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000
FXUS63 KFSD 121121
AFDFSD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SIOUX FALLS SD
621 AM CDT WED MAR 12 2014

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 319 AM CDT WED MAR 12 2014

A BIT OF A MESSY AND SOMEWHAT CHALLENGING FORECAST FOR NOT A WHOLE
LOT GOING ON. THE FIRST CONCERN IS WHETHER OR NOT ANY MEASURABLE
SNOWFALL CAN OCCUR MAINLY THIS MORNING AND MAINLY OVER THE NORTHEAST
CWA. AN UPPER LEVEL WAVE WILL MOVE SOUTHEAST OF THE AREA WITH LOW
LEVEL WARM AIR ADVECTION EXPECTED TO DEVELOP. THE PROBLEM WILL BE
GETTING SATURATION IN THE DENDRITIC LAYER AND IF THAT CAN OCCUR
GETTING IT TO LAST LONG ENOUGH FOR MORE THAN A HANDFUL OF MINUTES OF
SNOWFALL. WILL MAINTAIN SOME LOW POPS THIS MORNING IN SOUTHWEST
MINNESOTA WHERE THE COMBINATION OF FORCING AND SATURATION LOOK BEST.
ALONG AND WEST OF INTERSTATE 29 WENT AHEAD AND RAISED HIGHS QUITE A
BIT AS THE LOW LEVEL THERMAL GRADIENT LOOKS TO SHIFT EAST AND SOME
MARGINALLY MIXY CONDITIONS DEVELOP. NORTHWEST WINDS ALONG AND WEST
OF THE JAMES RIVER VALLEY LIKELY TO CLIMB TO 10 TO 20 MPH THIS
AFTERNOON AS THE SKIES CLEAR AND MIXING INCREASES. WILL AIM FOR
HIGHS OF 30 TO 35 EAST OF THE BUFFALO RIDGE WHERE CLOUDS WILL LIKELY
LINGER LONGEST AND GO INTO THE LOWER 50S ALONG AND WEST OF THE JAMES
RIVER VALLEY.

BY TONIGHT A WEAK TROUGH OF LOW PRESSURE WILL KEEP WINDS PARTIALLY
MIXED AND LIKELY AVERAGE ABOUT 5 TO 12 MPH. THIS SHOULD KEEP LOW
FAIRLY MILD...ESPECIALLY CONSIDERING VERY LITTLE SNOW COVER EXISTS
ANYMORE. RAISED LOWS A COUPLE DEGREES IN MANY LOCATIONS.

.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 319 AM CDT WED MAR 12 2014

A WARM AND SUNNY DAY IS EXPECTED ACROSS THE REGION ON THURSDAY. 925
MB TEMPERATURES WARM INTO THE 11C TO 15C RANGE BY EVENING. ALLOWING
FOR FULL MIXING OUTSIDE THE SNOW COVER AREA...RESULTS IN HIGHS IN
THE LOW TO MID 60S. THUS DID CONTINUE THE TREND OF BUMPING HIGHS UP.
AS SNOW COVER CONTINUES TO SHRINK ACROSS SOUTHWEST
MINNESOTA...SHOULD BE ABEL TO GET INTO THE 50S EVEN THERE. A COLD
FRONT WILL MOVE THROUGH THURSDAY NIGHT...ALTHOUGH COLD AIR NOT
IMPRESSIVE BEHIND THE FRONT. AND GIVEN FULL MIXING AGAIN...BUMPED
HIGHS UP A FEW DEGREES...WITH MID 40S SOUTHWEST MINNESOTA TO MID 50S
SOUTHWEST HALF OF THE AREA.

A SECONDARY COLD FRONT WILL PUSH THROUGH FRIDAY NIGHT...WITH A
REINFORCING SHOT OF COLDER AIR. STILL NOTHING IMPRESSIVE...BUT
ENOUGH TO PUSH OUR TEMPERATURES INTO THE SLIGHTLY BELOW NORMAL
RANGE...MAINLY 30S AND 40S. MODELS COMING INTO BETTER
AGREEMENT...AND CONSISTENCY INCREASING THAT WE STAY ON THE COLDER
SIDE OF THE FRONT ON SUNDAY...WITH 30S AND 40S AGAIN COMMON. COULD
SEE A BIT OF PRECIPITATION...AS A WAVE RIDES ALONG THE FRONT LATER
SATURDAY INTO SATURDAY NIGHT. PRECIPITATION TYPE COULD BE EITHER
RAIN OR SNOW...ALTHOUGH WITH THERMAL PROFILES TRENDING COLDER...SNOW
SEEMS MORE PROBABLE. EITHER WAY AMOUNTS WILL BE LIGHT...WITH ONLY A
FEW HUNDREDTHS OF QPF AT MOST EXPECTED. AS THE FRONT BEGINS TO LIFT
BACK NORTH AS A WARM FRONT...ANOTHER WAVE WILL MOVE ACROSS THE
NORTHERN PLAINS ON SUNDAY. THIS IS TRENDING FURTHER NORTH...AND THUS
WILL ONLY KEEP POPS ALONG THE HIGHWAY 14 CORRIDOR. THIS WOULD
PROBABLY BE IN THE FORM OF LIGHT SNOW...BUT AGAIN ANY AMOUNTS WOULD
BE VERY LIGHT.

MODEL SOLUTIONS THEN BEGIN TO DIVERGE AS WE HEAD INTO EARLY NEXT
WEEK. RIDGING DEVELOPS ON MONDAY AHEAD OF OUR NEXT WAVE IN THE
NORTHWEST FLOW. GFS IS MUCH WARMER IN THE LOW LEVELS THAN THE ECMWF
AND GEM...AND THE GFS ENSEMBLE MEAN IS CLOSER TO THE ECMWF AND GEM.
SO WHILE IT LOOKS MILD ON MONDAY...PROBABLY NOT TO THE EXTENT OF
THE GFS. ALTHOUGH MODEL CONSISTENCY HAS BEEN LOW AND THUS
CONFIDENCE IS ALSO LOW. FOR NOW WILL STICK WITH HIGHS IN THE MID 40S
SOUTHWEST MINNESOTA TO MID TO UPPER 50S ALONG THE MISSOURI RIVER.
ECMWF AND GEM ARE STRONGER WITH THE WAVE MONDAY NIGHT INTO
TUESDAY....DRIVING THE COLD AIR FURTHER SOUTH AND BRINGING A
PRECIPITATION THREAT TO THE AREA. STAYED CLOSE TO CONSENSUS FOR
NOW...RESULTING IN HIGHS IN THE 40S TO AROUND 50 AND LOW POPS. IF
THE ECMWF AND GEM VERIFY TEMPERATURES WOULD BE COLDER AND WE WOULD
SEE AN AREA OF RAIN AND SNOW. STILL DOES NOT LOOK LIKE A SIGNIFICANT
PRECIPITATION PRODUCER...BUT SOMETHING TO KEEP AN EYE ON...AS IT
LOOKS POTENTIALLY STRONGER THAN ANY OF THE WAVES THIS WEEK.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 619 AM CDT WED MAR 12 2014

MAINLY VFR CONDITIONS THROUGH THE PERIOD. THROUGH 18Z SOME SPOTTY
SHORT LIVED MVFR CEILINGS WILL BE POSSIBLE AS WELL AS A FEW FLAKES
OF SNOW...ALTHOUGH VISIBILITIES ARE EXPECTED TO REMAIN IN THE VFR
CATEGORY. THE BEST CHANCE FOR THIS WILL BE ALONG AND EAST OF THE
INTERSTATE 29 CORRIDOR.

&&

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

$$

SHORT TERM...08
LONG TERM...CHENARD
AVIATION...08