National Weather Service Weather Forecast Office

• Home
• Site Map
• News
• Organization
• Search for: NWS All NOAA 

000
FXUS63 KFSD 110012
AFDFSD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SIOUX FALLS SD
612 PM CST TUE DEC 10 2013

.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 341 PM CST TUE DEC 10 2013

STILL ON TRACK FOR LIGHT SNOW ACROSS THE AREA LATE THIS AFTERNOON
AND INTO TONIGHT AS A CLIPPER TYPE SHORTWAVE DROPS ACROSS THE REGION
ON A NORTHWESTERLY UPPER LEVEL FLOW. CURRENT SURFACE ANALYSIS
INDICATES A SURFACE TROUGH RESIDING FROM EASTERN NORTH DAKOTA BACK
INTO WESTERN SOUTH DAKOTA...WITH THE ONLY PLACE REPORTING SNOW AT
THIS TIME BEING MOBRIDGE. HI RES MODELS SUGGEST LIGHT SNOW
DEVELOPING IN OUR WESTERN ZONES BETWEEN 22Z TO 23Z...THEN EXPANDING TO
THE EAST THROUGH THE EVENING AS LIFT INCREASES. MODELS HAVE NOT
CHANGED A WHOLE LOT WITH RESPECT TO ORIENTATION OF THE SLIGHTLY
HEAVIER BAND...RUNNING APPROXIMATELY FROM HURON TO SIOUX FALLS TO
SPENCER...WITH AMOUNTS FROM AROUND 1 INCH WEST OF INTERSTATE 29 TO
1.5 TO 2 INCHES THROUGH PORTIONS OF SOUTHWESTERN MINNESOTA THROUGH
THE IOWA GREAT LAKES AREA. PER BUFKIT SOUNDINGS...USED AN AVERAGE OF
A 16:1 SNOW RATIO. DOES APPEAR THAT MODELS ARE A LITTLE QUICKER
EXITING THE LIGHT SNOW OUT OF THE AREA...COMING TO AN END QUICKLY
AFTER 06Z. WILL SEE NORTHWESTERLY WINDS PICK UP TO 10 TO 15 KTS
LATER THIS EVENING WITH THE PASSAGE OF THE SYSTEM...THOUGH FOR THE
MOST PART...IT LOOKS LIKE THE SNOW WILL BE WINDING DOWN BY THE TIME
THE WIND PICKS UP...SO THINK THAT BLOWING SNOW WILL ONLY LOCALIZED.
THERE WILL BE STRONG COLD AIR ADVECTION BEHIND THE SYSTEM...AND
TEMPERATURES WILL PLUNGE TO AROUND 10 BELOW ZERO IN OUR NORTH TO
SINGLE DIGITS BELOW SOUTH. WITH THESE TEMPERATURES AND THE
AFOREMENTIONED WINDS...WAS PRUDENT TO KEEP THE WIND CHILL ADVISORY
GOING ACROSS THE AREA TONIGHT INTO TOMORROW MORNING. DID EXPAND THE
ADVISORY TO INCLUDE OUR LOWER NORTHWESTERN IOWA ZONES AS THEY WILL
ALSO BE MEETING CRITERIA.

ON WEDNESDAY...HIGH PRESSURE BUILDS SOUTHWARD ACROSS THE REGION. IT
WILL BE A VERY COLD DAY WITH 925 MB TEMPERATURES RANGING FROM THE
MID TEENS TO LOWER 20S BELOW ZERO C...AND WENT WITH HIGHS JUST ABOVE
ZERO NORTHEAST TO THE LOWER TEENS SOUTHWEST. WITH A RELAXING
GRADIENT UNDER HIGH PRESSURE...WINDS WILL BE LIGHTER...TRANSITIONING
TO SOUTHERLY BY AFTERNOON AS THE HIGH PRESSURE MOVES OFF TO THE
EAST.

.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 341 PM CST TUE DEC 10 2013

NOT TOO MUCH GOING ON IN THE LONGER TERM...WITH NORTHWESTERLY FLOW
CONTINUING THROUGH THE PERIOD. THUS PRECIPITATION CHANCES LOOK
MINIMAL...WITH JUST A FEW LIGHT QPF EVENTS POSSIBLE. GIVEN THE SNOW
COVER...TEMPERATURES WILL REMAIN BELOW NORMAL THROUGH THE
PERIOD...ALTHOUGH THIS PATTERN WILL FEATURE A FEW RELATIVELY WARMER
DAYS HERE AND THERE IN THE WARM AIR ADVECTION PATTERN AHEAD OF ANY
WAVE EMBEDDED IN THE NORTHWEST FLOW. WEDNESDAY NIGHT INTO THURSDAY
WILL SEE THIS TYPE OF PATTERN...WITH TEMPERATURES LIKELY WARMING
THROUGH AT LEAST THE FIRST HALF OF THE NIGHT. SO AFTER A DAY OF
TEMPERATURES STUCK IN THE SINGLE DIGITS...WEDNESDAY NIGHT SHOULD
ACTUALLY FEATURE LOW TO MID TEENS OVER A MAJORITY OF THE AREA.
THURSDAY WILL BE A MILD DAY ALOFT...BUT WITH SNOW COVER AND NOT THE
BEST MIXING PATTERN...DO NOT THINK WE WILL REALIZE MUCH OF THIS
WARMING AT THE SURFACE. STILL SHOULD SEE HIGHS INTO THE 20S...TO
AROUND 30 ALONG THE MISSOURI RIVER.

OUR NEXT COLD FRONT BEGINS TO WORK ITS WAY SOUTH ON
FRIDAY...ALTHOUGH ANOTHER RELATIVELY WARMER DAY IS EXPECTED WITH
HIGHS IN THE 20S. UPPER SUPPORT WILL MOVE ACROSS THE PLAINS FRIDAY
NIGHT INTO SATURDAY...ALTHOUGH IT IS FAIRLY DISORGANIZED WITH LITTLE
CONNECTION BETWEEN THE NORTHERN AND SOUTHERN STREAMS. THUS AT THIS
TIME WOULD ONLY EXPECT THE POTENTIAL FOR A PERIOD OF FLURRIES OR
LIGHT SNOW FRIDAY NIGHT INTO SATURDAY MORNING. ANOTHER ARCTIC BLAST
WILL PUSH INTO THE AREA SATURDAY INTO SUNDAY. HIGHS BOTH DAYS ARE
ONLY EXPECTED TO BE IN THE SINGLE DIGITS AND TEENS...WITH SUNDAY THE
COLDER OF THE TWO. OPERATIONAL MODELS ARE IN PRETTY GOOD AGREEMENT
NOW ON THE COLD TEMPERATURES SUNDAY...ALTHOUGH THIS IS STILL THE DAY
FEATURING THE LARGEST SPREAD AMONG ENSEMBLE MEMBERS. SO NOT
COMPLETELY OUT OF THE QUESTION IT ENDS UP WARMER THAN THE CURRENT
FORECAST...BUT THE COLDER SOLUTIONS SEEM MORE LIKELY AT THIS POINT.
COULD BE AN AREA OF LIGHT SNOW ALONG THE MID LEVEL FRONTAL BOUNDARY
SATURDAY NIGHT INTO SUNDAY...WITH CURRENT INDICATIONS HINTING AT
AREAS ALONG OR WEST OF THE MISSOURI RIVER HAVING THE BEST CHANCE.
LOWS BELOW ZERO SATURDAY NIGHT AND A BRISK NORTHWESTERLY WIND COULD
BRING WIND CHILLS INTO ADVISORY CRITERIA...ESPECIALLY ACROSS
SOUTHWEST MINNESOTA...SO SOMETHING TO KEEP AN EYE ON. EXPECT A SLOW
WARMING TREND TO BEGIN MONDAY INTO TUESDAY...ALTHOUGH SNOW COVER
SHOULD KEEP HIGHS MAINLY IN THE 20S.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 611 PM CST TUE DEC 10 2013

BROAD BAND OF SNOWFALL FEATURING MVFR TO IFR VISIBILITIES AND MVFR
TO VFR CEILINGS ACROSS THE AREA THIS EVENING...WITH MAIN AXIS WEST
NORTHWEST TO EAST SOUTHEAST THROUGH KFSD. MAIN PV AND FRONTAL SUPPORT
EXISTS FROM KFSD AREAS EAST AND SOUTHEAST FOR THE NEXT 2-5 HOURS...
WITH PRECIP ALREADY DROPPING OFF AROUND KHON...ALONG WITH CEILINGS
LIFTING INTO VFR RANGE. LOW LEVEL CONVERGENCE WITH FRONTAL ZONE
EXHIBITING A NARROW BAND OF HIGHER REFLECTIVITY...AND LIKELY TO
GET ANOTHER SHOT AT A 1-2SM VISIBILITY FOR A BRIEF TIME AS WIND
SHIFT MOVES THROUGH...AROUND 02Z AT KHON...04Z AT KFSD...AND
TOWARD 06Z AT KSUX. WINDS WILL SHIFT SHARPLY TO 330 TO 350 DEGREES
BEHIND BOUNDARY...AND INCREASE WITH GUSTS TO 25 TO 30 KNOTS FOR A
SHORT TIME. THIS SHOULD CREATE SOME POCKETS OF BLOWING SNOW...BUT
SHOULD NOT GET VISIBILITIES TO DROP INTO MVFR RANGE...OR IF SO FOR
VERY LONG.

&&

.FSD WATCHES/WARNINGS/ADVISORIES...
SD...WIND CHILL ADVISORY FROM 3 AM TO 10 AM CST WEDNESDAY FOR
     SDZ052>054-057>071.

     WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO NOON CST WEDNESDAY
     FOR SDZ038>040-055-056.

MN...WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO NOON CST WEDNESDAY
     FOR MNZ071-072-080-081-089-090-097-098.

IA...WIND CHILL ADVISORY FROM 3 AM TO 10 AM CST WEDNESDAY FOR
     IAZ001>003-012>014-020>022-031-032.

NE...WIND CHILL ADVISORY FROM 3 AM TO 10 AM CST WEDNESDAY FOR NEZ013-
     014.

&&

$$

SHORT TERM...JM
LONG TERM...CHENARD
AVIATION...CHAPMAN