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000
FXUS63 KFSD 081153
AFDFSD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SIOUX FALLS SD
553 AM CST SAT MAR 8 2014

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 354 AM CST SAT MAR 8 2014

FOCUS IN THE NEAR TERM IS ON TEMPERATURES AND CLOUD COVER CONCERNS.
MODELS DID NOT INITIALIZE WELL WITH LOW LYING STRATUS POURING OUT OF
NORTH DAKOTA INTO SOUTH DAKOTA.  EXPECT THIS AREA OF CLOUD COVER TO
QUICKLY WORK INTO AT LEAST THE NORTHERN HALF OF THE FORECAST AREA
THIS MORNING...AND POTENTIALLY FURTHER SOUTH.  THIS INCREASED CLOUD
COVER WILL LIMIT THE AMOUNT OF WARMING ACROSS THE NORTH AND EASTERN
PORTIONS OF THE FORECAST AREA...AND HAVE SIDED WITH COOLER GUIDANCE
VALUES IN THESE AREAS.  ACROSS CENTRAL SOUTH DAKOTA...EXPECT TO SEE
SOME CLEARING THROUGHOUT THE AFTERNOON HOURS AND ALONG WITH LIMITED
SNOW COVER SHOULD SEE SOME NICE WARMING. WITH SURFACE RIDGE PASSING
OVER THE AREA...WINDS SHOULD BE RELATIVELY LIGHT TILL TONIGHT WHEN
PRESSURE GRADIENT INCREASES AND WIND SPEEDS INCREASE.

STRONGEST WINDS ARE EXPECTED IN EXPOSED AREAS ALONG THE BUFFALO
RIDGE.  WITH RELATIVELY COOL TEMPERATURES SINCE THE LAST SNOWFALL
EVENT...ADDED BLOWING SNOW TO THE FORECAST AFTER 06Z TONIGHT.  WITH
INCREASING WINDS...EXPECT TEMPERATURES TO RISE LEADING TO LOWS IN
THE EARLY TO MID EVENING HOURS.

.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 354 AM CST SAT MAR 8 2014

CONTINUES TO LOOK WARM ON SUNDAY AS RIDGING AND SOUTHERLY FLOW
RETURNS TO THE AREA. TWO THINGS THAT COULD POTENTIALLY INHIBIT
WARMING WILL BE SNOW COVER AND CLOUDS. TOUGH CALL OVER THE DEEPER
SNOWPACK ACROSS SOUTHWEST MINNESOTA AND ADJACENT AREAS OF NORTHWEST
IOWA...BUT WILL CONTINUE WITH MID TO UPPER 40S IN THOSE AREAS.
RECORD TEMPERATURES WITH OVER 6 INCHES OF SNOW ON THE GROUND ARE
RIGHT AROUND 50...SO MAKES SENSE TO STAY BELOW THAT IN THOSE DEEPER
SNOW COVERED AREAS. OVER THE SNOW FREE AREAS ACROSS SOUTH CENTRAL
SOUTH DAKOTA AND ALONG THE MISSOURI RIVER...BUMPED HIGHS UP A FEW
DEGREES WITH 60S LIKELY. COULD EVEN SEEM UPPER 60S TOWARDS
CHAMBERLAIN AND GREGORY. TOUGHER CALL IS ON THE EDGE OF THE SNOWPACK
FROM HURON TO SIOUX FALLS...BUT WILL CONTINUE WITH 50S IN THOSE
AREAS. OVERALL THINK CLOUD COVER WILL BE THIN AND HIGH ENOUGH TO
ONLY HAVE A MINIMAL IMPACT ON TEMPERATURES...WITH THE GREATEST
IMPACT IN THE NORTH...WHERE THESE CLOUDS MAY BE SLIGHTLY THICKER.

THESE MID AND HIGH CLOUDS WILL SINK SOUTH ON SUNDAY NIGHT...BEFORE
LIFTING BACK NORTH ON MONDAY. SO EXPECTING PARTLY TO EVEN MOSTLY
CLOUDY SKIES. HIGHS MONDAY HAVE A SLIGHTLY BETTER CHANCE OF BEING
IMPACTED BY THE CLOUDS...AS THEY SHOULD BE THICKER. 925 MB
TEMPERATURES WILL ALSO RUN A BIT COOLER ON MONDAY. THESE NEGATIVES
WILL BE OFFSET BY CONTINUED DECREASED SNOW COVER THOUGH. SO WENT
WITH HIGHS SIMILAR TO SUNDAY IN THE SNOW COVERED AREAS...AND A
LITTLE COOLER THAN SUNDAY IN THE SNOW FREE AREA DUE TO THE ABOVE
FACTORS. STILL WELL ABOVE AVERAGE ACROSS THE AREA THOUGH.

OUR NEXT PRECIPITATION THREAT WILL BE MONDAY NIGHT INTO TUESDAY.
PRETTY STRONG FRONTOGENESIS AS A COLD FRONT DROPS SOUTH...COMBINED
WITH LIFT AHEAD OF THE APPROACHING WAVE AND IN THE RIGHT ENTRANCE OF
AN UPPER JET...SHOULD SET THE STAGE FOR A PERIOD OF LIGHT TO
MODERATE PRECIPITATION. GFS...ECMWF AND GEM IN PRETTY GOOD
AGREEMENT...AND THUS BUMPED POPS INTO THE HIGH LIKELY TO
CATEGORICAL RANGE. EXPECTING PRECIPITATION TO START IN OUR WEST
AROUND MIDNIGHT...THEN SPREAD TOWARDS SIOUX FALLS BY EARLY MORNING.
PRECIPITATION WILL THEN EXIT FROM NORTHWEST TO SOUTHEAST FROM MID
MORNING INTO THE EARLY AFTERNOON HOURS. PRECIPITATION TYPE IS UP IN
THE AIR...BUT WOULD EXPECT IT TO START AS RAIN. THEN AS COLD AIR
FILTERS IN BEHIND THE FRONT WE SHOULD MIX WITH AND CHANGE TO
SNOW...ALTHOUGH IT WILL BE A WET SNOW WITH TEMPERATURES RIGHT AROUND
OR JUST ABOVE FREEZING. TOUGH TO PIN DOWN DETAILS THIS FAR OUT...AND
STILL DIFFERENCES AMONG MODELS AS TO HOW MUCH QPF FALLS AS SNOW. IF
THIS WAS ALL SNOW...QPF COULD BE HIGH ENOUGH FOR SEVERAL INCHES OF
ACCUMULATION SOMEWHERE. BUT THOUGHT NOW IS THAT THE COMBINATION OF
RAIN TO BEGIN...AND THEN LOW RATIOS AFTER THE CHANGEOVER...SHOULD
LIMIT AMOUNTS TO JUST AN INCH OR TWO...WITH THE BEST CHANCE OF THAT
ALONG AND NORTH OF INTERSTATE 90. BUT WILL NEED TO CONTINUE TO
MONITOR THERMAL TRENDS OVER THE COMING DAYS.

COOLER AIR MOVES IN BEHIND THE FRONT FOR TUESDAY AND WEDNESDAY. KEPT
THE COOLER TEMPERATURES OF 30S AND 40S GOING ON TUESDAY...AS CLOUD
COVER AND THE POTENTIAL NEW LIGHT SNOW COVER SHOULD LIMIT WARMING.
SHOULD BE A COUPLE TO SEVERAL DEGREES WARMER ON WEDNESDAY...WITH
MODELS TRENDING A BIT QUICKER WITH THE EXIT OF THE COLDER LOW LEVEL
TEMPERATURES. PRETTY GOOD MODEL AND ENSEMBLE AGREEMENT THAT WE
RETURN TO ABOVE NORMAL TEMPERATURES BY THURSDAY AND FRIDAY...WITH
40S AND 50S COMMON. AFTER THE PRECIPITATION EXITS TUESDAY...THE REST
OF THE WORK WEEK CONTINUES TO LOOK DRY.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 541 AM CST SAT MAR 8 2014

BATCH OF STRATUS MOVING INTO THE AREA THIS MORNING. CEILINGS WILL
GRADUALLY BUILD DOWN TOWARDS THE SURFACE THROUGHOUT THE DAY.
CEILINGS THIS MORNING WILL BE IN THE 5-6K FOOT RANGE...BUT MAY
FALL AS LOW AS 2-3K FEET THIS AFTERNOON. TIMING AND CONFIDENCE IN
THIS IS UNCERTAIN HOWEVER...SO IT WAS LEFT OUT OF THE TAFS FOR
NOW. BEST CHANCES IN THIS OCCURING WAS AT KHON...BUT CAN NOT RULE
OUT EITHER OF THE OTHER TWO TAF SITES. EXPECT SKIES TO CLEAR
TONIGHT WITH INCREASING SOUTHERLY WINDS.

&&

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

$$

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