Area Forecast Discussion
Issued by NWS Salt Lake City, UT

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000
FXUS65 KSLC 111047
AFDSLC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
447 AM MDT FRI JUL 11 2014

.SYNOPSIS...A DEEPLY MOIST AIRMASS WILL REMAIN OVER MUCH OF THE
AREA TODAY. SLOW DRYING WILL BEGIN ACROSS UTAH SATURDAY WITH THIS
TREND CONTINUING THROUGH MONDAY MAINLY OVER THE NORTHWEST.
MOISTURE WILL START TO INCREASE AGAIN TUESDAY THROUGH THE END OF
NEXT WEEK.

&&

.SHORT TERM (THROUGH 12Z SUNDAY)...ANOTHER ROUND OF MONSOONAL
CONVECTION IS EXPECTED TODAY...WITH THE LARGEST THREAT OF FLASH
FLOODING ANTICIPATED ACROSS CENTRAL UTAH THIS AFTERNOON AND
EVENING. SEVERAL SHORTWAVES CAN BE DISCERNED IN WATER VAPOR
IMAGERY THIS MORNING. THESE WAVES ARE EXPECTED TO CONSOLIDATE
LATER THIS MORNING INTO EARLY THIS AFTERNOON OVER SOUTHERN UTAH
AND THEN SLOWLY MOVE NORTH TO NORTHEASTWARD ACROSS THE AREA
THROUGH THE AFTERNOON.

PW VALUES NEAR 1.00 TO 1.33 INCHES OR SO ARE STRETCHED ACROSS MUCH
OF THE STATE THIS MORNING. EXPECT A DRY SLOT TO BRING DRIER AIR
INTO THE FAR SOUTHEASTERN AREAS TODAY. SOME MODEL GUIDANCE
INDICATES THIS DRIER AIR WILL MOVE AS FAR NORTH AS THE SAN RAFAEL
SWELL. THIS MAY BE A BIT OF A WRENCH IN THE CURRENT FLASH FLOOD
WATCH FOR THE SWELL.

GIVEN THE ENHANCED LIFT WITH THE PREVIOUSLY MENTIONED
SHORTWAVES...THE MORE THAN SUFFICIENT MOISTURE AND FAIRLY LOW STORM
MOTIONS...ANTICIPATE CONVECTION WILL BRING ANOTHER ROUND OF HEAVY
RAINFALL FOR MUCH OF THE STATE THIS MORNING INTO THIS AFTERNOON.

ISSUED A FLASH FLOOD WATCH FROM 16Z THROUGH 03Z THIS EVENING FOR
PORTIONS OF CENTRAL AND EASTERN UTAH. EXPECT A DECENT THREAT OF
HEAVY RAINFALL ACROSS LOCATIONS NORTH OF THIS AREA INCLUDING THE
WASATCH FRONT AND WASATCH MOUNTAINS...BUT THE TERRAIN IN THESE AREAS
IS LESS PRONE TO FLASH FLOODING. THEREFORE...DECIDED TO KEEP THE
FLASH FLOOD WATCH FOR THE HIGHEST THREAT AREA INCLUDING SLICK ROCK
AREAS...SLOT CANYONS...NORMALLY DRY WASHES AND SMALL STREAMS IN
STEEP TERRAIN. THE SEELEY BURN SCAR EXPERIENCED A DEBRIS FLOW
THURSDAY...AND THIS BURN SCAR IN PARTICULAR HAS A THREAT OF
ANOTHER DEBRIS FLOW TODAY.

THE MAIN PORTION OF THE WAVE WILL MOVE NORTHEASTWARD TONIGHT AND
EXIT THE AREA LATE FRIDAY INTO EARLY SATURDAY. HIGH PRESSURE IS
EXPECTED TO STRENGTHEN ACROSS THE AREA SATURDAY. PWS DO NOT
DECREASE MARKEDLY...REMAINING BETWEEN 0.75 AND 1.00 INCH ACROSS
MUCH OF THE CWA SATURDAY AFTERNOON. CURRENT MODEL GUIDANCE
SUGGESTS SUBSIDENCE IN ASSOCIATION WITH THE STRENGTHENING HIGH
PRESSURE WILL BE ENOUGH TO KEEP ANY CONVECTION ASSOCIATED WITH THE
HIGHER TERRAIN AND OF A LOW COVERAGE. THIS MAY BE UNDERDONE AND
COVERAGE OF CONVECTION MAY BE HIGHER THAN CURRENTLY FORECAST.
FUTURE MODEL RUNS WILL BE MONITORED FOR TRENDS.

&&

.LONG TERM (AFT 12Z SUN)...BY SUNDAY MORNING THE HIGH IS CENTERED
OVER NRN NV WITH A NELY FLOW OVER OUR CWA. SUBSIDENCE FROM THIS
HIGH WILL CONTINUE TO SUPPRESS CONVECTION AND KEEP A GRADUAL
DRYING TREND GOING. HOWEVER...EXPECT SUFFICIENT RESIDUAL MOISTURE
TO GENERATE DIURNAL TERRAIN BASED CONVECTION THAT COULD DRIFT
SWWD INTO THE SWRN UT VALLEYS...BUT NOT ENOUGH MOISTURE FOR A
HEAVY RAIN THREAT.

BY MONDAY THE HIGH CENTER HAS SHIFTED OVER SRN UT WITH ENOUGH LINGERING
MOISTURE FOR ISOLATED MTN TSTMS. ON TUE THE RIDGE AXIS SHIFTS
SOUTH AND A NWLY FLOW IS OVER THE CWA. THIS KEEPS THE NORTH DRY
WHILE MOISTURE SEEPS BACK THRU THE RIDGE AXIS INTO SRN UT...WITH A
SIMILAR PATTERN FOR WED AND THU. THE FLOW BACKS TO SWLY FRI INTO
THE WEEKEND AND MOISTURE THAT HAD SPREAD UP THRU CA AND WRN NV
SPREADS INTO OUT CWA.

TEMPS WILL REMAIN WARMER THAN NORMAL THRU MOST OF THE PERIOD ALTHO
COULD BE MODIFIED TO SOME EXTENT BY CONVECTION.

&&

.AVIATION...SOUTHERLY WINDS WILL CONTINUE AT THE SLC TERMINAL
THROUGH THE DAY. CONVECTION IS EXPECTED TO INCREASE IN THE
VICINITY OF THE TERMINAL THIS AFTERNOON AND EVENING. THERE IS A 30
PERCENT CHANCE A THUNDERSTORM MAY DIRECTLY IMPACT THE TERMINAL.
GUSTY AND ERRATIC WINDS ARE LIKELY NEAR ANY SHOWERS OR
THUNDERSTORMS.

&&

.FIRE WEATHER...DEEP MOISTURE WILL REMAIN IN PLACE ACROSS MUCH OF
THE DISTRICT TODAY. WETTING RAINS ARE LIKELY NEAR ANY SHOWERS OR
THUNDERSTORMS DISTRICT-WIDE TODAY...THOUGH THE CHANCE OF WETTING
RAIN WILL BE QUITE A BIT LOWER THAN THE PAST FEW DAYS ACROSS THE FAR
SOUTHWESTERN PORTION OF THE DISTRICT. CONVECTION IS EXPECTED TO BE
CONFINED TO MAINLY THE HIGHER TERRAIN SATURDAY AS HIGH PRESSURE
STRENGTHENS OVER THE AREA. THIS TREND WILL CONTINUE THROUGH EARLY
NEXT WEEK...WITH CONVECTION IS EXPECTED TO REMAIN ACROSS THE HIGHER
TERRAIN AND ADJACENT VALLEYS THROUGH MONDAY. THESE STORMS WILL TEND
TO BE DRIER...WITH WETTING RAINS UNLIKELY AFTER TODAY.

&&

.SLC WATCHES/WARNINGS/ADVISORIES...
UT...FLASH FLOOD WATCH FROM 10 AM MDT THIS MORNING THROUGH THIS
     EVENING FOR UTZ010-012-013-517.

WY...NONE.
&&

$$

SHORT TERM/FIRE WEATHER/AVIATION...KRUSE
LONG TERM...WILENSKY


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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