Area Forecast Discussion
Issued by NWS Salt Lake City, UT

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000
FXUS65 KSLC 261552
AFDSLC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
952 AM MDT TUE AUG 26 2014

.SYNOPSIS...AN UPPER LOW OVER NEVADA THIS MORNING WILL MOVE INTO
WESTERN UTAH THIS AFTERNOON AND THEN INTO THE UINTA BASIN
WEDNESDAY MORNING.

&&

.DISCUSSION...UPPER LOW OVER NEVADA THIS MORNING IS FORECAST BY
ALL MODELS TO MOVE/REDEVELOP INTO WEST CENTRAL UTAH BY THIS
EVENING. STRONG SOUTHWEST FLOW AHEAD OF THE LOW HAS BROUGHT
MOISTURE NORTHWARD INTO SOUTHERN UTAH. PRECIPITABLE WATER VALUES
OVER SOUTHERN UTAH ARE NEAR ONE INCH WITH THE HIGHEST VALUES BEING
NEAR LAKE POWELL AND THE COLORADO/GREEN RIVERS. AMPLE VERTICAL
SHEAR IN THIS SAME AREA AS THE JET AXIS IN THE 12Z RAOB DATA
EXTENDS FROM APPROXIMATELY THE GRAND CANYON TO GRAND JUNCTION.

VARIOUS OVERNIGHT MODELS...12Z NAM...AND 12/13Z HRRR OFFER A WIDE
VARIETY OF FORECASTS ON EXACT LOCATION OF TODAY`S PRECIPITATION...SO
CONFIDENCE IS NOT HIGH ON DETAILS...BUT GENERAL IDEA IN HRRR SEEMS
REASONABLE...AND THIS GENERAL IDEA IS FOR CONVECTION TO DEVELOP
BENEATH THE JET FROM ABOUT KANAB TO LAKE POWELL AND THEN QUICKLY
EXTEND NORTHWARD THIS AFTERNOON AND EVENING...WHILE ANOTHER AREA
OF CONVECTION DEVELOPS IN THE VICINITY OF THE UPPER LOW OVER THE
MOUNTAINS OF EAST CENTRAL NEVADA...AND THIS AREA MOVES INTO THE
WESTERN UTAH DESERTS LATE THIS AFTERNOON. SOME OF THIS DESERT CONVECTION
COULD EXTEND INTO THE WASATCH FRONT THIS EVENING.

THE CONVECTION BENEATH THE JET HAS A GOOD CHANCE OF GENERATING
SOME THUNDERSTORMS WITH HAIL AND STRONG WINDS. YESTERDAY SAW
WIDESPREAD HAIL WITH SOME STORMS PRODUCING SO MUCH SMALL HAIL THAT
IT HAD TO BE PLOWED. BELIEVE THIS COULD HAPPEN AGAIN TODAY...BUT
MAINLY OVER SOUTHEAST/SOUTH CENTRAL UTAH. LESS SHEAR OVER THE
NORTH AND WEST SO THUNDERSTORMS LESS LIKELY TO BE ORGANIZED.

POTENTIAL FOR HEAVY RAIN AND FLASH FLOODING ALSO EXISTS OVER
SOUTHEAST/SOUTH CENTRAL UTAH...BUT STORMS WILL BE MOVING QUITE
FAST AND IT WILL TAKE REPEAT CELLS OR A STORM MOVING DIRECTLY DOWN
A DRAINAGE TO PRODUCE FLOODING.

THE UPPER LOW REDEVELOPS OVER THE UINTA BASIN OVERNIGHT AND EXPECT
SCATTERED SHOWERS AND THUNDERSTORMS TO CONTINUE THROUGH THE NIGHT
OVER MUCH OF THE FORECAST AREA.

THE UPPER LOW AND RESIDUAL MOISTURE INDICATE A CONTINUED THREAT OF
RAIN WEDNESDAY OVER ABOUT THE EASTERN 2/3RDS OF THE FORECAST AREA.

DRYING AND WARMING THUR/FRI.

NO CHANGES TO CURRENT FORECAST AT THIS TIME.

&&

.AVIATION...SURFACE WINDS AT THE KSLC TERMINAL ARE EXPECTED TO
PREVAIL OUT OF THE NORTHWEST...BUT GUSTY AND ERRATIC OUTFLOW WINDS
WILL BE POSSIBLE THIS AFTERNOON AND EVENING. ISOLATED SHOWERS AND
THUNDERSTORMS ARE EXPECTED TO DEVELOP OVER THE SURROUNDING TERRAIN
AFTER 18-19Z WITH COVERAGE LIKELY INCREASING AFTER 00Z AND LASTING
THROUGH THE EVENING. WITH THIS ACTIVITY A 20 PERCENT CHANCE EXISTS
PERIODIC MVFR CONDITIONS WILL OCCUR IN STORMS AFTER 00Z.

&&

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

$$

PUBLIC...DUNN
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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