Special Weather Statement, NWS Salt Lake City, UT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
335 PM MDT FRI AUG 8 2014

.SYNOPSIS...ENOUGH MOISTURE REMAINS OVER THE NORTHERN HALF OF THE
FORECAST AREA TO PRODUCE SCATTERED AFTERNOON AND EVENING SHOWERS
AND THUNDERSTORMS THROUGH SATURDAY. THE AIRMASS DRYS SOMEWHAT ON
SUNDAY BEFORE MOISTURE BEGINS TO RETURN TO THE AREA FROM THE SOUTH
EARLY NEXT WEEK.

&&

.DISCUSSION...AIRMASS CONVECTION HAS DEVELOPED OVER MUCH OF
NORTHERN NEVADA AND SOUTHERN IDAHO WITH LESS WIDESPREAD COVERAGE
OVER NORTHERN UTAH AND SOUTHWEST WYOMING THUS FAR. PER THE HRRR
WHICH HAS A REASONABLE HANDLE ON CURRENT CONDITIONS...THE
UPSTREAM ACTIVITY SHOULD CONTINUE EASTWARD INTO UTAH THROUGH THE
NEXT FEW HOURS BEFORE DYING OUT AFTER DARK. INCREASED POPS ACROSS
CENTRAL UTAH TO ACCOUNT FOR SOUTHERN EXTENT OF ACTIVITY. TAKING
THE HRRR LITERALLY...NOT RECOMMENDED...INDICATES STORMS WILL
MOSTLY DIE OUT BEFORE REACHING THE WASATCH FRONT.

SATURDAY LOOKS LIKE MORE OF THE SAME...AFTERNOON/EVENING
CONVECTION NEAR TERRAIN AND DRIFTING OFF INTO THE DOWNSTREAM
VALLEYS.

SOMEWHAT DRIER ON SUNDAY PER MODEL PREDICTIONS OF LOWERING
PRECIPITABLE WATER. HOWEVER THESE DRYING TRENDS ARE TYPICALLY
OVERDONE...SO THERE WILL LIKELY STILL BE SOME MOUNTAIN BASED
DIURNAL CONVECTION.

GENERALLY DRY WITH SEASONAL TEMPERATURES ACROSS THE SOUTHERN UTAH
PARKS AND CANYON COUNTRY THROUGH THE WEEKEND.

BY LATE SUNDAY/MONDAY THE MONSOON HIGH IS BECOMING ESTABLISHED
OVER NEW MEXICO AND A TROUGH DEVELOPS ALONG THE CA COAST. RESULT
IS SOUTHERLY FLOW THAT RAPIDLY ADVECTS MOISTURE NORTHWARD BACK
INTO THE GREAT BASIN MONDAY. BY MONDAY NIGHT UPPER LEVEL JET
EXTENDS FROM UTAH TO SOUTHERN CA ADDING DYNAMIC LIFT TO
SITUATION. 12Z EC GENERATES WIDESPREAD MONSOON PRECIP OVER THE
AREA MONDAY THROUGH WEDNESDAY...WHILE 12Z GFS IS A BIT SLOWER AND
FOCUS IS MORE ON TUESDAY/WEDNESDAY. HANDLING OF TROUGH/LOW ALONG
THE WEST COAST BEGINS TO DIFFER BETWEEN EC/GFS FROM MONDAY
ONWARDS...BUT MAIN MESSAGE OF BOTH MODELS IS THE SAME...A PERIOD
OF WET MONSOON PRECIP SEEMS LIKELY OVER NEARLY THE ENTIRE FORECAST
AREA EARLY NEXT WEEK. HAVE GONE WITH ABOVE AVERAGE POPS FOR THE
TUES/WED PERIOD.

&&

.AVIATION...NORTHWEST WINDS WILL CONTINUE AT THE SLC TERMINAL
THROUGH 02-04Z AND THEN SOUTHEAST WINDS WILL RETURN. THERE IS A 10
PERCENT CHANCE OF A THUNDERSTORM AFFECTING THE TERMINAL THIS
AFTERNOON AND EVENING. GUSTY AND ERRATIC WINDS WOULD BE THE MAIN
THREAT.

&&

.FIRE WEATHER...MOISTURE REMAINS IN PLACE OVER NORTHERN UTAH THIS
AFTERNOON WHILE SOUTHERN UTAH STAYS DRY. CONDITIONS WILL REMAIN DRY
OVER SOUTHERN UTAH THROUGH THE WEEKEND WHILE NORTHERN UTAH WILL SEE
SLOW DRYING AT BEST. ENOUGH MOISTURE WILL REMAIN FOR AFTERNOON
CONVECTION OVER NORTHERN UTAH PRIMARILY FOCUSED OVER THE HIGHER
TERRAIN. MONSOONAL MOISTURE IS EXPECTED TO RETURN TO THE ENTIRE FIRE
DISTRICT EARLY IN THE UPCOMING WEEK.

&&

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

PUBLIC...DUNN
FIRE WEATHER...TRAPHAGAN
AVIATION...SOLUM

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)

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
436 AM MDT FRI AUG 8 2014

UTZ001>016-019>021-517-518-WYZ021-091230-
CACHE VALLEY/UTAH PORTION-NORTHERN WASATCH FRONT-
SALT LAKE AND TOOELE VALLEYS-SOUTHERN WASATCH FRONT-
GREAT SALT LAKE DESERT AND MOUNTAINS-WASATCH MOUNTAIN VALLEYS-
WASATCH MOUNTAINS I-80 NORTH-WASATCH MOUNTAINS SOUTH OF I-80-
WESTERN UINTA MOUNTAINS-WASATCH PLATEAU/BOOK CLIFFS-
WESTERN UINTA BASIN-CASTLE COUNTRY-SAN RAFAEL SWELL-
SANPETE/SEVIER VALLEYS-WEST CENTRAL UTAH-SOUTHWEST UTAH-
UTAHS DIXIE AND ZION NATIONAL PARK-SOUTH CENTRAL UTAH-
GLEN CANYON RECREATION AREA/LAKE POWELL-CENTRAL MOUNTAINS-
SOUTHERN MOUNTAINS-SOUTHWEST WYOMING-
436 AM MDT FRI AUG 8 2014

THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE WESTERN TWO THIRDS OF
UTAH AND SOUTHWEST WYOMING.

.DAY ONE...TODAY AND TONIGHT

ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS CAN BE EXPECTED
AGAIN THIS AFTERNOON ACROSS MAINLY THE NORTHERN PORTIONS OF THE
OUTLOOK AREA. ALTHOUGH BRIEF HEAVY RAIN MAY BE POSSIBLE FROM THE
STRONGER STORMS...THE THREAT OF HEAVY RAIN WILL GENERALLY DECREASE
TODAY.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY

A FEW SHOWERS AND THUNDERSTORMS ARE EXPECTED OVER THE
WEEKEND...MAINLY DEVELOPING OVER THE HIGH TERRAIN.

MOISTURE WILL INCREASE FROM THE SOUTH AGAIN FOR THE FIRST PART OF
NEXT WEEK BRINGING A RENEWED THREAT OF HEAVY RAIN WITH
THUNDERSTORMS.

.SPOTTER INFORMATION STATEMENT...

WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER
CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES.

FOR MORE INFORMATION FROM NOAA/S NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/SALTLAKECITY/ (ALL LOWER CASE)

FOR INFORMATION ON POTENTIAL ROAD TRAVEL IMPACTS VISIT...
HTTP://WWW.UDOTTRAFFIC.UTAH.GOV/ROADWEATHERFORECAST.ASPX