000
FXUS63 KUNR 272200
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
300 PM MST TUE JAN 27 2015

.SHORT TERM...THIS EVENING THROUGH WEDNESDAY NIGHT
ISSUED AT 243 PM MST TUE JAN 27 2015

AT 21Z THE WATER VAPOR SAT IMAGE SHOWED A BROAD HIGH AMPLITUDE
RIDGE OVER THE FORECAST AREA. AT THE SFC A WEAKLY DEFINED LOW
PRESSURE TROUGH WAS LOCATED OVER ERN MT/WY/CO AND WRN ND/SD/NEB.
ABUNDANT SUNSHINE...SUBSIDENCE AND WARM AIR HAVE PRODUCED RECORD
HIGH TEMPERATURES AT MANY LOCATIONS AGAIN TODAY.

CLOUD COVER WILL INCREASE OVER THE AREA LATE TONIGHT AS THE UPPER RIDGE
SHIFTS TO THE EAST AND A SHORTWAVE TROUGH APPROACHES FROM THE
WEST. THE SHORTWAVE WILL CROSS THE FORECAST AREA ON WEDNESDAY
PRODUCING A CHANCE OF SHOWERS OVER PARTS OF NORTHEASTERN
WYOMING...THE BLACK HILLS AND SOUTHWESTERN SOUTH DAKOTA. A SURFACE
LOW WILL DROP SOUTHEASTWARD ACROSS THE DAKOTAS ON WEDNESDAY
TIGHENING THE SFC PRESSURE GRADIENT OVER THE FORECAST AREA. VERY
WINDY CONDITIONS ARE EXPECTED TO DEVELOP OVER NORTHWESTERN SOUTH
DAKOTA AND ON THE PLAINS EAST OF THE BLACK HILLS DUE TO THE TIGHT
SFC PRESS GRAD AND LL INSTABILITY DUE TO THE LOW-MID COLD ADVECTION.
HAVE ISSUED A WIND ADVISORY FOR THOSE AREAS...STARTING LATE
WEDNESDAY MORNING. THE WIND WILL DIMINISH EARLY WEDNESDAY EVENING AS THE
LOW MOVES AWAY TO THE SOUTHEAST AND THE GRADIENT BEGINS TO SLACKEN
AS HIGH PRESSURE MOVES IN FROM THE NORTHEST.

.LONG TERM...THURSDAY THROUGH TUESDAY
ISSUED AT 243 PM MST TUE JAN 27 2015

TEMPERATURES WILL GRADUALLY LOWER TO NEAR OR BELOW
AVERAGE LEVELS BY THE WEEKEND AS NORTHWEST FLOW BRINGS COLDER AIR
INTO THE REGION. MODELS NOW SHOWING AGREEMENT IN KEEPING THE COLDEST
TEMPERATURES EAST OF THE AREA FOR THE WEEKEND WITH HIGHS NEAR TO
SLIGHTLY BELOW AVERAGE. SLIGHT CHANCES FOR LIGHT SNOW ARE EXPECTED
AS A STRONGER WAVE CROSSES THE REGION...MAINLY OVER NW SD AND NE WY.
SOME MILDER AIR COULD SLIDE BACK EASTWARD INTO THE REGION EARLY NEXT
WEEK...BUT THAT REMAINS UNCERTAIN AT THIS POINT.

&&

.AVIATION...FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING
ISSUED AT 243 PM MST TUE JAN 27 2015

VFR CONDITIONS CAN BE EXPECTED THROUGH THE FORECAST
PERIOD. A COLD FRONT WILL BRING GUSTY NORTHWEST WINDS AT 20-30KT
WITH HIGHER GUSTS WEDNESDAY...MAINLY OVER THE WRN SD PLAINS.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...WIND ADVISORY FROM 11 AM TO 7 PM MST WEDNESDAY FOR SDZ001-002-
     012>014-025-026-031-032-072-073.

WY...NONE.
&&

$$

SHORT TERM...10
LONG TERM...13
AVIATION...13