155
FXUS65 KSLC 131004 CCA
AFDSLC
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
400 AM MDT TUE AUG 13 2013
.SYNOPSIS...DRIER AND WARMER CONDITIONS WILL SPREAD EAST ACROSS
UTAH THE NEXT COUPLE OF DAYS. MOISTURE POOLED TO THE SOUTH OF UTAH
WILL RETURN NORTH FOR THE UPCOMING WEEKEND.
&&
.DISCUSSION...THE RELATIVELY MOIST AIR OVER THE EASTERN HALF OF
UTAH HAS ONCE AGAIN SPAWNED ISOLATED NOCTURNAL CONVECTION ACROSS
SOUTHEAST UTAH. CONVECTION WILL AGAIN INCREASE IN AREAL COVERAGE
THROUGHOUT THE MOISTURE PLUME OVER THE EAST THIS AFTERNOON...WITH
ANY WEAK DYNAMIC LIFT GENERATE ENHANCED SHOWERS AND STORMS THIS
AFTERNOON THROUGH EARLY EVENING.
A VORTICITY LOBE LIFTING NORTHEAST THROUGH NORTHERN NEVADA EARLY
THIS MORNING HAS PRODUCED CONVECTION ACROSS NORTHEAST NEVADA AND
SOUTHWEST IDAHO OVERNIGHT. THE TAIL END OF THIS VORTICITY LOBE
WILL GRAZE EXTREME NORTHWEST UTAH AS IT LIFTS NORTHEAST. RADAR
DOES INDICATE ISOLATED WEAK CONVECTION OVER THE NORTHWEST CORNER AT
TIME. SUSPECT THAT CONVECTION WILL INCREASE A BIT THE NEXT SEVERAL
HOURS...THOUGH IT DOES NOT APPEAR THAT ANY DEEP CONVECTION WILL
RESULT FROM THIS PASSING VORTICITY LOBE.
LATEST GOES IMAGERY SHOWS AN EXTENSIVE AREA OF RATHER DRY AIR
EXTENDING ACROSS WESTERN ARIZONA/SOUTHERN CALIFORNIA NORTH THROUGH
EASTERN NEVADA AND WESTERN UTAH. GUIDANCE CONTINUES TO NUDGE THIS
DRIER AIR EAST THE NEXT COUPLE OF DAYS...WITH ONLY RESIDUAL
MOISTURE HANGING ON OVER EASTERN UTAH/WESTERN COLORADO. REDUCED
MOISTURE ALONG WITH BUILDING HEIGHTS ACROSS THE REGION SHOULD
CAUSE CONVECTION TO TREND DOWNWARD IN AREAL COVERAGE THE NEXT
COUPLE OF DAYS. TEMPS WILL ALSO CLIMB A FEW DEGREES...WITH MOST
AREAS OF THE STATE EXPERIENCING ABOVE NORMAL READINGS FOR MID-AUGUST.
MOISTURE POOLING OVER NORTHWEST MEXICO THE NEXT COUPLE OF DAYS
WILL LIKELY SURGE NORTH ACROSS THE GREAT BASIN BY LATE IN THE
WEEK. THE TRIGGER FOR THIS SURGE WILL COME FROM A WEAKENING UPPER
TROUGH MOVING EAST INTO THE WESTERN CONUS BY FRIDAY NIGHT OR EARLY
SATURDAY. THIS FEATURE SHOULD TAP INTO THE DEEP MOISTURE BY LATE
FRIDAY...WITH A RAPID INCREASE IN PWAT VALUES EXPECTED ACROSS
NEVADA AND WESTERN/NORTHERN UTAH FRIDAY NIGHT THROUGH SATURDAY.
ISOLATED TO SCATTERED CONVECTION SHOULD DEVELOP ON SATURDAY WITH
THE INITIAL MOISTURE SURGE. SUNDAY COULD BECOME QUITE ACTIVE AS
THE ABOVE MENTIONED UPPER TROUGH MOVES EAST THROUGH UTAH AND
SUPPLIES THE NECESSARY LIFT FOR DEEP CONVECTION. HIGH-TERRAIN
CONVECTION WILL LIKELY LINGER ACROSS MAINLY NORTHERN AND CENTRAL
UTAH EARLY NEXT WEEK AS THE FLOW ALOFT WEAKENS AND LEAVES THE
MOISTURE IN PLACE OVER THE GREAT BASIN.
&&
.AVIATION...SOUTH TO SOUTHEAST WINDS UNDER VFR CONDITIONS WILL
PREVAIL AT KSLC INTO THE AFTERNOON HOURS TUESDAY. THERE IS A 30
PERCENT CHANCE WINDS REMAINS SOUTHERLY THROUGH THE PERIOD...ALTHOUGH
WINDS WILL LIKELY ONCE AGAIN BECOME DRIVEN BY THUNDERSTORM OUTFLOWS
BETWEEN 21Z AND 03Z. THERE IS A 10 PERCENT CHANCE A THUNDERSTORM
CROSSES THE AIRFIELD...WITH AN ATTENDANT THREAT FOR CLOUD TO GROUND
LIGHTNING IN ADDITION TO GUSTY ERRATIC WINDS.
&&
.FIRE WEATHER...LINGERING MOISTURE WILL ALLOW FOR ANOTHER ROUND OF
SHOWERS AND THUNDERSTORMS PRIMARILY OVER THE HIGHER TERRAIN EAST OF
I-15 TODAY. MOISTURE HAS DECREASED A BIT FROM MONDAY...THUS
THUNDERSTORM COVERAGE IS NOT EXPECTED TO BE AS GREAT. HIGH PRESSURE
IS FORECAST TO STRENGTHEN ACROSS THE REGION WEDNESDAY THROUGH
THURSDAY. THIS WILL FURTHER STABILIZE AND DRY THE AIRMASS ACROSS THE
REGION...GREATLY LIMITING ANY POTENTIAL FOR SHOWERS AND
THUNDERSTORMS. A SLIGHT WARMING TREND IS ALSO EXPECTED AS THIS HIGH
STRENGTHENS. MOISTURE LOOKS TO RETURN NORTHWARD INTO THE REGION LATE
FRIDAY THROUGH THE UPCOMING WEEKEND.
&&
.SLC WATCHES/WARNINGS/ADVISORIES...
UT...NONE.
WY...NONE.
&&
$$
PUBLIC...CONGER
FIRE WEATHER/AVIATION...SEAMAN
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...
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