238 
FXUS63 KFSD 011735
AFDFSD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SIOUX FALLS SD
1135 AM CST SUN FEB 1 2015

.UPDATE...
ISSUED AT 1131 AM CST SUN FEB 1 2015

AS EXPECTED...SEEING A GENERAL DECREASE IN SNOW FROM WEST TO
EAST. OBS ARE STILL REPORTING REDUCED VISIBILITIES ALL THE WAY
BACK INTO CENTRAL SOUTH DAKOTA HOWEVER IN BLOWING SNOW...SO IN
COORDINATION WITH SURROUNDING OFFICES DID EXTEND SOME OF OUR
HEADLINES INTO LATE AFTERNOON OR EVENING.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 335 AM CST SUN FEB 1 2015

SNOWSTORM HAS BEEN BEHAVING PRETTY WELL DURING THE NIGHT WITH 
ACCUMULATIONS CONTINUING IN THE WARNING AND ADVISORY AREAS. 
STORM TOTALS SHOULD RANGE FROM AN INCH OR SO EXTREME NORTH TO 
AROUND 7 INCHES SOUTHEAST. EVEN WHILE THERE HAS BEEN A LITTLE 
DROPOFF IN INTENSITY IN SOME AREAS INCLUDING FSD...A MINOR SECONDARY 
SURGE ASSOCIATED WITH WEST NORTHWESTERLY SHORT WAVE APPEARS TO BE 
MERGING IN THE MAIN SNOW AREA AND IS LIKELY TO CAUSE A LITTLE 
RESURGENCE IN INTENSITY. WINDS HAVE PICKED UP AND THE SNOW IS 
DRIFTING PRETTY WELL AT LOW LEVELS...BUT THE BLOWING SNOW DOES NOT 
GET UP REAL HIGH AND  REALLY CUT VISIBILITIES DOWN...SO WILL 
CONTINUE TO HANDLE THAT PART OF THE FORECAST WITH PATCHY BLOWING 
SNOW.

THE CURRENT WARNING AND ADVISORY SETUP IS WORKING OUT WELL AND WILL 
CONTINUE WITH THE SAME. IT DOES APPEAR THAT CONDITIONS WILL IMPROVE 
A LITTLE FASTER WITH THE SNOW ENDING FAIRLY QUICKLY DURING THE 
MIDDLE OF THE DAY. HAVE CHOSEN TO LET THE WARNING FAR SOUTHEAST IN 
NORTHWEST IOWA GO UNTIL 6 PM AS PLANNED...AND WILL LET THE ADVISORY 
OUT WEST GO UNTIL THE CURRENT NOON EXPIRATION. IN BETWEEN...WILL 
MOVE UP THE EXPIRATION TIME OF THE HIGHLIGHTS BY 3 HOURS TO 3 PM 
FROM YKN TO FSD AND IN SOUTHWEST MN. EVENTUALLY WE MAY BE ABLE TO 
CUT THE HIGHLIGHTS EVEN A LITTLE SOONER. SINCE WE ARE NOT DEALING 
WITH A BLIZZARD...HIGHLIGHTS EXTENDING INTO THE TIME OF IMPROVING 
CONDITIONS MAY NOT BE TOO BAD GIVEN THE DRIFTING SNOW AFFECTING 
TRAVEL.

SKIES WILL START TO CLEAR QUICKLY FROM THE NORTH DURING THE MIDDLE 
OF THE DAY AND IT SHOULD BECOME RATHER CLEAR BY EARLY EVENING. 
TEMPERATURES WILL GENERALLY FALL SLOWLY EXCEPT FOR A SMALL RECOVERY 
WEST THIS AFTERNOON AFTER THE BETTER COOLING TAKES PLACE THERE 
THROUGH THIS MORNING. WIND CHILLS WILL CONTINUE TO GO DOWN TO 5 
BELOW SOUTHEAST...AND IN THE TEENS BELOW NORTHWEST BEFORE SLIGHT 
AFTERNOON RECOVERY. 

TONIGHT WILL BRING MOSTLY CLEAR SKIES EXCEPT FOR A START OF WARM 
ADVECTION MID AND HIGH CLOUDS FROM THE WEST LATE. TEMPERATURES WILL 
DROP TO SEVERAL DEGREES BELOW ZERO. WIND CHILLS MIGHT BARELY TOUCH 
20 BELOW IN SOME PLACES LATE WITH THE COOLING. SINCE THESE WIND 
CHILLS WILLS WILL AT WORST GET BARELY AND BRIEFLY TO ADVISORY 
CRITERIA...AND GET THERE BECAUSE OF WIND SPEEDS WHICH WILL HAVE 
DROPPED WELL INTO THE SINGLE DIGITS IN MPH...WILL NOT ISSUE A WIND 
CHILL ADVISORY. ACTUAL LOW TEMPERATURES SHOULD BE IN THE SINGLE 
DIGITS BELOW ZERO...AND THERE COULD BE SOME VERY SLIGHT REBOUNDING OF 
A COUPLE DEGREES FAR WEST BEFORE DAYBREAK AS THE WARM ADVECTION 
CLOUDS START TO ARRIVE.

.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 335 AM CST SUN FEB 1 2015

ACTIVE WEATHER WILL PERSIST INTO THE MIDDLE OF THE WEEK AS A SERIES 
OF SHORTWAVE TRAVERSE THE UPPER LEVEL NORTHWEST INTO THE NORTHERN 
PLAINS.

THE FIRST MINOR SHORTWAVE CLIPS THE NORTHEASTERN HALF OF THE 
FORECAST AREA ON MONDAY AFTERNOON AND EVENING. STRATUS WILL BUILD IN 
AHEAD OF THE WAVE...HOWEVER MID LEVELS LOOK TO REMAIN PRETTY DRY AS 
THE WAVE PASSES THROUGH THE REGION. UPPER LEVEL SUPPORT IS GOOD WITH 
THIS FAST MOVING WAVE...BUT THINK THAT SNOW WILL HAVE A HARD TIME 
MATERIALIZING. THE BEST POTENTIAL FOR ANY PRECIPITATION WILL BE EAST 
OF I29...BUT CHANCES FOR MEASURABLE SNOW ARE VERY SLIM. MODEST 
RETURN FLOW WILL ALLOW TEMPERATURES TO MODERATE SOME...MAINLY IN OUR 
WESTERN HALF. A LARGE RANGE OF HIGHS ACROSS THE FORECAST AREA ARE 
EXPECTED...FROM THE MID TEENS EAST TO NEAR 30 IN SOUTH CENTRAL SD.
 
ANOTHER MID LEVEL WAVE DROPPING ALONG THE NORTHWEST FLOW WILL BRING 
A GREATER POTENTIAL FOR SOME LIGHT SNOWFALL ON TUESDAY. MODELS HAVE 
COME INTO MUCH BETTER AGREEMENT IN DROPPING THE WAVE ACROSS OUR 
NORTHEASTERN HALF. WHILE UPPER SUPPORT IS DECENT...MOISTURE AND 
FRONTOGENETIC LIFT IS MORE IMPRESSIVE THAN MONDAY. A STRONGER WAVE 
DIGS ACROSS THE NORTHERN PLAINS CLOSE ON THE SECOND WAVES HEELS LATE 
TUESDAY NIGHT INTO WEDNESDAY. THIS WAVE TRACKS FURTHER SOUTH NEAR 
THE MISSOURI VALLEY AND I80 CORRIDOR...SO WILL FOCUS SNOW CHANCES IN 
OUR FAR SOUTH. THE GFS IS SOMEWHAT OF AN OUTLIER IN TRACKING WELL 
SOUTH OF THE FORECAST AREA. COLDER AIR FILTERING BACK INTO THE 
REGION WILL PREVENT TEMPERATURES FROM WARMING MUCH FROM TUESDAY 
NIGHT LOWS. HIGHS WILL ONLY BE IN THE TEENS.

UPPER LEVEL RIDGING FINALLY BEGINS TO REBOUND TO OUR WEST ON 
THURSDAY AND FRIDAY...BECOMING MORE ZONAL ON SATURDAY. WITH 
SOUTHERLY RETURN FLOW AND WARM AIR ADVECTION DEVELOPING ON 
THURSDAY...TEMPERATURES MODERATE SOME ON THURSDAY. BUT BY FRIDAY AND 
SATURDAY...READINGS IMPROVE INTO THE 30S AND EVEN SOME 40S IN SOUTH 
CENTRAL SD. EXPECT HIGHS TO BE TEMPERED SOME BY THE RECENT HEAVY 
SNOWFALL...SO LOWERED ALL BLEND HIGHS A FEW DEGREES.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1109 AM CST SUN FEB 1 2015

LIFR/IFR VISBYS AND CEILINGS WILL IMPROVE AFTER 20Z AS SNOW TAPERS
OFF THROUGH THE LATE AFTERNOON. NORTHERLY WINDS WILL DIMINISH TO
LIGHT AND VARIABLE DURING THE EVENING.


&&

.FSD WATCHES/WARNINGS/ADVISORIES...
SD...WINTER STORM WARNING UNTIL 6 PM CST THIS EVENING FOR SDZ061-062-
     065>071.

     WINTER WEATHER ADVISORY UNTIL 3 PM CST THIS AFTERNOON FOR SDZ050-
     052>055-057>060-063-064.

     WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR SDZ056.

MN...WINTER STORM WARNING UNTIL 6 PM CST THIS EVENING FOR MNZ098.

     WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR MNZ080-
     081-089-090-097.

IA...WINTER STORM WARNING UNTIL 6 PM CST THIS EVENING FOR IAZ001>003-
     012>014-020>022-031-032.

NE...WINTER STORM WARNING UNTIL 6 PM CST THIS EVENING FOR NEZ013-014.

&&

$$

UPDATE...JM
SHORT TERM...
LONG TERM...
AVIATION...JM