000
FXUS63 KFSD 062144
AFDFSD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SIOUX FALLS SD
344 PM CST THU MAR 6 2014

.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 342 PM CST THU MAR 6 2014

BLOWING/DRIFTING SNOW HAS BECOME A PROBLEM ACROSS NORTHEAST PARTS OF
THE AREA THIS AFTERNOON...DUE TO GUSTY SOUTH WINDS IN AREAS WHICH
HAD RECEIVED GREATEST SNOWFALL EARLIER THIS WEEK. VISIBILITY DOWN TO
A MILE OR LESS AT TIMES...BUT DID NOT APPEAR WIDESPREAD NOR FREQUENT
ENOUGH TO WARRANT WINTER WEATHER ADVISORY. GREATER TRAVEL ISSUES DUE
TO DRIFTING SNOW MELTING ON WARMING ROAD SURFACES...THEN REFREEZING
AS ADDITIONAL SNOW DRIFTS ACROSS THE ROADS. ISSUED SPECIAL WEATHER
STATEMENT TO COVER THE ICY ROAD CONDITIONS...AND POSTED INFORMATION
ON OUR SOCIAL MEDIA/HOMEPAGE. WINDS EXPECTED TO EASE SOME BY LATE
AFTERNOON/EVENING...BUT ICY ROAD CONDITIONS LIKELY TO CONTINUE.

MAIN WEATHER CONCERN OVERNIGHT/FRIDAY TURNS TO POTENTIAL FOR LIGHT
MIXED PRECIP WITH COLD FRONT/WEAK MID LEVEL WAVE MOVING ACROSS THE
REGION. HAVE FINALLY SCOURED OUT A GOOD PORTION OF THE WIDESPREAD
STRATUS DECK...BUT STILL REMNANTS AROUND...ALONG WITH LIGHT FOG WITH
2-4SM VISIBILITY. THIS MOISTURE WILL ONLY BE TRAPPED AS WEAK WARM
ADVECTION ALOFT CONTINUES AHEAD OF THE FRONT THIS EVENING...AND THUS
EXPECTING STRATUS/FOG TO REDEVELOP IN CENTRAL/EASTERN PORTIONS OF
THE CWA BY LATE EVENING. ALL MODELS SHOWING PRETTY DEEP DRY LAYER
BETWEEN THIS NEAR SURFACE MOISTURE AND MID CLOUDS ADVANCING IN WITH
THE UPPER WAVE...THUS DO NOT THINK MEASURABLE PRECIP CHANCE IS THAT
GREAT OVERNIGHT...AND HAVE REMOVED POPS AS A RESULT. HOWEVER...WITH
INCREASING LIFT JUST ABOVE THE EXPECTED DEVELOPING STRATUS LAYER...
THINK DRIZZLE IS A POSSIBILITY...AND AREAS OF FREEZING DRIZZLE ARE
UNFORTUNATELY ALSO POSSIBLE AS TEMPERATURES HOVER RIGHT AROUND 32F.
HAVE ADDED MENTION OF THIS TO AREAS AHEAD OF THE BOUNDARY...MAINLY
06Z-14Z TIME FRAME...DIMINISHING FROM WEST TO EAST THROUGH THE EARLY
MORNING AS THE FRONT MOVES IN.

LATER MORNING/AFTERNOON WE SEE A LITTLE DEEPER MOISTURE STREAM INTO
SOUTHERN PARTS OF THE AREA...AND WILL MAINTAIN CHANCE POPS SOUTH OF
I-90. ANY PRECIP AMOUNTS EXPECTED TO BE ON THE LIGHT SIDE...LESS
THAN 0.05 INCH. PROBLEM IS THAT WARM LAYER ALOFT COULD LEAD TO A MIX
OF PRECIP TYPES. MOST LIKELY RAIN OR A LITTLE SLEET TO START...WITH
TEMPERATURES THROUGH EARLY AFTERNOON EXPECTED TO STILL BE ABOVE
FREEZING IN OUR FAR SOUTHERN AREAS DUE TO WARM AND MOIST SOUTHERLY
FLOW. COULD CHANGE TO A LITTLE LIGHT SNOW AS TEMPERATURES CONTINUE
TO COOL BEHIND THE BOUNDARY/WAVE...BUT DO NOT EXPECT MUCH SNOW
ACCUMULATION DUE TO RELATIVELY SHORT DURATION BEFORE PRECIP BEGINS
TO WIND DOWN. AS FOR TEMPERATURES...HIGHS WILL LIKELY BE SEEN IN THE
MORNING...BELOW FREEZING ALONG AND NORTH OF I-90 WITH READINGS JUST
ABOVE FREEZING TO THE SOUTH. SLIGHT COOLING INTO THE MID-UPPER 20S
FOR MOST THROUGH THE AFTERNOON...ALTHOUGH COOLING CURRENTLY DOES NOT
LOOK QUITE AS SHARP AS EARLIER THOUGHTS...WHICH WILL ALSO MINIMIZE
POTENTIAL FOR ANY FREEZING RAIN.

.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 342 PM CST THU MAR 6 2014

THE FRONTAL BOUNDARY WILL BE WELL TO OUR SOUTH BY FRIDAY
EVENING...AND ANY LINGERING PRECIPITATION WILL BE IN THE FORM OF
SNOW IN OUR FAR SOUTHEAST...WITH ONLY A TENTH OR TWO OF ADDITIONAL
ACCUMULATION. OTHERWISE...WILL HAVE GENERALLY DECREASING CLOUDS
THROUGH THE NIGHT...AND WITH THE BULK OF THE COLDEST AIRMASS
SETTLING INTO THE REGION TEMPERATURES WILL DROP INTO THE LOWER TEENS
THROUGH THE MISSOURI RIVER VALLEY TO MAINLY SINGLE DIGITS ELSEWHERE
ACROSS THE AREA.

HIGH PRESSURE WILL SETTLE INTO THE REGION ON SATURDAY...AND IN AN
EVOLVING SOUTHWESTERLY FLOW BEHIND THE EXITING HIGH PRESSURE
TEMPERATURES WILL BEGIN TO MODERATE IN OUR WEST BY SATURDAY
AFTERNOON. THIS WILL BE REALIZED WITH TEMPERATURES CLIMBING INTO THE
LOWER 40S IN OUR SOUTH CENTRAL SOUTH DAKOTA ZONES...WHILE BACK TO
THE EAST WHERE THERMAL PROFILES ARE COOLER HIGHS WILL REMAIN IN THE
20S. WITH WARM AIR ADVECTION STRENGTHENING ON SATURDAY NIGHT AND
SOUTHERLY WINDS PICKING UP A BIT IN A TIGHTENING GRADIENT...IT WILL
BE A MILDER NIGHT WITH LOWS GENERALLY RANGING FROM THE 20S WEST OF
INTERSTATE 29 TO THE TEENS TO THE EAST.

THE MORE NOTICEABLE WARMING WILL BEGIN ON SUNDAY AND MONDAY AS UPPER
LEVEL RIDGING BUILDS INTO THE REGION AND 925 MB TEMPERATURES
MODERATE INTO THE 10 TO 15 DEGREES C RANGE. READINGS WILL BE
SOMEWHAT DEPENDENT ON THE AMOUNT OF SNOWCOVER IN PLACE BY THAT
POINT...BUT APPEARS THAT HIGHS WILL CLOSE IN ON 60 DEGREES THROUGH
THE MISSOURI RIVER CORRIDOR ON THOSE DAYS...BUT REMAINING IN THE 40S
AROUND AND EAST OF A LINE RUNNING ROUGHLY FROM BROOKINGS TO SPENCER
WHERE SNOW COVER IS DEEPER.

MODELS IN PRETTY DECENT AGREEMENT ON A SHORTWAVE TRACKING THROUGH
THE REGION SOMETIME IN THE TUESDAY TIME FRAME...BRINGING A CHANCE OF
PRECIPITATION TO THE AREA ON MONDAY NIGHT AND TUESDAY. USED A
RAIN/SNOW PRECIP TYPE AT THIS POINT DEPENDENT ON SURFACE
TEMPERATURES...THOUGH CANNOT RULE OUT SOME OTHER TYPE OF MIXED
PRECIPITATION ON MONDAY NIGHT BEFORE TEMPERATURES COOL ALOFT. THIS
WAVE WILL BRING IN COOLER TEMPERATURES FOR TUESDAY AND
WEDNESDAY...THOUGH REMAINING ABOVE NORMAL FOR THIS TIME OF YEAR.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1152 AM CST THU MAR 6 2014

IFR CEILINGS BELOW 1K FEET AND MVFR-IFR VISIBILITY EXPECTED TO
PERSIST BENEATH STRENGTHENING INVERSION ACROSS NORTHWEST IOWA AND
NEARBY AREAS THROUGH MUCH OF THE AFTERNOON. CONTINUED SOUTHERLY FLOW
WILL PULL THE LOW LEVEL MOISTURE BACK NORTHWARD...WITH AREAS OF IFR
CEILINGS AND/OR MVFR-IFR VISIBILITY EXPECTED TO EXPAND BACK INTO
AREAS EAST OF THE JAMES VALLEY THROUGH THE EVENING. WITH THE LOW
STRATUS COULD BE AREAS -FZDZ AS WARM ADVECTION LIFT INCREASES ABOVE
THE INVERSION...AND HAVE ADDED A MENTION OF THIS IN PRE-FRONTAL AIR
MASS AT KFSD/KSUX DURING 06Z-12Z PERIOD.

COLD FRONT WILL DROP SOUTHEAST ACROSS THE AREA DURING THE EARLY
MORNING...FOLLOWED BY PREDOMINANTLY MVFR CEILINGS AND VISIBILITY.
WHILE THE FRONT SHOULD SCOUR OUT THE LOWEST IFR CONDITIONS ALONG AND
EAST OF I-29...MVFR CONDITIONS EXPECTED TO PERSIST AT ALL AREAS
THROUGH THE END OF THE PERIOD. LACK OF MOISTURE BETWEEN LOW STRATUS
AND MID LEVEL CLOUD LAYER SHOULD LIMIT POST-FRONTAL PRECIPITATION
DEVELOPMENT.

OCCASIONAL SOUTHERLY SURFACE GUSTS ABOVE 25 KNOTS EAST OF THE JAMES
RIVER AT THE START OF THE PERIOD EXPECTED TO DIMINISH BY 07/00Z.


&&

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

$$

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