Area Forecast Discussion
Issued by NWS Salt Lake City, UT

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000
FXUS65 KSLC 120933
AFDSLC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
333 AM MDT SAT APR 12 2014

.SYNOPSIS...A WEAK WEATHER SYSTEM WILL CROSS THE REGION TODAY. A
COLD FRONT WILL THEN CROSS NORTHERN UTAH TONIGHT...THEN CONTINUE
SOUTHWARD DURING THE DAY SUNDAY. HIGH PRESSURE WILL RETURN EARLY
NEXT WEEK.

&&

.SHORT TERM (THROUGH 00Z WEDNESDAY)...TWO SHORTWAVE FEATURES WILL
AFFECT THE FORECAST AREA THROUGH THE REMAINDER OF THE WEEKEND. THE
FIRST IS AN UPPER LOW CURRENTLY WORKING ITS WAY ACROSS SOUTHERN
CA...WITH A DOWNSTREAM DEFORMATION AXIS CURRENTLY DEVELOPING
ACROSS SOUTHERN UT. THIS AXIS COMBINED WITH INCREASING MID LEVEL
MOISTURE WILL ALLOW FOR A CHANCE OF SHOWERS TODAY...MOST NUMEROUS
ACROSS CENTRAL AND SOUTHERN UT. INSTABILITY LOOKS SUFFICIENT TO
SUPPORT A THREAT FOR THUNDERSTORMS DURING THE AFTERNOON HOURS AS
WELL.

MEANWHILE A NORTHERN STREAM SHORTWAVE NOTED IN WV IMAGERY DIGGING
THROUGH THE NORTHERN ROCKIES WILL PUSH A COLD FRONT THROUGH
NORTHERN UT THIS EVENING...WITH THIS BOUNDARY CONTINUING SOUTHWARD
ACROSS THE REMAINDER OF THE FORECAST AREA OVERNIGHT THROUGH SUNDAY
MORNING. EXPECT SHOWERS TO DEVELOP ALONG AND BEHIND THIS BOUNDARY
AS IT PROGRESSES SOUTHWARD THIS EVENING...WITH ANOTHER ROUND OF
PRECIPITATION DURING THE DAY SUNDAY AS THE UPPER TROUGH AXIS DROPS
SOUTH THROUGH THE AREA.

MUCH COOLER AIR WILL FILTER SOUTHWARD ACROSS THE AREA IN THE WAKE
OF THIS FRONT...WITH 700MB TEMPS FALLING TO NEAR -6C ACROSS THE
NORTH SUNDAY...DRAGGING SNOW LEVELS DOWN TO THE BENCHES AT TIMES.
THIS COLDER AIR SHOULD KEEP MAX TEMPS SUNDAY ROUGHLY 5 DEGREES
BELOW NORMAL ACROSS NORTHERN AND CENTRAL UT

ADDITIONALLY...A MODEST PRESSURE GRADIENT COUPLED WITH 700MB FLOW
IN THE 30 KT RANGE WILL ALLOW FOR WINDY CONDITIONS ACROSS THE
SOUTHERN/EASTERN VALLEYS DURING THE DAY SUNDAY.

THIS TROUGH IS FORECAST TO QUICKLY MOVE EAST SUNDAY EVENING...WITH
MID LEVEL RIDGING BUILDING ACROSS THE REGION IN ITS WAKE. THIS
RIDGING WILL ALLOW FOR A QUICK WARMING TREND WITH TEMPERATURES
RETURNING TO NEAR NORMAL MONDAY...AND SURGING TO 10 DEGREES ABOVE
CLIMO BY TUESDAY.

&&

.LONG RANGE (AFTER 00Z WEDNESDAY)...SHORT WAVE RIDGE IS FORECAST TO
BE EAST OF THE AREA TUESDAY EVENING AS THE NEXT SYSTEM HEADS TOWARDS
UTAH. MODELS CONTINUE TO HANDLE THIS FEATURE QUITE DIFFERENTLY. GFS
BRINGS A ROBUST TROUGH SOUTH ACROSS THE STATE WEDNESDAY...WHILE THE
ECMWF JUST BRINGS A VERY WEAK SHORT WAVE THROUGH THE STATE WITH THE
BRUNT OF THE ENERGY REMAINING NORTH OF THE CWA. THE FORMER WOULD
ALLOW PLENTY OF PRECIPITATION ACROSS THE AREA WHILE THE LATTER WOULD
BRING LITTLE IN THE WAY OF SHOWERS. CURRENT POP GRIDS CURRENTLY
ADDRESS THIS WITH A CROSS BETWEEN THE TWO MODELS AND WITH PLENTY OF
TIME UNTIL EXTENDED PERIOD...SEE NO REASON TO MAKE ANY WHOLESALE
CHANGES. RIDGE FOLLOWS FOR THURSDAY AND FRIDAY WITH A SERIES OF WEAK
SHORT WAVES DRIFTING THROUGH MAINLY NORTHERN UTAH. THIS PATTERN
SHOULD PERSIST INTO THE WEEKEND.

&&

.AVIATION...SOUTHEAST WINDS WILL CONTINUE AT THE SLC TERMINAL
THROUGH AROUND 18-19Z THEN TURN NORTHWEST. WINDS SHOULD BECOME
BREEZY IN THE AFTERNOON...BUT SHOULD REMAIN BELOW AWW CRITERIA.
VFR CONDITIONS SHOULD PREVAIL THROUGH THE VALID TAF PERIOD.


&&

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

$$

SEAMAN/YOUNG

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)



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