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000
FXUS63 KUNR 220850
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
250 AM MDT WED MAY 22 2013

.SHORT TERM...TODAY THROUGH THURSDAY NIGHT
ISSUED AT 218 AM MDT WED MAY 22 2013

CURRENT SURFACE MAP SHOWS WEAK RIDGE OF HIGH PRESSURE ACROSS THE
WESTERN DAKOTAS. UPPER LOW THAT HAS BEEN OVER THE EASTERN DAKOTAS
THE PAST FEW DAYS IS SHIFTING EASTWARD...WITH MOST OF THE SHOWERS
ACTIVITY OVER EASTERN SOUTH DAKOTA. ISOLATED SHOWERS/DRIZZLE
POSSIBLE ACROSS WESTERN SOUTH DAKOTA THIS MORNING. ABUNDANT LOW
LEVEL STRATUS WILL REMAIN ACROSS MUCH OF THE FORECAST AREA THROUGH
THE DAY AS WINDS BECOME NE-E THIS WILL KEEP HIGHS AROUND 10
DEGREES BELOW AVERAGE.

DEEP UPPER LOW OVER THE PACIFIC NORTHWEST WILL BEGIN TO INFLUENCE
THE AREA THURSDAY WITH STRONG PRESSURE FALLS ACROSS
MONTANA/WYOMING WITH DEVELOPING SURFACE LOW. TIGHT PRESSURE
GRADIENT ACROSS NORTHEAST WYOMING/WESTERN SOUTH DAKOTA WILL RESULT
IN WINDY CONDITIONS. SOME WEAK SURFACE BASED INSTABILITY ACROSS
NORTHEAST WYOMING AND THE BLACK HILLS THURSDAY AFTERNOON.
HOWEVER...WITH LACK OF UPPER LEVEL FORCING AND STRONG CAP WIN
PLACE WILL NOT ADD THUNDERSTORMS TO THE FORECAST.


.LONG TERM...FRIDAY THROUGH TUESDAY
ISSUED AT 218 AM MDT WED MAY 22 2013

SOUTHWESTERLY FLOW ALOFT DEVELOPS OVER THE REGION FRIDAY AS RIDGE
SHIFTS TO THE EAST AND UPPER LOW SPINS IN PLACE OVER THE PACIFIC NW.
THIS PATTERN WILL PERSIST THROUGH AT LEAST THE FIRST HALF OF NEXT
WEEK AND BRING DAILY CHANCES FOR SHOWERS AND THUNDERSTORMS. LEE
TROUGH/DRY LINE WILL REMAIN NEARLY STATIONARY ACROSS EASTERN MT AND
EASTERN WY THROUGH THE PERIOD. MOIST SOUTH/SOUTHEAST LOW LEVEL FLOW
WILL PERSIST TO THE EAST OF THE TROUGH ACROSS THE BLACK HILLS AREA
AND THE PLAINS TO THE EAST. THIS IS WHERE THE BETTER CHANCES FOR
THUNDERSTORMS AND POTENTIAL SEVERE WEATHER WILL BE...ESPECIALLY
SUNDAY AND EARLY NEXT WEEK. TEMPERATURES WILL RISE TO ABOVE AVERAGE
LEVELS ON FRIDAY AND PERSIST THROUGH THE HOLIDAY WEEKEND...WITH THE
WARMEST TEMPS ACROSS WESTERN PORTIONS OF THE CWA.

&&

.AVIATION...FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT
ISSUED AT 218 AM MDT WED MAY 22 2013

ISOLATED LIGHT RAIN SHOWERS WILL PERSIST ACROSS AREAS EAST OF THE
BLACK HILLS THIS MORNING. FAIRLY WIDESPREAD MVFR/IFR CIGS WILL
REMAIN ACROSS THE FORECAST AREA THIS MORNING AS LOW LEVEL MOISTURE
REMAINS. CONDITIONS WILL IMPROVE TO VFR OVER NORTHEASTERN WYOMING BY
MIDDAY...AND OVER MUCH OF WESTERN SOUTH DAKOTA BY LATE IN THE
AFTERNOON. HOWEVER...AT LEAST SOME AREAS OF MVFR/IFR CIGS ARE
LIKELY TO REDEVELOP TONIGHT ACROSS THE PLAINS.

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

$$

SHORT TERM...7
LONG TERM...26
AVIATION...26