Area Forecast Discussion
Issued by NWS Aberdeen, SD

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000
FXUS63 KABR 272007
AFDABR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ABERDEEN SD
307 PM CDT MON JUL 27 2015

.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 305 PM CDT MON JUL 27 2015

HOT AND HUMID CONDITIONS PERSIST ACROSS THE REGION THIS
AFTERNOON...WITH DEWPOINTS SOLIDLY IN THE 70S ACROSS THE EASTERN
CWA. TEMPERATURES ARE IN THE 90S...AND THE COMBINATION HAS RESULTED
IN ML CAPE VALUES IN THE 4000-5000 J/KG RANGE ACROSS THE EASTERN 2/3
OF THE CWA. LITTLE TO NO CAP IS IN PLACE OVER THE REGION AS
WELL...ALTHOUGH WARMING TEMPERATURES ALOFT IS KEEPING THE WESTERN
THIRD OF THE CWA SUFFICIENTLY CAPPED. 0-6 KM SHEAR IS IN THE 20 TO
30 KTS RANGE AS WELL. IF STORMS COULD INITIATE IN THIS
ENVIRONMENT...DO BELIEVE ISOLATED SEVERE STORMS ARE POSSIBLE. THE
PROBLEM IS FORCING. NO NOTABLE UPPER LEVEL FORCING...SO INITIATION
WILL DEPEND ON LOW LEVEL MOISTURE CONFERENCE...AND THAT REMAINS
QUITE UNCERTAIN AT THIS TIME AS WELL. A FEW HI RES MODELS DO SHOW
ISOLATED STORMS...SO PERSISTED WITH A 20 POP FOR NOW.

TONIGHT...BETTER UPPER LEVEL FORCING AND A COLD FRONT WILL TRACK
ACROSS THE REGION. BULK SHEAR WILL INCREASE AS THE UPPER LEVEL
TROUGH APPROACHES...AND MU CAPE REMAINS QUITE HIGH THROUGH THE
NIGHT. THE BEST CHANCES STILL REMAIN ACROSS NORTH DAKOTA...BUT
SEVERE STORMS ARE POSSIBLE. DUE TO THE STRONG LOW LEVEL WIND
SHEAR...HIGH WINDS MAY BE A CONCERN WITH OVERNIGHT STORMS. STEEP
LAPSE RATES AND HIGH PWATS ALSO SUPPORT THE HAIL AND HEAVY RAIN
THREAT. AT THIS POINT CANNOT RULE OUT AN ISOLATED TORNADO EITHER.

ON THE BACK SIDE OF THIS SYSTEM SUBSIDENCE AND PRIME MIXING
CONDITIONS WILL RESULT IN VERY STRONG AND GUSTY WEST TO NORTHWEST
WINDS TUESDAY. A HIGH WIND WATCH HAS BEEN ISSUED FOR A FEW COUNTIES
ACROSS THE NORTHERN CWA. WINDS THIS STRONG ARE QUITE ANOMALOUS FOR
JULY IN SOUTH DAKOTA. THE AIRMASS WILL BE MUCH LESS HUMID AND HIGH
TEMPERATURES IN THE 70S AND 80S ARE EXPECTED TUESDAY AFTERNOON. DRY
AND RELATIVELY COOLER CONDITIONS PERSIST INTO WEDNESDAY AS WELL.

.LONG TERM...(THURSDAY THROUGH MONDAY)
ISSUED AT 305 PM CDT MON JUL 27 2015

THERE IS A GENERAL AGREEMENT AMONG MODELS WITH THE EVOLUTION OF THE
UPPER LEVEL FLOW PATTERN THROUGH THE WEEKEND. MOST OF THE PERIOD
WILL FEATURE A WEST TO NORTHWEST FLOW ALOFT WITH DRY AND SEASONAL
CONDITIONS. BY THE WEEKEND...A FEW MODELS ARE SUGGESTING SCATTERED
THUNDERSTORMS POSSIBLE...MAINLY FOR THE EASTERN CWA. LATE
SUNDAY...THE ECWMF SHOWS THE FLOW PATTERN BECOMING ZONAL WITH COOLER
TEMPERATURES AND BETTER CHANCES FOR PCPN. THE GFS ON THE OTHER HAND
SHOWS RIDGING WITH WARMER TEMPERATURES AND DRY CONDITIONS. WITH LOW
CONFIDENCE...WILL RUN WITH GUIDANCE FROM SUPERBLEND.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1244 PM CDT MON JUL 27 2015

A WARM FRONT LIFTING NORTHWARD TODAY COULD BRING ISOLATED
THUNDERSTORMS TO THE TERMINAL OF KATY THIS AFTERNOON. CONFIDENCE
IS LOW SO WILL NOT MENTION TS IN THE TAF. A STRONG COLD FRONT WILL
CROSS THE REGION TONIGHT. THIS FRONT COULD BRING SCATTERED SHOWERS
AND THUNDERSTORMS FOR SOME TERMINALS. SOUTHERLY WINDS THROUGH THIS
EVENING WILL SHIFT TO THE NORTHWEST BEHIND THE COLD FRONT.
SUSTAINED WINDS OF 20-25 KNOTS OR GREATER WILL BE POSSIBLE FOR
MOST TERMINALS ON TUESDAY.

&&

.ABR WATCHES/WARNINGS/ADVISORIES...
SD...HIGH WIND WATCH FROM TUESDAY AFTERNOON THROUGH TUESDAY EVENING FOR
     SDZ003>005-009-015.

MN...NONE.
&&

$$

SHORT TERM...SERR
LONG TERM...SD
AVIATION...SD



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