337 PM MDT FRI MAY 1 2015

.SYNOPSIS...A MILD WEST TO SOUTHWEST FLOW ALOFT WILL DEVELOP
ACROSS THE REGION THROUGH THE WEEKEND AND REMAIN INTO EARLY NEXT
WEEK. THIS FLOW WILL BE ACCOMPANIED BY A GRADUAL INCREASE IN
MOISTURE.




&&

.SHORT TERM (THROUGH 06Z TUESDAY)...HIGH PRESSURE CENTERED OVER
THE DESERT SOUTHWEST HAS LED TO ANOTHER WARM AFTERNOON ACROSS UTAH
AND SOUTHWEST WYOMING...WITH SOME MID AND HIGH LEVEL CLOUDS
DRIFTING ACROSS THE AREA IN THE SOUTHWESTERLY FLOW. AFTERNOON
CONVECTIVE ACTIVITY HAS BEEN ABOUT AS EXPECTED...WITH THE BEST
COVERAGE OF SHOWERS AND THUNDERSTORMS ALONG THE HIGHER TERRAIN OF
NORTHEAST UTAH...AS WELL AS SOME SHOWERS DRIFTING INTO FAR WESTERN
UTAH AFTER THEIR INITIATION IN NEVADA.

THE RIDGE WILL SLOWLY SHIFT EASTWARD THROUGH THE WEEKEND...BUT
UTAH WILL LARGELY REMAIN UNDER A SIMILAR WEST-SOUTHWESTERLY
FLOW...WITH GRADUALLY INCREASING MOISTURE ALOFT. COMBINED WITH
WEAK DISTURBANCES...COVERAGE OF SHOWERS AND THUNDERSTORMS COULD
INCREASE A BIT OVER THE WEEKEND. THE AIRMASS WILL REMAIN FAIRLY
WARM...THOUGH A SLIGHT COOLING TREND COULD BEGIN AS EARLY AS
SUNDAY...WITH INCREASING CLOUD COVER POSSIBLE.

A WEAK UPPER LOW IS STILL FORECAST TO SLIDE THROUGH SOUTHERN
CALIFORNIA AND ARIZONA ON MONDAY...PERHAPS ADDING A LITTLE MORE
MOISTURE AND SYNOPTIC SCALE FORCING TO FUEL CONVECTIVE ACTIVITY
AND CLOUD COVER...THOUGH THIS LOW MIGHT BE JUST FAR ENOUGH AWAY
THAT MONDAY MAY NOT LOOK CONSIDERABLY DIFFERENT THAN SUNDAY
ACROSS UTAH. THIS LOW IS CURRENTLY PROGGED TO PUSH SLOWLY INTO THE
FOUR CORNERS HEADING INTO MONDAY NIGHT.


.LONG TERM (AFTER 06Z TUESDAY)...VERY NONDESCRIPT FLOW ACROSS THE
UTAH REGION TUESDAY AS THERE IS A REMNANT LOW OVER THE ARIZONA TO
4 CORNERS REGION WITH A SHORTWAVE TROUGH DIGGING SOUTHEAST INTO
THE PACIFIC NORTHWEST. VERY LITTLE DYNAMICS OVERHEAD BUT RESIDUAL
MOISTURE AT MID LEVELS WILL LIKELY BE ENOUGH FOR SCATTERED SHOWERS
AND ISOLATED THUNDERSTORMS OVER THE HIGHER TERRAIN AND ISOLATED
ACTIVITY OVER THE VALLEYS. HAVE BACKED OFF ON THE POPS FOR THE
OVERNIGHT PERIOD AS LITTLE IN THE WAY IN DYNAMICS FORECAST AT THIS
TIME TO KEEP CONVECTION GOING ONCE THE SUN GOES DOWN.

HAVE KEPT SLIGHT CHANCE TO CHANCE POPS ACROSS THE NORTHERN HALF OF
THE CWA WEDNESDAY AND WEDNESDAY NIGHT AS THE EC AND GFS SHOW A WEAK
BOUNDARY DRIFTING SOUTH AND STALLING OVER CENTRAL UTAH BY WEDNESDAY
NIGHT. SOUTH OF HERE EXPECT LESS THREAT OF SHOWERS AND THUNDERSTORMS
AS LOWER PWS GET PULLED IN FROM ARIZONA.

AS THE CLOSED LOW MOVES INTO SOUTHERN NEVADA THURSDAY DYNAMIC LIFT
IS EXPECTED TO SPREAD OVER MUCH OF WESTERN AND NORTHERN UTAH. HAVE
INCREASED POPS TO CHANCE CATEGORY IN MOST OF THIS AREA...BUT LEFT IT
DRY IN THE EAST WHERE THE AIR MASS WITH LOWER PW REMAINS.

THE MODELS HINT THAT THE CLOSED LOW WILL RECEDE BACK NORTHWARD AND
WEAKEN. HAVE LEFT POPS ALONE FOR NOW AS LOW CONFIDENCE WITH
FORECAST.

&&

.AVIATION...THE SLC TERMINAL WILL SEE VFR CONDITIONS THROUGH THE TAF
PERIOD. NORTHWEST WINDS WILL SHIFT TO SOUTHEAST BY ABOUT 03Z. THERE
IS A SMALL CHANCE...10 PERCENT...THAT AN OUTFLOW FROM A COLLAPSING
CELL WILL IMPACT THE TERMINAL BETWEEN 23 AND 02Z.


&&

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

$$

SHORT TERM...SCHOENING
LONG TERM/AVIATION...STRUTHWOLF

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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