Special Weather Statement, NWS Salt Lake City, UT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
307 PM MDT WED AUG 3 2011

.SYNOPSIS...MOISTURE WILL LINGER ACROSS THE REGION THROUGH
TONIGHT. A DRYING TREND WILL BEGIN THURSDAY WITH A MUCH DRIER
AIRMASS SPREADING INTO THE AREA FOR FRIDAY THROUGH THE WEEKEND.

&&

.DISCUSSION...FORECAST AREA REMAINS WITHIN A MEAN SOUTWHESTESRLY
FLOW ALOFT...SANDWICHED BETWEEN A DOMINANT SUBTROPICAL RIDGE
STRETCHING FROM THE SOUTHERN PLAINS WESTWARD ACROSS THE DESERT
SOUTHWEST...AND AN UPPER TROUGH LOCATED ALONG THE PACIFIC
NORTHWEST COASTLINE.

CONSIDERABLE MOISTURE REMAINS IN PLACE ACROSS THE AREA AS
WELL...WITH SURFACE DEW POINTS GENERALLY IN THE 50S...AND PW VALUES
IN THE 0.75 TO 1.00 INCH RANGE. A WEAK VORTICITY MAXIMA ROTATING
THROUGH THIS FLOW ALOFT IS AIDING CONVECTION ACROSS CENTRAL/SOUTHERN
UT THIS AFTERNOON...WHILE ADDITIONAL CONVECTION IS NOTED UPSTREAM
ACROSS EAST CENTRAL NV.

ANTICIPATE CONVECTION TO PERSIST ACROSS SOUTHERN UT THROUGH THE
EVENING HOURS...WHILE ACROSS THE NORTH EXPECT ACTIVITY ACROSS NV
TO GRADUALLY SPREAD EAST LATER THIS AFTERNOON THROUGH THIS
EVENING. AS SUCH HAVE MAINTAINED SCATTERED SHOWERS/THUNDERSTORMS
THROUGH THE EVENING HOURS. ALSO MAINTAINED 20-30 POPS ACROSS
NORTHERN/CENTRAL UT OVERNIGHT WITHIN MOIST AIRMASS.

MID LEVEL DRYING NOTED IN WV IMAGERY EXTENDING INTO CENTRAL CA AND
SOUTHERN NV IS FORECAST TO SPREAD EAST ACROSS THE EASTERN GREAT
BASIN THURSDAY THROUGH FRIDAY...AND THE TROUGH ALONG THE PACIFIC
NORTHWEST COASTLINE SPREADS INLAND. THIS WILL ACT TO SLOWLY SCOUR
MOISTURE OUT OF THE REGION FROM WEST TO EAST BEGINNING
THURSDAY...AND CONTINUING THROUGH FRIDAY. SUFFICIENT MOISTURE
LOOKS TO REMAIN IN PLACE ALONG/EAST OF I-15 THURSDAY TO WARRANT
ANOTHER CHANCE OF SHOWERS/THUNDERSTORMS. BY FRIDAY ANY CHANCE FOR
CONVECTION WILL LIKELY REMAIN CONFINED TO THE HIGHER TERRAIN
FROM THE CENTRAL SPINE OF UTAH EASTWARD.

MODELS ARE IN GENERAL AGREEMENT MAINTAINING A VERY DRY AIRMASS
ACROSS THE FORECAST AREA DURING THE WEEKEND THROUGH THE FIRST HALF
OF NEXT WEEK...AS MID LEVEL RIDGE BECOMES SUPPRESSED WELL SOUTH OF
THE AREA ALLOWING A DRY WESTERLY FLOW TO PREVAIL. AS SUCH HAVE
KEPT FORECAST DRY THROUGH THIS PERIOD WITH SEASONAL TEMPERATURES.

&&

.AVIATION...SOUTHERLY WINDS ARE EXPECTED TO CONTINUE AT THE SLC
TERMINAL THROUGH THE FORECAST PERIOD. A DISTURBANCE MOVING
NORTHEAST OUT OF NEVADA IS EXPECTED TO INCREASE CONVECTION ACROSS
THE SLC TERMINAL AREA AFTER 00Z THIS EVENING. THERE IS A 40
PERCENT THAT OUTFLOW OR A THUNDERSTORM WILL DIRECTLY IMPACT THE
SLC TERMINAL BETWEEN 00Z AND 03Z. WIND GUSTS OVER 30 MPH AND
TEMPORARY MVFR CONDITIONS ARE POSSIBLE DURING THAT TIME.

&&

.FIRE WEATHER...MONSOONAL MOISTURE WILL CONTINUE TO SUPPORT ISOLATED
TO SCATTERED SHOWER AND THUNDERSTORM ACTIVITY INTO TONIGHT. ASIDE
FROM CLOUD TO GROUND LIGHTNING...THE GREATEST THREATS FROM THIS
ACTIVITY WILL BE LOCALLY HEAVY RAINFALL AND GUSTY WINDS.

A BUILDING WEST COAST TROUGH WILL CAUSE THE DEEP MOISTURE TO SLIDE
TO OUR EAST BEGINNING TOMORROW WITH A DRYING TREND CONTINUING
THROUGH THE WEEKEND. SOUTHERLY WINDS INCREASE ENOUGH TOMORROW TO
SUPPORT A THREAT OF LOCALIZED CRITICAL FIRE WEATHER CONDITIONS
ACROSS THE WEST DESERTS WHERE FUELS ARE CRITICAL. ISOLATED TO
SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED MAINLY EAST OF
INTERSTATE 15 TOMORROW.

DRYING CONTINUES FRIDAY THROUGH MONDAY WITH POOR NOCTURNAL MOISTURE
RECOVERY AND LIGHTER WINDS...AS A RIDGE OF HIGH PRESSURE DOMINATES
THE SOUTHWEST CONUS.

&&

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

SEAMAN/STRUTHWOLF/ROGOWSKI

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
638 AM MDT WED AUG 3 2011

UTZ001>016-019>021-517-518-WYZ021-041300-
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-
638 AM MDT WED AUG 3 2011

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

.DAY ONE...TODAY AND TONIGHT

SHOWERS AND THUNDERSTORMS ARE EXPECTED AGAIN TODAY ACROSS THE
ENTIRE OUTLOOK AREA WITH THE BEST CHANCE IN THE AFTERNOON AND
EVENING. THE THREAT OF LOCAL HEAVY RAIN AND ISOLATED FLASH
FLOODING WILL ALSO CONTINUE.

STORMS WILL PERSIST WELL INTO THE NIGHT TONIGHT AND COULD GO ALL
NIGHT ACROSS NORTHERN AND EASTERN PORTIONS OF THE AREA.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY

DRIER AIR WILL BEGIN TO SPREAD INTO THE OUTLOOK AREA THURSDAY.
ALTHOUGH SHOWERS AND THUNDERSTORMS ARE AGAIN POSSIBLE...THEY WILL
BE A LITTLE LESS NUMEROUS AND SHOULD FORM PRIMARILY ACROSS THE
NORTH AND EAST.

THE DRYING TREND WILL CONTINUE INTO FRIDAY AND ONLY ISOLATED
STORMS ARE EXPECTED OVER THE EASTERN MOUNTAINS FRIDAY AFTERNOON.

ISOLATED CRITICAL FIRE WEATHER CONDITIONS WILL BE POSSIBLE ACROSS
THE WEST DESERTS THURSDAY AND FRIDAY.

IT STILL LOOKS DRY THROUGH THE WEEKEND AND INTO THE FIRST PART OF
NEXT WEEK.

.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)

PRELIMINARY LOCAL STORM REPORT...CORRECTED
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
510 PM MDT WED AUG 03 2011

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0502 PM     FLASH FLOOD      15 ENE BIG WATER        37.15N 111.41W
08/03/2011                   KANE               UT   PARK/FOREST SRVC

            CROTON CANYON EXPERIENCED FLASH FLOOD, WASHING OUT THE
            CROTON CANYON ROAD.

&&

BMCINERN

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
511 PM MDT WED AUG 03 2011

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0502 PM     FLASH FLOOD      5 WSW ESCALANTE         37.74N 111.69W
08/03/2011                   GARFIELD           UT   PARK/FOREST SRVC

            FLASH FLOOD IN ALVEY AND HARRIS WASHES AS THEY FLOW INTO
            THE ESCALANTE RIVER

&&

BMCINERN

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
515 PM MDT WED AUG 03 2011

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0502 PM     FLASH FLOOD      12 S HANKSVILLE         38.19N 110.72W
07/27/2011                   WAYNE              UT   DEPT OF HIGHWAYS

            VERY LARGE FLASH FLOOD FROM MULTIPLE DRAINAGES IN THE
            HENRY MOUNTAINS. DAMAGE TO SR 95 AND SR24.

&&

BMCINERN

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
516 PM MDT WED AUG 03 2011

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0502 PM     FLASH FLOOD      20 SE HANKSVILLE        38.16N 110.46W
07/27/2011                   WAYNE              UT   DEPT OF HIGHWAYS

            ADDITIONAL FLASH FLOODING FROM HENRY MOUNTAINS DAMAGING
            MULTIPLE ROADWAYS IN THE AREA.

&&

BMCINERN

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
626 PM MDT WED AUG 3 2011

UTZ014-517-518-040100-
CENTRAL AND SOUTHWEST MOUNTAINS UT-SANPETE/SEVIER VALLEYS UT-SOUTHERN
UTAH MOUNTAINS UT-
626 PM MDT WED AUG 3 2011

...SIGNIFICANT WEATHER ADVISORY FOR SOUTHEASTERN MILLARD...
SOUTHWESTERN SEVIER...EXTREME NORTHEASTERN BEAVER AND EXTREME
NORTHWESTERN PIUTE COUNTIES UNTIL 700 PM MDT...

AT 621 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM 9 MILES EAST OF COVE FORT...OR 22 MILES NORTHEAST
OF BEAVER...MOVING NORTHEAST AT 20 MPH.

PENNY TO NICKEL SIZE HAIL AND WIND GUSTS OF 40 TO 55 MPH ARE EXPECTED
WITH THIS STORM...ALONG WITH FREQUENT DANGEROUS LIGHTNING.

* LOCATIONS IMPACTED INCLUDE...I-70 BETWEEN COVE FORT AND FREMONT
INDIAN STATE PARK.

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

LAT...LON 3872 11237 3861 11220 3844 11243 3856 11256
TIME...MOT...LOC 0023Z 232DEG 17KT 3856 11242

STRUTHWOLF

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
854 PM MDT WED AUG 3 2011

UTZ518-040315-
SOUTHERN UTAH MOUNTAINS UT-
854 PM MDT WED AUG 3 2011

...SIGNIFICANT WEATHER ADVISORY FOR CENTRAL GARFIELD COUNTY UNTIL 915
PM MDT...

AT 851 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM 15 MILES NORTHEAST OF PANGUITCH...OR 22 MILES
SOUTH OF JUNCTION...MOVING NORTH AT 25 MPH.

PENNY TO NICKEL SIZE HAIL AND WIND GUSTS OF 40 TO 55 MPH ARE EXPECTED
WITH THIS STORM...ALONG WITH FREQUENT DANGEROUS LIGHTNING.

* LOCATIONS IMPACTED INCLUDE...
  SMITH CANYON ALONG THE SEVIER PLATEAU IN GARFIELD COUNTY
  COTTONWOOD PEAK ALONG THE SEVIER PLATEAU IN GARFIELD COUNTY

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

LAT...LON 3814 11233 3814 11178 3781 11212 3787 11233
TIME...MOT...LOC 0251Z 199DEG 21KT 3794 11219

RG