Area Forecast Discussion
Issued by NWS Rapid City, SD

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

000
FXUS63 KUNR 251549
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
949 AM MDT TUE AUG 25 2015

.UPDATE...
ISSUED AT 944 AM MDT TUE AUG 25 2015

UPPER LEVEL RIDGE DOMINATING THE WEATHER PATTERN TODAY. QUITE A
BIT OF SMOKE IS CROSSING THE AREA IN THE MID LEVELS...SO WILL
LIKELY NOT REACH FULL POTENTIAL ON HIGH TEMPERATURES THIS
AFTERNOON...SO REDUCED FORECAST MAX TEMPS A COUPLE OF DEGREES.
SURFACE HIGH PRESSURE WILL SHIFT EAST TODAY...WITH RETURN FLOW
PICKING UP BY LATE THIS MORNING. SOUTHEAST WINDS SHOULD BECOME
BREEZY ACROSS THE SOUTH DAKOTA PLAINS BY EARLY AFTERNOON.
REMAINDER OF FORECAST IN GOOD SHAPE.

&&

.SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT
ISSUED AT 226 AM MDT TUE AUG 25 2015

UPPER RIDGE COVERS THE WESTERN 2/3 OF THE CONUS...WITH
AN UPPER LOW SPINNING JUST NORTH OF THE GREAT LAKES REGION. A FEW
HIGH CLOUDS ARE STREAMING OVER THE RIDGE INTO THE NORTHER PLAINS.
SURFACE HIGH PRESSURE STRETCHES ACROSS THE DAKOTAS. WINDS ARE LIGHT
AND SOUTHERLY...AND TEMPS AT 2AM ARE IN THE 50S.

ANOTHER MOSTLY SUNNY AND WARM DAY IS EXPECTED TODAY WITH UPPER RIDGE
IN PLACE. BREEZY RETURN FLOW WILL HELP TEMPS WARM INTO THE 80S AND
LOWER 80S. LOWS TONIGHT WILL BE IN THE 50S TO LOWER 60S.

MODELS ARE IN AGREEMENT THAT AN UPPER WAVE WILL APPROACH THE REGION
WEDNESDAY AS IT PASSES THROUGH THE RIDGE. SOUTHEASTERLY WINDS WILL
INCREASE AHEAD OF THE SURFACE LOW...ADVECTING IN MOISTURE AND WARM
AIR. TEMPS WILL RISE INTO THE UPPER 80S TO MID 90S...WITH DEW POINTS
IN THE 50S TO LOWER 60S. SOME INSTABILITY DEVELOPS WEDNESDAY
MORNING...ALLOWING FOR THE POSSIBLE FORMATION OF A FEW
SHOWERS/STORMS OVER THE HILLS BY MIDDAY. NAM SHOWS NOTABLY MORE
PRECIP AND INSTABILITY THAN THE GFS AND ECM...BUT THERE IS
CONSENSUS ABOUT THE BEST INSTABILITY STRETCHING ACROSS THE
WESTERN/CENTRAL SD PLAINS IN THE AFTERNOON AND EVENING.
HOWEVER...A STRONG CAP IN PLACE MAY INHIBIT MUCH STORM
DEVELOPMENT. 0-6KM SHEAR IN THIS AREA WILL BE 30-40 KTS...WITH
BETTER SHEAR FARTHER EAST. EXPECT SHOWERS AND THUNDERSTORMS TO
INCREASE ACROSS THE CWA WEDNESDAY EVENING AND OVERNIGHT AS THE
UPPER WAVE MOVES OVER THE AREA...WITH SOME ISOLATED SEVERE STORMS
POSSIBLE.

.LONG TERM...THURSDAY THROUGH MONDAY
ISSUED AT 226 AM MDT TUE AUG 25 2015

FAIRLY STRONG UPPER LOW IS PROGGED TO MOVE THROUGH THE
CNTRL CONUS RIDGE AND ACROSS THE NRN PLAINS ON THURSDAY...BRINGING A
GOOD CHANCE OF PCPN TO OUR AREA. UPPER RIDGE IS THEN EXPECTED TO
QUICKLY REBUILD AND BRING ABOVE AVERAGE TEMPS TO THE THE REGION
THROUGH THE WEEKEND. ALTHOUGH A FEW UPPER IMPULSES MAY BRING A SMALL
CHANCES FOR STORMS AT TIMES...WDSPRD COVERAGE IS NOT EXPECTED. THE
ECMWF BREAKS DOWN THE RIDGE EARLY NEXT WEEK...WHILE THE GFS DOES
NOT...SO FCST CONFIDENCE NOT VERY HIGH FOR EARLY NEXT WEEK.

&&

.AVIATION...FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING
ISSUED AT 226 AM MDT TUE AUG 25 2015

VFR CONDITIONS WILL CONTINUE NEXT 24 HOURS.


&&

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

$$

UPDATE...15
SHORT TERM...POJORLIE
LONG TERM...JOHNSON
AVIATION...JOHNSON


USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.