688 
FXUS63 KFSD 161040
AFDFSD

AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NATIONAL WEATHER SERVICE SIOUX FALLS SD
540 AM CDT WED MAY 16 2012

.DISCUSSION...
SOUTHERLY FLOW WILL STRENGTHEN TODAY AS A TROUGH OF LOW PRESSURE 
BEGINS TO DEVELOP OVER THE HIGH PLAINS. AS MIXING ENSUES...WINDS WILL
BECOME BREEZY. PROGGED SPEEDS AT THE TOP OF THE MIXED LAYER ARE 
AROUND 35 KTS ON NAM/GFS MODELS. TRANSLATING THIS DOWN TO THE SFC 
WOULD YIELD FORECAST SPEEDS JUST BELOW ADVISORY CRITERIA...MAINLY 
WEST OF THE JAMES RIVER. HAVE INCLUDED SUSTAINED SPEEDS AROUND 25 
KTS...WITH GUSTS OVER 30 KTS. TEMPERATURES WILL CLIMB INTO THE 
MID/UPPER 70S FOR THE MOST PART...WITH A SLIGHT EASTERLY COMPONENT 
TO THE FLOW.

A LLVL JET CIRCA 50 KTS NOSES INTO NERN SD ON WEDNESDAY
NIGHT. COULD SEE SOME ELEVATED CONVECTION DEVELOP...MAINLY NORTH
OF HIGHWAY 14. HAVE RETAINED 20 POPS IN THE FAR NERN CWA.

TEMPERATURES WILL CONTINUE TO MODERATE ON THURSDAY AND FRIDAY AS
THE AFOREMENTIONED PLAINS TROUGH DEEPENS UNDER THE BUILDING RIDGE.
HIGHS BETWEEN 85 AND 90 DEGREES WILL BE COMMON FOR THURSDAY AND
FRIDAY...ALONG WITH LOWS IN THE 50S AND 60S. WINDY CONDITIONS WILL
EXPAND EASTWARD...WITH WINDS ABOVE THE MIXED LAYER FORECAST TO
INCREASE BY A FEW KNOTS. WILL NEED TO MONITOR THE POTENTIAL NEED
FOR A WIND ADVISORY ON THURSDAY AND FRIDAY...ESPECIALLY IN THE
HIGHER TERRAIN AREAS OF SWRN MN AND E CNTRL SD.

THE UPPER LEVEL WAVE AND COOL FRONT WILL MOVE ACROSS THE AREA ON
SATURDAY INTO SUNDAY. SHEAR AND INSTABILITY PARAMETERS ARE
CONSISTENT WITH A LOW POTENTIAL FOR A FEW STRONG/SEVERE
STORMS...ALONG WITH LOCALLY HEAVY RAIN DUE TO THE ORIENTATION OF
THE LLVL/MLVL JETS WITH ONE ANOTHER. 

A FEW SHOWERS WILL LINGER ON SUNDAY...MAINLY EAST OF INTERSTATE
29. AFTER SUNDAY...A SURFACE HIGH WILL FOSTER MILD/DRY CONDITIONS
ACROSS THE AREA UNTIL THE NEXT TROUGH ARRIVES MID TO LATE IN THE
WORK WEEK.

&&

.AVIATION.../FOR THE 12Z TAF ISSUANCE/
VFR CONDITIONS EXPECTED THROUGH THE PERIOD. SOUTHEASTERLY WINDS WILL 
INCREASE FROM WEST TO EAST THROUGHOUT THE DAY. WIND GUSTS WEST OF 
THE JAMES COULD EXCEED 30 KNOTS AFER 21Z.  STRONG LOW LEVEL JET IS 
EXPECTED TO DELOP TONITH WITH NEARLY 50 KNOTS JUST ABOVE THE MIXED 
LAYER. 

&&

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

$$