Area Forecast Discussion
Issued by NWS Rapid City, SD

Home | Current Version | Previous Version | Text Only | 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 302345
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
545 PM MDT THU JUL 30 2015

.SHORT TERM...THIS EVENING THROUGH FRIDAY NIGHT
ISSUED AT 229 PM MDT THU JUL 30 2015

20Z SFC ANALYSIS SHOWS WEAK HIGH PRESSURE OVER THE FORECAST AREA
PRODUCING MOSTLY SUNNY SKIES. A WEAK TROUGH OVER THE EASTERN
DAKOTAS HAS TIGHTENED THE SFC PRESSURE GRADIENT AND IS HELPING TO
PRODUCE BREEZY CONDITIONS OVER PARTS OF NORTHWESTERN AND CENTRAL
SOUTH DAKOTA.

TONIGHT/FRIDAY...THE UPPER RIDGE WILL CONTINUE TO BUILD OVER THE
WESTERN CONUS WITH A THERMAL RIDGE EXPANDING EASTWARD OVER THE
FORECAST AREA. ON FRIDAY SOUTHERLY RETURN FLOW WILL DEVELOP AS
THE SFC HIGH SHIFTS EAST. MLCAPE WILL INCREASE TO 250-750J/KG BY
LATE FRIDAY AFTN OVER PARTS OF NERN WY...THE BLKHLS AND SWRN SD.
MODELS INDICATE THAT A WEAK SHORTWAVE MAY PROVIDE ENOUGH FORCING
TO OVERCOME THE CIN BY LATE AFTN SO HAVE INCLUDED A SLIGHT CHANCE
OF THUNDERSTORMS OVER THOSE AREAS FROM LATE AFTN INTO EARLY
EVENING. HIGHS ON THE PLAINS ON FRIDAY ARE EXPECTED TO RANGE FROM
THE UPPER 80S TO LOWER 90S WITH MID 70S TO MID 80S IN THE BLKHLS.

.LONG TERM...SATURDAY THROUGH THURSDAY
ISSUED AT 229 PM MDT THU JUL 30 2015

 MEDIUM RANGE MODELS ARE IN GOOD AGREEMENT THROUGH THE
FIRST PART OF THE EXTENDED PERIOD AND THEN DIFFER SOME TOWARD THE
MIDDLE OF NEXT WEEK...WHEN CONDITIONS ARE EXPECTED TO BECOME AT
LEAST A BIT MORE UNSETTLED. DRIER NORTHWEST FLOW ALOFT WILL REMAIN
ACROSS THE REGION THROUGH THE WEEKEND AND INTO MONDAY MORNING. OTHER
THAN THE POSSIBILITY FOR A FEW SHOWERS AND THUNDERSTORMS FROM FAR
SOUTHWEST INTO SOUTH CENTRAL SD ON SATURDAY...MAINLY DRY CONDITIONS
SHOULD PERSIST THROUGH AT LEAST EARLY MONDAY. TEMPS WILL BE ABOVE
AVERAGE THROUGH THE WEEKEND...WITH HIGHS IN THE 90S ACROSS MUCH OF
THE PLAINS...80S IN THE BLACK HILLS.

AS MENTIONED...THE WEATHER PATTERN WILL LIKELY BECOME MORE UNSETTLED
FOR THE MIDDLE PART OF THE WEEK...ESPECIALLY TUESDAY... AS EAST TO
SOUTHEAST WINDS BRING INCREASING MOISTURE AND FLOW ALOFT BECOME MORE
ZONAL. MODELS ARE STILL IN SOME DISAGREEMENT ON THE TIMING OF
DISTURBANCES PASSING ACROSS...WITH THE ECMWF STILL SHOWING MORE
POTENTIAL FOR STORMS THEN THE GFS. ALTHOUGH THERE IS PLENTY OF
UNCERTAINTY...TUESDAY AND TUESDAY NIGHT STILL LOOK LIKE THE BEST
PERIODS FOR PCPN POTENTIAL AT THIS TIME. TEMPS WILL BE SLIGHTLY
COOLER NEXT WEEK...BUT STILL AROUND AVERAGE.

&&

.AVIATION...FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING
ISSUED AT 542 PM MDT THU JUL 30 2015

CLR TO SCT CLDS THRU FRI MRNG. AS SFC HI PRES BLDS OVR FCST
AREA...N WNDS WL DIMINISH AND BCM LGT/VRBL.

&&

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

$$

SHORT TERM...10
LONG TERM...26
AVIATION...55


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