000
FXUS63 KUNR 242157
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
257 PM MST SAT JAN 24 2015

.SHORT TERM...THIS EVENING THROUGH SUNDAY NIGHT
ISSUED AT 241 PM MST SAT JAN 24 2015

LATEST SFC ANALYSIS SHOWS THE LOW PRESSURE CENTER CURRENTLY OVER
NORTHEASTERN SOUTH DAKOTA DIVING SOUTHEASTWARD...WITH HIGH
PRESSURE OVER THE NORTHERN ROCKIES. THIS IS RESULTING IN A TIGHT
SFC PRESSURE GRADIENT OVER THE FORECAST AREA THIS AFTERNOON. THE
SFC PRESSURE GRADIENT ALONG WITH WEAK CAA TO AID MIXING HAS
CREATED STRONG WINDS OVER NORTHWESTERN SOUTH DAKOTA AND ON THE
PLAINS EAST OF THE BLACK HILLS. VERY WINDY CONDITIONS EXIST ACROSS
THE REST OF THE AREA. ANOTHER SFC TROUGH IS CURRENTLY ROTATING
AROUND THE WEST SIDE OF THE SFC LOW...MOVING FROM SERN MT INTO
NERN WY AND NWRN SD AND TIGHTENING THE GRADIENT AGAIN. THEREFORE
WILL KEEP THE CURRENT WIND HEADLINES IN PLACE OVER THE SOUTH
DAKOTA SIDE OF THE FORECAST AREA. INSTABILITY ASSOCIATED WITH MID
LEVEL COOLING AND THE UPPER SHORTWAVE IS PRODUCING A FEW RAIN
SHOWERS OVER THE AREA LATE THIS AFTERNOON WHICH MAY CONTINUE INTO
THE EVENING OVER CENTRAL SOUTH DAKOTA...AND POSSIBLY IN THE WEAK
BAROCLINIC ZONE OVER NERN WY. THE VERY WINDY CONDITIONS WILL IMPROVE
SLIGHTLY EARLY THIS EVENING AS THE SURFACE LOW CONTINUES TO MOVE
OFF TO THE SOUTHEAST...ALTHOUGH BREEZY NORTHWEST WINDS WILL
CONTINUE THROUGH MUCH OF THE NIGHT. LOW TEMPERATURES TONIGHT ARE
EXPECTED TO GENERALLY RANGE FROM THE MID 20S TO THE MID 30S.

ON SUNDAY...THE UPPER RIDGE WILL BEGIN TO BUILD INTO THE AREA FROM
THE WEST WITH HIGH PRESSURE AT THE SURFACE. DRY WEATHER IS
EXPECTED ON SUNDAY...WITH HIGH TEMPS FROM 40 TO 50 DEGREES AND
WESTERLY WINDS AT 10 TO 15 MPH.

.LONG TERM...MONDAY THROUGH SATURDAY
ISSUED AT 241 PM MST SAT JAN 24 2015

MEDIUM RANGE MODELS STILL IN AGREEMENT ON AN UPPER
LEVEL RIDGE MOVING EAST ACROSS THE ROCKIES EARLY NEXT WEEK AND
FLATTENING OUT ACROSS THE PLAINS MIDWEEK. VERY MILD AIR WILL BE IN
PLACE FOR MONDAY AND TUESDAY...WITH HIGHS IN THE 50S AND LOWER
60S...WARMEST OVER THE EASTERN SLOPES OF THE BLACK HILLS. AS THE
RIDGE BREAKS DOWN DURING MIDWEEK...SHORTWAVE ENERGY WILL PUSH
THROUGH...BRINGING INCREASING CLOUDS AND COOLER AIR FOR THE LATTER
PART OF THE WEEK. MODELS DIVERGE SOME TOWARD THE END OF THE FORECAST
PERIOD...WITH GFS SHOWING A STRONGER SHORTWAVE PASSING THROUGH
FRIDAY NIGHT INTO SATURDAY. THIS WOULD BRING A CHANCE FOR SNOW AND
ANOTHER SHOT OF COLDER AIR FOR NEXT WEEKEND.

&&

.AVIATION...FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING
ISSUED AT 241 PM MST SAT JAN 24 2015

VERY STRONG NORTHWESTERLY WINDS WILL PERSIST ACROSS THE
SD PLAINS THROUGH EARLY EVENING. THE STRONGEST WINDS WILL GENERALLY
BE FROM K2WX TO KRAP...WHERE SOME GUSTS TO NEAR 50 KT ARE EXPECTED
THROUGH LATE AFTERNOON. ISOLATED RAIN SHOWERS WILL PERSIST THROUGH
EARLY EVENING. VFR CONDITIONS ARE EXPECTED THROUGH SUNDAY MORNING.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...WIND ADVISORY UNTIL 7 PM MST /8 PM CST/ THIS EVENING FOR SDZ014-
     025-030-032-042>044-046-047-074.

     HIGH WIND WARNING UNTIL 7 PM MST THIS EVENING FOR SDZ001-002-012-
     013-026-031-072-073.

WY...HIGH WIND WARNING UNTIL 7 PM MST THIS EVENING FOR WYZ071.

&&

$$

SHORT TERM...10
LONG TERM...15
AVIATION...15