Flash Flood Warning 38, NWS Salt Lake City, UT

701 
WGUS75 KSLC 052354
FFSSLC

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
554 PM MDT THU AUG 5 2010

UTC025-053-060003-
/O.EXP.KSLC.FF.W.0038.000000T0000Z-100806T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
WASHINGTON UT-KANE UT-
554 PM MDT THU AUG 5 2010

...THE FLASH FLOOD WARNING WILL EXPIRE AT 600 PM MDT FOR WEST CENTRAL
KANE AND EAST CENTRAL WASHINGTON COUNTIES...

RAINFALL IN THE ZION NATIONAL PARK AREA HAS DIMINISHED IN THE ZION 
NATIONAL PARK AREA.  THERE WERE NO REPORTS OF FLASH FLOODING AT THIS 
TIME...AND AS A RESULT...THE FLASH FLOOD WARNING WILL BE ALLOWED TO 
EXPIRE.

DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE
ROADWAY. THE WATER DEPTH MAY BE TOO GREAT TO ALLOW YOUR CAR TO CROSS
SAFELY.

LAT...LON 3719 11313 3724 11299 3726 11286 3707 11287
      3704 11305

$$

MCINERNEY

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
1018 AM MDT THU AUG 5 2010

.SYNOPSIS...A MOIST AIR MASS WILL REMAIN IN PLACE ACROSS THE AREA
TODAY...PARTICULARLY ACROSS EASTERN AND SOUTHERN UTAH. DRYING
WILL BE THE TREND ACROSS THE REGION BEGINNING FRIDAY AND
CONTINUING THROUGH EARLY NEXT WEEK AS SOUTHERLY FLOW INCREASES
AHEAD OF A WEST COAST TROUGH.

&&

.DISCUSSION...REGIONAL WATER VAPOR LOOP CLEARLY INDICATES A LONG
WAVE TROUGH DIGGING SOUTH ALONG THE CALIFORNIA COAST WITH RIDGING
HOLDING PLACE ACROSS THE ROCKIES STATES. OF NOTE FOR OUR WEATHER
TODAY ARE THREE VISIBLE SHORT WAVES EJECTING NORTH/NORTHEAST FROM
THE PARENT TROUGH THIS MORNING...ONE OVER SOUTHERN
CALIFORNIA...ONE OVER EAST CENTRAL NEVADA AND ONE OVER SOUTHERN
UTAH. THE LATTER TWO ARE ALREADY SPARKING CONVECTION IN THE
VICINITY OF LAKE POWELL AND FURTHER TO THE NORTH...SOLDIER SUMMIT
NORTHWEST TO SKULL VALLEY. HAVE ADJUSTED POPS UP FOR THESE AREAS
FOR THE REMAINDER OF THE MORNING TO ACCOUNT FOR THESE RECENT
TRENDS.

ANTICIPATING YET ANOTHER ACTIVE DAY ACROSS THE FORECAST AREA
TODAY. DEEP MOISTURE REMAINS ABUNDANT ACROSS MUCH OF THE REGION
THIS MORNING PER BLENDED PWAT...AND INSTABILITY REMAINS ELEVATED
AND PRIME FOR CONVECTIVE DEVELOPMENT. 12Z KSLC RAOB SUPPORTS THIS
WITH .91 INCHES PWAT AND JUST OVER 1500 J/KG CAPE...ALMOST A
MIRROR IMAGE OF YESTERDAY. SPC SHORT RANGE ENSEMBLES SHOW ZONE OF
GREATEST INSTABILITY THIS AFTERNOON WILL SPAN FROM NORTHERN UTAH
SOUTH AND EAST ACROSS SOUTHERN UTAH. SPC MESO ANALYSIS CURRENTLY
INDICATES WIDESPREAD CIN LINGERING FROM BOUNDARY LAYER
STABILIZATION OVERNIGHT...BUT THIS WILL ERODE RAPIDLY COME MIDDAY.
EFFECTIVE SHEAR GREATER THAN 30 KNOTS REMAINS CONFINED TO THE SOUTHEAST.

THIS AFTERNOON...COMBINATION OF AFOREMENTIONED
MOISTURE/INSTABILITY COUPLED WITH SHORT WAVE ENERGY MOVING INTO
BOTH SOUTHERN/NORTHERN UTAH PROMPTED UPDATE TO RAISE POPS FOR
THESE REGIONS FOR THE AFTERNOON HOURS. GOING FLASH FLOOD WATCH
ACROSS EASTERN/SOUTHERN UTAH APPEARS ON TRACK WITH THREAT OF
RELATIVELY SLOW MOVING DEEP THUNDERSTORMS CAPABLE OF INTENSE
RAINFALL...ISOLATED SEVERE POTENTIAL REMAINS ACROSS THE
EAST/SOUTHEAST ASSOCIATED WITH ELEVATED SHEAR THROUGH THE
CONVECTIVE COLUMNS THIS AFTERNOON. THUNDERSTORMS ACROSS THE NORTH
DO HAVE THE POTENTIAL TO BECOME BRIEFLY ORGANIZED DUE TO FAT CAPE
IN PLACE...BUT LACK OF SHEAR SHOULD LIMIT LIFE SPANS SOMEWHAT.
WILL BE LOOKING FOR OUTFLOW/PULSE DEVELOPMENT TO SUSTAIN STORMS
ACROSS THE NORTH.

THIS EVENING...DIURNAL TRENDS WITH LOSS OF SOLAR INSOLATION IS
EXPECTED TO SQUELCH ACTIVITY ACROSS MUCH OF THE STATE. THAT
SAID...TIMING OF SOUTHERN CALIFORNIA SHORT WAVE LOOKS TO SWING
THROUGH NORTHERN UTAH THIS EVENING PER NAM12...WHICH SHOULD
SUPPORT CONVECTIVE ACTIVITY LINGERING THROUGH THE MIDDLE OF THE
NIGHT

UPDATES MADE AS STATED ABOVE. NONE OTHER PLANNED AT THIS TIME.
PREVIOUS DISCUSSION FOLLOWS...

BY TOMORROW MOST OF THE FORECAST AREA IS BACK TO NORMAL WITH REGARD
TO PRECIPITABLE WATER...WITH PERHAPS THE EXCEPTION OF THE FAR
EASTERN FORECAST AREA. CONVECTION SHOULD BE LIMITED TO THE TERRAIN
AND EASTERN VALLEYS AS DRIER AIR ADVECTS INTO THE REGION ON
STRENGTHENING SOUTHWESTERLY FLOW AHEAD OF THE TROUGH. THIS TREND
CONTINUES THROUGH THE WEEKEND AS THE UPSTREAM TROUGH WEAKENS.
SEVERAL WEAK PIECES OF THE SHEARING TROUGH MOVE THROUGH THE REGION
DURING THE WEEKEND...WHICH WILL NEED TO BE MONITORED FOR CONVECTIVE
DEVELOPMENT DESPITE THE DRIER AIRMASS.

ANOTHER TROUGH IS EXPECTED TO REDEVELOP ALONG THE WEST COAST NEXT
WEEK...WHICH SHOULD CONTINUE TO DRY OUT THE REGION ON A DRY BREEZY
SOUTHERLY FLOW.

&&

.AVIATION...THE LINE OF THUNDERSTORMS SOUTH OF THE SLC TERMINAL AS
OF 16Z MAY BRIEFLY IMPACT THE TERMINAL...BUT MOST OF THE LINE WILL
STAY WELL SOUTH OF THE AREA. THROUGH THE REST OF THE DAY...THERE IS
A 50 PERCENT CHANCE OF THE TERMINAL BEING IMPACTED BY
THUNDERSTORMS...WITH GUSTY ERRATIC WINDS BEING THE MOST LIKELY
IMPACT.

&&

.FIRE WEATHER...WETTING RAINS WILL ACCOMPANY THUNDERSTORMS AGAIN
TODAY...ESPECIALLY THOSE EAST OF THE INTERSTATE 15 CORRIDOR...WITH
DRIER BUT STILL POTENTIALLY ACTIVE CONDITIONS IN THE WESTERN HALF OF
THE STATE. SOUTH WINDS AND SUBSTANTIAL DRYING WILL BRING THE FIRST
THREAT OF CRITICAL CONDITIONS TO THE NORTHWEST DESERT FRIDAY AND
SATURDAY...THOUGH WINDS APPEAR TO BE SLIGHTLY TOO LIGHT AT THIS
TIME. AS UPPER TROUGH MOVES VERY SLOWLY INLAND...THESE DRYING AND
BREEZY CONDITIONS WILL LIKELY SPREAD ACROSS ALL WESTERN VALLEYS BY
EARLY NEXT WEEK.

&&

.SLC WATCHES/WARNINGS/ADVISORIES...
UT...FLASH FLOOD WATCH THROUGH THIS EVENING FOR
     UTZ009>014-020-021-517-518.

WY...NONE.
&&

MERRILL/SCHOENING/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
248 AM MDT THU AUG 5 2010

UTZ001>016-019>021-517-518-WYZ021-061200-
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-
248 AM MDT THU AUG 5 2010

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

.DAY ONE...TODAY AND TONIGHT

A VERY MOIST AIRMASS REMAINS ACROSS EASTERN...CENTRAL AND PORTIONS
OF SOUTHERN UTAH...POSING AN ELEVATED RISK FOR FLASH FLOODING. SLOT
CANYONS...SMALL STREAMS..AND NORMALLY DRY WASHES MAY BE
PARTICULARLY HAZARDOUS LOCATIONS TODAY. OTHER THREATS FROM THESE
STORMS INCLUDE LIGHTNING...WIND GUSTS IN EXCESS OF 50 MPH AND
SMALL HAIL.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY

A DRIER AIRMASS IS EXPECTED FRIDAY THROUGH NEXT WEEKEND. THERE IS
AN INCREASING THREAT OF CRITICAL FIRE WEATHER CONDITIONS
ESPECIALLY ACROSS WESTERN UTAH BEGINNING SATURDAY AND BECOMING
MORE LIKELY EARLY NEXT WEEK.

.SPOTTER INFORMATION STATEMENT...

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

ROGOWSKI

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