Area Forecast Discussion
Issued by NWS Salt Lake City, UT

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000
FXUS65 KSLC 312206
AFDSLC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
406 PM MDT MON AUG 31 2015

.SYNOPSIS...WEAK HIGH PRESSURE ALOFT WILL CONTINUE TO BUILD INTO
THE AREA TONIGHT. A WARMER SOUTHWEST FLOW ALOFT WILL DEVELOP
AHEAD OF A PACIFIC NORTHWEST STORM SYSTEM STARTING TUESDAY...AND
WILL PERSIST THROUGH AT LEAST THURSDAY.



&&

.SHORT TERM (THROUGH 12Z THURSDAY)...SHOWERS AND THUNDERSTORMS
HAVE FORMED ACROSS EASTERN UTAH AND SOUTHWEST WYOMING THIS
AFTERNOON...WHILE DRIER AND MORE STABLE AIR CONTINUES TO PUSH INTO
NORTHERN AND WESTERN UTAH. THE FORECAST AREA IS UNDER A WEAK
SHORTWAVE RIDGE BETWEEN THE SHORTWAVE THAT IMPACTED THE REGION
YESTERDAY AND THE NEXT TROUGH EXPECTED TO DROP INTO THE PACIFIC
NORTHWEST TOMORROW.

AS THAT TROUGH PUSHES SOUTHWARD OVER THE NEXT FEW
DAYS...SOUTHWESTERLY FLOW IS FORECAST TO INCREASE OVER THE GREAT
BASIN...CONTINUING TO PUSH A DRIER AND WARMER AIRMASS INTO THE
CWA. COVERAGE OF THUNDERSTORMS IS EXPECTED TO SLOWLY DECREASE EACH
AFTERNOON...AND TEMPERATURES SHOULD GENERALLY BE NEAR OR SLIGHTLY
ABOVE CLIMATOLOGICAL NORMALS FOR THE BEGINNING OF SEPTEMBER.
BREEZY CONDITIONS WILL DEVELOP EACH DAY...WITH THE STRONGEST WINDS
LIKELY IN WESTERN UTAH.

.LONG TERM (AFTER 12Z THURSDAY)...A STRONG FALL-LIKE TROUGH
IS EXPECTED TO TRACK OUT OF THE PACIFIC NORTHWEST INTO THE NORTHERN
INTERMOUNTAIN REGION LATE NEXT WEEK THROUGH THE WEEKEND. GLOBAL
MODELS CONTINUE TO SHOW SPREAD REGARDING AMPLIFICATION AND TRACK OF
THIS...WITH THE GFS MORE PROGRESSIVE AND CARRYING LOWER AMPLITUDE
THAN BOTH THE ECMWF AND CANADIAN. THE ECMWF REMAINS THE DEEPEST
SOLUTION AND WOULD POSE A GREATER IMPACT TO THE EASTERN GREAT BASIN
AS IT BACKS FLOW MORE SUBSTANTIALLY...THIS OPENING A TAP TO DEEPER
MOISTURE FROM THE SOUTH THAT WOULD THEN INTERACT WITH THE DYNAMICS
OF THE TROUGH AS IT APPROACHES. THE CANADIAN LIES CLOSER TO THE
ECMWF AND HAVE TRENDED FORECAST GRIDS TOWARDS SOMEWHAT OF A BLEND OF
THESE SOLUTIONS. LOOKING FORWARD TO MORE CONSISTENCY IN THE GLOBAL
GUIDANCE AS WE HEAD INTO THIS HOLIDAY WEEKEND HOWEVER.

REGARDING SENSIBLE WEATHER...CONFIDENCE IS GREATEST REGARDING A
SIGNIFICANT COOL DOWN NEXT WEEKEND...GREATEST OVER THE NORTH BUT
NOTEWORTHY MOST ALL AREAS OUTSIDE OF THE EXTREME SOUTHEAST.
REGARDLESS OF MODEL CHOICE...RAW H7 TEMP PROGS FALL TO +2 C COME
SUNDAY WITH POTENTIAL TO MAKE IT DIFFICULT TO CLIMB OUT OF THE UPPER
60S ALONG THE WASATCH FRONT. CONTINUED TO TREND TEMPS DOWN DUE TO
INCREASED CONFIDENCE IN THIS. ADDITIONALLY...LEANING TOWARDS THE
ECMWF/CANADIAN INCREASES THE POTENTIAL OF SHOWERS AND STORMS
BEGINNING FRIDAY AFTERNOON AND CONTINUING INTO SUNDAY MORNING. HAVE
INCREASED POPS TO SLIGHT CHANCE/CHANCE WITH GENERAL TRENDS SPREADING
SOUTH TO NORTH FRIDAY AS FLOW BACKS...BECOMING MOST AREALLY
EXPANSIVE SATURDAY AFTERNOON/OVERNIGHT WHEN TROUGH DYNAMICS
PEAK...THEN DRYING DURING THE DAY SUNDAY AS THE TROUGH LIFTS
NORTHEAST OF THE AREA.

&&

.AVIATION...NORTHERLY WINDS WILL PREVAIL AT KSLC THROUGH THE
REMAINDER OF THE AFTERNOON BEFORE SWITCHING BACK TO THE SOUTH
BETWEEN 02-03Z. VFR CONDITIONS WILL PREVAIL THROUGH THE PERIOD.


&&

.FIRE WEATHER...DRIER AND MORE STABLE AIR CONTINUES TO MOVE INTO
WESTERN UTAH THIS AFTERNOON...WHILE ENOUGH MOISTURE IS LINGERING
OVER THE EASTERN HALF OF THE STATE TO PRODUCE SHOWERS AND
THUNDERSTORMS. SHOWERS WILL SLOWLY DECREASE IN COVERAGE AS THE
WEEK GOES ON AND MORE DRY AIR MOVES INTO THE AREA. SOUTHWESTERLY
WINDS WILL BEGIN TO INCREASE ON TUESDAY...AND THEN PEAK ON
WEDNESDAY AND THURSDAY OUT AHEAD OF AN APPROACHING STORM SYSTEM.
COMBINED WITH DECREASING RELATIVE HUMIDITY VALUES...LOCALIZED
CRITICAL FIRE WEATHER CONDITIONS WILL BE POSSIBLE...PARTICULARLY
ON WEDNESDAY AND THURSDAY.

&&

.SLC WATCHES/WARNINGS/ADVISORIES...
UT...NONE.
WY...FIRE WEATHER WATCH FOR WYZ277 FROM 11 AM WEDNESDAY THROUGH
9 PM FRIDAY.

&&

$$

SHORT TERM/FIRE WEATHER...SCHOENING
LONG TERM...MERRILL
AVIATION...SEAMAN

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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