Area Forecast Discussion
Issued by NWS Sioux Falls, SD

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000
FXUS63 KFSD 302339
AFDFSD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SIOUX FALLS SD
639 PM CDT SUN AUG 30 2015

.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 328 PM CDT SUN AUG 30 2015

SOUTHERLY FLOW CONTINUES TO BUILD INTO THE AREA THROUGH THE NIGHT
WHICH SHOULD KEEP MOST LOCATIONS MARGINALLY MIXED THROUGH MONDAY.
THIS SHOULD MEAN A LITTLE LESS FOG AND LOW CLOUD COVER THAN THE PAST
TWO NIGHTS BUT THE GRADIENT WILL INCREASE LATEST IN NORTHWEST IOWA
SO STILL SOME POTENTIAL FOR FOG AND STRATUS DEVELOPMENT LATE
TONIGHT. OTHERWISE A BIT HUMID AND WARM TONIGHT WITH MONDAY MORNING
LOWS IN THE MID TO UPPER 60S.

A WEAK BOUNDARY MOVES INTO THE AREA ON MONDAY BUT AT THIS TIME LOOKS
TOO DRY FOR SHOWERS OR THUNDERSTORMS. OTHERWISE WARM AND HUMID WITH
HIGHS IN THE 80S.

.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 328 PM CDT SUN AUG 30 2015

MODELS IN THE EXTENDED TO ADVERTISE A RELATIVELY WARM...MUGGY AND
BREEZY WEEK AHEAD COMPARED TO CLIMATOLOGICAL NORMS.  UPPER LEVEL
RIDGE ORIENTED FROM THE SOUTHWEST TO THE NORTHEAST IS NOT STRONG
ENOUGH TO LIMIT PRECIPITATION CHANCES...AND HAVE PERIODIC POPS
SPRINKLED THROUGH THE EXTENDED.

THERE IS A SLOW MOVING BOUNDARY THAT WORKS THROUGH THE WESTERN THIRD
OF THE FORECAST AREA MONDAY NIGHT BEFORE STALLING.  IT IS POSSIBLE
THAT A FEW ELEVATED STORMS MAY FORM IN THE ENVIRONMENT AHEAD OF THE
BOUNDARY. NAM SHOWS A SHORTWAVE LIFTING NORTHEAST TOWARDS THE
AREA...WHILE OTHER SOLUTIONS DON/T REALLY ADVERTISE MUCH OF A WAVE.

BY TUESDAY NIGHT...THE STATIONARY FRONT ACROSS THE AREA IS EXPECTED
TO HAVE LIFTED NORTH OF THE AREA AS A WARM FRONT AND A 25-35 KNOT
LOW LEVEL JET IS EXPECTED TO NOSE INTO THE FORECAST AREA.  NOT A LOT
OF SPEED CONVERGENCE WITH BROAD LOW LEVEL JET ACROSS THE AREA...BUT
COULD GET ENOUGH CONVERGENCE IN WEAKLY UNSTABLE ENVIRONMENT ACROSS
THE EASTERN CWA TO SPROUT A FEW STORMS.

HAVE CONTINUED LOW POP MENTION ACROSS THE EASTERN CWA WEDNESDAY INTO
THURSDAY AS A WEAK SHORTWAVE TRAIN MOVES THROUGH THE AREA.

MORE ACTIVE PATTERN APPEARS TO BE SETTING UP FOR LATE IN THE WEEK
WITH SHORTWAVES STREAMING FROM SOUTHWEST TO NORTHEAST AND LARGE
UPPER LEVEL TROUGH ACROSS THE PACIFIC NW TRANSLATING EAST.  HAVE
KEPT MID TO UPPER CHANCE RANGE POPS FOR NEXT WEEKEND.  PLENTY OF LOW
LEVEL SHEAR NEXT WEEKEND...BUT MID LEVEL SUPPORT SEEMS LIMITED THUS
KEEPING SEVERE CHANCES SOMEWHAT LIMITED.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 635 PM CDT SUN AUG 30 2015

PRETTY THICK SMOKE PLUME EXISTS ACROSS THE FORECAST AREA AT THIS
TIME. VISUALLY AT KFSD...AND ON WEBCAMS IN SIOUX CITY...DECIDED TO
GO 6SM IN SMOKE TONIGHT AS THE SLANT VISIBILITY MAY NOT BE THE
BEST. HURON WEBCAMS LOOKED A LITTLE BETTER IN TERMS OF VISIBILITY.
ONE OTHER CONCERN TONIGHT IS STRATUS AGAIN AT KFSD AND KSUX.
DESPITE MIXING BETTER TODAY...THE LOW CLOUDS DID NOT ERODE VERY
FAR FROM OUR FAR SOUTHEAST ZONES NEAR STORM LAKE IOWA LATE THIS
AFTERNOON. THIS IS BOTHERSOME...SO IT IS POSSIBLE THAT IFR TO MVFR
STRATUS COULD FORM AGAIN LATE TONIGHT OR AROUND SUNRISE AT KFSD
AND KSUX. WILL MONITOR THIS CLOSELY TONIGHT. FINALLY...LOW LEVEL
JET IS STOUT TONIGHT...MOST PROMINENT AT KHON WHERE THE SPEED IS
40 KNOTS AT 1500 FEET AGL. LEFT NON CONVECTIVE LOW LEVEL WIND
SHEAR OUT OF THE TAFS AS SURFACE MIXING SHOULD STAY FAIRLY
ROBUST...WHICH IS ALSO THE MAIN REASON CHOSE NOT TO PUT IN LIFR
AT KFSD AND KSUX LATE TONIGHT.

&&

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

$$

SHORT TERM...08
LONG TERM...
AVIATION...MJ



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