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000
FXUS63 KUNR 130433
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
1033 PM MDT WED JUN 12 2013

.SHORT TERM...THIS EVENING THROUGH THURSDAY NIGHT
ISSUED AT 218 PM MDT WED JUN 12 2013

CURRENT SURFACE ANALYSIS PLACES HIGH OVER THE WRN DAKOTAS WITH
LOW OVER THE NORTHERN ROCKIES. UPPER LEVEL ANALYSIS PLACES RIDGE
AXIS NEAR THE MONTANA/DAKOTA BORDER WITH BROAD LOW OFF THE PACIFIC
NORTHWEST. A VARIETY OF WEAK DISTURBANCES ROTATING UP AHEAD OF THE
UPPER LOW CONTINUES TO PRODUCE A FEW SMALL AREAS OF CONVECTION OVER
PTNS OF WRN MT/WY.

FOR TONIGHT...RIDGE AXIS SLOWLY SCOOTS EAST A BIT WITH UPPER FLOW
BECOMING SWRLY OVER FAR WRN CWA. WITH WEAK DISTURBANCES MOVING
THROUGH MAY SEE A FEW THUNDERSTORMS DEVELOP OVER NERN WY INTO
PORTIONS OF FAR WRN SD. ALTHOUGH DEEP LAYER SHEAR WILL BE QUITE
STRONG...INSTABILITY WILL BE MODEST AT BEST. THEREFORE DO NOT
EXPECT MUCH IN THE WAY OF SEVERE...THOUGH A STORM OR TWO GETTING
STRONG WILL NOT BE OUT OF THE QUESTION...PARTICULARLY NEAR THE
MT/WY BORDER.

ON THURSDAY...RIDGE AXIS CONTINUES TO SLIDE EAST AS UPPER LOW/TROF
PUSHES TOWARDS THE ROCKIES ALLOWING A VARIETY OF WAVES TO LIFT
THROUGH SOUTHWESTERLY FLOW. SURFACE LOW SHIFT FROM SERN MT INTO
NERN WYOMING THROUGH THE AFTERNOON/EVE WITH PRESSURE GRADIENT
TIGHTENING OVER THE AREA BRINGING BREEZY SERLY WINDS. EXPECT SCT
THUNDERSTORMS TO DEVELOP IN THE AFTERNOON/EVENING MAINLY OVER THE
WRN/CTRL PARTS OF THE CWA WITH FOCUS SHIFTING MORE TO THE
NORTH/EAST OVERNIGHT WITH INCREASING LOW LEVEL JET/THETA-E
ADVECTION. SEVERE STORMS WILL BE POSSIBLE WITH INSTABILITY
INCREASING (1000-2500 J/KG) AND PLENTY OF 0-6 KM BULK SHEAR (45
KT+).

&&

.LONG TERM...FRIDAY THROUGH WEDNESDAY
ISSUED AT 218 PM MDT WED JUN 12 2013

SOUTHWEST FLOW ON FRIDAY TRANSITIONS TO RIDGING FOR THE
WEEKEND...THEN BACK TO SOUTHWEST FLOW FOR EARLY NEXT WEEK.
THUNDERSTORM CHANCES CONTINUE THROUGH MUCH OF THE PERIOD...WITH THE
EXCEPTION OF SATURDAY INTO EARLY SUNDAY...WHEN RIDGING IS STRONGEST.
TEMPERATURES WILL REMAIN AT OR ABOVE AVERAGE THROUGH THE PERIOD.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1028 PM MDT WED JUN 12 2013

(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 517 PM MDT WED JUN 12 2013

ISOLD-SCT SHOWERS AND THUNDERSTORMS WILL BE FOUND OVER
NORTHWESTERN SOUTH DAKOTA THROUGH MUCH OF THE REST OF THE NIGHT
GRADUALLY DECREASING IN COVERAGE AND INTENSITY. AREAS OF MVFR
CIGS WILL DEVELOP OVER PARTS OF NORTHEASTERN WYOMING AND
SOUTHWESTERN SOUTH DAKOTA AFT 09Z WITH CONDITIONS IMPROVING BACK
TO VFR THERE BY 15Z THURSDAY MORNING. THERE IS A CHANCE OF
THUNDERSTORM OVER NORTHEASTERN WYOMING LATE THURSDAY
AFTERNOON...MOVING EASTWARD INTO WESTERN SOUTH DAKOTA THURSDAY
NIGHT.

&&

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

$$

SHORT TERM...77
LONG TERM...15
AVIATION...10