Area Forecast Discussion
Issued by NWS Sioux Falls, SD

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000
FXUS63 KFSD 232053
AFDFSD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SIOUX FALLS SD
253 PM CST FRI JAN 23 2015

.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 252 PM CST FRI JAN 23 2015

NOT MUCH GOING ON THROUGH MIDDAY SATURDAY EXCEPT FOR MILD AIR
CONTINUING. NORTHWESTERLY FLOW OF SURFACE AIR WILL GRADUALLY BACK TO
A WESTERLY DIRECTION LATER TONIGHT...AND GENERALLY MAINTAIN THAT
DIRECTION THROUGH THE DAY SATURDAY. THEREFORE CONTINUED TO FOLLOW
THE WARMER GUIDANCE VALUES FOR LOWS TONIGHT WHICH WERE GENERALLY THE
ECMWF AND GEM BIAS CORRECTED READINGS. ON SATURDAY...THE NEXT WELL
ADVERTISED SHORT WAVE BEGINS TO INFLUENCE THE WEATHER IN OUR
FORECAST AREA BY AFTERNOON. PRECIPITATION WILL BEGIN IN OUR
NORTHWEST ZONES WHERE SATURATION IS REACHED FIRST...THEN HEAD TO THE
SOUTHEAST TO GIVE SLIGHT CHANCE OF CHANCE POPS TO ALL ZONES TOWARD
EVENING EXCEPT IN OUR FAR EAST. FURTHER WEST...BUMPED UP THE POPS TO
THE LIKELY CATEGORY IN OUR NORTHWEST ZONES WHERE LIGHT RAIN MAY
MEASURE A BIT OVER FIVE HUNDREDTHS ON AN INCH. HIGH TEMPERATURES ON
SATURDAY STILL LOOK TO BE VERY MILD...HOWEVER AN INCREASE IN CLOUD
COVER THROUGH THE AFTERNOON HOURS MAY PUT THE BRAKES ON TEMPERATURES
RISING A LOT AFTER MIDDAY WHEN COMPARED TO TODAY. ONCE AGAIN...THE
ECMWF AND GEM BIAS CORRECTED VALUES ARE LIKELY TO BE THE MOST
ACCURATE AS MANY GUIDANCE VALUES ARE TOO COLD GIVEN THE FORECAST
925MB TEMPERATURES.


.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 252 PM CST FRI JAN 23 2015

WILL BE WATCHING A WAVE MOVE ACROSS THE REGION SATURDAY NIGHT INTO
SUNDAY. MODELS HAVE COME INTO BETTER AGREEMENT...ALTHOUGH STILL SOME
DIFFERENCES. NAM IS AN OUTLIER AND WAS NOT USED. AT THIS TIME FEEL A
BLEND OF THE GFS...ECMWF AND GEM GIVES THE MOST PROBABLE SOLUTION.
WENT AHEAD AND INCREASED POPS...AS LIFT AND SATURATION APPEAR ENOUGH
TO AT LEST GET SOME LIGHT QPF. WOULD EXPECT MOST OF THE
PRECIPITATION TO FALL SATURDAY EVENING INTO THE NIGHT...ALTHOUGH
SOME LINGERING VERY LIGHT PRECIPITATION SEEMS POSSIBLE SUNDAY
MORNING. WARM LAYER WILL BE BASED AT THE SURFACE...AND SEEMS LIKE A
RAIN OR SNOW SITUATION. GFS SEEMED TOO COLD DUE TO BOUNDARY LAYER
ISSUES. THUS WEIGHTED SURFACE TEMPERATURES TOWARDS THE ECMWF AND GEM
AND DERIVED PRECIPITATION TYPE FROM THAT. WOULD EXPECT SOUTHWEST
MINNESOTA TO FIRST MIX WITH SNOW IN THE EVENING...WITH THE
TRANSITION PUSHING SOUTHWEST THROUGH THE NIGHT. AT THIS TIME SEEMS
LIKE THE MIX AND CHANGEOVER WOULD NOT GET TO SIOUX FALLS UNTIL 3 AM
OR SO. AREAS ALONG THE MISSOURI RIVER WILL PROBABLY STAY ALL RAIN.

SNOWFALL AMOUNTS ARE EXPECTED TO BE LIGHT...WITH 1 TO 2 INCHES
POSSIBLE NORTHEAST OF A BROOKINGS TO SPIRIT LAKE LINE. FURTHER
SOUTHWEST...INCLUDING SIOUX FALLS...THINKING LESS THAN A HALF INCH.
OF COURSE WILL NEED TO MONITOR TRENDS. IF THE SYSTEM CONTINUES TO
TREND DEEPER...COULD SEE A QUICKER CHANGEOVER TO LIGHT SNOW FURTHER
SOUTHWEST...WHICH COULD RESULT IN THE 1 INCH LINE PUSHING CLOSER TO
SIOUX FALLS. BUT AT THIS TIME THIS SEEMS UNLIKELY. DID TREND HIGHS
DOWN ON SUNDAY...WITH LOW 30S TO LOW 40S EXPECTED.

THE STORY NEXT WEEK WILL BE THE WELL ABOVE NORMAL TEMPERATURES AS
UPPER RIDGING BEGINS TO BUILD IN. MONDAY AND WEDNESDAY SHOULD BE THE
WARMEST...WITH 40S AND 50S LIKELY. STAYED ON THE WARMER SPECTRUM OF
GUIDANCE...BUT WOULD NOT BE SURPRISED IF MONDAY AND OR WEDNESDAY END
UP EVEN A BIT WARMER...WITH WIDESPREAD 50S NOT OUT OF THE QUESTION.
MODELS ARE ABOUT A DAY QUICKER TODAY WITH SOME TROUGHING MOVING BACK
INTO THE PLAINS. THIS COULD RESULT IN A LITTLE LIGHT RAIN
WEDNESDAY. WILL KEEP THE FORECAST DRY FOR NOW UNTIL BETTER
CONSISTENCY DEVELOPS. BUT DOES LOOK COLDER BEHIND THIS WAVE FOR
THURSDAY INTO FRIDAY. EXPECT HIGHS TO RETURN INTO THE 30S...ALTHOUGH
STILL PROBABLY ABOVE NORMAL. A NORTHERN STREAM WAVE COULD BRING OUR
NEXT DECENT THREAT OF LIGHT SNOW BY FRIDAY OR FRIDAY NIGHT.


&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1137 AM CST FRI JAN 23 2015

VFR IS EXPECTED THROUGH THE TAF PERIOD ENDING 18Z SATURDAY.


&&

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

$$

SHORT TERM...MJ
LONG TERM...CHENARD
AVIATION...MJ



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