Area Forecast Discussion
Issued by NWS Sioux Falls, SD

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000
FXUS63 KFSD 062345
AFDFSD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SIOUX FALLS SD
545 PM CST SAT FEB 6 2016

.SHORT TERM...(THIS EVENING THROUGH MONDAY MORNING)
ISSUED AT 332 PM CST SAT FEB 6 2016

TEMPERATURES THIS AFTERNOON HAVE WARMED INTO THE UPPER 30S TO MID
40S MOST LOCALES...AND HAS HAD EFFECTS ON THE NATURE OF THE SNOW
COVER ACROSS THE AREA...AND PER OBSERVATION AND A COUPLE OF REPORTS
HAS MADE THE TOP LAYER OF SNOW RATHER MUSHY. BECAUSE OF THIS...HAVE
HAD TO REEVALUATE SOME OF OUR THOUGHTS REGARDING HEADLINES WITH THE
UPCOMING SYSTEM ON SUNDAY. IN THE SHORTER TERM...LOOKING AT A
RELATIVELY QUIET NIGHT TONIGHT WITH A UNEVENTFUL COLD FRONT SLIDING
ACROSS THE REGION OVERNIGHT. A COUPLE OF MODELS ACTUALLY TRY TO SPIT
OUT SOME LIGHT PRECIPITATION WITH THIS FEATURE IN THE EVENING OVER
PARTS OF THE AREA...BUT MOISTURE LOOKS TO BE PRETTY LIMITED SO DID
NOT INCLUDE IN THE FORECAST. OTHERWISE...WITH COLD AIR ADVECTION
BEHIND THE FRONT AND A TIGHTENING GRADIENT...WILL SEE
WEST/NORTHWESTERLY WINDS PICK UP LATER TONIGHT. IN SPITE OF THE COLD
AIR ADVECTION...WINDS WILL KEEP TEMPERATURES RELATIVELY MILD TONIGHT
WITH LOWS IN THE UPPER 20S TO LOWER 30S.

OUR ATTENTION THEN TURNS TO THE MORE ACTIVE PERIOD...SUNDAY AND
SUNDAY NIGHT. AN UPPER LEVEL LOW SLIDES INTO THE NORTHERN PLAINS
LATE TONIGHT AND EARLY SUNDAY...THEN TRACKS INTO THE WESTERN GREAT
LAKES REGION BY SUNDAY EVENING. BEHIND THIS FEATURE...A VORT LOBE
SWINGS SOUTHWARD INTO OUR AREA DURING THE DAY ON SUNDAY. WITH
THAT...WINDS AT THE TOP OF THE MIXED LAYER WILL STEADILY INCREASE TO
50 TO 60 KTS...AND WITH MIXING WILL RESULT IN A VERY WINDY
DAY...WITH HIGHEST WINDS IN THE WESTERN PORTIONS OF OUR CWA. THE
VERY STRONGEST WINDS LOOK TO BE THROUGH SOUTH CENTRAL SOUTH
DAKOTA...SO WENT AHEAD AND TRANSITIONED THE CURRENT HIGH WIND WATCH
TO A WARNING FOR THAT AREA DURING THE DAY ON SUNDAY. MODELS HAVE
AGAIN SLOWED DOWN THE ONSET OF SNOW SHOWERS JUST A BIT...PROBABLY
WAITING UNTIL MID DAY TO DEVELOP IN OUR NORTH THEN EXPANDING TO THE
SOUTH AND EAST ACROSS THE CWA DURING THE DAY. THE BETTER SNOW
CHANCES CONTINUE TO RESIDE IN OUR NORTH AND EAST WHERE THE OPTIMAL
FORCING WILL EXIST. THERE IS THE POSSIBILITY THAT SOME OF THE
PRECIPITATION COULD BRIEFLY START AS RAIN IN OUR SOUTH AND WEST
WHERE TEMPERATURES WILL BE IN THE UPPER 30S...BUT SHOULD QUICKLY WET
BULB DOWN AND CHANGE TO SNOW SHORTLY AFTER ONSET. THE LIGHT SNOW
WILL CONTINUE IN OUR EAST THROUGH SUNDAY NIGHT.....THOUGH TOTAL SNOW
ACCUMULATIONS WILL BE LIGHT...TOPPING OUT AROUND 1 INCH THROUGH EAST
CENTRAL SOUTH DAKOTA/SOUTHWESTERN MINNESOTA/AND THE IOWA GREAT LAKES
REGION...THEN TAPERING DOWNWARD TO THE WEST WITH ONLY TRACE AMOUNTS
BACK THROUGH SOUTH CENTRAL SOUTH DAKOTA.

TURNING TO HEADLINES...WITH THE MELTING THAT OCCURRED
TODAY...ELECTED TO REMAIN WITH A BLIZZARD WATCH IN LIEU OF A WARNING
IN OUR NORTHEAST AND FAR EAST FOR SUNDAY AFTERNOON INTO MONDAY
MORNING WITH THE UNCERTAINTY OF HOW MUCH SNOW CAN BE LOFTED SINCE
THE TOP LAYER MAY HAVE CRUSTED OVER IN SOME AREAS. AS FOR HEADLINES
BETWEEN THE AFOREMENTIONED HIGH WIND WARNING IN OUR FAR WEST AND THE
BLIZZARD WATCH IN OUR FAR EAST...CONTEMPLATED THE POSSIBILITY OF A
WINTER WEATHER ADVISORY FOR BLOWING SNOW OVER A GOOD PORTION OF THAT
AREA WITH THE STRONG WINDS...IN SPITE OF MINIMAL SNOWFALL
AMOUNTS...BUT WITH THE MELTING TODAY IT BECOMES EVEN MORE UNCERTAIN
THAT VISIBILITIES CAN BE SUCCESSFULLY REDUCED TO JUSTIFY THIS
HEADLINE. IN LIGHT OF THAT...ISSUED A WIND ADVISORY FOR THE ENTIRE
CWA BETWEEN THE TWO PREVIOUSLY MENTIONED HEADLINES...WITH THE
POSSIBILITY THAT THIS MAY HAVE TO BE UPGRADED TO A WINTER ADVISORY AT
SOME POINT IF THE SNOW BLOWS AROUND MORE THAN EXPECTED.

.LONG TERM...(MONDAY MORNING THROUGH SATURDAY)
ISSUED AT 332 PM CST SAT FEB 6 2016

BY MONDAY....LINGERING SNOW MAY CONTINUE IN THE FAR EASTERN
PORTIONS OF THE CWA...UNTIL VORTICITY AXIS SLIDES EASTWARD BY MID-
DAY. STILL ANTICIPATING NEAR ADVISORY LEVEL WINDS INTO THE MORNING
HOURS OF MONDAY...SO WILL HOLD ONTO PRODUCTS UNTIL MID-DAY.

TUESDAY-FRIDAY...OVERALL SYNOPTIC PATTERN WILL FEATURE A RIDGE OVER
THE WESTERN CWA AND TROUGH OVER THE EASTERN THIRD OF THE CONUS. THIS
WILL PUT THE LOW-LVL THERMAL GRADIENT SQUARELY OVER THE NORTHERN
PLAINS...AND TO SOME DEGREE LEADS TO SOME UNCERTAINTIES WHEN IT
COMES TO PRECIPITATION. COULD EASILY SEE 1 OR 2 EPISODES OF LIGHT
SNOW FORM AS SUBTLE SHORTWAVES CREST THE RIDGE AND AMPLIFY WARM
ADVECTION ALOFT.  CONFIDENCE VERY LOW ON WHERE THESE AXIS WILL
FORM...BUT FEEL POPS MAY BE FOCUSED AROUND WEDNESDAY AND WEDNESDAY
NIGHT ALONG THE BUFFALO RIDGE...AND A SECOND CHANCE AROUND FRIDAY AS
A SLIGHTLY STRONGER WAVE CRESTS THE RIDGE. POPULATED GUIDANCE LOOKS
A TAD LOW...AND IF CONFIDENCE INCREASES ON LOCATION...COULD BE
INCREASED.

AS FAR AS TEMPERATURES ARE CONCERNED...THERE WILL LIKELY BE A
SIGNIFICANT GRADIENT ACROSS THE REGION.  TEMPERATURES IN CENTRAL
MINNESOTA MAY BE IN THE TEENS...WHILE READINGS IN SOUTH CENTRAL
SOUTH DAKOTA COULD CLIMB INTO THE 30S EACH DAY.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 545 PM CST SAT FEB 6 2016

VFR THROUGH 08/00Z EXCEPT CEILINGS WILL LOWER TO 2-3K FEET 9V9 TO
BKX AND NORTHWEST INCLUDING KHON TAF SITE AFTER 07/18Z. SURFACE
GUSTS ABOVE 25 KNOTS FROM THE WEST/NORTHWEST WILL SPREAD OVER THE
AREA FROM THE NORTHWEST AFTER 07/09Z. SURFACE GUSTS WILL INCREASE
TO 40 KNOTS NEAR AND WEST OF THE JAMES RIVER AFTER 07/18Z. NON
CONVECTIVE LOW LEVEL WIND SHEAR WILL ACCOMPANY THE WIND INCREASE
AS WINDS INITIALLY INCREASE MUCH FASTER JUST ABOVE THE SURFACE.


&&

.FSD WATCHES/WARNINGS/ADVISORIES...
SD...WIND ADVISORY FROM NOON SUNDAY TO NOON CST MONDAY FOR SDZ039-
     054>056-060>062-065>071.

     WIND ADVISORY FROM 6 AM SUNDAY TO NOON CST MONDAY FOR SDZ038-052-
     053-058-059-064.

     BLIZZARD WATCH FROM SUNDAY AFTERNOON THROUGH MONDAY MORNING FOR
     SDZ040.

     HIGH WIND WARNING FROM 6 AM TO 9 PM CST SUNDAY FOR SDZ050-057-
     063.

MN...WIND ADVISORY FROM NOON SUNDAY TO NOON CST MONDAY FOR MNZ098.

     BLIZZARD WATCH FROM SUNDAY AFTERNOON THROUGH MONDAY MORNING FOR
     MNZ071-072-080-081-089-090-097.

IA...WIND ADVISORY FROM NOON SUNDAY TO NOON CST MONDAY FOR IAZ001-012-
     020-031.

     BLIZZARD WATCH FROM SUNDAY AFTERNOON THROUGH MONDAY MORNING FOR
     IAZ002-003-013-014-021-022-032.

NE...WIND ADVISORY FROM NOON SUNDAY TO NOON CST MONDAY FOR NEZ013-014.

&&

$$

SHORT TERM...JM
LONG TERM...DUX
AVIATION...


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