231 
FXUS63 KFSD 021654
AFDFSD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SIOUX FALLS SD
1054 AM CST SUN MAR 2 2014

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 326 AM CST SUN MAR 2 2014

WITH SNOW OUT OF THE PICTURE...THE OBVIOUS FEATURE FOR TODAY IS THE 
RECORD COLD. ARCTIC AIR AND SNOW COVER PRETTY MUCH GUARANTEES SOME 
DAILY RECORD LOW MAXIMUMS WITH ACTUAL HIGHS AT OR A LITTLE BELOW 
ZERO. ENOUGH WIND WILL REMAIN TO KEEP THE WIND CHILL WARNING AND 
ADVISORY THROUGH THIS MORNING AND THE ADVISORY EAST OF THE JAMES 
RIVER THROUGH THE DAY. WILL KEEP THESE HIGHLIGHTS AS WE HAVE HAD 
THEM...USING THE DISCRETION THAT WHILE WIND CHILLS WILL TECHNICALLY 
STAY AT ADVISORY LEVELS INTO TONIGHT...AT LEAST IN THE EAST...WINDS 
WILL GET QUITE LIGHT...BUT THIS CAN BE REVISITED DURING THE DAY. 
PATCHY MID CLOUDS MOVING OVER THE AREA SHOULD GENERALLY 
DECREASE...THOUGH SOME MORE MAY MOVE OVER THE SOUTHWEST CORNER OF 
THE AREA LATER. FOR TONIGHT...TEMPERATURES WILL DROP TO QUITE COLD 
LEVELS AGAIN...10 TO 20 BELOW...WITH THOSE LIGHT WINDS...ALTHOUGH 
SOME LEVELING OFF AND A LITTLE WARMING SHOULD TAKE PLACE WEST LATE 
TONIGHT AS WEAK LOW LEVEL WARM ADVECTION STARTS. ALSO...CLOUDS ARE 
EXPECTED TO INCREASE AGAIN FROM THE WEST LATE TONIGHT...THOUGH NO 
PRECIPITATION SHOULD THREATEN WITH LITTLE OR NO LIFT AND DRY AIR 
BELOW THE MID LEVELS.  

.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 326 AM CST SUN MAR 2 2014

BIGGEST CHALLENGE FOR MONDAY IS HOW MUCH WE CAN WARM WITH FRESH SNOW
COVER. GFS AND ECMWF SHOW FAIR AMOUNT OF WARMING INTO OUR WESTERN CWA
DURING THE AFTERNOON AND QUESTION IS HOW MUCH OF THAT WILL TRANSLATE
TO THE SURFACE. GIVEN THE FRESH SNOW...NOT ONLY IN PLACE BUT
UPSTREAM...ALONG WITH SOUTHEASTERLY LOW LEVEL FLOW BENEATH THE
INVERSION...OPTED TO STICK CLOSER TO COOLER GUIDANCE VALUES. THIS
GIVES UPPER SINGLE DIGITS IN OUR EAST AND UPPER TEENS IN THE FAR
SOUTHWEST...BUT POTENTIAL IS THERE FOR READINGS ABOUT 5-7 DEGREES
WARMER IF BOUNDARY LAYER MIXING IS DEEPER THAN ANTICIPATED.
 
MONDAY NIGHT WAVE LOOKS TO TRACK A LITTLE FARTHER NORTHEAST THAN 
EARLIER RUNS...SO HAVE TRIMMED BACK POPS THERE TO JUST A SLIGHT 
CHANCE IN OUR FAR NORTHEAST. BIGGER CHANGE IN PRECIPITATION CHANCE 
IS FOR TUESDAY/TUESDAY NIGHT PERIOD THOUGH. 02/00Z RUNS OF BOTH GFS 
AND ECMWF HAVE TRENDED FASTER WITH THE STRONGER WAVE TRACKING ACROSS 
THE REGION...RESULTING IN LIGHT SNOW ZIPPING THROUGH DURING THE DAY 
ON TUESDAY...FOLLOWED BY DRYING CONDITIONS TUESDAY NIGHT. MOISTURE 
AND LIFT ALSO FOCUSED A LITTLE FARTHER NORTHEAST THAN WITH PREVIOUS 
TUESDAY NIGHT WAVE...SO HAVE HIGHEST POPS NORTHEAST OF KMHE-KSLB 
LINE WITH JUST SLIGHT CHANCE INTO THE MISSOURI VALLEY. STILL LOOKS 
LIKE RELATIVELY LIGHT AMOUNTS...AROUND AN INCH OR LESS FROM EAST 
CENTRAL SD INTO SOUTHWEST MN. TEMPS JUST SLIGHTLY WARMER THAN 
MONDAY...WITH HIGHS GENERALLY MID TEENS TO LOWER 20S.

LONGER RANGE WEDNESDAY THROUGH SATURDAY STILL PLAGUED BY LACK OF 
MODEL CONSENSUS REGARDING TIMING/STRENGTH OF MID-UPPER LEVEL WAVES 
IN FAST WEST-NORTHWEST FLOW. FAIR AGREEMENT IN KEEPING DRY WEATHER 
IN OUR AREA THROUGH WEDNESDAY AS SHARPER WAVE SLIDES THROUGH WESTERN 
NEBRASKA AND KEEPS PRECIP CHANCE FOCUSED SOUTHWEST OF US. WEDNESDAY 
NIGHT AND THURSDAY SEES A STRONGER TROUGH MOVING ACROSS THE CANADIAN 
PRAIRIES...WITH SOME QUESTION HOW FAR SOUTH INTO THE NORTHERN PLAINS 
ANY WEAKER ENERGY WILL TRACK. OPTING TO LEAVE THESE PERIODS ON THE 
DRIER SIDE AS WELL...WITH JUST SOME SMALL POPS IN OUR FAR NORTH. 
LOOKS A LITTLE BETTER FOR SOME ENERGY SLIDING FARTHER SOUTH INTO OUR 
AREA THURSDAY NIGHT OR FRIDAY...THOUGH STILL SOME TIMING DIFFERENCES 
SO WILL KEEP POPS ON THE LOW SIDE IN 20-30 PERCENT RANGE...FOLLOWED 
WITH DRYING BY SATURDAY. AS FAR AS TEMPERATURES...THURSDAY CONTINUES 
TO LOOK LIKE WARMEST DAY...THOUGH DIFFERENCES IN TIMING NOTED ABOVE 
LEAD TO COOLER GFS THAN PREVIOUS RUNS/CONSENSUS. WILL STICK WITH 
WARMER TREND OF HIGHS IN 30S/40S FOR NOW...BUT THIS REMAINS A PERIOD 
OF UNCERTAINTY. FRIDAY/SATURDAY STILL LOOK GOOD WITH COOLER HIGHS IN 
THE 20S AND 30S...THOUGH STILL RELATIVELY MILD COMPARED TO THE START 
OF THE WEEK.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1053 AM CST SUN MAR 2 2014

VFR CONDITIONS EXPECTED THROUGH THE PERIOD. LIGHT NORTHERLY WINDS
TODAY WILL TRANSITION TO LIGHT SOUTHERLY TOMORROW WITH INCREASING
HIGH CLOUDS.

&&

.FSD WATCHES/WARNINGS/ADVISORIES...
SD...WIND CHILL ADVISORY UNTIL 6 PM CST THIS EVENING FOR SDZ061-062-
     066-067-070-071.

     WIND CHILL ADVISORY UNTIL NOON CST TODAY FOR SDZ050-057>060-
     063>065-068-069.

     WIND CHILL WARNING UNTIL NOON CST TODAY FOR SDZ038>040-052>056.

     WIND CHILL ADVISORY UNTIL 6 PM CST THIS EVENING FOR SDZ039-040-
     055-056.

MN...WIND CHILL ADVISORY UNTIL 6 PM CST THIS EVENING FOR MNZ098.

     WIND CHILL WARNING UNTIL NOON CST TODAY FOR MNZ071-072-080-081-
     089-090-097.

     WIND CHILL ADVISORY UNTIL 6 PM CST THIS EVENING FOR MNZ071-072-
     080-081-089-090-097.

IA...WIND CHILL ADVISORY UNTIL 6 PM CST THIS EVENING FOR IAZ001-012-
     020-031.

     WIND CHILL WARNING UNTIL NOON CST TODAY FOR IAZ002-003-013-014-
     021-022-032.

     WIND CHILL ADVISORY UNTIL 6 PM CST THIS EVENING FOR IAZ002-003-
     013-014-021-022-032.

NE...WIND CHILL ADVISORY UNTIL 6 PM CST THIS EVENING FOR NEZ013-014.

&&

$$

SHORT TERM...
LONG TERM...JH
AVIATION...CHENARD