National Weather Service Raw Text Product

098 
FXUS63 KFSD 160405
AFDFSD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SIOUX FALLS SD
1105 PM CDT TUE APR 15 2014

.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 352 PM CDT TUE APR 15 2014

SOUTHERLY FLOW INCREASING ACROSS THE AREA FROM WEST TO EAST AND 
EXPECT STOUT FLOW TO REMAIN ACROSS THE FORECAST AREA THROUGH THE 
OVERNIGHT. WITH THE WARM BUT DRY AIR ACROSS THE AREA...HAVE KEPT 
FORECAST LOWS QUITE MILD BUT HAVE SHAVED OFF A FEW DEGREES FROM THE 
PREVIOUS FORECAST.  STILL ABOVE MOST GUIDANCE IN THE UPPER 30S AND 
LOWER 40S.  EXPECT LOWS ACROSS SOUTHWEST MINNESOTA EARLY...WITH 
RISING TEMPERATURE MUCH OF THE NIGHT AS WARM FRONT LIFTS NORTH. 

STRONG COLD FRONT IS EXPECTED TO WORK THROUGH THE AREA ON 
WEDNESDAY.  EXPECT TO SEE FALLING TEMPERATURES BEHIND THE FRONT. AM 
WEAKLY UNSTABLE BEHIND THE FRONT WHICH MAY LEAD TO SOME SCATTERED 
SHOWERS ACROSS NORTHWEST IOWA. EXPECT THIS PRECIPITATION TO MAINLY 
BE RAIN...BUT FURTHER TO THE NORTH ALONG THE HIGHWAY 14 CORRIDOR 
TEMPERATURE PROFILES GET COLD ENOUGH TO SUPPORT SNOW.  THIS 
PRECIPITATION FURTHER TO THE NORTH IS MORE SYNOPTICALLY DRIVEN 
FOLLOWING THE 700 MB FRONTOGENETIC BAND SHIFT FROM WEST TO EAST 
ALONG AND NORTH OF I-90. UPPER LEVEL DIV Q QUICKLY SHIFTS EAST 
THROUGH THE AFTERNOON HOURS...SO EXPECT PROFILES TO START DRYING OUT 
FROM WEST TO EAST THROUGH THE MID AND LATE AFTERNOON HOURS. AS FOR 
SNOWFALL ACCUMULATIONS...HAVE SHIFTED THE HEAVIEST SNOWFALL BACK TO 
THE WEST SLIGHTLY TOWARDS THE BROOKINGS AREA WHERE AN INCH OR TWO OF 
SNOWFALL IS POSSIBLE.  HAVE MENTION OF SNOWFALL FURTHER TO THE 
SOUTH...BUT NO ACCUMULATIONS IN THE GRIDS AS WARMER SOIL 
TEMPERATURES SHOULD LIMIT ACCUMULATION POTENTIAL.

.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 352 PM CDT TUE APR 15 2014

LOW PRESSURE WILL CONTINUE TO EXIT THE AREA WEDNESDAY EVENING. 
PROBABLY WILL SEE A LITTLE LIGHT SNOW OR RAIN LINGER ACROSS PORTIONS 
OF SOUTHWEST MINNESOTA AND NORTHWEST IOWA IN THE EVENING...ALTHOUGH 
NOT EXPECTING MUCH MORE THAN AN ADDITIONAL COATING TO FEW TENTHS OF 
ACCUMULATION. MODELS SEEM TO BE A LITTLE QUICKER TO SCOUR OUT THE 
LOW LEVEL MOISTURE THURSDAY NIGHT...AND LATEST INDICATIONS ARE THAT 
EITHER THE MOISTURE WILL BE TOO SHALLOW...OR THAT CLOUDS DISSIPATE 
ALTOGETHER LATER THURSDAY NIGHT...THUS REMOVED THE FREEZING DRIZZLE 
AND FLURRY MENTION AFTER MIDNIGHT. ALTHOUGH WILL NEED TO CONTINUE TO 
MONITOR.

MODELS ALREADY BEGIN TO DIVERGE THURSDAY INTO FRIDAY. ECMWF
AND GEM ARE QUICKER BUILDING IN THE RIDGING ALOFT...WITH THE NAM AND
GFS STRONGER WITH NORTHERN STREAM WAVE AND THUS MORE SUPPRESSED WITH
THE RIDGE. BASED ON RECENT PERFORMANCE...AND THE FACT THAT RUN TO RUN
CONSISTENCY HAS INCREASED WITH THE ECMWF AND GEM...WILL LEAN TOWARDS
THE INTERNATIONAL MODEL SOLUTION. SO WHILE THE NAM AND GFS SHOW SOME
PRECIPITATION THURSDAY INTO FRIDAY...BELIEVE THE WEAKER WAVE AND
FURTHER NORTH FRONTAL BOUNDARY WILL PREVENT US FROM SEEING MUCH IN
THE WAY OF PRECIPITATION. THUS DECIDED TO REMOVE POPS FOR
NOW...ALTHOUGH NOT OUT OF THE QUESTION WE SEE A FEW LIGHT SHOWERS
THURSDAY NIGHT INTO FRIDAY SOMEWHERE IN THE CWA. THIS COULD EITHER BE
IN THE FORM OF RAIN OR SNOW...BUT EVEN IF IT DID OCCUR AMOUNTS SHOULD
BE MINIMAL. THURSDAY WILL SEE HIGHS IN THE 40S...SO EVEN WITH PARTLY
TO MOSTLY SUNNY SKIES IT WILL BE A CHILLY ONE. IN GOING WITH THE
ECMWF AND GEM SOLUTIONS AS MENTIONED ABOVE...WENT AHEAD AND WARMED
HIGHS SEVERAL DEGREES ON FRIDAY INTO THE 50S AND 60S.

OUR NEXT CHANCE OF PRECIPITATION WILL COME ON SATURDAY INTO SATURDAY 
NIGHT...AS AN UPPER WAVE AND COLD FRONT PUSHES ACROSS THE AREA. 
LOOKS LIKE DECENT MOISTURE WILL BE ADVECTED NORTH AHEAD OF THE 
FRONT...WITH PWAT VALUES 1 TO 2 STANDARD DEVIATIONS ABOVE NORMAL. 
FORCING SHOULD BE ENOUGH TO THUS GET SOME SHOWERS OUT OF THIS SYSTEM 
SATURDAY INTO SATURDAY NIGHT. WE DO GET SOME ELEVATED INSTABILITY 
INTO EXTREME SOUTHEAST SOUTH DAKOTA AND NORTHWEST IOWA...SO COULD 
VERY WELL SEE SOME THUNDER THERE. WITH INSTABILITY AND SHEAR BOTH 
WEAK...SEVERE WEATHER IS NOT ANTICIPATED. FOR NOW WILL JUST KEEP THE 
CHANCE POPS...WITH SOME UNCERTAINTY ON COVERAGE OF SHOWER 
ACTIVITY...ESPECIALLY GIVEN THE LACK OF INSTABILITY...BUT IF MODEL 
CONSISTENCY CONTINUES TO GROW WILL EVENTUALLY NEED TO RAISE THESE 
POPS. DID WARM HIGHS SATURDAY...AS LOOKS LIKE WE SHOULD WARM AHEAD 
OF THE FRONT INTO THE 50S AND 60S. IN FACT AM PROBABLY NOT WARM 
ENOUGH IN OUR EAST...WHERE WOULD NOT BE TOO SURPRISED IF WE SEE SOME 
70S. BUT GIVEN UNCERTAINTY IN FRONTAL TIMING AND CLOUD AND SHOWER 
COVERAGE...FELT TRENDING UP WAS GOOD ENOUGH FOR NOW.

SUNDAY INTO TUESDAY LOOKS DRY...WARM AND MOSTLY SUNNY. DID BUMP 
HIGHS UP SOME OVER CONSENSUS FOR EACH DAY WITH 60S AND 70S EXPECTED. 
SO SHOULD BE A PLEASANT END OF THE WEEKEND AND EARLY NEXT WEEK. 
BASED ON FORECAST 925 MB TEMPERATURES...MAY EVEN NEED TO NUDGE HIGHS 
UP A BIT MORE AS WE GET CLOSER. KEPT TUESDAY DRY FOR NOW...BUT AS A 
STRONG UPPER TROUGH MOVES FROM THE WEST COAST INTO THE 
PLAINS...WOULD EXPECT THE SHOWER AND THUNDERSTORM THREAT TO INCREASE 
FROM LATER TUESDAY INTO MID WEEK. BUT BEING THAT FAR OUT...TIMING 
AND DETAILS ARE HARD TO PIN DOWN AT THIS POINT.

&&

.AVIATION...(FOR THE 06 TAFS THROUGH 06Z WEDNESDAY EVENING)
ISSUED AT 1105 PM CDT TUE APR 15 2014

GUSTY SOUTHEAST WINDS WILL BECOME WEST-NORTHWESTERLY AS LOW PRESSURE 
MOVES THROUGH THE REGION TONIGHT AND WEDNESDAY. LOW LEVEL JET ACROSS 
THE SOUTHEAST HALF OF THE FORECAST AREA WILL RESULT IN POTENTIAL FOR 
LOW LEVEL WIND SHEAR AT KSUX/KFSD OVERNIGHT.

VFR CONDITIONS ARE EXPECTED AHEAD OF THE LOW PRESSURE...AND AS TEMPS
SURFACE AND ALOFT COOL BEHIND THE SYSTEM WEDNESDAY....MVFR CEILINGS
WILL DEVELOP. PERIODS OF MVFR VISIBILITY ALSO LIKELY IN RAIN/SNOW
SHOWERS...PARTICULARLY NEAR AND NORTH OF I-90 CORRIDOR. SURFACE
TEMPERATURES HOLDING JUST ABOVE FREEZING SHOULD MINIMIZE ANY SNOW 
ACCUMULATION OR ICING ON RUNWAYS/TARMACS. GRADUAL IMPROVEMENT TO VFR 
EXPECTED AFTER 17/00Z.

&&

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

$$

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