Area Forecast Discussion
Issued by NWS Sioux Falls, SD

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FXUS63 KFSD 241131
AFDFSD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SIOUX FALLS SD
631 AM CDT MON AUG 24 2015

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 345 AM CDT MON AUG 24 2015

LITTLE WEATHER OF NOTE EXPECTED OVER THE NEXT 24 HOURS. AREA REMAINS
IN NORTHWEST FLOW BEHIND SLOWLY EXITING UPPER LOW ACROSS THE GREAT
LAKES...WITH DRY SURFACE RIDGE GRADUALLY EXPANDING INFLUENCE ACROSS
THE CWA THROUGH TONIGHT. COOLER THAN NORMAL READINGS WILL TAKE PLACE
ONCE AGAIN...WITH HIGHS EXPECTED GENERALLY IN THE LOWER TO MID
70S...AND AS WINDS DIMINISH TONIGHT...AN EXPANDED DIURNAL RANGE
AGAIN TO ALLOW A DROP INTO THE 40S OVER MOST OF THE AREA.

MOST SIGNIFICANT WILL BE WINDS TODAY...AS STRONGER GRADIENT ALOFT
WILL MOST READILY MIX DOWN TODAY ACROSS THE NORTHEASTERN HALF TO TWO
THIRDS OF THE CWA...AND SOME GUSTS 20 TO 25 KNOTS ARE LIKELY TO
REDEVELOP AS EARLY AS LATE MORNING. WINDS WILL DROP OFF VERY QUICKLY
TOWARD EVENING.

.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 345 AM CDT MON AUG 24 2015

HIGH PRESSURE WILL CONTINUE TO DOMINATE ACROSS THE REGION ON TUESDAY
AS THE SURFACE RIDGE AXIS SLIDES ONLY VERY SLOWLY EASTWARD. THIS
WILL RESULT IN ANOTHER VERY NICE DAY WITH LIGHT WINDS AND
TEMPERATURES REMAINING BELOW NORMAL FOR THIS TIME OF YEAR. WILL SEE
A SUBTLE CLIMB IN TEMPERATURES OVER TODAY HOWEVER...WITH HIGHS
RUNNING LOWER 70S EAST TO LOWER 80S THROUGH SOUTH CENTRAL SD. ON
TUESDAY NIGHT WINDS WILL REMAIN LIGHT AS THE HIGH PUSHES ONLY
SLIGHTLY TO THE EAST. WHILE IT WILL STILL BE A RELATIVELY COOL
NIGHT...IT WILL NOT BE AS COOL AS RECENT NIGHTS WITH A LITTLE MORE
SOUTHERLY INFLUENCE BEHIND THE DEPARTING HIGH...AND LOWS WILL DROP
TO THE UPPER 40S EAST OF THE INTERSTATE 29 CORRIDOR TO THE MID 50S
THROUGH SOUTH CENTRAL SD.

BY WEDNESDAY THE RIDGE AXIS FINALLY MOVES INTO THE MISSISSIPPI VALLEY
WITH AN INCREASING SOUTHERLY FLOW INTO OUR AREA. WITH THIS...WINDS
WILL BEGIN TO PICK UP A BIT IN OUR WEST DURING THE AFTERNOON IN AN
INCREASING GRADIENT...AND THE SUBTLE WARMING TREND WILL CONTINUE
WITH HIGHS INTO THE MID/UPPER 70S EAST TO THE MID 80S FAR WEST.

FOR WEDNESDAY NIGHT AND THURSDAY A SHORTWAVE BEGINS TO TOP THE UPPER
LEVEL RIDGE LOCATED THROUGH THE CENTRAL CONUS...WITH SOME MODEL
DIFFERENCES IN HANDLING THIS WAVE...WITH THE GFS TAKING A MORE
NORTHERLY COURSE THAN THE ECMWF AND GEM. IN ANY EVENT...MODEL
CONSENSUS TRENDED TOWARD THE ECMWF/GEM WOULD POINT TO INCREASING
SHOWER AND THUNDERSTORM CHANCES THURSDAY AND ESPECIALLY THURSDAY
NIGHT AS THE SYSTEM MOVES THROUGH THE REGION. TEMPERATURES ARE A BIT
TRICKY ON THURSDAY DEPENDENT ON AMOUNT OF CLOUD
COVER/CONVECTION...BUT CONSENSUS YIELDS HIGHS IN THE MID AND UPPER
70S...THOUGH IT COULD BE COOLER DEPENDENT ON HOW THE SCENARIO
EVENTUALLY PLAYS OUT.

THE SYSTEM PULLS AWAY ON FRIDAY...THEN MODEL DIFFERENCES WITH RESPECT
TO BOTH UPPER LEVEL AND SURFACE FEATURES BECOME EVEN MORE APPARENT
THROUGH THE REMAINDER OF THE EXTENDED...SO CONFIDENCE IS LOW FOR
NEXT WEEKEND INTO THE BEGINNING OF THE FOLLOWING WEEK.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 631 AM CDT MON AUG 24 2015

VFR CONDITIONS WILL PERSIST THROUGH 12Z TUESDAY. WINDS ACROSS
SOUTHWEST MINNESOTA AND PARTS OF NORTHWEST IOWA WILL GUST TO NEAR
25 KNOTS BY MIDDAY AND THROUGH THE AFTERNOON.

&&

.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&

$$

SHORT TERM...CHAPMAN
LONG TERM...JM
AVIATION...CHAPMAN



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