Severe Thunderstorm Warning 16, NWS Salt Lake City, UT

931 
WWUS55 KSLC 010213
SVSSLC

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
813 PM MDT FRI AUG 31 2012

UTC003-045-010245-
/O.CON.KSLC.SV.W.0016.000000T0000Z-120901T0245Z/
TOOELE UT-BOX ELDER UT-
813 PM MDT FRI AUG 31 2012

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 845 PM MDT
FOR SOUTHWESTERN BOX ELDER AND NORTHWESTERN TOOELE COUNTIES...

AT 811 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A LINE OF SEVERE THUNDERSTORMS CAPABLE OF PRODUCING DAMAGING
WINDS IN EXCESS OF 60 MPH.  THESE STORMS WERE LOCATED ALONG A LINE
EXTENDING FROM LUCIN TO 10 MILES SOUTH OF WENDOVER...MOVING EAST AT
30 MPH.

* LOCATIONS IN THE WARNING INCLUDE...
  WENDOVER...LUCIN AND BONNEVILLE SALT FLATS
  I-80 FROM WENDOVER EAST TO KNOLLS

PRECAUTIONARY/PREPAREDNESS ACTIONS...

IN ADDITION TO LARGE HAIL AND DAMAGING WINDS...CONTINUOUS CLOUD TO
GROUND LIGHTNING IS OCCURRING WITH THIS STORM. MOVE INDOORS
IMMEDIATELY! LIGHTNING IS ONE OF NATURES NUMBER ONE KILLERS.
REMEMBER...IF YOU CAN HEAR THUNDER...YOU ARE CLOSE ENOUGH TO BE
STRUCK BY LIGHTNING.

&&

LAT...LON 4154 11352 4041 11344 4026 11404 4148 11403
TIME...MOT...LOC 0213Z 254DEG 26KT 4133 11395 4056 11397

$$

MPS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
600 PM MDT FRI AUG 31 2012

.SYNOPSIS...DEEP MOISTURE WILL REMAIN OVER THE AREA THROUGH
TOMORROW. A GRADUAL DRYING TREND WILL DEVELOP ACROSS MAINLY THE
NORTHERN HALF OF UTAH LATE IN THE WEEKEND...THEN SPREAD INTO ALL
BUT THE EXTREME SOUTH EARLY NEXT WEEK.

&&

.DISCUSSION...WATER VAPOR SATELLITE LOOP SHOWS SOUTHWEST FLOW ALOFT
AS A TROUGH APPROACHES THE WEST COAST. THE LEAD SHORTWAVE IS ABOUT
TO EJECT NORTHEAST INTO CENTRAL CALIFORNIA AS THE ASSOCIATED UPPER
LEVEL JET NOSES INTO CENTRAL NEVADA.

RUC INDICATES PRECIPITABLE WATER OF 1-1.33" HAS ESTABLISHED ITSELF
ACROSS THE REGION...WITH DEWPOINTS CLIMBING AN AVERAGE 5-15F DURING
THE PAST 24 HOURS WELL INTO THE 50S ACROSS MOST VALLEYS. 15Z SHORT
RANGE ENSEMBLES INDICATE AT LEAST 250 J/KG OF MUCAPE OVERNIGHT TO AS
MUCH AS 750 J/KG.

MEANWHILE THE EXIT REGION OF THE UPPER LEVEL JET THAT IS CURRENTLY
SUPPORTING NUMEROUS SHOWERS AND THUNDERSTORM ACROSS NEVADA WILL NOSE
INTO WEST CENTRAL UTAH LATE THIS EVENING AND STRETCH ACROSS UTAH
FROM SOUTHWEST TO NORTHEAST BY MORNING. THE COMBINATION OF
APPROACHING DYNAMICS...AND MOISTURE/INSTABILITY IN PLACE SHOULD LEAD
TO NUMEROUS SHOWERS AND THUNDERSTORMS ACROSS WESTERN AND NORTHERN
UTAH OVERNIGHT. UPDATING TO INCREASE POPS...INCLUDING INTO SCATTERED
CATEGORY FOR THE REMAINDER OF CENTRAL AND SOUTHERN UTAH OVERNIGHT.

TOUCHED UP SKY (BASED ON IR SATELLITE AND PROPAGATION OF THE JET)
AND WINDS. LOWERED OVERNIGHT LOWS WHERE ACTIVITY SHOULD BE ENOUGH TO
COOL TEMPERATURES CLOSER TO DEWPOINTS.

PREVIOUS DISCUSSION FOLLOWS...
UPSTREAM TROUGH EDGING INLAND IS QUICKLY BECOMING
THE DOMINANT FEATURE OF NOTE ON THE LARGE SCALE. HIGH PRESSURE
EAST OF THE AREA CONTINUES TO FEED MOISTURE INTO THE DESERT
SOUTHWEST ...THIS ALLOWING THE INCREASING SOUTHWESTERLY FLOW ALOFT
IN ADVANCE OF SAID TROUGH TO ADVECT DEEP LAYER MOISTURE ON THE
ORDER OF 1 PLUS INCH PWAT ACROSS THE AREA. DYNAMIC SUPPORT REMAINS
UPSTREAM AT THIS TIME ALLOWING FOR GENERALLY FAST MOVING AND
UNORGANIZED CONVECTION THIS AFTERNOON...THOUGH AREAL COVERAGE IS
INCREASING VERSUS THE LAST FEW DAYS. WITH FURTHER DOWNSTREAM
PROGRESSION OF TROUGH WILL SEE THIS CHANGE HOWEVER.

250MB ANALYSIS INDICATE A STRENGTHENING 70 KNOT SW-NE ORIENTED JET
OVER SOCAL AT THIS TIME...WITH 12Z NAM12/GFS CAPTURING THIS QUITE
NICELY. PROGS OF SAID GUIDANCE CONTINUE TO STRENGTHEN
AFOREMENTIONED JET OVER THE NEXT 24 HOURS WHILST FAVORABLY
POSITIONING IT OVER NORTHERN UTAH COME SATURDAY AFTERNOON. AREA OF
GREATEST LIFT/DIVERGENCE ALOFT WITHIN ENTRANCE REGION OF STREAK
EXPECTED TO BE OVER CENTRAL/SOUTHERN UTAH WHERE THE BEST POTENTIAL
OF ORGANIZED AND LIKELY STRONG CONVECTION WILL TAKE PLACE. SEVERE
CAN NOT BE RULED OUT. ALTHOUGH STORM MOTIONS WILL BE
ELEVATED...FEEL THE THREAT OF TRAINING STORMS AND LIKELIHOOD OF
HEAVY RAINERS WITHIN A STILL DEEPLY MOIST AND UNSTABLE AIRMASS
WARRANTS A FLASH FLOOD WATCH...THIS COVERING MUCH OF CENTRAL AND
SOUTHERN UTAH AND THE BURN SCARS IN THE NORTH FOR SATURDAY. AS THE
TROUGH LIFTS NORTHEAST LATE DAY THE UPPER JET WILL BEGIN TO FAVOR
NORTHEASTERN PORTIONS OF THE AREA WELL INTO THE EVENING HOURS.

A DRYING WESTERLY FLOW WILL DEVELOP OVER NORTHERN UTAH BY SUNDAY
GRADUALLY PINNING DEEP MOISTURE SOUTH OF THE AREA INTO EARLY NEXT
WEEK. REMNANT LOW LEVEL MOISTURE WILL RETAIN A THREAT OF TERRAIN
BASED CONVECTION THROUGH THAT TIME BUT SIGNIFICANCE WILL TREND
MORE TOWARDS RUN OF THE MILL AIRMASS SHOWERS AND STORMS OVER THE
TERRAIN ACROSS THE SOUTH.

GLOBAL MODELS A BIT BETTER ALIGNED FOR THE MIDWEEK PERIOD
REGARDING A CONTINUED DRY WESTERLY FLOW OVER THE AREA. HAVE
TRENDED MID AND LATTER PERIODS TOWARDS A DRIER SOLUTION DUE TO
THIS.

&&

.AVIATION...SOUTH WINDS LOOK TO PREVAIL THROUGH THE EVENING HOURS AT
KSLC. THUNDERSTORM POTENTIAL LOOKS TO INCREASE SUBSTANTIALLY BY 04Z
WITH GUSTY ERRATIC WINDS AND A 30 PERCENT CHANCE FOR MVFR VIS.
THUNDERSTORMS WILL LIKELY LINGER INTO THE OVERNIGHT HOURS BEFORE
DIMINISHING LATE.

&&

.FIRE WEATHER...STORMS WILL CONTINUE TO DEVELOP THROUGH THIS
EVENING...WITH POTENTIAL FOR DEVELOPMENT STATEWIDE. WITH DEEP
MOISTURE...THE MAJORITY OF STORMS WILL BE ACCOMPANIED BY WETTING
RAIN. MOISTURE WILL REMAIN IN PLACE TOMORROW...WITH STORMS
DEVELOPING STATEWIDE.

DRIER AIR WILL BEGIN TO MOVE INTO THE STATE SUNDAY...LIMITING
STORM ACTIVITY.

&&

.SLC WATCHES/WARNINGS/ADVISORIES...
UT...FLASH FLOOD WATCH FROM SATURDAY MORNING THROUGH SATURDAY EVENING
     FOR UTZ008-010-012-013-016-019>021-517-518.

WY...NONE.
&&

PUBLIC...ROGOWSKI/MERRILL
FIRE WEATHER...HOSENFELD
AVIATION...SEAMAN

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
540 PM MDT FRI AUG 31 2012

UTZ001>016-019>021-517-518-WYZ021-011300-
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-
540 PM MDT FRI AUG 31 2012

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

.DAY ONE...TONIGHT

SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS WILL PERSIST
THROUGH THE NIGHT...MAINLY ACROSS WESTERN AND NORTHERN UTAH.
PRIMARY THREATS INCLUDE CLOUD TO GROUND LIGHTNING...LOCALLY HEAVY
RAINFALL AND LOCALLY GUSTY WINDS.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY

THE DEEP LAYER MOISTURE WILL REMAIN ACROSS THE OUTLOOK AREA
THROUGH SATURDAY. SCATTERED SHOWERS AND THUNDERSTORMS WILL FORM
AGAIN DURING THE AFTERNOON AND EVENING HOURS SATURDAY...WITH THE
POTENTIAL FOR STRONG THUNDERSTORMS WITH LOCALLY HEAVY RAIN ACROSS
CENTRAL AND SOUTHERN UTAH DURING THE AFTERNOON.

A GRADUAL DRYING TREND WILL BEGIN ACROSS NORTHWEST UTAH SUNDAY...
THEN SPREAD SOUTH AND EAST EARLY NEXT WEEK. MOISTURE WILL REMAIN
ACROSS THE SOUTHERN THIRD OF UTAH EARLY NEXT WEEK....FUELING
ADDITIONAL SHOWER AND THUNDERSTORMS ACTIVITY. SOME MOISTURE WILL
WORK NORTH MIDWEEK...RESULTING IN ISOLATED THUNDERSTORMS OVER
NORTHERN UTAH AND SOUTHWEST WYOMING AND SCATTERED STORMS ACROSS
THE SOUTHERN AND CENTRAL PORTIONS OF THE OUTLOOK AREA.

.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)

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