000
FXUS65 KSLC 180228
AFDSLC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
828 PM MDT FRI MAY 17 2013

.SYNOPSIS...A COOL MOIST UPPER TROUGH WILL CROSS THE GREAT BASIN
THROUGH EARLY SATURDAY. A COLDER SYSTEM WILL CROSS THE REGION
SATURDAY NIGHT AND SUNDAY. HIGH PRESSURE WILL RETURN FOR THE FIRST
PART OF NEXT WEEK.


&&

.DISCUSSION...AN UPPER TROUGH SLOWLY ROTATING ACROSS NV WILL SLIDE
EAST ACROSS NORTHERN AND CENTRAL UT OVERNIGHT THROUGH SATURDAY
MORNING. SHOWERS AND ISOLATED THUNDERSTORMS HAVE BEEN ON THE
UPSWING ACROSS NORTHERN UT OVER THE PAST COUPLE OF HOURS...AND
ANTICIPATE THIS TREND TO CONTINUE INTO THE OVERNIGHT HOURS.
PRECIPITATION WILL LIKELY BECOME MORE STRATIFORM LATE TONIGHT
INTO SATURDAY MORNING WITH THE PASSAGE OF THE UPPER TROUGH AXIS.
FURTHER SOUTH CONVECTION HAS REMAINED MORE ISOLATED TO SCATTERED
IN NATURE...ALTHOUGH AGAIN THIS ACTIVITY HAS BEGUN TO INCREASE IN
THE LAST HOUR OR SO. THIS IS PARTICULARLY THE CASE ALONG THE
SURFACE FRONT ACROSS SOUTHERN NV...WHICH WILL SWING EAST ACROSS
SOUTHERN UT OVERNIGHT. THE 18/00Z MODELS ALL SUGGEST PRECIPITATION
ALONG THIS BOUNDARY WILL DIMINISH QUICKLY BY LATE EVENING.

UPDATED EARLIER TO INCREASE POPS OVERNIGHT INTO SATURDAY MORNING
ACROSS THE NORTHERN HALF OF THE AREA...AND ONCE PRECIP SETS IN
ALONG THE WASATCH FRONT WILL LIKELY UPDATE TO REMOVE EVENING
WORDING.

IN THE WAKE OF THIS INITIAL SHORTWAVE...AS SECONDARY SHORTWAVE
TROUGH WILL DIG ACROSS UT SUNDAY AFTERNOON THROUGH SUNDAY
NIGHT...BRINGING A RE-ENFORCING SHOT OF COOL AIR ALONG WITH AN
ADDITIONAL CHANCE FOR SHOWERS. MID LEVEL RIDGING RETURNS EARLY IN
THE WEEK ALLOWING FOR A WARMING TREND. MEDIUM RANGE MODELS
CONTINUE TO STRUGGLE A BIT WITH EVOLUTION OF UPPER LOW EXPECTED TO
DEVELOP OVER THE PACIFIC NORTHWEST FOR THE LATTER HALF OF THE
WEEK.

&&

.AVIATION...SHOWERS WILL INCREASE LATE THIS EVENING INTO THE
OVERNIGHT HOURS AT KSLC...LIKELY BRINGING CIGS BELOW 6000FT AGL
AND BRIEF BUT ERRATIC GUSTY WINDS AND/OR PERIODIC LIGHT AND
VARIABLE CONDITIONS. THIS SAID...WINDS ARE EXPECTED TO PREVAIL
FROM THE NORTHWEST WITH SPEEDS GREATER THAN 8 KNOTS THROUGH THIS
EVENING. ALTHOUGH THUNDERSTORMS REMAIN A SLIGHT THREAT...ONLY A 20
PERCENT CHANCE EXISTS FOR ANY DIRECT IMPACT TO THE TERMINAL.

THE HEAVIEST RAIN THREAT EXISTS TOMORROW MORNING...WITH A 40 PERCENT
CHANCE THAT CIGS LOWER TO OR BELOW 3000FT AGL AT TIMES BETWEEN
13-16Z.

&&

.FIRE WEATHER...A SLOW MOVING TROUGH WILL BRING COOLER AND MORE
MOIST CONDITIONS TO NORTHERN AND CENTRAL UTAH TONIGHT THROUGH
SATURDAY WITH ANOTHER DISTURBANCE AFFECTING MAINLY NORTHERN UTAH
SUNDAY. SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WILL ACCOMPANY
THIS COOL AND HIGHER RH PERIOD. A WARMING AND DRYING TREND WILL SET
IN FOR THE MONDAY THROUGH WEDNESDAY PERIOD WITH INCREASING SOUTHERLY
WINDS. RAIN AMOUNTS FOR MOST AREAS WILL BE 0.10 TO 0.40 OF AN INCH
BUT COULD LOCALLY REACH 1 INCH.

&&

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

$$

SEAMAN/MERRILL/STRUTHWOLF

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