Scientific Forecaster Discussion

NWS Discussion
			
				
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
843 PM MDT WED JUN 19 2013

.SYNOPSIS...AN UPPER LOW PRESSURE SYSTEM PARKED OVER THE PACIFIC
NORTHWEST WILL PUSH A SERIES OF MOSTLY DRY COLD FRONTS ACROSS
NORTHERN UTAH THROUGH THE WEEKEND. SOUTHERN UTAH WILL REMAIN WARM
AND WINDY AHEAD OF THESE FRONTS THROUGH THE WEEKEND.

&&

.DISCUSSION...A SHORTWAVE TROUGH LIFTING THROUGH SOUTHERN ID HAS
PUSHED A DRY COLD FRONT WELL INTO CENTRAL UT THIS EVENING. THIS
FRONT HAS BROUGHT MUCH COOLER TEMPERATURES TO NORTHERN UT...ALONG
WITH GUSTY NORTHWEST WINDS. ANTICIPATE THESE WINDS TO SUBSIDE OVER
THE NEXT HOUR OR TWO WITH THE LOSS OF DAYTIME MIXING AND A
WEAKENING GRADIENT. CONVECTION ASSOCIATED WITH EJECTING SHORTWAVE
HAS REMAINED CONFINED TO AREAS NORTH OF THE ID BORDER...AND THIS
WILL REMAIN THE CASE THROUGH THE REMAINDER OF THE
EVENING/OVERNIGHT PERIOD. WILL TWEAK GRIDDED FORECAST TO REMOVE
POPS FROM THE NW CORNER OF UT...OTHERWISE GOING FORECAST LOOKS
GOOD THROUGH TONIGHT. 

THE PARENT UPPER LOW IS CURRENTLY SPINNING OVER THE INTERIOR
PACIFIC NORTHWEST...AND WILL MORE OR LESS REMAIN IN PLACE THROUGH
THE REMAINDER OF THE WEEK BEFORE SLIDING EAST THIS WEEKEND. A
COUPLE OF WAVES ROTATING AROUND THIS LOW WILL BRING RE-ENFORCING
SHOTS OF COOL AIR INTO NORTHERN UT...WHILE THE SOUTH REMAINS
WARM...DRY AND BREEZY. 

&&

.AVIATION...GUSTY NORTHWEST WINDS WILL CONTINUE AT KSLC THROUGH
THE REMAINDER OF THE EVENING BEFORE SLOWLY DIMINISHING AFTER 04Z.
THERE IS A 30 PERCENT CHANCE WINDS TURN LIGHT SOUTHEASTERLY
BETWEEN 10-15Z. VFR CONDITIONS ARE EXPECTED THROUGHOUT THE
PERIOD.

&&

.FIRE WEATHER...THE DRY COLD FRONT HAS PUSHED INTO NORTHERN
PORTIONS OF ZONE 492 AND WILL SOON STALL JUST SOUTH OF THERE.
GUSTY SOUTH WINDS AND VERY DRY CONDITIONS WILL REMAIN IN PLACE
ACROSS THE SOUTHERN AND EASTERN PORTIONS AHEAD OF THIS FRONT
THROUGH FRIDAY THOUGH SPEEDS WILL TREND A BIT LOWER EACH
DAY...WHEREAS THE GUSTY POST FRONTAL WEST/NORTHWESTERLY WINDS WILL
PEAK THIS AFTERNOON/EVENING ACROSS ALL OF ZONE 478 AND THE
NORTHERN PORTION OF ZONE 492 BEFORE TAPERING OVERNIGHT THROUGH
TOMORROW. WILL RETAIN RFW THROUGH THIS EVENING ACROSS MOST ALL
ZONES OUTSIDE OF THE NORTHERN MOUNTAINS...AND ALL AREAS SOUTH OF
THE FRONTAL BOUNDARY TOMORROW.

MARGINAL CALL FOR FRIDAY ACROSS THE SOUTH REGARDING CRITICAL FIRE
WEATHER CONDITIONS. EXPECTING LOCALIZED SOUTHWESTERLY WINDS TO HIT
CRITICAL LEVELS WITHIN CONTINUED BONE DRY CONDITIONS FROM NAMELY
498 EAST THROUGH THE SOUTHEASTERN ZONES. HIGH PRESSURE MOVING
OVERHEAD SATURDAY WILL BRING MORE STABLE CONDITIONS/LIGHTER
WINDS...BUT THE APPROACH OF ANOTHER COLD FRONT LOOKS TO BRING
CRITICAL CONDITIONS TO MOST AREAS AGAIN LATE SUNDAY
AFTERNOON/EVENING ON INTO MONDAY WITH POTENTIAL FOR ISOLATED
THUNDERSTORMS IN THE NORTH MONDAY.


&&

.SLC WATCHES/WARNINGS/ADVISORIES...
UT...RED FLAG WARNING UNTIL 10 PM MDT THURSDAY BELOW 7000 FEET FOR 
     UTZ488-489-493-494.

     RED FLAG WARNING UNTIL 10 PM MDT THURSDAY BELOW 9000 FEET FOR 
     UTZ496.

     RED FLAG WARNING UNTIL 10 PM MDT THIS EVENING BELOW 6500 FEET 
     FOR UTZ478-492.

     RED FLAG WARNING UNTIL 10 PM MDT THURSDAY BELOW 6000 FEET FOR 
     UTZ495.

     RED FLAG WARNING UNTIL 10 PM MDT THURSDAY FOR UTZ497-498. 

WY...NONE.
&&

$$

SEAMAN/MERRILL

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