Area Forecast Discussion
Issued by NWS Sioux Falls, SD

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000
FXUS63 KFSD 290847
AFDFSD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SIOUX FALLS SD
347 AM CDT SAT AUG 29 2015

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 347 AM CDT SAT AUG 29 2015

STRATUS CONTINUES TO HOLD OVER THE SOUTHEASTERN PORTIONS OF OUR CWA
VERY EARLY THIS MORNING. MODELS DIFFERING ON HOW QUICKLY THIS PULLS
OFF TO THE EAST...BUT THE LOW CLOUDS SEEM TO BE TIED TO AREAS WITH A
LIGHT NORTHEASTERLY FLOW...SO USED THE LOW LEVEL WIND FIELD TO TIME
ITS DEPARTURE...IN THE MID TO LATE MORNING. HAVE NOT SEEN ANY FOG
FORMATION AT THIS POINT...THOUGH STILL A POSSIBILITY WITH ABUNDANT
NEAR SURFACE MOISTURE AND LIGHT WINDS SO KEPT IT IN THE FORECAST
THROUGH THE MORNING HOURS. OTHERWISE...SURFACE AND UPPER LEVEL
RIDGING BUILD INTO THE REGION TODAY...PROVIDING FOR RELATIVELY LIGHT
WINDS AND WARMING TEMPERATURES. HIGHS ARE LOOKING TO RANGE FROM
AROUND 80 FROM THE INTERSTATE 29 CORRIDOR EASTWARD...TO NEAR 90 OVER
SOUTH CENTRAL SOUTH DAKOTA.

WITH HIGH PRESSURE CONTINUING TO DOMINATE ACROSS THE REGION...WINDS
WILL AGAIN BE LIGHT TONIGHT...ESPECIALLY IN OUR EAST...AND MODELS
AGAIN HINTING AT FOG AND POSSIBLE STRATUS FORMATION EAST OF
INTERSTATE 29. LOWS WILL BE A LITTLE MILDER...GENERALLY LOWER 60S.


.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 347 AM CDT SAT AUG 29 2015

PATCHY FOG ACROSS THE EASTERN FORECAST AREA WILL LIFT QUICKLY SUNDAY
MORNING...STRATUS ACROSS PORTIONS OF NORTHWEST IOWA MAY BE A BIT
SLOWER TO MIX OUT IN THE MORNING. OTHERWISE...SOUTHERLY WINDS WILL
BE ON THE INCREASE THROUGH DAY...BECOMING WINDY ACROSS SOUTH CENTRAL
SD WHERE THE PRESSURE GRADIENT TIGHTENS UP DUE TO STRENGTHENING LOW
PRESSURE IN WESTERN NORTH DAKOTA. HOWEVER...THE WARM AIR
ADVECTION...COPIOUS SUNSHINE AND STRONG MIXING WEST OF I29 WILL
ALLOW TEMPERATURES TO SOAR INTO THE MID 80S TO LOWER 90S. FURTHER
EAST...SOME LINGERING MORNING CLOUDS AND WEAKER MIXING WILL KEEP
TEMPERATURES SLIGHTLY COOLER IN THE LOWER 80S.

FOR THE FIRST HALF OF THE WORK WEEK...TEMPERATURES WILL BE
SEASONALLY WARM WITH GENERALLY DRY CONDITIONS PREVAILING. THE
AFOREMENTIONED SYSTEM IN THE NORTHERN PLAINS SLIDES EAST AND
SQUASHES THE UPPER RIDGE ON MONDAY. A DIFFUSE FRONTAL BOUNDARY WILL
APPROACH THE AREA MONDAY EVENING AND OVERNIGHT...BUT WITH WEAK LIFT
AND POOR UPPER SUPPORT...PRECIPITATION CHANCES LOOK SLIM. WILL LEAVE
SOME VERY LOW END THUNDERSTORM CHANCES IN THE EVENING...BUT
CONFIDENCE IS PRETTY LOW.

UPPER FLOW REMAINS SOUTHWESTERLY THROUGH THE END OF THE WORK
WEEK...WITH SEVERAL VERY WEAK WAVES LIKELY TO IMPACT THE AREA. WITH
NO REAL CONFIDENCE IN ANY PARTICULAR SOLUTION...HAVE REMOVED MOST OF
THE VERY SPOTTY POPS FROM THE ALLBLEND MID WEEK. BY LATE WEEK
HOWEVER...MODELS BEGIN CONVENING ON A SOLUTION OF BRINGING A
SLIGHTLY MORE SUBSTANTIAL WAVE INTO THE CENTRAL PLAINS SO WILL LEAVE
SOME LOW END POPS FRIDAY...RAMPING UP INTO CHANCES FOR SATURDAY.


&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1047 PM CDT FRI AUG 28 2015

MVFR TO IFR STRATUS WILL PREVAIL ACROSS NORTHWEST IOWA FOR MUCH OF
THE REST OF TONIGHT IMPACTING THE KSUX TAF SITE...WHO MAY WAVER
BETWEEN LOWER END MVFR AND UPPER END IFR. NAM HUMIDITY TIME
SECTIONS AND SOUNDINGS SUGGEST THAT THE STRATUS MAY ERODE CLOSE TO
09Z AT KSUX...BUT THIS WILL BE MONITORED. IF IT DOES ERODE...THEN
FOG IS A CERTAINLY A POTENTIAL LATE TONIGHT AND EARLY SATURDAY
MORNING. FOG COULD ALSO OCCUR DURING THE SAME TIME FRAME AT KFSD.


&&

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

$$

SHORT TERM...JM
LONG TERM...
AVIATION...MJ



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