Flash Flood Warning 105, NWS Salt Lake City, UT

974 
WGUS75 KSLC 120255
FFSSLC

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
855 PM MDT WED SEP 11 2013

WYC041-120304-
/O.CAN.KSLC.FF.W.0105.000000T0000Z-130912T0330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
UINTA WY-
855 PM MDT WED SEP 11 2013

...THE FLASH FLOOD WARNING HAS BEEN CANCELLED FOR EASTERN UINTA
COUNTY...

RAINFALL IN THE AREA HAS TAPERED OFF AND FLASH FLOODING HAS ENDED.  
AS A RESULT...THE FLASH FLOOD WARNING HAS BEEN 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 4136 11046 4152 11015 4144 11015 4126 11021
      4109 11033 4110 11049 4122 11055

$$

MCINERNEY

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
357 PM MDT WED SEP 11 2013

.SYNOPSIS...AN UPPER LOW NEAR ST. GEORGE WILL DRIFT VERY SLOWLY
NORTH THROUGH EASTERN NEVADA THURSDAY AND THEN INTO NORTHERN UTAH
FRIDAY BRINGING PERIODS OF RAIN TO THE AREA.

&&

.DISCUSSION...THE UPPER LOW IS NEAR ST. GEORGE THIS AFTERNOON. ALL
MODELS CONTINUE TO FORECAST A SLOW DRIFT NORTHWESTWARD INTO
EASTERN NV THURSDAY. ON FRIDAY THIS LOW DRIFTS INTO NORTHERN UTAH
ON THE GFS/EC...WHILE THE NEW 18Z NAM MOVES THE LOW THROUGH UTAH
EARLY FRIDAY AND INTO SOUTHERN IDAHO FRIDAY AFTERNOON...THEN
BRINGS A PIECE OF THE LOW BACK INTO NORTHERN UTAH SATURDAY.

ANYWAY YOU LOOK AT IT...PERIODS OF RAIN LIKELY WITH EMBEDDED
THUNDERSTORMS AND LOCALLY HEAVY RAIN FOR MUCH OF THE FORECAST
AREA THURSDAY THROUGH SATURDAY.

LOOKS LIKE TODAY WAS THE BIG DAY FOR WASHINGTON COUNTY...EXPECT
SOMEWHAT LESS RAINFALL IN WASHINGTON AND KANE COUNTY THURSDAY AS
THE UPPER LOW GETS FURTHER NORTH. HOWEVER STILL HIGH ENOUGH THREAT
OF ADDITIONAL RAINFALL AND SATURATED CONDITIONS SUGGEST IT WOULD
NOT TAKE MUCH TO PRODUCE ADDITIONAL FLOODING. HAVE EXTENDED FLASH
FLOOD WATCH OVER THE SOUTH FOR ANOTHER DAY.

JUST ENOUGH EASTERLY COMPONENT IN THE FLOW THURSDAY TO CONTINUE
THE THREAT OF HEAVY RAIN AND FLOODING IN GRAND STAIRCASE ESCALANTE
NM AND CAPITAL REEF NP...ALONG WITH THE SAN RAFAEL SWELL ON
THURSDAY. VERY HIGH FLOWS NOW IN PROGRESS IN THE ESCALANTE AND
DIRTY DEVIL RIVERS.

FURTHER NORTH EXPECT WIDESPREAD RAIN SHOWERS WITH SCATTERED
THUNDERSTORMS THURSDAY. MAIN THREAT WILL BE TO THE BURN SCARS
WHERE HEAVY RAIN COULD PRODUCE DEBRIS FLOWS IF THEY TAKE A DIRECT
HIT FROM A HEAVY SHOWER. ALSO CONCERNED ABOUT ROCK FALL ONTO ROADS
IN STEEP CANYONS OF THE WASATCH MOUNTAINS. HAVE ISSUED FLASH FLOOD
WATCH FOR MANY PARTS OF THE NORTH FOR THURSDAY.

RAINFALL WILL ABATE SOMEWHAT THURSDAY NIGHT BUT
REDEVELOP...ESPECIALLY OVER NORTHERN AND CENTRAL UTAH ON FRIDAY.
DRIER OVER EXTREME SOUTHERN UTAH ON FRIDAY.

DEPENDING ON EXACT TRACK OF THE LOW...IT APPEARS ANOTHER DAY OF
ACTIVE SHOWERS AND THUNDERSTORMS LIKELY ON SATURDAY OVER THE NORTH
AND PERHAPS CENTRAL UTAH AS WELL.

DRYING AND WARMING TREND SUNDAY.

GFS/EC DEVELOP BROAD TROUGH OVER THE PACIFIC NORTHWEST AND
NORTHERN ROCKIES NEXT WEEK WITH WESTERLY FLOW SWEEPING ACROSS
UTAH. 12Z GFS KEEPS THESE TROUGHS MAINLY NORTH OF UTAH WITH
INCREASING DRY SOUTHWEST FLOW AND EVENTUALLY A DRY COLD FRONT. 12Z
EC IS MUCH MORE INTERESTING WITH A SERIES OF DEEPER AND SHARPER
TROUGHS MOVING THROUGH UTAH NEXT WEEK WITH THE FIRST ONE ON
TUESDAY INTERACTING WITH REMNANT MOISTURE TO PRODUCE WIDESPREAD
PRECIP EVENT OVER THE NORTH...FOLLOWED BY DEEPER AND COLDER
TROUGHS LATER IN THE WEEK...BY THE END OF THE WEEK THE 12Z EC
WOULD PRODUCE SNOW TO 8K IN THE NORTHERN MOUNTAINS. THE DRAMA IN
THE 12Z EC IS NEW AND WAS NOT PRESENT IN EARLIER RUNS...SO HAVE
ONLY HINTED AT TUESDAY EVENT IN THE POPS AND OTHERWISE GRIDS ARE
BASED ON 12Z GFS.

&&

.AVIATION...WINDS AT THE SLC TERMINAL WILL BE GENERALLY FROM THE
NORTHWEST THROUGH 3Z THIS EVENING. HOWEVER...WITH SHOWERS AND
THUNDERSTORMS IN THE AREA...IT IS LIKELY THAT OUTFLOW WINDS WILL
RESULT IN ERRATIC WIND SPEEDS THROUGH 3Z TO 4Z. AFTER ABOUT
3Z...WINDS WILL SHIFT TO THE SOUTHEAST. WITH THE DEVELOPING
STORMS...THERE IS A 30 PERCENT CHANCE THAT CEILINGS AT THE SLC
TERMINAL WILL DROP BELOW 6000FT THIS EVENING...WITH A 10 PERCENT
CHANCE THAT A THUNDERSTORM WILL DIRECTLY IMPACT THE TERMINAL THROUGH
3Z TO 4Z.

&&

.FIRE WEATHER...UPPER LEVEL LOW IN ARIZONA WILL DRIFT SLOWLY NORTH
ALONG THE UTAH/NEVADA BORDER THROUGH THE END OF THE WEEK. A VERY
MOIST AIRMASS WILL ACCOMPANY THIS SYSTEM AS IT MOVES NORTH.
PRECIPITATION WILL BE FAIRLY WIDESPREAD...WITH A GOOD CHANCE FOR
WETTING RAINS...ACROSS THE STATE ON THURSDAY WITH SLOW SHIFT TO
THE NORTH FRIDAY INTO SATURDAY. OVERNIGHT RECOVERIES WILL BE VERY
STRONG IN THIS MOIST AIRMASS AND AFTERNOON MINIMUM RELATIVE
HUMIDITY VALUES WILL REMAIN QUITE HIGH. IN ADDITION...WINDS WILL
GENERALLY BE LIGHT AND TERRAIN DRIVEN THROUGH THE REMAINDER OF THE
WEEK UNDER LIGHT FLOW ALOFT. DRIER AND WARMER CONDITIONS ARE
EXPECTED TO BUILD BACK INTO UTAH LATE THIS WEEKEND INTO EARLY NEXT
WEEK.

&&

.SLC WATCHES/WARNINGS/ADVISORIES...
UT...FLASH FLOOD WATCH THROUGH THURSDAY EVENING FOR
     UTZ010-012>014-016-019>021-517-518.

     FLASH FLOOD WATCH FROM THURSDAY MORNING THROUGH THURSDAY EVENING
     FOR UTZ001>004-006>008-015.

WY...NONE.
&&

PUBLIC...DUNN
FIRE WEATHER...GRAHAM
AVIATION...HOSENFELD

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
635 AM MDT WED SEP 11 2013

UTZ001>016-019>021-517-518-WYZ021-121200-
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-
635 AM MDT WED SEP 11 2013

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

.DAY ONE...TODAY AND TONIGHT

SHOWERS AND THUNDERSTORMS WILL CONTINUE AT TIMES ACROSS MUCH OF
THE OUTLOOK AREA TODAY THROUGH TONIGHT.

HEAVY RAIN IS LIKELY WITH SOME OF THE STORMS OVER ABOUT THE
SOUTHEASTERN TWO THIRDS OF THE AREA AND THIS WILL CONTINUE TO
GENERATE LOCAL FLASH FLOODING THROUGH THIS EVENING.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY

SHOWERS AND THUNDERSTORMS WILL CONTINUE ACROSS MOST OF THE
OUTLOOK AREA THROUGH THURSDAY ALONG WITH A THREAT OF HEAVY RAIN
AND LOCAL FLASH FLOODING. SHOWERS WILL GRADUALLY TAPER OFF FROM
THE SOUTHWEST FRIDAY THROUGH THE WEEKEND.

.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 TRAVEL IMPACTS VISIT...
HTTP://WWW.UDOTTRAFFIC.UTAH.GOV/ROADWEATHERFORECAST.ASPX