559
FXUS63 KFSD 210009
AFDFSD
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SIOUX FALLS SD
709 PM CDT MON MAY 20 2013
SHORT TERM
(THIS EVENING THROUGH TUESDAY)
ISSUED AT 353 PM CDT MON MAY 20 2013
UPPER LEVEL LOW SPINNING AROUND WITH THE BEST MOISTURE DELIVERY TO
THE NORTH OF THE CWA. THE AFFECTS OF SOME OF THIS WILL WRAP INTO
WESTERN PARTS OF THE CWA TONIGHT AND CONTINUE INTO TUESDAY. A FEW
INSTABILITY SHOWERS WILL REMAIN POSSIBLE OVER THE REMAINDER OF THE
CWA BUT WITH CAPE VALUES MAINLY 250 J/KG OR LESS AND SHEAR MINIMAL
NOT EXPECTING ANY THING OTHER THAN SHOWERS AND ISOLATED
THUNDERSTORMS. A FEW OF THE THUNDERSTORMS COULD PRODUCE BRIEFLY
GUSTY WINDS AND SMALL HAIL BUT NOT SEVERE. THE MOST ORGANIZED AREA
WILL BE WITH THE TROWAL LIKE FEATURE TO THE NORTH AND EAST OVER
WESTERN ARTS IF THE CWA WHILE AREAS IN THE SOUTHERN CWA WILL SEE THE
LOW WOBBLE EAST THIS EVENING WITH A POTENTIAL BAND OF SHOWERS AND
ISOLATED THUNDERSTORMS DEVELOPING IN FAR SOUTHERN SD INTO NORTHWEST
IOWA.
UNDER CLOUDY CONDITIONS AND A CONTINUED WEST WIND OVERNIGHT
TEMPERATURES SHOULD NOT DROP SIGNIFICANTLY...SO EXPECTING LOWS FROM
ABOUT 50 TO 55...COOLEST IN CENTRAL SD. COOL AIR WILL REMAIN IN
PLACE ON TUESDAY AN LOCAL FORECAST SOUNDINGS NOT VERY SUPPORTIVE ON
SUNSHINE SO EVEN IF THE CLOUDS CAN DISSIPATE A BIT ANY WARMING WILL
JUST INDUCE ADDITIONAL CUMULUS DEVELOPMENT. THUS TEMPERATURES WILL
NOT GO FAR AND SUSPECT MOST LOCATIONS WILL ONLY REACH THE MID 50S TO
LOWER 60S FOR HIGHS AS THIS IS ABOUT THE TEMPERATURES THAT WE WOULD
GET CUMULUS REDEVELOPMENT AND HALT ANY WARMING.
LONG TERM
(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 353 PM CDT MON MAY 20 2013
SCATTERED SHOWERS WILL REMAIN APPROPRIATE FOR TUESDAY NIGHT INTO
WEDNESDAY AS THE UPPER LEVEL LOW MAKES A SLOW EASTWARD PROGRESSION
THROUGH THE PERIOD. COOLEST THERMAL PROFILES WILL BE LOCATED ACROSS
THE AREA ON TUESDAY NIGHT...WITH LOWS DROPPING DOWN INTO MID AND
UPPER 40S. ONLY SUBTLE WARMING ON WEDNESDAY WITH SHOWERS TAPERING
OFF FROM WEST TO EAST DURING THE DAY...AND HIGHS UPPER 50S TO LOWER
60S.
THE UPPER LEVEL LOW FINALLY PUSHES OFF INTO THE GREAT LAKES/OHIO
VALLEY REGION ON THURSDAY...AS SURFACE HIGH PRESSURE BUILDS
SOUTHWARD THROUGH THE PLAINS STATES. THIS WILL RESULT IN A DRY
DAY...AND WITH THE SUN FINALLY BREAKING OUT WILL HAVE SOME
WARMING...TEMPERED SOMEWHAT BY A EAST/NORTHEASTERLY LOW LEVEL FLOW
AND AFTERNOON HIGHS IN THE MID AND UPPER 60S. MOST OF FRIDAY LOOKS
TO BE DRY IN A TRANSITIONING SOUTHERLY LOW LEVEL FLOW AS THE HIGH
PRESSURE MOVES EAST. EVEN WITH WARMING THERMAL PROFILES HIGHS WILL
BE SIMILAR TO THURSDAY WITH CLOUDS INCREASING DURING THE
DAY...TOPPING OUT IN THE UPPER 60S TO AROUND 70.
UNSETTLED CONDITIONS RETURN FOR LATER ON FRIDAY AND THROUGH THE
WEEKEND WITH A CHANCE OF CONVECTION EACH DAY AS A SERIES OF
SHORTWAVES TRACK THROUGH THE UPPER LEVEL RIDGE PARKED OVER THE
REGION. DOES LOOK TO BE A SLOW WARMING TREND DURING THE
PERIOD...ALBEIT AROUND NORMAL FOR THIS TIME OF YEAR.
AVIATION
(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 708 PM CDT MON MAY 20 2013
DUE TO AN UPPER LEVEL LOW...SHOWERS WITH VFR TO MVFR CONDITIONS
WILL PERSIST TONIGHT AND TUESDAY.
FSD WATCHES/WARNINGS/ADVISORIES
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
SHORT TERM...08
LONG TERM...JM
AVIATION...
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