Damaging Wind in Wyoming, August 5, 2015

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
221 PM MDT WED AUG 5 2015

.SHORT TERM...THIS EVENING THROUGH THURSDAY NIGHT
ISSUED AT 218 PM MDT WED AUG 5 2015

UPPER WAVE CONTINUES TO APPROACH THE REGION...AS UPPER
LOW CIRCULATES OVER SOUTHWEST CANADA. WEAK SHOWERS ACROSS NORTHEAST
WYOMING HAVE BEEN DISSIPATING AS THEY MOVE EASTWARD...WITH JUST SOME
CLOUDS PUSHING INTO THE CWA. WITH LIGHT AND VARIABLE WINDS...TEMPS
ARE GENERALLY IN THE 80S.

SHOWERS AND THUNDERSTORMS STILL EXPECTED TO DEVELOP ALONG A LINE OF
FRONTOGENESIS/Q-VECTOR CONVERGENCE ACROSS THE WESTERN CWA AND EXPAND
EASTWARD. MODELS ARE HINTING AT AN INITIAL WAVE WITH BEST FORCING
JUST NORTHWEST OF THE CWA BRINGING A BAND OF STORMS THROUGH THE
NORTHERN HILLS AND NORTHWESTERN SD...WITH A SECONDARY WAVE
IMMEDIATELY FOLLOWING WITH SCATTERED SHOWERS/STORMS. HRRR THIS
MORNING WAS PRETTY CONSISTENT WITH A SQUALL LINE MOVING ACROSS THE
NORTHERN HILLS AND NORTHWEST SD EARLY THIS EVENING...BUT LATER RUNS
ARE SHOWING A MORE SCATTERED FORM. MLCAPE IS UNIMPRESSIVE AROUND
750 J/KG ON THE PLAINS WITH 1500 J/KG OVER THE HILLS...BUT SHEAR
IS 35-45 KTS SO WOULD NOT RULE OUT A STRONG TO SEVERE STORM. MAIN
THREAT WILL BE STRONG WINDS.

SURFACE LOW WILL MOVE ACROSS SD THURSDAY. A TIGHT PRESSURE GRADIENT
BEHIND THE LOW WILL CREATE SOME BREEZY NORTHWEST WINDS ACROSS THE SD
PLAINS AND ALSO BRING IN SOME COOLER AIR TO NORTHWESTERN SD.
SHOWERS/THUNDERSTORMS WILL CONTINUE ACROSS NORTHWESTERN/CENTRAL SD
DURING THE DAY UNTIL THE WAVE FINALLY TRANSITIONS EASTWARD OUT OF
THE REGION. DRY WEATHER IS THEN EXPECTED FOR THURSDAY NIGHT. HIGHS
THURSDAY WILL BE IN THE 80S...70S IN THE BLACK HILLS.

.LONG TERM...FRIDAY THROUGH WEDNESDAY
ISSUED AT 218 PM MDT WED AUG 5 2015

PROGRESSIVE FLOW WILL CONTINUE THROUGH THE WEEKEND WITH
A STRONGER UPPER LEVEL TROUGH ON TRACK FOR SAT-SUN. HOWEVER...STRONG
INDICATIONS ARE IN PLACE FOR SIG LONG WAVE RIDGING OVER CENTRAL NOAM
EARLY NEXT WEEK WHICH WOULD SUPPORT A MUCH WARMER PERIOD FOR THE
REGION BY THE MIDDLE OF NEXT WEEK. HIGHEST POPS IN THE PERIOD ARE IN
THE SAT-SUN PERIOD AS THE CURRENT UPPER LOW OFF THE COAST OF CA
EJECTS NE ACROSS THE ROCKIES AND INTO THE REGION. PLENTY OF LL
MOISTURE WILL BE IN PLACE WITH INCREASING LARGE SCALE ASCENT AND
MONSOON MOISTURE TO SUPPORT SCT SHRA/TS IN THIS PERIOD ESP ACROSS
THE NORTHERN ZONES. LINGERING CHANCES FOR PRECIP SUNDAY NIGHT WITH
DRY WEATHER EXPECTED EARLY NEXT WEEK...PERHAPS A SLIGHT CHANCE OF A
TS OVER THE BLACK HILLS TUES WHEN BETTER MOISTURE RETURNS TO THE
AREA AHEAD OF A LEE TROUGH. SOME SEVERE THREAT WILL BE IN PLACE
SAT/SUN WITH INCREASING FLOW SUPPORTING DECENT BULK SHEAR /0-6KM/
NUMBERS ABOVE 35 KNOTS...WITH 1-2 KJ/KG OF CAPE OVER THE SE FA.
HOWEVER...STILL MUCH UNCERTAINTY PER SYSTEM TRACK/SPEED TO ASCERTAIN
A BETTER GRASP ON SEVERE PROBS.

AFTER A SEASONAL DAY FRIDAY...COOLER TEMPS ARE ON TRACK FOR THE
WEEKEND...WITH A MODEST COOL DOWN EXPECTED SUNDAY.. MUCH WARMER
WEATHER ON TRACK FOR TUE AND BEYOND WITH 90S EXPECTED. A FEW 100/S A
CERTAINLY NOT OUT OF THE QUESTION...ESP ON THE SD PLAINS.

&&

.AVIATION...FOR THE 18Z TAFS THROUGH 18Z THURSDAY
ISSUED AT 218 PM MDT WED AUG 5 2015

ISOLD TSRA ARE POSSIBLE OVER THE BLKHLS AND NERN WY IN THE
AFTN/EVNG...WITH SCT TSRA OVERNIGHT...SPREADING WEST TO EAST. SOME
THUNDERSTORMS MAY PRODUCE GUSTY WINDS. MVFR CIGS/IFR VSBY WITH
THE TSRA.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&

SHORT TERM...POJORLIE
LONG TERM...JC
AVIATION...JC

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE RAPID CITY SD
302 AM MDT WED AUG 5 2015

SDZ001-002-012>014-024>032-041>044-046-047-049-072>074-WYZ054>058-
071-061300-
HARDING-PERKINS-BUTTE-NORTHERN MEADE CO PLAINS-ZIEBACH-
NORTHERN BLACK HILLS-NORTHERN FOOT HILLS-RAPID CITY-
SOUTHERN FOOT HILLS-CENTRAL BLACK HILLS-SOUTHERN BLACK HILLS-
CUSTER CO PLAINS-PENNINGTON CO PLAINS-HAAKON-FALL RIVER-SHANNON-
JACKSON-BENNETT-MELLETTE-TODD-TRIPP-STURGIS/PIEDMONT FOOT HILLS-
SOUTHERN MEADE CO PLAINS-HERMOSA FOOT HILLS-NORTHERN CAMPBELL-
SOUTHERN CAMPBELL-WESTERN CROOK-WYOMING BLACK HILLS-WESTON-
NORTHEASTERN CROOK-
302 AM MDT WED AUG 5 2015

THIS HAZARDOUS WEATHER OUTLOOK IS FOR WESTERN SOUTH DAKOTA AND
NORTHEASTERN WYOMING.

.DAY ONE...TODAY AND TONIGHT

THUNDERSTORMS ARE EXPECTED TO REDEVELOP ACROSS NORTHEAST WYOMING
AND THE BLACK HILLS AREA THIS AFTERNOON...THE PUSH ACROSS WESTERN
SOUTH DAKOTA TONIGHT. A FEW STORMS MAY BECOME STRONG TO SEVERE
WITH HAIL AND GUSTY WINDS...HOWEVER WIDESPREAD SEVERE WEATHER IS
NOT EXPECTED AT THIS TIME.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY

THERE IS A DAILY CHANCE FOR THUNDERSTORMS THURSDAY THROUGH THE
WEEKEND...HOWEVER WIDESPREAD SEVERE WEATHER IS NOT EXPECTED AT
THIS TIME.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL NOT BE NEEDED TODAY.

&&

STAY TUNED TO NOAA WEATHER RADIO FOR FURTHER DETAILS OR UPDATES...
OR CHECK OUR WEB SITE AT WEATHER.GOV/RAPIDCITY