585 
FXUS63 KUNR 261640
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
1040 AM MDT FRI JUN 26 2015

.SHORT TERM...TODAY THROUGH SATURDAY NIGHT
ISSUED AT 232 AM MDT FRI JUN 26 2015

CURRENT SURFACE MAP PLACES HIGH PRESSURE ACROSS THE NORTHERN
PLAINS. OTHER THAN A FEW LOW CLOUDS ACROSS SOUTHWEST/SOUTH CENTRAL
SOUTH DAKOTA...MOSTLY CLEAR SKIES ACROSS THE FORECAST AREA.
BUILDING UPPER RIDGE ACROSS THE PACIFIC NORTHWEST/NORTHERN ROCKIES
WILL RESULT IN LARGE SCALE SUBSIDENCE ACROSS THE AREA TODAY AND
SATURDAY. 300-500J/KG MLCAPE ACROSS THE BLACK HILLS THIS AFTERNOON
MAY RESULT IN AN ISOLATED THUNDERSTORM. OTHERWISE...WARMER AND
DRIER CONDITIONS FOR THE AREA.

.LONG TERM...SUNDAY THROUGH THURSDAY
ISSUED AT 232 AM MDT FRI JUN 26 2015

MASSIVE WESTERN NOAM RIDGE WILL BE IN PLACE AT THE START OF THE
PERIOD WITH THE REGION ON THE EASTERN PERIPHERY. MAIN THERMAL
RIDGE WILL BE LOCATED WEST OF THE FA. HOWEVER A RIDGE TOPPING
IMPULSE WILL SHIFT A CORE OF WARMER AIR ALOFT OVER THE REGION
TUE...SUPPORTING THE WARMEST DAY IN THE PERIOD WITH HIGHS IN THE
90S MOST LOCATIONS. REMAINED TAME WITH HIGHS GIVEN VERY MOIST SOIL
CONDS WHICH WILL QUELL TEMP RISES TO A DEGREE. DRY CONDS EXPECTED
MOST OF THE PERIOD...SAVE FOR TUE/TUE NIGHT WHEN A CHANCE FOR
ISOLD/SCT SHRA/TS WILL BE POSSIBLE WITH PASSING TROUGH. IT IS
CERTAINLY POSSIBLE THAT MORE SUBTLE IMPULSES COULD RETURN IN NW
FLOW GIVEN SEMI-RIDGE FLATTENING BY THE MIDDLE/END OF NEXT WEEK.
ALTHOUGH THIS WOULD RESULT IN ISOLD CONVECTION AT BEST. GROWING
INDICATIONS FOR MORE PRONOUNCED RIDGE FLATTENING TOWARD NEXT
WEEKEND WHEN SOME FORECAST SOLUTIONS LIFT THE PAC NE UPPER TROUGH
INTO THE RIDGE. THIS WOULD SUPPORT MUCH COOLER CONDS WITH MORE
SUBSTANTIAL CHANCES FOR RAIN. HOWEVER MODEL DISCREPANCY PER THIS
EVOLUTION REMAIN WITH THE GFS AND ECMWF/GEM WELL OUT OF SYNC BY
NEXT SAT. THE GEM/ECMWF OFFER MUCH FLATTER AND ACTIVE FLOW BY THE
END OF NEXT WEEKEND. SOMETHING TO KEEP AN EYE ON AT LEAST.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY)
ISSUED AT 1038 AM MDT FRI JUN 26 2015

ISOLATED TSTMS ARE POSSIBLE IN THE BLKHLS THIS AFTN...PRODUCING
MVFR CONDITIONS. OTHERWISE...VFR CONDITIONS WILL CONTINUE THROUGH
SATURDAY MORNING.

&&

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

$$

SHORT TERM...7
LONG TERM...JC
AVIATION...JOHNSON