Area Forecast Discussion
Issued by NWS Aberdeen, SD

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000
FXUS63 KABR 070901
AFDABR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ABERDEEN SD
401 AM CDT MON JUL 7 2014

.SHORT TERM...THROUGH WEDNESDAY

A FEW ELEVATED STORMS MOVING ACROSS THE CWA THIS AM ON THE NOSE OF
A 35KT LOW LEVEL JET ORIENTED FROM WEST TO EAST. THE ENVIRONMENT
IS DOMINATED BY STRONG WEST/NORTHWEST WINDS ALOFT THAT WILL ALLOW
THESE STORMS TO CONTINUE TO ZIP ACROSS THE CWA. ANOTHER WAVE
POSITIONED IN NORTHERN MONTANA WILL PROVIDE FOR A BIT MORE
EXCITEMENT LATER IN THE DAY.

COOL MID LEVEL TEMPERATURES AND ENOUGH LOW LEVEL MOISTURE WILL
SUPPORT CAPE VALUES APPROACHING 1000J/KG. SHEAR...ON THE OTHER
HAND...IS QUITE STRONG THANKS TO THE NEAR 100KT JET MAX PLACEMENT
OVERHEAD. THE RESULT WILL BE AN ENVIRONMENT FAVORABLE FOR FAST
MOVING/POSSIBLY SPLITTING SUPERCELLS...WITH A HAIL/WIND THREAT FOR
LATER TODAY. EVEN IN THE POST FRONTAL AIRMASS HIGH RES MODELS
INDICATE AN ENVIRONMENT THAT MAY FAVOR A STORM OR TWO THIS
AFTERNOON.

THE REST OF THE FORECAST LOOKS DRY THANKS TO AN AMPLIFYING RIDGE
ALOFT UPSTREAM OF THE CWA. NAM PROFILES SUGGEST SOME CU DEVELOPING
DURING PEAK HEATING FOR TUESDAY...BUT WITH A CAP ABOVE 10KFT. LOW
LEVEL FLOW WILL REMAIN OUT OF THE NORTH WITH WEAK COLD ADVECTION
SO TEMPERATURES AT OR A TAD BELOW NORMAL WITH COMFORTABLE HUMIDITY
THROUGH MID WEEK.

.LONG TERM...WEDNESDAY NIGHT THROUGH SUNDAY

PRIMARY FORECAST CONCERNS IN THE EXTENDED PERIOD ARE
PRECIPITATION/THUNDERSTORM CHANCES AND TEMPERATURE TRENDS.

WEDNESDAY NIGHT THROUGH THURSDAY NIGHT...FORECAST CONFIDENCE: MODERATE

RETURN SLY FLOW ON THE BACKSIDE OF THE DEPARTING SFC HIGH IN
TANDEM WITH AN INTENSIFYING LLJ ON WEDNESDAY NIGHT WILL RESULT IN
A CHANCE FOR THUNDERSTORMS...MAINLY ACROSS SRN SECTIONS OF THE CWA
CLOSER TO THE NOSE OF THE LLJ. COULD SEE A FEW STORMS LINGER
INTO THE EARLY MORNING HOURS ON THURSDAY...BEFORE THE TYPICAL
MID-MORNING BREAK IN PRECIPITATION. DEPENDING ON CLOUD
COVER...EXPECTING AT LEAST MODEST DESTABILIZATION BY LATE THURSDAY
AFTERNOON. A WEAK UPPER SHORTWAVE APPROACHING FROM THE WEST SHOULD
TRIGGER AT LEAST WDLY SCATTERED TSTMS BY THU EVENING. STORMS WILL
LIKELY GROW UPSCALE ON THURSDAY NIGHT AS THE LLJ STRENGTHENS...WITH
THE GREATEST POTENTIAL FOR STORMS ALONG AND TO THE EAST OF THE
JAMES RIVER VALLEY. KEPT POPS IN THE HIGH CHANCE CATEGORY FOR NOW
/40-50 PCT RANGE/ BUT WOULD NOT BE SURPRISED IF POPS WILL NEED TO
BE RAISED FURTHER AS THE EVENT APPROACHES. HIGH TEMPS ON THURSDAY
WILL BE TYPICAL FOR EARLY JULY...LOWER 80S EAST TO UPPER 80S CENTRAL.

FRIDAY THROUGH SUNDAY...FORECAST CONFIDENCE: LOW TO MODERATE

LOWER CONFIDENCE FORECAST FOR LATE IN THE WEEK AND INTO THE
WEEKEND. EXPECTING A CONTINUATION OF THE ZONAL FLOW PATTERN...WITH
THE POSSIBILITY OF WEAK AND HARD TO TIME SHORTWAVE IMPULSES MOVING
ACROSS THE NORTHERN PLAINS. AS SUCH...GENERALLY FOLLOWED A
CONSENSUS FORECAST WHICH YIELDS LOWER END /20 TO 30 PCT/ CHANCES
FOR THUNDERSTORMS THROUGH SATURDAY NIGHT...PRIMARILY IN THE USUAL LATE
AFTERNOON THROUGH OVERNIGHT PERIODS. TEMPERATURES IN THIS
TIMEFRAME ALSO LOOK TO REMAIN CLOSE TO SEASONAL AVERAGES...WITH
HIGHS IN THE 80S AND LOWS IN THE 50S AND 60S.


&&

.AVIATION...
06Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS

A WEAKENING AREA OF SHOWERS AND THUNDERSTORMS CONTINUES TO MOVE
SEWD ACROSS NORTH-CENTRAL SD AS OF 06Z. CURRENT TRENDS WILL TAKE
ANY TSTMS EAST OF KMBG. KABR COULD SEE A LIGHTNING STRIKE OR TWO
IN THE VICINITY OF THE TERMINAL...BUT MORE LIKELY WILL ONLY SEE
HIGH BASED SHOWERS OR VIRGA. OTHERWISE...EXPECT VFR CONDITIONS TO
PREVAIL DURING A MAJORITY OF THE VALID TAF PERIOD. LATER IN THE
DAY ON MONDAY...DAYTIME HEATING AND THE INFLUENCE OF A LOW
PRESSURE SYSTEM WORKING THROUGH THE REGION HAS THE POTENTIAL TO
GENERATE ADDITIONAL ISOLATED TO WIDELY SCATTERED HEAT-OF-THE-DAY
SHOWERS AND THUNDERSTORMS. DUE TO UNCERTAINTY IN COVERAGE/TIMING...WILL
LEAVE OUT OF THE TAFS ATTM.


&&

.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&

$$
SHORT TERM...CONNELLY
LONG TERM...FOWLE
AVIATION...FOWLE

WEATHER.GOV/ABERDEEN




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