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000
FXUS65 KSLC 230206
AFDSLC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
806 PM MDT WED MAY 22 2013

.SYNOPSIS...A LOW PRESSURE SYSTEM WILL REMAIN OVER THE PACIFIC
NORTHWEST THROUGH THIS WEEK...KEEPING MOST OF UTAH AND SOUTHWEST
WYOMING IN A DRY SOUTHWEST FLOW.  SEVERAL WEAK COLD FRONTS WILL
ENTER NORTHWEST UTAH THROUGH THE END OF THE WEEK BUT WILL TEND TO
DISSIPATE BEFORE REACHING CENTRAL UTAH.

&&

.DISCUSSION...WATER VAPOR LOOP SHOWS A LARGE PACIFIC STORM OVER THE
PACIFIC NORTHWEST. ACARS 400-250MB WIND OBSERVATIONS SHOW A 75-110KT
CYCLONICALLY CURVED JET OVER THE PACIFIC NORTHWEST. RAP...GOES...GPS
SENSORS...AND 00Z SLC RAOB INDICATE PRECIPITABLE WATER VALUES IN THE
0.15"-0.65" RANGE ACROSS THE REGION.

COLD FRONT HAS CROSSED THE NORTHWEST THIRD OF UTAH AS OF EARLY
EVENING. 24HR TEMPERATURE CHANGE IS -15F TO -25F BEHIND THE
BOUNDARY.

REGIONAL RADAR INDICATES THAT DRY SHOWERS ARE AFFECTING THE WEST
DESERT AS DIVERGENCE ALOFT INCREASES. BASED ON 00Z SOUNDING...THIS
ACTIVITY POSES MORE OF A GUSTY WIND THREAT THAN MEASURABLE
PRECIPITATION. EXPANDED COVERAGE OF THIS ACTIVITY ACROSS THE WEST
THIS EVENING.

UPDATED TO REFINE WINDS TONIGHT. BOTH THE HRRR-3KM AND LOCAL 4KM
WRF-ARW INDICATE WINDS WILL SLACKEN FIRST AHEAD OF...THEN BEHIND THE
BOUNDARY LATE THIS EVENING OR EARLY OVERNIGHT.

ALSO SLIGHTLY ADJUSTED SKY GRIDS BASED ON IR SATELLITE TRENDS.
OTHERWISE VERY MINOR CHANGES TO TEMPERATURES OVERNIGHT. REST
UNCHANGED.

PREVIOUS DISCUSSION FOLLOWS...
A LARGE AND SOMEWHAT STATIONARY UPPER LEVEL LOW IS
CURRENTLY NEAR THE PACIFIC NORTHWEST COAST THIS AFTERNOON. A
DISTURBANCE ROTATING OFF THIS LOW WILL CONTINUE TO PUSH A COLD
FRONT THROUGH NORTHERN UTAH THIS AFTERNOON. THIS FRONT IS EXPECTED
TO STALL IN CENTRAL UTAH LATER THIS EVENING. THE BOUNDARY IS THEN
EXPECTED TO SLOWLY DIMINISH BEFORE LIFTING NORTH AHEAD OF ANOTHER
DISTURBANCE THURSDAY.

A FEW SHOWERS HAVE DEVELOPED ALONG THE BOUNDARY THIS AFTERNOON.
A THUNDERSTORM OR TWO IS POSSIBLE...MAINLY OVER THE HIGHER TERRAIN
OF NORTHERN UTAH. ANY THREAT WILL QUICKLY END AFTER SUNSET.

GUSTY SOUTH WINDS HAVE ALSO DEVELOPED ACROSS SOUTHERN UTAH THIS
AFTERNOON...WITH A FEW GUSTS OVER 50 MPH. WINDS WILL CONTINUE TO
BE GUSTY IN THIS AREA INTO THE EVENING BUT SHOULD DIMINISH AFTER
SUNSET. GIVEN THE LIMITED DURATION OF THE WIND GUSTS OVER 45
MPH...DECIDED NOT TO ISSUE A WIND ADVISORY. TRAVELERS IN THIS AREA
SHOULD BE PREPARED FOR STRONG CROSSWINDS ON PRIMARILY EAST-WEST
RUNNING ROUTES IN THIS AREA.

WITH A COOLER AIRMASS OVER NORTHERN UTAH TOMORROW...EXPECT
TEMPERATURES TO BE A FEW DEGREES COOLER THAN TODAYS
READINGS...WHICH WERE CLOSE TO RECORD LEVELS IN SALT LAKE CITY.

ANOTHER DISTURBANCE WILL BRING A MAINLY DRY COLD FRONT THROUGH THE
AREA THURSDAY AFTERNOON. THIS FRONT WILL LIKELY STALL ONCE AGAIN
ACROSS NORTHERN UTAH BEFORE DIMINISHING.

THE PERSISTENT TROUGH NEAR THE PACIFIC NORTHWEST COAST IS FORECAST
TO RETROGRADE WESTWARD FRIDAY INTO SATURDAY. DEPENDING ON HOW FAR
WEST THIS TROUGH MOVES DETERMINES THE EXTENT OF THE WARMUP FOR
UTAH THIS WEEKEND INTO EARLY NEXT WEEK. FAVORED THE SLIGHTLY
WARMER EC SOLUTION AND NUDGED TEMPERATURES UP A BIT IN THE
EXTENDED. REGARDLESS...IT LOOKS TO BE QUITE DRY ACROSS THE CWA FOR
THE NEXT SEVEN DAYS...PARTICULARLY ACROSS CENTRAL AND SOUTHERN
UTAH.

&&

.AVIATION...VFR CONDITIONS AND NORTHWESTERLY WINDS SHOULD PERSIST AT
THE SLC TERMINAL THROUGH THE OVERNIGHT HOURS. WIND GUSTS ARE
EXPECTED TO DROP BELOW 30 MPH BETWEEN 02Z AND 03Z...WITH A 20
PERCENT CHANCE THAT THESE GUSTS PERSIST THROUGH 05Z.

&&

.FIRE WEATHER...STRONG SOUTHERLY WINDS CONTINUE AHEAD OF A COLD
FRONT MOVING EAST THROUGH NORTHERN UTAH THIS AFTERNOON. ALONG THE
FRONT ISOLATED CONVECTION HAS FORMED...THOUGH GENERALLY OUTSIDE THE
FIRE DISTRICTS OVER NORTHEAST NEVADA AND SOUTHEAST IDAHO. COULD SEE
ONE OR TWO SHOWERS/THUNDERSTORMS POP UP OVER THE HIGHER TERRAIN OF
NORTHWEST UTAH EARLY THIS EVENING.

THE UPPER LOW CURRENTLY OVER THE PACIFIC NORTHWEST WILL REMAIN IN
THAT GENERAL AREA THROUGH THE UPCOMING WEEKEND. A PERSISTENT SOUTH
TO SOUTHWEST FLOW ALOFT WILL CONTINUE TO GENERATE BREEZY...WARM AND
DRY CONDITIONS ACROSS SOUTHERN...CENTRAL AND EASTERN UTAH THROUGH
THE FORECAST PERIOD. NOT PLANNING ON ANY FIRE WEATHER HIGHLIGHTS AT
THIS TIME...THOUGH FUELS MAY REACH CRITICAL LEVELS BY LATE IN THE
WEEK OR EARLY IN THE WEEKEND.

NORTHERN UTAH WILL BE PRONE TO WEAK SYSTEMS EJECTING OUT OF THE MAIN
LOW PRESSURE CLIPPING THE NORTHWEST QUARTER OF THE STATE.
PRECIPITATION IS NOT EXPECTED TO GENERATE WETTING RAINS...THOUGH THE
ASSOCIATED SURFACE FRONTS WILL SHAVE A FEW DEGREES OFF TEMPERATURES
IN THEIR WAKE. MOISTURE LOOKS TO BE SOMEWHAT LIMITED THROUGH THE
PERIOD...SO THE THREAT FOR SIGNIFICANT RAINFALL IS MINIMAL AT THIS
TIME.

&&

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

$$

PUBLIC...ROGOWSKI/KRUSE
FIRE WEATHER...CONGER
AVIATION...SCHOENING

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)