000
FXUS65 KSLC 190222
AFDSLC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
822 PM MDT SAT MAY 18 2013

.SYNOPSIS...NEXT COLDER SYSTEM WILL CROSS THE REGION TONIGHT
THROUGH MONDAY MORNING. HIGH PRESSURE WILL BRIEFLY RETURN ON
TUESDAY THEN SHIFT EAST WEDNESDAY.


&&

.DISCUSSION...THE UPPER TROUGH WHICH BROUGHT WIDESPREAD RAINFALL
AND HIGH ELEVATION SNOW TO MUCH OF NORTHERN UT FRIDAY
NIGHT/SATURDAY MORNING CONTINUES TO SLOWLY MOVE EAST INTO THE
CENTRAL ROCKIES. IN ITS WAKE A BROAD CYCLONIC FLOW REMAINS IN
PLACE ACROSS THE GREAT BASIN...WITH AN UPSTREAM SHORTWAVE TROUGH
NOTED OVER THE INTERIOR PACIFIC NORTHWEST. THIS CYCLONIC FLOW
COMBINED WITH MOIST AND UNSTABLE AIRMASS CONTINUES TO SUPPORT
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ACROSS A GOOD PORTION
OF THE FORECAST AREA. THIS CONVECTION WILL LIKELY WANE A BIT WITH
THE LOSS OF DAYTIME HEATING...HOWEVER WILL LIKELY STILL SEE A FEW
OVERNIGHT SHOWERS HOLD ON. UPDATED EARLIER TO ADJUST
EVENING/OVERNIGHT POPS...AND WILL LIKELY UPDATE AGAIN LATER ON TO
REMOVE EVENING WORDING.

THE UPSTREAM SHORTWAVE IS FORECAST TO TRANSLATE
SOUTHEAST...CROSSING THE FORECAST AREA DURING THE DAY SUNDAY. THIS
FEATURE SHOULD ENHANCE SHOWERS AND THUNDERSTORMS ONCE
AGAIN...WHICH LOOK TO BE MOST CONCENTRATED ACROSS CENTRAL AND
SOUTHERN UT IN CLOSER PROXIMITY TO PASSING WAVE. CYCLONIC FLOW
WILL HOLD ON INTO THE DAY MONDAY MAINTAINING COOL TEMPERATURES AND
CONSIDERABLE CLOUD COVER...BEFORE MID LEVEL RIDGING AND AN
ATTENDANT WARMING TREND RETURNS FOR MIDWEEK. MODELS CONTINUE TO
STRUGGLE A BIT IN HANDLING UPPER LOW FOR LATE IN THE WEEK INTO
NEXT WEEKEND...WHICH IS FORECAST TO DEVELOP ACROSS THE PACIFIC
NORTHWEST.

&&

.AVIATION...LIGHT NORTH WINDS AT KSLC TO BECOME SOUTHERLY DURING
THE 04-05Z TIMEFRAME. OTHERWISE VFR CONDITIONS WITH PREVAILING
CIGS ABOVE 7 KFT TO PERSIST THROUGH THE OVERNIGHT HOURS...WITH
ONLY A 10 PERCENT CHANCE OF A BRIEF RAIN SHOWER AFFECTING THE
TERMINAL.

&&

.FIRE WEATHER...A SERIES OF STORM SYSTEMS WILL KEEP A COOL AND WET
PATTERN IN PLACE INTO MONDAY. DOWNSLOPE/CANYON WINDS WILL GUST
ACROSS PRONE AREAS ACROSS THE STATE AT TIMES THROUGH MONDAY NIGHT AS
REINFORCING COOLER AIR ARRIVES. IT COULD BE DRY AND BREEZY ENOUGH TO
PRESENT LOCAL CRITICAL FIRE WEATHER CONDITIONS IN DIXIE ON MONDAY.

SHOWERS DIMINISH IN COVERAGE THIS AFTERNOON THROUGH TONIGHT. THEN
THE NEXT SYSTEM WILL BRING ANOTHER ROUND OF WETTING RAIN (SNOW ABOVE
7.5KFT) TO NORTHERN AND CENTRAL UTAH SUNDAY. A THIRD SYSTEM WILL
MAINLY AFFECT EASTERN UTAH MONDAY.

THE PATTERN SHIFTS AS A RIDGE BUILDS IN TUESDAY AND WEDNESDAY. A
WARMING AND DRYING TREND WILL TAKE PLACE WITH MOISTURE RECOVERIES AT
NIGHT BEGINNING TO LAG.

SOUTHWEST WINDS BEGIN TO DEVELOP TUESDAY NIGHT AS A LARGE STORM
SYSTEM DEVELOPS OVER THE PACIFIC NORTHWEST. THESE WINDS INCREASE AND
BECOME STRONG AND GUSTY WEDNESDAY THROUGH SATURDAY. AT THE SAME
TIME...DAYTIME HUMIDITY LEVELS BECOME VERY DRY...5-12% ACROSS MOST
VALLEYS...MAKING FOR WIDESPREAD CRITICAL FIRE WEATHER CONDITIONS IF
ANY FUELS ARE CRITICAL.

&&

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

$$

SEAMAN/ROGOWSKI

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