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000
FXUS63 KUNR 120423
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
1023 PM MDT SAT MAY 11 2013

.SHORT TERM...THIS EVENING THROUGH SUNDAY NIGHT
ISSUED AT 200 PM MDT SAT MAY 11 2013

A QUIET WEATHER PATTERN IS IN STORE THROUGH SUNDAY NIGHT.
NORTHWEST FLOW PREVAILED TODAY WITH AN UPPER RIDGE AXIS OVER THE
NWRN CONUS. A WEAK SHORT-WAVE TROUGH WAS SPILLING OVER THE RIDGE
AND SPREADING SOME MIDLEVEL CLOUDS TOWARD THE WRN CWA. MODELS HAVE
BEEN CONSISTENT IN SHOWING THIS FEATURE THE PAST SEVERAL RUNS. A
FEW MODELS HAVE ALSO INDICATED LIGHT PRECIP AMOUNTS. HOWEVER...
VERY WEAK Q-G FORCING AND LOW-LEVEL FGEN...COMBINED WITH MARGINAL
MOISTURE... PRECLUDES MENTION OF PRECIP. EXPECT SOME WEAK RADAR
RETURNS WITH PERHAPS SPRINKLES.

ON SUNDAY THE UPPER HEIGHTS WILL CONTINUE TO BUILD AS THE UPPER
RIDGE MOVES OVER MT/WY. PRECIPITABLE WATER INCREASES TO AROUND
AVERAGE AND AFTN MLCAPE WILL REACH 75-200 J/KG OVER THE BLKHLS. HAVE
THUS PUT IN SMALL CHANCES FOR -SHRA/-TSRA FOR THIS AREA. CONVECTION-
ALLOWING MODELS SUGGEST THIS IS POSSIBLE. UPPER FORCING WILL BE
RATHER WEAK SO DO NOT EXPECT ANYTHING TO SURVIVE OFF THE HILLS.

ON SUNDAY NIGHT THE UPPER RIDGE...AS WELL AS THE LOW-LEVEL THERMAL
RIDGE...WILL MOVE OVER THE CWA. THE SURFACE TROUGH WILL SHIFT EAST A
LITTLE AND THUS ALLOW FOR WESTERLY BOUNDARY LAYER FLOW TO KEEP PARTS
OF THE BLKHLS AREA RATHER MILD OVERNIGHT...THUS SETTING THE STAGE
FOR A WARM MONDAY.

&&

.LONG TERM...MONDAY THROUGH SATURDAY
ISSUED AT 200 PM MDT SAT MAY 11 2013

UPPER LEVEL RIDGE BUILDS OVER THE NORTHERN PLAINS EARLY NEXT WEEK.
THIS WILL BRING MAINLY DRY CONDITIONS AND VERY WARM TEMPERATURES TO
THE AREA. THERMAL RIDGE CROSSES THE CWA ON MONDAY...BRINGING NEAR
RECORD HIGHS IN THE UPPER 80S AND LOWER 90S ACROSS THE PLAINS. COULD
SEE AN ISOLATED AFTERNOON THUNDERSTORM DEVELOP OVER THE BLACK HILLS
MONDAY AFTERNOON. LOW AFTERNOON HUMIDITIES AND SOME POTENTIAL FOR
BREEZY CONDITIONS NORTH AND EAST OF THE BLACK HILLS WOULD INCREASE
THE THREAT FOR CRITICAL FIRE WX CONDITIONS IN SOME AREAS. WILL LET
OVERNIGHT SHIFT HAVE A LOOK AT NEW DATA AND SEE IF A FIRE WX WATCH
MAY BE NEEDED FOR SOME AREAS.

UPPER RIDGE FLATTENS A BIT FOR THE REMAINDER OF THE WEEK...AS A WEAK
COLD FRONT CROSSES THE REGION LATE MONDAY NIGHT AND TUESDAY. WEAK
DISTURBANCES WITHIN THE FLOW WILL MOVE MOSTLY NORTH OF THE REGION
DURING THE MIDDLE OF THE WEEK AND THEN LIKELY FURTHER SOUTH LATE IN
THE WEEK. THE TIMING OF THESE DISTURBANCES IS STILL RATHER UNCERTAIN
AT THIS POINT...BUT WILL KEEP SOME SLIGHT CHANCES FOR SHOWERS AND
THUNDERSTORMS ACROSS A GOOD PORTION OF THE CWA FOR THURSDAY INTO
FRIDAY. THE GFS AND ECMWF ARE BOTH SHOWING A BIT BETTER POTENTIAL
FOR SHOWERS AND THUNDERSTORMS BY THE WEEKEND AS BETTER LOW-LEVEL
MOISTURE IS PROGGED TO BUILD INTO THE NORTHERN PLAINS.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1023 PM MDT SAT MAY 11 2013

VFR CONDITIONS THROUGH THE PERIOD.

&&

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

$$

SHORT TERM...BUNKERS
LONG TERM...26
AVIATION...JC