Area Forecast Discussion
Issued by NWS Salt Lake City, UT

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000
FXUS65 KSLC 080528 AAA
AFDSLC

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
1128 PM MDT TUE JUL 7 2015

.UPDATE...BASED ON RADAR TRENDS AND HRRR-3KM GUIDANCE HAVE PLACED
ISOLATED CONVECTION INTO THE FORECAST FOR SOUTHERN UTAH OVERNIGHT.

.SYNOPSIS...ABUNDANT MOISTURE ALONG WITH WEAK WEATHER DISTURBANCES
MOVING THROUGH THE REGION WILL GENERATE SHOWERS AND THUNDERSTORMS
THROUGH WEDNESDAY. A DRIER SOUTHWESTERLY FLOW DEVELOPS FOR
THURSDAY. A BROAD UPPER LOW WILL LIFT THROUGH THE WESTERN GREAT
BASIN LATE IN THE WEEK.

&&

.DISCUSSION...AN UPPER LOW REMAINS OFF THE CA COAST THIS EVE WITH
A BROAD LOOSELY ORGANIZED DEFORMATION AXIS ACROSS THE GREAT BASIN.
CONVECTION WAS ACTIVE THRU LATE AFTN ACROSS PORTIONS OF THE CWA
AND IS WANING THIS EVE. ACTIVITY WILL PERSIST SEVERAL MORE HOURS
ASSOCIATED WITH A NEW AREA OF DEFORMATION ACROSS SRN UT AND MAY
CONTINUE OVER THE NORTHWEST DESERT AS OUTFLOW FROM A CLUSTER OF
STORMS OVER NERN NV WORKS ACROSS THIS AREA AND SPARKS NEW CELLS.

EXPECT THE NEW DEFORMATION ZONE TO LIFT NWD INTO THE CWA OVERNIGHT
WITH AN ISOLATED CELL OR TWO AND HAVE LEFT THE ISOLATED MENTION IN
THE FORECAST ACROSS THE NRN 2/3 OF THE CWA FOR THE 06-12Z TIME
FRAME.

EXPECT WED TO SEE ACTIVE CONVECTION AGAIN MOST AREAS WITH A
CONTINUED THREAT OF HEAVY RAIN ALTHO THE SOUTH STARTS TO DRY AND
MAY BE A BIT SUPPRESSED. STRONGER SLY FLOW DEVELOPS THU AS THE CA
LOW MOVES INLAND WITH DRYING OVER MORE OF THE CWA BUT LIKELY NOT
ENOUGH TO ELIMINATE THE THREAT OF CONVECTION. THE THREAT OF HEAVY
RAIN HOWEVER DOES LOOK TO BE MUCH LESS. THE LOW IS FORECAST TO
LIFT NWD THRU WRN NV ON FRI WITH A STRONG VORT LOBE LIFTING THRU
UT LIKELY SPARKING MORE WIDESPREAD CONVECTION. A FEW STRONG STORMS
ARE POSSIBLE FRI BUT RIGHT NOW THE MODEL TIMING OF THIS LOBE TAKES
IT NORTH OF THE CWA BY EARLY AFTN SO THE THREAT IS LESS THAN IT
WOULD HAVE BEEN WITH SLIGHTLY LATER TIMING.

UPDATED EARLIER TO LOWER POPS MOST AREAS FOR THE REST OF THIS EVE
AND MADE A FEW SKY COVER TWEAKS. NO ADDITIONAL UPDATES PLANNED.

&&

.AVIATION...WIND WILL REMAIN SOUTHEASTERLY AT THE KSLC TERMINAL
OVERNIGHT INTO WED. ANY CIGS WILL REMAIN WELL ABV 7000 FT.

&&

.FIRE WEATHER...MOIST AIRMASS IN PLACE WILL HOLD OVER MUCH OF THE
DISTRICT THROUGH TOMORROW BEFORE A DRIER SOUTHWESTERLY FLOW ALOFT
MOVES SW-NE THROUGH THE EASTERN GREAT BASIN. ONE MORE DAY OF
ELEVATED WETTING RAIN POTENTIAL CAN BE EXPECTED AS SUCH. AS THE
DRIER AIR MOVES IN A DOWNWARD TREND IN RH IS EXPECTED FOR THE
LATTER HALF OF THE WEEK...BUT IT WILL TAKE SOME TIME TO SCOUR THE
PLENTIFUL LOW LEVEL MOISTURE IN PLACE. AS THIS FLOW ARRIVES...AND
A BROAD UPPER LOW APPROACHES THE AREA THURSDAY...LOCALLY BREEZY
WINDS CAN BE EXPECTED ACROSS THE WESTERN VALLEYS. AT THIS TIME RH
LOOKS TO REMAIN ABOVE CRITICAL LEVELS WHERE FUELS ARE CURED...AND
WINDS ONLY BORDERLINE CRITICAL DURING THE PM HOURS.

PASSAGE OF THE UPPER LOW LATE THURSDAY AFTERNOON AND NIGHT WILL
LIKELY SPARK HIGH BASED CONVECTION WITH MINIMAL RAINFALL BUT A
THREAT THUNDERSTORMS PRODUCING GUSTY AND ERRATIC OUTFLOW WINDS.
THIS POTENTIALLY COULD BE THE MOST CONCERNING FIRE WEATHER ISSUE
IN THE SHORT TERM.

YET ANOTHER MOISTURE SURGE IS POSSIBLE LATE NEXT WEEKEND OR EARLY
NEXT WEEK.

&&

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

$$

ROGOWSKI/WILENSKY/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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