Area Forecast Discussion
Issued by NWS Sioux Falls, SD

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS63 KFSD 180439
AFDFSD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SIOUX FALLS SD
1039 PM CST MON NOV 17 2014

.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 355 PM CST MON NOV 17 2014

STRONG NORTHWEST WINDS TO GRADUALLY DIMINISH OVER THE EVENING...BUT
NOT LIKELY TO BECOME COMPLETELY CALM. SOME BLOWING AND DRIFTING
STILL POSSIBLE OVER SOUTHWEST MN AND NORTHWEST IA BUT PRETTY
LIMITED. LETTING THE ADVISORY HANG IN THERE THROUGH 6 PM AS A FEW
WEBCAMS STILL SHOW BLOWING AND DRIFTING. LOWS A LITTLE TRICKY
OVERNIGHT WITH CLOUDS TO THE NORTHWEST POSSIBLY MOVING INTO THE AREA
BUT ALSO CONCERNS THAT WINDS WILL DROP PRETTY LOW AND TEMPERATURES
ARE ALREADY GETTING A PRETTY COLD START. SO AIMING FOR ABOUT ZERO TO
5 BELOW IN MOST LOCATIONS BUT COULD SEE SOME THAT DROP OFF MORE THAN
THAT IF CLOUDS AND WIND ARE LESS. LIKELY TO SEE A FEW RECORDS BROKEN
OVERNIGHT AS WELL AS RECORD LOWS ARE PRETTY MINIMAL ON THE 18TH.
ALSO WENT AHEAD AND ISSUED A WIND CHILL ADVISORY AS 10 MPH WINDS
WILL COUPLE WITH THESE COLD TEMPERATURES TO PRODUCE WIND CHILLS OF
20 BELOW TO 25 BELOW ZERO. THE MAIN EFFECTS WILL BE OVER SOUTHWEST
MINNESOTA AND NORTHWEST IOWA.

AFTER A COLD START ON TUESDAY MORNING...TEMPERATURES WILL REBOUND AS
SOUTHWEST WINDS DEVELOP. HOWEVER QUITE A BIT OF CLOUD COVER WILL
MOVE IN AND WITH SNOW COVER TEMPERATURES WILL BE KEPT IN CHECK...BUT
STILL LESS COLD THAN TODAY. HIGHS SHOULD RANGE FROM 15 TO 20 IN
NORTHWEST IOWA TO 30 TO 35 IN SOUTH CENTRAL SD.

.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 355 PM CST MON NOV 17 2014

NEXT IMPULSE IN NORTHWEST FLOW ALREADY NORTH OF THE AREA BY EARLY
TUESDAY EVENING...WITH ANOTHER STRONG COLD FRONT POISED JUST
NORTHWEST OF THE CWA. PULSE OF STRONG COLD AIR ADVECTION WILL
DEVELOP BEHIND THE FRONT DURING THE EVENING...WITH WIND SPEEDS IN
925-900 HPA LAYER INCREASING TO 25 TO 35 KNOTS. ISALLOBARIC
GRADIENT LINES UP DIRECTLY DOWNSTREAM...BUT WEAKENS TO 3-4 HPA/3H
AS SLIDING SOUTHEAST TOWARD EASTERN SOUTH DAKOTA LATE NIGHT. WAVE
DOES BRING ALONG WITH IT A PERIOD OF MOISTURE DEEPENING INTO THE
MID LEVELS...AND GAVE CONSIDERATION TO PUTTING IN A LOW CHANCE
POP FOR LIGHT SNOW ACROSS THE NORTH/EAST DURING THE EVENING.
MAINTAINED ONLY A MENTION OF FLURRIES THE FORECAST GIVEN SHORT
DURATION TO ANY FORCING. ANY BLOWING SNOW SHOULD BE FAIRLY
SPOTTY. WELL MIXED DAY WEDNESDAY WITH CONTINUED PATCHES OF
BLOWING SNOW ESPECIALLY NORTHEAST HALF IN STRONGER GRADIENT.
TEMPS HOVERING AGAIN UPPER TEENS TO MID 20S DURING THE DAY.

NARROW RIDGE EXPANDS ACROSS THE CWA OVERNIGHT...AND WITH RIDGE
PROXIMITY AND WINDOW FOR AT LEAST A CONSIDERABLE CLEARING
PERIOD...HAVE KEPT A COOLISH SIDE TO TEMPS WED NIGHT. FAIRLY QUIET
AIR ACROSS THE AREA THURSDAY WILL PUT ADDITIONAL STRUGGLE TO TEMPS
AS TRY TO WARM...AND SHOULD BE COOLEST DAY OF THE PERIOD FOR MOST.

INCREASING SOUTHERLY GRADIENT IN PLAY FOR THURSDAY NIGHT THROUGH
FRIDAY...LIKELY RESULTING IN NON DIURNAL TREND. WILL BE NEXT
CHANCE OF 30S ACROSS THE SOUTH CENTRAL ON FRIDAY...WITH OTHER
LOCATIONS FINALLY SHAKING THE TEENS OFF. SOME LOWER LEVEL MOISTURE
WILL SEEP NORTHWARD FRIDAY NIGHT AND WILL HAVE TO WATCH FOR
INCREASE IN LOW CLOUDS TO BE ACCOMPANIED BY SOME DRIZZLE/FREEZING
DRIZZLE.

BIGGEST QUESTION HEADING INTO THE WEEKEND AND BEYOND DEALS WITH
EVOLUTION OF THE CENTRAL U.S. TROUGH.  ENSEMBLES ALL OVER THE
PLACE WITH RELATIVE STRENGTH OF NORTHERN STREAM WITH LEADING
WAVE...HOW MUCH ENERGY SPLITS NORTH AND SOUTH...HOW MUCH PHASING
AND WHEN PHASING OCCURS...AND HOW WARM TEMPS ALOFT MAY BE AT TIME
OF MORE SIGNIFICANT CYCLOGENESIS. GENERAL IDEA OF HOLDING BACK
ENERGY TOWARD SECOND WAVE OVER FIRST STILL SEEMS MORE
PLAUSIBLE...MEANING FIRST WAVE SLIDES PAST SATURDAY NIGHT AND
SUNDAY...AND SETS STAGE FOR MORE VIGOROUS DEVELOPMENT ON SUNDAY
NIGHT INTO MONDAY...WITH GREATER IMPACT AT THE MOMENT PERHAPS FOR
THE EAST. HOWEVER ONE LOOKS...TEMPS ALOFT APPEAR TOO WARM BY
SATURDAY NIGHT AND SUNDAY FOR ANY SIGNIFICANT SNOWFALL...AND MORE
LIKELY TO BE A VERY LIGHT LIQUID FORM OF PRECIPITATION DEPENDENT
ON SURFACE TEMPS. A LOT CAN CHANGE BETWEEN NOW AND THEN...AND WILL
PLAY A BIT BROADER ON TYPE THROUGH SUNDAY.  WITH BULK COOLING
OCCURRING WITH SECONDARY SYSTEM AND GREATER TENDENCY FOR MORE
SNOWFALL. TEMP RANGES CLAM UP SOMEWHAT MORE...WITH HIGHS STILL
BELOW NORMAL...BUT LOWS COMING UP A SOLID 10 TO 20 DEGREES FROM
WHERE WE HAVE BEEN RECENTLY.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1037 PM CST MON NOV 17 2014

A FAIRLY WIDESPREAD STRATUS FIELD CONTINUES TO DROP SOUTHWARD
LATER THIS EVENING. MOST OF THESE CEILINGS ARE VFR...BUT COULD SEE
VERY BRIEF REDUCTIONS TO MVFR AT TIMES. ALSO...GIVEN COLD
TEMPERATURES ALOFT...FLURRIES MAY BE POSSIBLE INTO TUESDAY.

CLOUDS MAY THIN BY MID-MORNING WITH MID-LVL CLOUDS AND BACKING
WINDS THROUGH THE DAY. SOME QUESTIONS ON IF WE MAY HAVE A
REDEVELOPED SCATTERED 2-3K FT AGL DECK BY THE AFTERNOON AHEAD OF
AN APPROACHING SHORTWAVE. OTHERWISE...ANOTHER FRONT POISED TO MOVE
THROUGH IN THE EVENING HOURS.

&&

.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...WIND CHILL ADVISORY FROM 4 AM TO 10 AM CST TUESDAY FOR MNZ071-
     072-080-081-089-090-097-098.

IA...WIND CHILL ADVISORY FROM 4 AM TO 10 AM CST TUESDAY FOR IAZ002-
     003-013-014-021-022.

NE...NONE.
&&

$$

SHORT TERM...08
LONG TERM...CHAPMAN
AVIATION...DUX



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.