Area Forecast Discussion
Issued by NWS Salt Lake City, UT

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000
FXUS65 KSLC 201047
AFDSLC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
447 AM MDT SUN JUL 20 2014

.SYNOPSIS...A WEAK SYSTEM WILL MOVE NORTH ACROSS UTAH TODAY. A
DRIER SOUTHWEST FLOW WILL FOLLOW FOR MONDAY AND TUESDAY. MOISTURE
WILL INCREASE FROM THE SOUTH AGAIN ON WEDNESDAY.

&&

.DISCUSSION...THE MEAN UPPER RIDGE REMAINS CENTERED OVER SRN NEW
MEXICO EARLY THIS MORNING WITH A WEAK CLOSED LOW OFF THE CA COAST.
A WEAK SHORT WAVE ROTATING NWD AROUND THIS LOW IS SHEARING APART
WITH THE EASTERN PORTION LIFTING ACROSS SRN UT AT THIS TIME.

THIS FEATURE IS BRINGING AN INCREASE IN MOISTURE TO THE CWA BUT IT
IS MAINLY AT MID AND UPPER LEVELS AND IS MOVING TOO QUICKLY FOR
THE LOWER LEVELS TO GET A CHANCE TO MOISTEN UP. THERE ARE
CURRENTLY A FEW LIGHT SHOWERS WITH THIS TROF BUT EXPECT THESE TO
BECOME MORE NUMEROUS AS DAYTIME HEATING ADDS TO THE LIFT. STORMS
SHOULD BE HIGH BASED WITH A GREATER THREAT OF GUSTY WINDS THAN
RAIN.

THE RAPID MOVEMENT OF THIS TROF PLACES SRN UT IN A SUBSIDENT
ENVIRONMENT BY THIS AFTN AND CONVECTION THERE SHOULD BE SUPPRESSED
ALTHO A FEW WEAK CELLS COULD STILL FORM.

THE WAVE MOVES NORTH THIS EVE AND MOST CONVECTION SHOULD END NOT
LONG AFTER 06Z TONIGHT. THE MEAN UPPER HIGH REMAINS IN PLACE THRU
MID WEEK WITH A MUCH DRIER SOUTHWESTERLY FLOW FOR MON/TUE BEFORE
ANOTHER BRIEF MOISTURE SURGE ARRIVES WED. 00Z GFS CAME IN MUCH
FASTER WITH THIS NEXT MOIST SURGE BRINGING IT UP STARTING LATE
TUE WHILE THE EC WAITED TIL WED AND HOLDS ONTO THE MOISTURE
LONGER. THE 06Z GFS MOVED TOWARDS THE EC BUT REMAINED FASTER...DUE
TO THE DEPTH AND TRACK OF THE PACNW TROF. LEANED TOWARDS THE
FASTER AND LOWER AMPLITUDE EC WHICH ALLOWS THE UPPER HIGH TO
REMAIN MORE DOMINANT FOR OUR CWA.

THIS HIGH DOES ELONGATE E-W TOWARDS THE END OF THE WEEK AND IS
FARTHER NORTH IN THE EC ALLOWING MORE MOISTURE TO PERSIST ACROSS
THE CWA. CONFIDENCE IN THE FORECAST IS NOT VERY HIGH HOWEVER DUE
TO THE MODEL DISAGREEMENT.

&&

.AVIATION...SOUTH WINDS ARE EXPECTED AT THE SLC TERMINAL
THROUGHOUT THE DAY ALTHOUGH THERE IS A 30 PERCENT CHANCE THAT
WINDS AROUND MIDDAY COULD SHIFT TO WEST NORTHWEST FOR A SHORT
PERIOD OF TIME. GUSTY WINDS ARE POSSIBLE FROM NEARBY SHOWERS AFTER
13-14Z. THUNDERSTORMS MAY IMPACT THE TERMINAL AFTER 18Z.

&&

.FIRE WEATHER...A DISTURBANCE MOVING NORTH ACROSS THE STATE TODAY
WILL BE THE FOCUS OF CONVECTION. THE LEADING EDGE OF THIS
DISTURBANCE WILL BE ACROSS CENTRAL UTAH THIS MORNING AND INTO
NORTHERN UTAH BY MIDDAY. SCATTERED SHOWERS AND THUNDERSTORMS WILL
ACCOMPANY THIS DISTURBANCE WHILE ISOLATED SHOWERS AND THUNDERSTORMS
MAY BE POSSIBLE ELSEWHERE. DRYING WILL DEVELOP ACROSS THE EXTREME
SOUTH BY EARLY AFTERNOON AND SPREAD INTO CENTRAL UTAH BY EVENING.
SOUTH WINDS WILL BECOME SOMEWHAT GUSTY OVER WEST
CENTRAL...SOUTHWEST...AND EAST CENTRAL AREAS TODAY BUT RELATIVE
HUMIDITY LEVELS SHOULD BE SOMEWHAT ELEVATED PREVENTING RFW
CRITERIA FROM BEING MET. THE MODELS ARE SOMEWHAT AT ODDS ABOUT
WINDS ON MONDAY BEING STRONG ENOUGH TO REACH RFW CRITERIA NOT ONLY
ACROSS THE WESTERN VALLEYS BUT ALSO ACROSS EASTERN ZONES 490 AND
491. NOT ENOUGH CONFIDENCE AT THIS POINT TO UPGRADE WATCH SO HAVE
PUSHED THE DECISION ONTO THE DAY SHIFT. TUESDAY LOOKS TO HAVE THE
STRONGEST WINDS WHICH MAY LINGER INTO WEDNESDAY BUT THE RELATIVE
HUMIDITIES MAY CLIMB ENOUGH WEDNESDAY TO PREVENT THE DEVELOPMENT
OF WIDESPREAD CRITICAL FIRE WEATHER CONDITIONS.

&&

.SLC WATCHES/WARNINGS/ADVISORIES...
UT...FIRE WEATHER WATCH FROM MONDAY AFTERNOON THROUGH TUESDAY EVENING
     FOR UTZ478-492-495.

WY...NONE.
&&

$$

PUBLIC...WILENSKY
FIRE WEATHER/AVIATION...STRUTHWOLF

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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