Area Forecast Discussion
Issued by NWS Sioux Falls, SD

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000
FXUS63 KFSD 041114
AFDFSD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SIOUX FALLS SD
514 AM CST WED MAR 4 2015

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 410 AM CST WED MAR 4 2015

MAIN THEME FOR TODAY WILL BE BITTERLY COLD TEMPERATURES AS A
SECONDARY COLD SURGE SLIDES THROUGH THE AREA. BUFKIT SOUNDINGS
SUGGEST THE POSSIBILITY OF ISOLATED FLURRIES AS THE COLDER AIR
STREAMS INTO THE REGION...SO DID INCLUDE THAT IN THE FORECAST OVER
PORTIONS OF THE AREA DURING THE EARLY PART OF THE DAY.
OTHERWISE...IT WILL BE A BREEZY AS NORTHWESTERLY WINDS INCREASE IN
RESPONSE TO THE STRONG COLD AIR ADVECTION AND RAPID PRESSURE RISES.
WITH HIGHS EXPECTED TO RANGE FROM THE SINGLE DIGITS THROUGH THE
HIGHWAY 14 CORRIDOR INTO MUCH OF SOUTHWESTERN MINNESOTA...TO THE
UPPER TEENS ALONG THE MISSOURI RIVER...THESE WINDS WILL COMBINE TO
PRODUCE WIND CHILLS BELOW ZERO.

SURFACE HIGH PRESSURE SLIDES ACROSS THE REGION TONIGHT...AND AS IT
DOES SO WINDS WILL DROP OFF. WITH MOSTLY CLEAR SKIES...THIS WILL
RESULT IN A VERY COLD NIGHT AS LOWS FALL TO 10 TO 15 BELOW THROUGH
OUR NORTHERN AND EASTERN ZONES...TO NEAR ZERO THROUGH THE MO RIVER
CORRIDOR. APPARENT TEMPERATURES WILL DROP INTO THE 20 TO 30 BELOW
ZERO RANGE IN OUR COLDEST AREAS...THOUGH WINDS WILL MOST LIKELY BE
LIGHT ENOUGH TO PRECLUDE A WIND CHILL ADVISORY.

.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 410 AM CST WED MAR 4 2015

TEMPERATURES REALLY THE PRIMARY CONCERN THROUGH THE END OF THIS WEEK
AND INTO NEXT. ARCTIC AIR MASS STILL HAS A BIT OF A HOLD ACROSS THE
REGION THURSDAY...ESPECIALLY EAST WHERE LINGERING COLD TEMPERATURES
ALOFT AND FRESH SNOW COVER WILL HOLD HIGHS AROUND 20 DEGREES. WARMER
LOW LEVEL AIR BEGINS TO WORK INTO THE WEST...AND WITH A SOUTHERLY
FLOW AND NO SNOW COVER TO OUR SOUTH...SHOULD BE ABLE TO WARM THE
SOUTHWEST PORTIONS OF THE FORECAST AREA WELL INTO THE 30S.

SOUTHWESTERLY LOW LEVEL JET AHEAD OF APPROACHING WARM FRONT WILL
PREVENT EASTERN AREAS FROM DROPPING OFF MUCH THURSDAY NIGHT...WITH
LOWS IN THE MID TEENS TO LOWER 20S EXPECTED. MILD WEST-SOUTHWEST LOW
LEVEL FLOW THEN BEGINS TO TAKE OVER ACROSS THE REGION...BRINGING OUR
FIRST TASTE OF ABOVE NORMAL HIGHS IN OVER A WEEK...HEADING INTO THE
FIRST EXTENDED STRETCH OF ABOVE NORMAL TEMPERATURES FOR MOST AREAS
IN NEARLY A MONTH. REMAINED SOMEWHAT CONSERVATIVE WITH WARMING OVER
OUR NORTHEAST FOR FRIDAY INTO THE WEEKEND GIVEN GREATER EXISTING
SNOW COVER. MODELS ALSO SHOWING POTENTIAL FOR A COUPLE OF WEAK MID
LEVEL WAVES SLIPPING INTO THE UPPER MIDWEST THIS WEEKEND. SHOULD SEE
GREATER CLOUD COVER AS A RESULT...AND COULD ALSO SEE A LITTLE LIGHT
PRECIPITATION OVER NORTHEAST PARTS OF OUR FORECAST AREA WITH THESE
WAVES...ALTHOUGH WITH LACK OF TIMING CONSENSUS IN THE MODELS MAKES
IT DIFFICULT TO PINPOINT A FAVORED TIME PERIOD JUST YET. LATEST RUNS
POINT TO FRIDAY NIGHT AND AGAIN SATURDAY NIGHT IN THE ECMWF...WHILE
THE GFS HAS A SHARPER WAVE DURING THE DAY SATURDAY FOLLOWED BY DRIER
FLOW THE REMAINDER OF THE WEEKEND. CANADIAN SPLITS THE DIFFERENCE...
SIDING WITH THE GFS FOR SATURDAY...WITH A SECOND SHOT SUPPORTING THE
ECMWF SATURDAY NIGHT INTO EARLY SUNDAY. INCONSISTENCY PROVIDES
LITTLE CONFIDENCE IN TIMING...SO WILL LEAVE PRECIP MENTION OUT OF
THE FORECAST FOR NOW. WILL BE SOMETHING TO MONITOR AS THE WEEKEND
APPROACHES THOUGH.

GREATER WARMING ON THE HORIZON FOR EARLY NEXT WEEK AS EASTERN TROUGH
CONTINUES TO WEAKEN AND FLOW BECOMES MORE ZONAL ALOFT.  MAINTAIN DRY
WEST-SOUTHWEST FLOW IN THE LOWER LEVELS...WHICH SHOULD LIMIT STRATUS
POTENTIAL. HIGHS IN THE UPPER 40S AND 50S SEEM QUITE REASONABLE FOR
MONDAY/TUESDAY...AND WOULD NOT BE SURPRISED TO SEE READINGS EVEN A
LITTLE HIGHER THAN THAT. THOUGH WITH SOME SUBTLE DIFFERENCES IN LOW
LEVEL PATTERN...NUDGED ONLY A LITTLE WARMER THAN A STRAIGHT MODEL
BLEND FOR NOW.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 503 AM CST WED MAR 4 2015

A SECONDARY COLD SURGE WILL SPREAD ACROSS THE AREA THROUGH THE
MORNING...BRINGING THE POSSIBILITY BRIEF FLURRIES TO PORTIONS OF
THE AREA DURING THE EARLY PART OF THE DAY...THOUGH EXPECTING
LITTLE IMPACT TO VISIBILITIES AT TAF SITES. A SMALL AREA OF
HEAVIER SNOW HAS DEVELOPED OVER NORTHEASTERN SD AND IF IT HOLDS
TOGETHER MAY BRING SOME BRIEF LOWER VISIBILITIES THROUGH EAST
CENTRAL SD/SOUTHWESTERN MINNESOTA DURING THE MORNING HOURS.

&&

.FSD WATCHES/WARNINGS/ADVISORIES...
SD...WIND CHILL ADVISORY UNTIL 9 AM CST THIS MORNING FOR SDZ038>040.

MN...WIND CHILL ADVISORY UNTIL 9 AM CST THIS MORNING FOR MNZ071-072-
     080-081.

IA...NONE.
NE...NONE.
&&

$$

SHORT TERM...JM
LONG TERM...JH
AVIATION...JM


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