Area Forecast Discussion
Issued by NWS Sioux Falls, SD

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000
FXUS63 KFSD 231132
AFDFSD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SIOUX FALLS SD
532 AM CST TUE DEC 23 2014

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 320 AM CST TUE DEC 23 2014

MAIN CONCERN TODAY IS SNOW AND WIND ACROSS THE AREA. ALL MODELS
AGREE WITH THE 700 MB THETA AXIS SETTING UP FROM WISCONSIN INTO NW
IA THIS MORNING. AS THE NEXT WAVE LIFTS NORTH TOWARD THE GREAT
LAKES...MOISTURE ADVECTING SOUTHWESTWARD INTO THE TROWAL WILL BE
CUTOFF AND THE TROWAL WILL BEGIN TO WEAKEN THROUGH THE MORNING.
THEREFORE...EXPECT THE GREATEST AMOUNT OF SNOW THIS MORNING IN NW
IA WITH SNOWFALL TAPERING OFF SLOWLY THROUGH THE AFTERNOON AND
EVENING AS THE WARM ADVECTION AND LIFT WEAKENS. ANOTHER AREA OF
SNOW WILL BE ACROSS CENTRAL SD...AGAIN PRIMARILY THIS MORNING.
AGAIN...SNOWFALL WILL BE LIGHT ACROSS THIS AREA. HOWEVER...WINDS
ARE STRONGER WITH GUSTS ALREADY TO 30 KTS AT WINNER SD. SO WHILE
SNOW IS FALLING...THERE WILL BE SOME BLOWING SNOW IN OPEN AREAS.
THIS MAY IMPACT TRAVEL THIS MORNING ALTHOUGH WITH TEMPERATURES
AROUND FREEZING...NOT EXPECTING A LOT OF SNOW TO REMAIN ON TREATED
SURFACES. IN BETWEEN THE SNOW OVER NRN IA AND THE SNOW ALONG AND
WEST OF THE JAMES RIVER...THERE WILL BE VERY LITTLE SNOW...AND
WHAT SNOW THERE IS WILL BE IN THE MORNING. RADAR ALREADY SHOWS
LIMITED SNOWFALL OVER MUCH OF MN AND THIS DRIER AIR IS ADVECTING
SOUTHEAST. WITH SW MN AND MUCH OF SE SD EAST OF THE JAMES RIVER ON
THE WRONG SIDE OF THE FRONTAL CIRCULATION...EXPECT THAT THERE WILL
NOT BE A LOT OF SNOW ACCUMULATION.

SNOWFALL ACCUMULATIONS ARE EXPECTED TO BE FROM 1 TO 2 INCHES
TODAY IN NW IA AND AROUND 2 INCHES IN GREGORY COUNTY WHERE THE
MOST PERSISTENT SNOWFALL WILL BE. FOR MUCH OF SW MN AND EASTERN
SD...SNOWFALL WILL BE LESS THAN AN INCH. AND WITH TEMPERATURES
AROUND FREEZING IN THESE AREAS...A LOT OF THIS SNOW MAY MELT UPON
CONTACT WITH THE GROUND SUCH THAT LITTLE IF ANY SNOW WILL BE LEFT
ON THE GROUND BY THIS EVENING. TEMPERATURES TODAY WILL NOT RISE
MUCH GENERALLY IN THE LOWER TO MID 30S. WITH CLOUDS
OVERNIGHT...TEMPERATURES WILL ALSO NOT FALL MUCH EAST OF THE JAMES
RIVER WHERE MID TO UPPER 20S ARE EXPECTED. ALONG AND WEST OF THE
JAMES RIVER...THERE LOOKS TO BE SOME LATE NIGHT BREAKS IN THE
CLOUDS SO THAT LOWS WILL BE CLOSER TO 20 DEGREES.

.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 320 AM CST TUE DEC 23 2014

A WEAK SURFACE RIDGE SLIDES ACROSS THE REGION FOR WEDNESDAY AND
WEDNESDAY NIGHT...SO WILL SEE WINDS DIMINISHING AS THE GRADIENT
WEAKENS. MODELS HINTING THAT LOW CLOUDS MAY HANG AROUND FOR MUCH OF
THE DAY...THEN DECREASE BY LATE AFTERNOON OR EVENING...THOUGH AT
THAT POINT MID/HIGH CLOUDS WILL BE INCREASING OUT AHEAD OF THE NEXT
SYSTEM SO IT LOOKS TO BE A MOSTLY CLOUDY PERIOD. WITH COOLER AIR
BEING PULLED SOUTHWARD BEHIND THE EXITING LOW PRESSURE TO OUR
EAST...IT WILL BE A COOLER DAY WITH HIGHS RANGING FROM THE UPPER 20S
TO LOWER 30S. AS THE HIGH PRESSURE SLIDES OFF TO THE EAST ON
WEDNESDAY NIGHT WINDS WILL BECOME SOUTHERLY...SO OVERNIGHT
TEMPERATURES WILL NOT FALL A WHOLE LOT...BOTTOMING OUT IN THE LOWER
TO MID 20S.

ON THURSDAY THE NEXT SYSTEM BEGINS TO TAKE SHAPE WITH A SHORTWAVE
EJECTING NORTHEASTWARD OUT OF A WESTERN CONUS UPPER LEVEL TROUGH.
MOST OF THE MODELS DO SEEM TO BE A LITTLE SLOWER IN DEVELOPING
PRECIPITATION OVER OUR AREA THAN PREVIOUSLY...SO DELAYED ONSET OF
PRECIPITATION ACROSS OUR NORTH UNTIL THURSDAY EVENING. DOES APPEAR
THAT DECENT MIDLEVEL FRONTOGENESIS DEVELOPS ACROSS THE AREA ON
THURSDAY NIGHT INTO FRIDAY...SO WILL BE INTERESTING TO WATCH...BUT
AT THIS POINT IT LOOKS LIKE THE SYSTEM WILL DROP 1 TO 3 INCHES OF
SNOW ACROSS THE AREA WITH HIGHEST AMOUNTS THROUGH THE HURON TO LAKE
ANDES CORRIDOR. THURSDAY WILL BE A LITTLE WARMER OUT AHEAD OF THE
APPROACHING SYSTEM...WITH HIGHS IN THE MID AND UPPER 30S. THEN
COOLER AIR BEGINS TO FILTER IN BEHIND THE SYSTEM ON FRIDAY WITH
HIGHS MAINLY IN THE 20S.

FARTHER OUT IN THE EXTENDED...LOOKS TO BE A COOLER PERIOD FOR
SATURDAY THROUGH MONDAY...WITH HIGHS ONLY IN THE TEENS AND 20S AND
LOWS IN THE SINGLE DIGITS AND LOWER TEENS. THERE DOES NOT APPEAR TO
BE ANY SIGNIFICANT SYSTEMS OF NOTE...SO WILL BE MAINLY DRY WITH ONLY
AN OUTSIDE CHANCE OF LIGHT SNOW FOR THE BEGINNING OF THE WEEK.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 532 AM CST TUE DEC 23 2014

LIGHT SNOW IS EXPECTED IN MUCH OF NORTHWEST IOWA AND ALONG AND
WEST OF THE JAMES RIVER THIS MORNING. BOTH AREAS OF SNOW WILL
GRADUALLY DISSIPATE LATE THIS MORNING AND THIS AFTERNOON. WHERE
SNOW IS FALLING VSBYS EXPECTED TO BE FROM 1 TO 3 SM THROUGH MID
MORNING WITH GRADUALLY IMPROVING VSBYS LATE THIS MORNIGN AND EARLY
THIS AFTERNOON AS SNOW COMES TO AN END. IN BETWEEN THESE TWO AREAS
OF SNOW...LITTLE PRECIPITATION EXPECTED. A BRIEF PERIOD OF LIGHT
SNOW THIS MORNING COULD REDUCE VSBYS TO 3SM AND THERE COULD ALSO
BE SOME LIGHT FOG IN SW MN INTO SE SD DURING DAY REDUCING VSBYS
BELOW 6SM. OTHERWISE...LOW CLOUDS EXPECTED TO PERSIST THROUGH 12Z
WED. CIGS WILL GENERALLY BE BELOW 1000 FT THROUGH 00Z WITH A SLOW
IMPROVEMENT ABOVE 1000 FT BETWEEN 00Z AND 12Z.

&&

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

$$

SHORT TERM...SCHUMACHER
LONG TERM...JM
AVIATION...SCHUMACHER


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