Special Weather Statement, NWS Salt Lake City, UT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
1107 AM MDT THU AUG 7 2014

.SYNOPSIS...AN UPPER LOW OVER NORTHEASTERN NEVADA WILL MOVE SLOWLY
EAST ACROSS NORTHERN UTAH THROUGH TONIGHT. A DRYING TREND WILL
DEVELOP FRIDAY AND CONTINUE INTO SATURDAY. MOISTURE WILL START TO
SPREAD BACK NORTH INTO THE AREA BY MONDAY.

&&

.DISCUSSION...AN UPPER LOW OVER WESTERN UTAH WILL TRACK EASTWARD
ACROSS NORTHERN UTAH TODAY. THE BIG FORECAST QUESTION FOR THE DAY
IS IN REGARDS TO PRECIPITATION COVERAGE THIS AFTERNOON. THE
GFS...NAM...AND HRRR ALL SHOW PRECIPITATION MOVING INTO THE
NORTHWEST CORNER OF UTAH THIS AFTERNOON AND THEN DISSIPATING
BEFORE REACHING THE WASATCH FRONT. WITH A DISTURBANCE CROSSING
NORTHERN UTAH AND PWAT VALUES NEAR AN INCH...ONE WOULD THINK THAT
PRECIPITATION WOULD BE WIDESPREAD THIS AFTERNOON. HOWEVER...THE
INTERESTING THING WITH THIS SYSTEM IS THE FACT THAT THE MODELS
INDICATE THAT THIS IS A WARM CORE SYSTEM...AND DUE TO WARM
ADVECTION AT 500 MB...CONDITIONS WILL BE STABILIZING THIS
AFTERNOON...WHICH IS NOT CONDUCIVE TO WIDESPREAD PRECIPITATION.
ALTHOUGH THE EC HAS THE SAME IDEA AS THE GFS...SHOWING WARMING AT
500MB THROUGH THE DAY...IT STILL HAS WIDESPREAD PRECIPITATION
ACROSS NORTHERN AND EVEN CENTRAL UTAH THIS AFTERNOON. SO...THE
BOTTOM LINE IS THAT THE PRECIPITATION FORECAST FOR THIS AFTERNOON
IS LOW CONFIDENCE.

MODELS DO AGREE THAT ANY PRECIPITATION THAT DOES DEVELOP THIS
AFTERNOON WILL CONTINUE INTO THE OVERNIGHT HOURS. MOISTURE WILL
LINGER ACROSS NORTHERN UTAH INTO TOMORROW...RESULTING IN TERRAIN
BASED CONVECTION ACROSS NORTHERN UTAH TOMORROW AFTERNOON. ACTIVITY
WILL CONTINUE TO DECREASE INTO SUNDAY AS THE DRYING TREND
CONTINUES. MOISTURE WILL SLOWLY SPREAD IN TO SOUTHERN AND CENTRAL
UTAH SUNDAY AND MONDAY...REACHING NORTHERN UTAH BY TUESDAY.
SO...EXPECT A GRADUAL INCREASE IN CONVECTION SUNDAY AND
MONDAY...WITH MORE WIDESPREAD CONVECTION BY TUESDAY.

CURRENT FORECAST LOOKS GOOD...AND WITH LOW CONFIDENCE IN THE
FORECAST FOR THIS AFTERNOON...AM NOT PLANNING ON ANY UPDATES AT
THIS TIME.

&&

.AVIATION...LIGHT NORTHERLY WINDS WILL CONTINUE AT THE SLC
TERMINAL...BECOMING STRONGER AROUND 18Z. THERE IS A 20 PERCENT
CHANCE THE TERMINAL WILL BE IMPACTED BY THUNDERSTORMS THIS
AFTERNOON...WHICH WOULD BRING ERRATIC AND GUSTY WINDS.

&&

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

PUBLIC...HOSENFELD
AVIATION...KRUSE

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
528 AM MDT THU AUG 7 2014

UTZ001>016-019>021-517-518-WYZ021-081230-
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-
528 AM MDT THU AUG 7 2014

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

.DAY ONE...TODAY AND TONIGHT

SHOWERS AND THUNDERSTORMS WILL ONCE AGAIN DEVELOP ACROSS NORTHERN
PORTIONS OF THE OUTLOOK AREA TODAY INTO TONIGHT. SOME OF THESE
WILL PRODUCE LOCALLY HEAVY RAIN. ISOLATED AFTERNOON THUNDERSTORMS
MAY ALSO DEVELOP OVER THE CENTRAL AND SOUTHERN MOUNTAINS.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY

SHOWERS AND THUNDERSTORMS WILL BECOME MORE ISOLATED ON FRIDAY AND
CONFINED MOSTLY TO THE NORTH. ISOLATED MOUNTAIN STORMS ARE
EXPECTED OVER THE WEEKEND.

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

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
236 PM MDT THU AUG 7 2014

UTZ010-011-072115-
WESTERN UINTA BASIN UT-WASATCH PLATEAU/BOOK CLIFFS UT-
236 PM MDT THU AUG 7 2014

...SIGNIFICANT WEATHER ADVISORY FOR WEST CENTRAL DUCHESNE COUNTY
UNTIL 315 PM MDT...

AT 235 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM NEAR FRUITLAND...OR 20 MILES WEST OF DUCHESNE...
MOVING EAST AT 10 MPH.  THIS STORM IS TRAVELLING ALONG US ROUTE 40
BETWEEN FRUITLAND AND DUCHESNE.

WINDS OF 40 TO 55 MPH WILL BE POSSIBLE. VERY HEAVY RAINFALL CAN BE
EXPECTED WITH THIS STORM WHICH MAY CAUSE PONDING ON ROADWAYS AND
POOR DRAINAGE AREAS.

LOCATIONS IMPACTED INCLUDE...
FRUITLAND.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

IF THREATENING WEATHER APPROACHES...TAKE SHELTER IN A STURDY
BUILDING.

TORRENTIAL RAINFALL IS ALSO OCCURRING WITH THIS STORM...AND MAY LEAD
TO FLASH FLOODING. DO NOT DRIVE YOUR VEHICLE THROUGH FLOODED
ROADWAYS.

&&

LAT...LON 4009 11083 4022 11085 4031 11050 4009 11044
TIME...MOT...LOC 2035Z 257DEG 10KT 4018 11078

CRK