000
FXUS63 KUNR 272118
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
218 PM MST FRI FEB 27 2015

.SHORT TERM...THIS EVENING THROUGH SATURDAY NIGHT
ISSUED AT 214 PM MST FRI FEB 27 2015

BROAD UPPER TROUGH SPANS THE CONUS...WITH ARCTIC AIR PLUNGING
INTO THE SOUTHEASTERN STATES. SKIES ARE MOSTLY CLEAR OVER THE
NORTHERN PLAINS...WITH THE EXCEPTION OF FAR SOUTHWEST SD AND THE
SOUTHERN HILLS...WHERE SOME LIGHT UPSLOPE SNOW HAS BEEN REPORTED.
SURFACE HIGH TO THE SOUTHEAST OF THE REGION IS PRODUCING SOME
BREEZY SOUTHERLY WINDS ACROSS THE AREA...BRINGING IN SOME WARMER
AIR. TEMPS ARE GENERALLY IN THE 20S.

SURFACE TROUGH CROSSES THE REGION TONIGHT...CAUSING WINDS TO BECOME
NORTHWESTERLY. CLOUDS WILL INCREASE...AND MORE CHILLY AIR WILL MOVE
INTO THE REGION AS ANOTHER COLD SURFACE HIGH SLIDES IN. LOWS TONIGHT
WILL BE IN THE SINGLE DIGITS.

COLD AIR AND CLOUDS WILL CONTINUE TO ADVECT INTO THE AREA ON
SATURDAY. LOWERED HIGH TEMPS ACROSS THE NORTHWESTERN HALF OF THE CWA
FOR THESE REASONS. EXPECT HIGHS TO RANGE FROM THE UPPER TEENS ACROSS
NORTHEAST WY AND FAR NORTHWEST SD TO THE LOWER 30S ACROSS SOUTH
CENTRAL SD. UPPER FLOW BEGINS TO SPLIT SATURDAY NIGHT AS LOW CUTS
OFF OVER CA AND NORTHERNMOST ENERGY PUSHES INTO THE NORTHERN PLAINS.
THE SOUTHERN PART OF THE CWA MAY SEE SOME LIGHT SNOW ON SUNDAY NIGHT
AS THIS WAVE PASSES THROUGH...BUT KEPT CHANCES SLIGHT AS BEST
FORCING STAYS SOUTH AND HIGH PRESSURE REMAINS OVER THE AREA. SINGLE
DIGITS ARE AGAIN EXPECTED FOR LOWS SATURDAY NIGHT.

.LONG TERM...SUNDAY THROUGH FRIDAY
ISSUED AT 214 PM MST FRI FEB 27 2015

COLD TEMPERATURES AND NORTHWESTERLY FLOW WILL CONTINUE
THROUGH SUNDAY AS AN UPPER LEVEL TROUGH MOVES OUT OF THE CWA. A
1035MB HIGH WILL SLIDE SOUTHEAST OF THE CWA DURING THE DAY SUNDAY...
GRADUALLY SWITCHING SURFACE WINDS FROM NW TO SE BY MONDAY MORNING.
MONDAY IS LOOKING TO BE MILD AS WARMER AIR ADVECTS INTO THE REGION
FROM THE WEST AHEAD OF A LONGWAVE TROUGH. THE WARMTH WILL BE SHORT
LIVED...AS AN ARCTIC FRONT WILL PUSH THROUGH THE REGION LATE MONDAY
NIGHT INTO TUESDAY MORNING. TEMPERATURES WILL DECLINE DURING THE
AFTERNOON TUESDAY AS STRONG COLD AIR ADVECTION TAKES PLACE...AND
OVERNIGHT LOWS WILL DROP BELOW ZERO FOR ALL OF THE CWA. THERE WILL
BE SOME MOISTURE BEHIND THE ARCTIC FRONT...BUT SNOW AMOUNTS WILL
GENERALLY BE LIGHT...AROUND 1 TO 3 INCHES FOR THE CWA.

THE GFS AND ECMWF ARE IN AGREEMENT OF A STRONG RIDGE BUILDING INTO
THE WESTERN US BY MIDWEEK AND PERSISTING BEYOND THE END OF THE
FORECAST PERIOD. AS A RESULT...EXPECT GENERALLY DRY CONDITIONS PAST
WEDNESDAY WITH A WARMING TREND FOR THE CWA. BY FRIDAY...AFTERNOON
HIGHS COULD BE WELL INTO THE 50S...ABOUT 10 DEGREES ABOVE
CLIMATOLOGY FOR THIS TIME OF YEAR.

&&

.AVIATION...FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING
ISSUED AT 214 PM MST FRI FEB 27 2015

AN AREA OF MVFR/NEAR-MVFR CIGS OVER SWRN SD WAS MOVING
NORTHEAST AND SPREADING INTO WCNTRL SD. SHORT-TERM GUIDANCE HAS BEEN
POOR IN HANDLING THIS...BUT GIVEN THE UPSTREAM CLOUDS/MOISTURE WOULD
EXPECT THE AREA TO CONTINUE ITS NEWD MOTION...AFFECTING WCNTRL AND
PARTS OF SCNTRL SD INTO EARLY EVNG. OTHERWISE...VFR CONDITIONS WILL
PREVAIL ACROSS THE CWA UNTIL LATE TNGT WHEN A WEAK UPPER-WAVE WILL
BRING INCREASING MVFR CIGS OVER PARTS OF NERN WY AND FAR NWRN SD.

&&

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

$$

SHORT TERM...POJORLIE
LONG TERM...MCKEMY
AVIATION...BUNKERS