000
FXUS63 KUNR 102038
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
238 PM MDT THU JUL 10 2014

.SHORT TERM...THIS EVENING THROUGH FRIDAY NIGHT
ISSUED AT 234 PM MDT THU JUL 10 2014

20Z SURFACE ANALYSIS SHOWED LOW OVER NORTHEAST MT WITH TROUGH INTO
WESTERN NE AND DEVELOPING WARM FRONT FROM EASTERN WY INTO NORTHEAST
SD. MORNING SHORTWAVE MOVING INTO EASTERN ND WITH SECONDARY
SHORTWAVE BECOMING EVIDENT OVER WESTERN WY. MOISTURE IS POOLING
ALONG AFOREMENTIONED FRONTAL BOUNDARIES...BUT MID/HIGH CLOUDS AS
WELL AS PERSISTENT WEAK ELEVATED CONVECTION/ACCAS HAS TEMPERED THE
MERCURY SOME THIS AFTERNOON. RESULT IS MLCAPE APPROACHING 1.5KJ/KG
AND MLCIN SLOWLY ERODING. EXPECT SURFACE BASED CONVECTION TO BE
MAINLY ROOTED OVER THE HIGHER TERRAIN THROUGH MID-AFTERNOON...AND
THEN DEVELOP IN/NEAR THE SURFACE FRONTAL BOUNDARIES. AS UPSTREAM
SHORTWAVE COMES IN EARLY THIS EVENING...COULD BE ANOTHER UPTICK IN
ACTIVITY. 0-6KM EFFECTIVE SHEAR IN THE 15-30M/S RANGE...SUFFICIENT
FOR SEVERE THUNDERSTORMS AND ESPECIALLY LARGE HAIL EARLY. SYSTEM
MAY GROW UPSCALE INTO A LARGER CONVECTIVE CLUSTER AND THEN SHIFT
EAST OVERNIGHT. TEMPERATURES WILL BE FAIRLY WARM GIVEN TD/S IN THE
60S.

FRIDAY...WEAK COOL FRONT/TROUGH SLIPS INTO THE CWA. ANOTHER
SHORTWAVE WILL MOVE THROUGH THE AREA DURING THE AFTERNOON/EVENING
HOURS. IT/LL HAVE AROUND 2KJ/KG MLCAPE...ERODING MLCIN...AND
15-20M/S 0-6KM BULK SHEAR TO WORK WITH. LOW LEVEL SOUTHEAST/EASTERLY
UPSLOPE FLOW WILL KEEP MOISTURE POOLING ALONG THE STALLING BOUNDARY.
RESULT SHOULD BE ANOTHER ROUND OF ACTIVE/SEVERE TSRA...PARTICULARLY
OVER SOUTHERN PORTIONS OF THE CWA. UNDERCUT GUIDANCE TEMPERATURES A
BIT.

&&

.LONG TERM...SATURDAY THROUGH THURSDAY
ISSUED AT 234 PM MDT THU JUL 10 2014

UPPER LEVEL RIDGING WILL BE IN PLACE ACROSS MUCH OF THE FAR
WESTERN CONUS DURING THE EXTENDED PERIOD. NORTHWESTERLY FLOW ALOFT
WILL ALSO PERSIST OVER THE NORTHERN PLAINS AS AN UNSEASONABLY
STRONG AND COOL UPPER LOW DRIFTS ACROSS SOUTH CENTRAL CANADA INTO
THE GREAT LAKES. A SERIES OF WEAK SHORTWAVES WILL MOVE
SOUTHEASTWARD ACROSS THE AREA SATURDAY INTO SUNDAY...BRINGING A
CHANCE OF SHOWERS AND THUNDERSTORMS. TEMPERATURES WILL BE NEAR TO
SLIGHTLY ABOVE AVERAGE THIS WEEKEND. MUCH COOLER AND DRIER WEATHER
IS EXPECTED FOR THE FIRST HALF OF NEXT WEEK AS A STRONG COLD FRONT
AND COOLER SURFACE HIGH PRESSURE PUSHES INTO THE REGION.
TEMPERATURES COULD BE 15 TO 20 DEGREES BELOW AVERAGE ON MONDAY AND
TUESDAY.

&&

.AVIATION...FOR THE 18Z TAFS THROUGH 18Z FRIDAY
ISSUED AT 234 PM MDT THU JUL 10 2014

SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED LATE THIS
AFTERNOON THROUGH THIS EVENING ACROSS MUCH OF THE AREA. THESE
STORMS COULD PRODUCE BRIEF MVFR CONDITIONS. OTHERWISE VFR
CONDITIONS ARE EXPECTED THROUGH THE FORECAST PERIOD.

&&

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

$$

SHORT TERM...HELGESON
LONG TERM...15
AVIATION...15