Area Forecast Discussion
Issued by NWS Sioux Falls, SD

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FXUS63 KFSD 130354
AFDFSD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SIOUX FALLS SD
1054 PM CDT SAT JUL 12 2014

.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 335 PM CDT SAT JUL 12 2014

QUASI-STATIONARY BOUNDARY DRAPED NEAR INTERSTATE 90 HAS BEGUN TO
SHIFT A BIT MORE SOUTHEAST THIS AFTERNOON WITH THE ADVANCEMENT OF A
SHORTWAVE TRAVERSING ALONG THE UPPER LEVEL NORTHWEST FLOW.
DEFORMATION BAND OF SHOWERS WITH SOME ISOLATED THUNDER NEAR OUR
NORTHERN BORDER IS ALSO FINALLY ACCELERATING TO THE EAST SECOND BAND
OF SHOWERS ACROSS FAR SOUTHEAST SOUTH DAKOTA INTO NORTHWEST IOWA IS
ALSO SLIDING EAST...HOWEVER THERE IS SOME REDEVELOPMENT OF RAIN
TRAINING INTO SOUTHEAST SD. WITH THE FRONT NOW ADVANCING INTO THIS
AREA...PRECIPITATION SHOULD BEGIN TO SHUT OFF AND FINALLY SHIFT EAST
OUT OF THE FORECAST AREA THROUGH THE LATE AFTERNOON/EARLY EVENING.
MODELS SUGGEST THAT SOME WEAK ELEVATED INSTABILITY EXISTS SOUTH OF
I90...SO WILL KEEP IN ISOLATED THUNDERSTORM MENTION.

CLOUDS WILL BEGIN CLEARING FROM WEST TO EAST THIS EVENING AND
TONIGHT BEHIND THE FRONT AND SHORTWAVE. WITH RELATIVELY LIGHT
WINDS...GENERALLY AROUND 6 MPH OR LESS...AM CONCERNED THAT SOME
PATCHY SHALLOW FOG MAY DEVELOP ACROSS OUR SOUTHEASTERN HALF WHERE
LOW LEVEL MOISTURE IS SLIGHTLY SLOWER TO SCOUR OUT AND COPIOUS
RAINFALL FELL LAST NIGHT. ADDED PATCHY FOG MENTION TO THE
GRIDS...HOWEVER IF CLOUDS HANG ON A BIT LONGER OR WINDS ARE SLIGHTLY
STRONGER FOG MAY BE HARDER TO COME BY. LOWS WILL BE IN THE UPPER 50S
TO LOWER OR MID 60S.

STRONGER FRONTAL PUSH ON SUNDAY ALLOWS THE COLD FRONT TO FINALLY
CLEAR THE AREA AND LOWER DEWPOINTS TO DROP INTO THE REGION. A WEAK
WAVE MAY PROVIDE ENOUGH FORCING TO ALLOW SOME ISOLATED SHOWERS AND
NON SEVERE THUNDERSTORMS WITH SOME MID LEVEL INSTABILITY IN PLACE
ACROSS OUR SOUTHERN HALF LATE MORNING INTO THE AFTERNOON. HIGHS WILL
BE IN THE MID 70S TO MID 80S.

.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 335 PM CDT SAT JUL 12 2014

DRYING SHOULD BRING MOSTLY CLEAR SKIES SUNDAY NIGHT AS COOL AIR FLOW
SLOWLY INCREASES. WEST END OF CANADIAN UPPER LOW DROPPING OVER THE
WESTERN GREAT LAKES WILL BRING A ROUND OF VERY COOL AIR ALOFT OVER
THE AREA MONDAY AND AN INCREASE IN CLOUD COVER BY MONDAY MORNING IS
A GIVEN. THE ONLY QUESTION IS WHETHER OR NOT THE CLOUD COVER WILL
BECOME SOLID OR SEMISOLID  FOR A CHUNK OF THE DAY. SOUNDINGS DO NOT
INDICATE SOLID AT THIS TIME BUT WITH HEATING OF THE VERY COOL AIR
MASS...FAVOR BECOMING MOSTLY CLOUDY IN THE NORTHEAST AT LEAST. AS
FOR SHOWERS...THE LOW LEVEL AIR SEEMS UNSTABLE ENOUGH FOR A FEW
LIGHT SHOWERS OR SPRINKLES BUT THE INSTABILITY DOES NOT GO UP TOO
HIGH AND EXPECT COVERAGE OF ANY MEASURABLE RAIN TO BE LIMITED AND
WILL KEEP THE MENTION AT SLIGHT CHANCE. ANY SPOTTY PRECIPITATION
AMOUNTS WILL ALSO BE LIMITED.

TEMPERATURES COOLING INTO THE 50S SUNDAY NIGHT WILL NOT BE MOVED TO
WARM A LOT MONDAY WITH HIGHS IN THE MID 60S TO LOWER 70S. A
NORTHERLY/NORTHWESTERLY WIND WILL ADD TO THE TOUCH OF MIDSUMMER COOL
FEELING...ASSURING AN APPEARANCE OF SWEATERS AND LIGHT COATS FOR
ANYTHING OUTDOORS. RECORD LOW MAXIMUMS COULD BE APPROACHED.

MONDAY NIGHT WILL SEE TEMPERATURES DIPPING TO AROUND 50...WHICH
MEANS SOME UPPER 40S ARE ON TAP FOR EARLY TUESDAY MORNING. THE
QUICKLY PASSING NATURE OF THE COOLEST SHOT SHOULD KEEP MINIMUMS
ABOVE DAILY RECORDS BUT WILL NEVER SAY NEVER.

A WARMING TREND SHOULD ACCOMPANY DRY WEATHER FOR TUESDAY ON...UNTIL
AN APPROACHING SHORT WAVE DENTS THE SLOWLY BUILDING UPPER HEIGHTS
NEAR THE START OF NEXT WEEKEND AND BRINGS AN UNCERTAIN CHANCE OF
SHOWERS OR STORMS. THE GFS HAS PREDICTABLY BACKED OFF ON ITS VERY
STRONG RIDGING AND THE EC ALSO KEEPS WARMING MODEST...SO BY THE END
OF THE FORECAST PERIOD HIGH TEMPERATURES SHOULD GET BACK INTO THE
80S...BUT NOT 90S.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1050 PM CDT SAT JUL 12 2014

PATCHY FOG IS EXPECTED TO DEVELOP THROUGH THE OVERNIGHT. HAVE FOG
IN BOTH KFSD AND KSUX...WITH LOWER VISIBILITIES AT KSUX WITH
SIGNIFICANT RAINFALL OVER THE LAST DAY. NORTHWEST FLOW IS EXPECTED
TO PREVAIL THROUGHOUT THE DAY ON SUNDAY AHEAD OF A STRONG COLD
FRONT THAT WILL WORK THROUGH SUNDAY NIGHT INTO MONDAY.

&&

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

$$

SHORT TERM...
LONG TERM...
AVIATION...





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