Area Forecast Discussion
Issued by NWS Rapid City, SD

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000
FXUS63 KUNR 302054
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
254 PM MDT TUE SEP 30 2014

.SHORT TERM...THIS EVENING THROUGH WEDNESDAY NIGHT
ISSUED AT 239 PM MDT TUE SEP 30 2014

20Z SFC ANALYSIS SHOWS THE STACKED LOW PRESSURE SYSTEM LOCATED
OVER NORTH CENTRAL SOUTH DAKOTA MOVING NORTHWARD. BANDS OF RAIN
ROTATING AROUND THE LOW WILL CONTINUE TO DECREASE IN COVERAGE AND
INTENSITY THIS EVENING AS THE LOW CONTINUES TO MOVE AWAY FROM THE
FORECAST AREA. A TIGHT SFC PRESSURE GRADIENT HAS PRODUCED GUSTY
WESTERLY WINDS OVER PARTS OF WEST CENTRAL...SOUTHWESTERN AND SOUTH
CENTRAL SOUTH DAKOTA SO WILL KEEP THE WIND ADVISORY IN EFFECT FOR
THOSE AREAS UNTIL 600 PM MDT. THE WIND WILL DIMINISH QUICKLY THIS
EVENING AS THE SFC PRESS GRADIENT SLACKENS BEHIND THE DEPARTING
LOW. CYCLONIC FLOW AROUND THE UPPER LOW WILL STILL SUPPORT A
CHANCE OF -SHRA OVERNIGHT MAINLY OVER NORTHEASTERN WYOMING AND FAR
WESTERN SOUTH DAKOTA. TEMPERATURES WILL BE NEAR GUIDANCE.

ON WEDNESDAY...A SECONDARY UPPER TROUGH WILL CROSS THE REGION
BRINGING A CHANCE OF SHOWERS. TEMPERATURES WILL BE NEAR GUIDANCE.

&&

.LONG TERM...THURSDAY THROUGH TUESDAY
ISSUED AT 239 PM MDT TUE SEP 30 2014

TROF AXIS CROSSES FORECAST AREA THURSDAY...WITH DRIER
AIR BEHIND IT. A SMALL WAVE ON THE CYCLONIC NORTHWEST FLOW MAY
PRODUCE SOME SHOWERS OVER PARTS OF NORTHEASTERN WY THURSDAY
NIGHT...BUT WAVE IS WEAKER THAN PREVIOUS MODEL RUNS. NO SIGNIFICANT
CHANCES OF PRECIPITATION ARE IN THE REST OF THE FORECAST. UPPER
RIDGE BUILDS OVER WESTERN US...WITH MAINLY DRY NORTHWEST FLOW ACROSS
THE AREA. THE EXTENDED PERIOD WILL ALSO SEE OCCASIONAL BOUTS OF
GUSTY WINDS...THURSDAY AS A SURFACE HIGH PUSHES INTO THE AREA AND
AGAIN SATURDAY BEHIND A TROF. TEMPERATURES WILL REMAIN COOL THROUGH
FRIDAY...THEN PEAK SATURDAY BEFORE COOLING AGAIN NEXT WEEK.

&&

.AVIATION...FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY
ISSUED AT 239 PM MDT TUE SEP 30 2014

STORM SYSTEM OVR NCNTRL SD CONTINUES TO MOVE NEWD...W/
SHWRS REMAINING OVER NWRN SD THIS AFTN AND EVEN...THEN DIMINISHING
OVERNIGHT. MVFR/IFR CIGS WITH THE PRECIP...WHILE CIGS ARE LIFTING
OVER SWRN SD WHERE DOWNSLOPE WINDS HAVE INCREASED. GUSTY NORTHWEST
WINDS WL DIMINISH THIS EVEN AND BCM WESTERLY.

&&

.HYDROLOGY...
ISSUED AT 239 PM MDT TUE SEP 30 2014

THE LOW PRESSURE CENTER CURRENTLY LOCATED OVER NORTH CENTRAL SOUTH
DAKOTA WILL CONTINUE TO ACCELERATE OFF TOWARD THE NORTH AND THE BANDS
OF SHOWERS OVER THE FORECAST AREA WILL GRADUALLY DECREASE IN
COVERAGE AN INTENSITY THIS EVENING AS THE LOW MOVES AWAY. A FLOOD
ADVISORY REMAINS IN EFFECT FOR FALL RIVER COUNTY AND PARTS OF
CUSTER...WESTERN PENNINGTON AND FAR WESTERN SHANNON COUNTIES UNTIL
700 PM MDT THIS EVENING. THOSE ARE THE AREAS WHICH RECEIVED THE
MOST RAIN OVER THE PAST COUPLE OF DAYS. SMALL CREEKS AND STREAMS
ARE RUNNING VERY HIGH IN THOSE AREAS. DEBRIS IN THOSE STREAMS CAN
QUICKLY BLOCK CULVERTS WHICH COULD CAUSE MINOR FLOODING.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...WIND ADVISORY UNTIL 6 PM MDT /7 PM CDT/ THIS EVENING FOR SDZ026-
     027-030>032-041>044-046-047-049-072>074.

WY...NONE.
&&

$$

SHORT TERM...10
LONG TERM...55
AVIATION...55
HYDROLOGY...10





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