Area Forecast Discussion
Issued by NWS Aberdeen, SD

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000
FXUS63 KABR 311148 AAA
AFDABR

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE ABERDEEN SD
648 AM CDT FRI JUL 31 2015

.UPDATE...
ISSUED AT 640 AM CDT FRI JUL 31 2015

SEE BELOW FOR AN UPDATED AVIATION FORECAST DISCUSSION.

&&

.SHORT TERM...(TODAY THROUGH SUNDAY AFTERNOON)
ISSUED AT 356 AM CDT FRI JUL 31 2015

THE REGION WILL BE UNDER NORTHWEST FLOW THROUGH THE PERIOD. WEAK
HIGH PRESSURE OVERHEAD WILL MOVE SOUTHEAST TODAY. WHILE SLIGHTLY
COOLER AIR HAS MOVED INTO EASTERN COUNTIES...DRY CONDITIONS AND
EFFICIENT MIXING WILL ALLOW TEMPERATURES TO TOP OUT ONLY A NOTCH OR
TWO BELOW THURSDAYS READINGS.  RETURN FLOW AROUND THIS HIGH WILL
GENERATE A SHORT LIVED 20 TO 30KT LOW LEVEL JET OVER NORTH CENTRAL
SOUTH DAKOTA. GIVEN THE PREDOMINANT FLOW AND LOCALIZED SCALE OF THIS
JET...PROFILES ARE EXPECTED TO REMAIN VERY DRY. SOUNDINGS SUGGEST
LESS THAN 200 J/KG MUCAPE...MUCH OF THAT CONFINED TO A SHALLOW LAYER
ABOVE 600MB. THUS...NOT EXPECTING MUCH OF ANY ACCAS. PROFILES
THROUGH THE AFTERNOON CONTINUE TO BE QUITE DRY. DEEP MIXING WILL
ALLOW FOR HIGHS AGAIN IN THE UPPER 80S/LOW 90S...WITH ANY SURFACE
BASED CONVECTION BEING RATHER ELEVATED. DESPITE THE LOW
CONFIDENCE...THERE MAY BE AN AREA WHERE MOISTURE POOLING ALONG THE
FRONT COULD GENERATE UPWARDS OF 1500 J/KG MLCAPE...ENOUGH TO WARRANT
A RISK FOR A STRONGER STORM OR TWO BEFORE CONVECTION SHIFTS
SOUTHEAST OF THE FORECAST AREA. THE REMAINDER OF THE PERIOD IS
DRY...WITH SEASONALLY HOT TEMPERATURES AGAIN FOR SUNDAY AHEAD OF
ANOTHER BACKDOOR FRONT.

.LONG TERM...(SUNDAY EVENING THROUGH THURSDAY)
ISSUED AT 356 AM CDT FRI JUL 31 2015

NOT A WHOLE LOT OF CHANGE IN TONIGHT`S 00Z GSM SOLUTIONS...COMPARED
TO WHAT THE THURSDAY DAYSHIFT WAS SERVED UP. TEMP-WISE...IT DOES
LOOK AS THOUGH THE WARMEST /NEAR CLIMO NORMAL/ FORECAST PERIODS WILL
BE TUESDAY AND WEDNESDAY. MONDAY AND THURSDAY/FRIDAY...BUT
ESPECIALLY THURSDAY/FRIDAY...LOOK COOL UNDER CANADA-SOURCED SURFACE
HIGH PRESSURE INFLUENCE.

AS FOR CHANCES OF RAIN IN THE OUT PERIODS...RATHER LATE TUESDAY
NIGHT/EARLY WEDNESDAY MORNING THROUGH LATE WEDNESDAY NIGHT/EARLY
THURSDAY MORNING CURRENTLY HOLD THE GREATEST POTENTIAL FOR
MEASURABLE PRECIPITATION. NOT ENTIRELY SURE THE GFS MODEL IS
BELIEVABLE...GIVEN THE STARK CONTRAST IN MASS-FIELD SOLUTIONS WITH
THE USUALLY MORE SUBDUED 00Z ECMWF. PERHAPS REALITY WILL END UP
BEING SOMEWHERE IN BETWEEN THE TWO. NEVERTHELESS...AT THIS
POINT...BOTH THE GFS AND ECMWF 00Z SOLUTIONS ARE PRODUCING SOME
PRECIPITATION ACROSS THE STATE DURING THE HIGHLIGHTED TIMEFRAME. AS
FAR AS SYNOPTIC SCALE LIFT...SURFACE OR NEAR SURFACE FEATURE/S FOR
FORCING AND AVAILABLE LLM FOR INSTABILITY AND DEEP LAYER SHEAR FOR
ORGANIZED CONVECTION GOES...THE GFS IS CERTAINLY PAINTING A THUMBS
UP PICTURE THIS MORNING FOR MAINLY WEDNESDAY NIGHT. THOSE PESKY MID-
LEVEL CAPPING INVERSION SUPER WARM MID-LEVEL TEMPS THAT ACT TO HOLD
CONVECTION AT BAY DURING THE DAY ON WEDNESDAY...COULD END UP BEING
THE ELEVATED MIXED LAYER NEEDED TO AIDE CONVECTIVE DEVELOPMENT
WEDNESDAY NIGHT WHEN A POTENTIALLY 40+ KNOT LOW LEVEL JET SETS UP.
THE JURY`S STILL OUT ON THAT ONE. A LOT OF IF`S TO NAIL DOWN AND
MORE QUESTION MARKS THAN ANSWERS RIGHT NOW SURROUNDING THE MIDDLE OF
NEXT WEEK. WHO KNOWS...MAYBE THERE WILL FINALLY BE A NIGHT-TIME
THUNDERSTORM EVENT OVER THIS CWA THIS YEAR.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 640 AM CDT FRI JUL 31 2015

HIGH PRESSURE IS INFLUENCING THE REGION WITH LIGHT WINDS AND A
MOSTLY CLEAR SKY. EXPECT THE GOOD VFR WEATHER TO CONTINUE OVER THE
NEXT 24 HOURS.

&&

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

$$

UPDATE...DORN
SHORT TERM...CONNELLY
LONG TERM...DORN
AVIATION...DORN



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