000
FXUS63 KUNR 151602
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
1002 AM MDT SAT JUN 15 2013

.UPDATE...
ISSUED AT 957 AM MDT SAT JUN 15 2013

EARLY MORNING CONVECTION ACROSS SOUTHERN SOUTH DAKOTA HAS SHIFTED
EAST OF THE AREA. SURFACE HIGH PRESSURE CONTINUES TO SETTLE OVER
THE AREA...WITH MOSTLY SUNNY SKIES EXPECTED FOR THE REMAINDER OF
THE DAY. WEAK ENERGY IN ZONAL FLOW MAY TOUCH OFF A SHOWER OR STORM
LATE THIS AFTERNOON OR EVENING ACROSS SOUTHWESTERN SOUTH DAKOTA.
BETTER CHANCES FOR CONVECTION SHOULD HOLD OFF UNTIL LATER TONIGHT
INTO SUNDAY MORNING. HAVE UPDATED FORECAST TO ACCOUNT FOR CURRENT
TRENDS IN TEMPS...WINDS...AND SKY COVER.

&&

.SHORT TERM...TODAY THROUGH SUNDAY NIGHT
ISSUED AT 321 AM MDT SAT JUN 15 2013

CURRENT SURFACE ANALYSIS SHOWS LOW PRESSURE OVER SOUTH
CENTRAL NEB...WITH FRONTAL BOUNDARY STRETCHING ACROSS THE CENTRAL
PLAINS. AN AREA OF HIGH PRESSURE IS LOCATED OVER THE NORTHERN
ROCKIES. UPPER LEVEL ANALYSIS HAS LOW OVER SOUTH CENTRAL CANADA...
WITH WEST-SOUTHWEST FLOW OVER THE NORTHERN PLAINS. A JET STREAK IS
LOCATED OVER NORTHERN PORTIONS OF THE NORTHERN PLAINS. SHORTWAVE
ENERGY IN THIS FLOW IS MOVING ACROSS SOUTHERN SD AND NEB AND
PRODUCING ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS ACROSS THE
WESTERN SD PLAINS AND WESTERN NEB. THE STRONGEST ACTIVITY IS TO THE
SOUTH OVER NEB. SKIES ARE PARTLY TO MOSTLY CLOUDY OVER THE AREA WITH
TEMPS MOSTLY IN THE 50S TO AROUND 60. WHERE SKIES ARE MAINLY CLEAR
IN NORTHEASTERN WY...TEMPS HAVE DROPPED INTO THE LOW TO MID 40S.

A SEASONABLY WARM WEEKEND IS ON TAP AS NEAR ZONAL FLOW REMAINS
ACROSS THE REGION. WEAK DISTURBANCES IN THE FLOW...COMBINED WITH
INCREASING LOW LEVEL MOISTURE FROM THE SOUTH...WILL BRING CHANCES
FOR SHOWERS AND THUNDERSTORMS AT TIMES...MAINLY ACROSS SOUTHERN
PORTIONS OF THE CWA. THE BETTER CHANCES BEYOND EARLY THIS MORNING
LOOK TO BE LATER TONIGHT AND SUNDAY FROM THE BLACK HILLS TO SOUTH
CENTRAL SD.

FOR TODAY...SKIES WILL START OFF PARTLY TO MOSTLY CLOUDY AS WEAK
SHORTWAVE ENERGY CONTINUES TO PUSH EAST ACROSS SOUTHERN SD AND NEB.
WILL KEEP ISOLATED TO SCATTERED SHOWERS AND STORMS ACROSS FAR
EASTERN PORTIONS OF THE CWA THROUGH MID MORNING. SKIES SHOULD BECOME
MOSTLY SUNNY FROM NORTHWEST TO SOUTHEAST THROUGH THE MORNING AND
EARLY AFTERNOON HOURS. HIGH TEMPERATURES WILL MOSTLY BE IN THE
70S...WITH SOME UPPER 60S ACROSS THE HIGHER BLACK HILLS. WINDS WILL
BE WESTERLY AND POSSIBLY BREEZY AT TIMES ACROSS NORTHWESTERN
SD...WITH WINDS MORE LIGHT AND VARIABLE TO THE SOUTH AS WEAK HIGH
PRESSURE MOVES INTO THE BLACK HILLS AREA IN THE AFTERNOON. WILL KEEP
A SLIGHT CHANCE FOR A SHOWER OR STORM OVER THE BLACK HILLS AREA AND
FAR SOUTHWESTERN SD LATE THIS AFTERNOON...BUT IT LOOKS LIKE THE MAIN
CHANCES WILL BE TONIGHT.

INCREASING MOISTURE AND STRONG THETA-E ADVECTION OVER THE AREA
TONIGHT WILL LIKELY RESULT IN AT LEAST ISOLATED SHOWERS AND STORMS
DEVELOPING OVER THE BLACK HILLS AREA AND SOUTHWESTERN SD. TIMING IS
A BIT UNCERTAIN AT THIS POINT...BUT IT LOOKS LIKE THE BULK OF THE
ACTIVITY WOULD BE FROM LATE EVENING THROUGH THE OVERNIGHT. LOWS WILL
MOSTLY BE IN THE 50S.

ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED ON
SUNDAY OVER SOUTHERN PORTIONS OF THE CWA...AS FAIRLY SIGNIFICANT LOW
LEVEL MOISTURE POOLS OVER THIS AREA AND WEAK SHORTWAVE ENERGY PASSES
ACROSS. THE BETTER CHANCES GENERALLY LOOK TO BE IN THE LATE MORNING
AND AFTERNOON. WITH CAPE VALUES PROGGED AROUND 2000 J/KG DURING THE
MIDDAY AND AFTERNOON HOURS...THERE IS A THREAT FOR A FEW SEVERE
STORMS TO DEVELOP ACROSS SOUTHWESTERN INTO SOUTH CENTRAL SD...WITH
LARGE HAIL THE MAIN THREAT. HIGH TEMPERATURES WILL BE IN THE 70S AND
LOWER 80S WITH MOSTLY LIGHT WINDS. ANY LINGERING PCPN SHOULD MOVE
OUT OF SOUTH CENTRAL SD IN THE EVENING.

&&

.LONG TERM...MONDAY THROUGH FRIDAY
ISSUED AT 321 AM MDT SAT JUN 15 2013

UPPER RIDGE BUILDS THROUGH THE NORTHERN ROCKIES INTO THE NORTHERN
PLAINS MON-WED AS UPPER LOW DIGS INTO THE PACIFIC NORTHWEST.
ISOLATED THUNDERSTORMS REMAIN POSSIBLE EACH DAY GIVEN AMOUNT OF
INSTABILITY. HOWEVER...CAP AND LACK OF SIGNIFICANT SHORTWAVES WILL
BE LIMITING FACTOR. UPPER RIDGE AXIS SHIFTS EAST OF THE REGION BY
LATE IN THE WEEK AS UPPER LOW MOVES TO THE NORTHERN ROCKIES...WITH
SOUTHWEST FLOW ALOFT BRINGING BETTER CHANCES FOR THUNDERSTORMS TO
THE REGION. TEMPERATURES WILL BE NEAR TO SLIGHTLY ABOVE AVERAGE
THROUGH THE PERIOD.

&&

.AVIATION...FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING
ISSUED AT 321 AM MDT SAT JUN 15 2013

ISOLATED THUNDERSTORMS POSSIBLE THIS AFTERNOON/EVENING
FROM THE BLACK HILLS INTO SOUTHWEST SOUTH DAKOTA. OTHERWISE...VFR
CONDITIONS EXPECTED.


&&

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

$$

UPDATE...15
SHORT TERM...26
LONG TERM...7
AVIATION...7