275 
FXUS63 KFSD 182052
AFDFSD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SIOUX FALLS SD
252 PM CST THU FEB 18 2016

.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 251 PM CST THU FEB 18 2016

CONCERNS TONIGHT FOCUS ON WINDS ACROSS THE AREA.  CLEARING ACROSS
THE AREA THIS EVENING SHOULD RESULT IN RADIATIONAL
CONDITIONS...THOUGH WILL BE MODIFIED SOME BY STEADY SOUTHEAST WIND.
HRRR CONTINUES TO SUGGEST SHOWERS DEVELOPING AFTER 03Z AND LIFTING
NORTHEAST THROUGH THE AREA.  ANY SHOWERS THAT WOULD DEVELOP WOULD BE
ROOTED AT 8-10K FEET...AND WOULD HAVE VERY DRY AIR TO FALL THROUGH
TO REACH THE SURFACE.  IF THE DOWNDRAFT WAS ABLE TO REACH THE
SURFACE...WOULD LIKELY NEED SOME SORT OF WIND HEADLINE WITH 45-50
KNOTS OF FLOW JUST OFF THE SURFACE.  AS THE TROUGH MOVES THROUGH THE
AREA OVERNIGHT...EXPECT TEMPERATURES TO WARM THROUGH MIXING.  THIS
COMBINED WITH COLD AIR ADVECTION WILL EASILY LEAD TO GUSTS TO 50-60
MPH THROUGH THE EARLY MORNING HOURS.  WENT AHEAD AN ISSUED A HIGH
WIND WARNING FOR PORTIONS OF CENTRAL SOUTH DAKOTA. STRUGGLED WITH
THE EASTERN EDGE OF THE HIGH WIND WARNING...WITH 60+ KNOTS JUST OFF
THE SURFACE BEHIND THE TROUGH. EVENING SHIFT WILL NEED TO KEEP A
CLOSE EYE ON THIS...AND POSSIBLY EXPAND THE HIGH WIND WARNING FOR
EITHER SHOWERS THIS EVENING OR FOR GRADIENT WINDS EARLY FRIDAY
MORNING.  

WINDS ALOFT GRADUALLY DECREASE THROUGH THE DAY ON FRIDAY. HAVE KEPT
WIND ADVISORY GOING AS MIXY ENVIRONMENT WILL CERTAINLY PROMOTE WIND
GUSTS TO 50 MPH THROUGHOUT THE DAY.  AS FOR HIGHS...HAVE MASSAGED
TEMPERATURES BACK SLIGHTLY OVER DEEPER SNOW PACK...BUT MECHANICAL
MIXING WILL STILL KEEP TEMPERATURES QUITE MILD RANGING FROM THE
UPPER 40S THROUGH THE 60S.  WITH WARM AND WINDY CONDITIONS...WILL
HAVE A VERY HIGH FIRE DANGER ACROSS CENTRAL SOUTH DAKOTA. FIRE
DANGER WILL GREATLY IMPROVE AS YOU APPROACH AND MOVE EAST OF THE
JAMES DUE TO MOIST SOIL CONDITIONS AND SNOWPACK.


.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 251 PM CST THU FEB 18 2016

WINDS DIMINISH FAIRLY QUICKLY FRIDAY NIGHT OVER MOST OF THE AREA...
THOUGH GUSTY WEST WINDS WILL PERSIST ALONG/EAST OF THE BUFFALO RIDGE
MUCH OF THE NIGHT. MUCH LIGHTER WINDS EXPECTED SATURDAY AND SATURDAY
NIGHT...THEN PICKING UP AGAIN BEHIND A COOL FRONT WHICH MOVES ACROSS
THE REGION LATE SATURDAY NIGHT/SUNDAY. THIS FRONT MAY BRING SOME
LIGHT PRECIP TO NORTHEAST PORTIONS OF THE REGION LATE SATURDAY NIGHT
INTO SUNDAY MORNING...WITH PRECIP TYPE LIKELY TO BE EITHER RAIN OR
SNOW. MODELS DO INDICATE TEMPERATURES ALOFT ABOVE FREEZING AS ANY
LIGHT PRECIP BEGINS TO MOVE IN SATURDAY NIGHT. HOWEVER...THIS LAYER
ALSO QUITE DRY SO WET-BULB COOLING SHOULD MINIMIZE POTENTIAL FOR
FREEZING PRECIP. LOWS BOTH FRIDAY NIGHT AND SATURDAY NIGHT SHOULD BE
CLOSE TO NORMAL HIGHS FOR THIS TIME OF YEAR...WITH READINGS A COUPLE
OF DEGREES EITHER SIDE OF FREEZING. SATURDAY AHEAD OF THE FRONT WILL
STILL BE A FAIRLY MILD DAY...WITH HIGHS RANGING MID 40S IN SOUTHWEST
MN TO NEAR 60 IN SOUTH CENTRAL SD. COOLER BUT STILL ABOVE NORMAL
TEMPERATURES WILL SETTLE IN BEHIND THE FRONT...WITH MID 30S NORTH TO
MID 40SSOUTH EXPECTED FOR HIGHS ON SUNDAY.

IN THE EXTENDED PERIOD...MONDAY THROUGH THURSDAY...IT GENERALLY
LOOKS ABOVE NORMAL THROUGH THE PERIOD WITH NO ORGANIZED
PRECIPITATION. THE ECMWF...GFS AND GFS ENSEMBLE ALL SHOW A BROAD
UPPER LEVEL NORTHWEST FLOW THROUGH THE PERIOD WITH WEAK WAVES
EMBEDDED IN THE FLOW. THE LACK OF ANY MOISTURE PREVENTS ANY
ORGANIZED PRECIPITATION BUT IT DOES RESULT IN PERIODS WITH
STRONGER WINDS BEHIND COLD FRONTS WHICH MAY ENHANCE THE MIXING.
THE GFS AND GFS ENSEMBLE TEND TO AMPLIFY THESE WAVES AND BRING
COLDER AIR INTO THE EASTERN PLAINS THAN THE OPERATIONAL ECMWF. THE
ECMWF IS MUCH WARMER THROUGH THE PERIOD AND WOULD KEEP
TEMPERATURES ABOVE NORMAL THROUGH NEXT THURSDAY...THE ECMWF
ENSEMBLE MEAN IS EVEN WARMER THAN THE OPERATIONAL ECMWF. BECAUSE
TEMPERATURES ARE SO DEPENDENT ON TIMING OF DIFFERENT FRONTS KEPT
TEMPS BETWEEN THE ECMWF AND GFS ALTHOUGH A LITTLE CLOSER TO THE
ECMWF. SHOULD THE ECMWF VERIFY...HIGHS MUCH OF NEXT WEEK COULD BE
ANOTHER 5 TO 10 DEGREES WARMER THAN FORECAST. EXCEPT FOR A SLIGHT
CHANCE OF LIGHT SNOW WEDNESDAY NIGHT AROUND HIGHWAY 14...THERE IS
NO SNOWFALL EXPECTED THROUGH THURSDAY. THERE WILL BE A SLIGHT
CHANCE OF RAIN IN NORTHWEST IOWA THURSDAY...BUT AGAIN...MOISTURE
IS LACKING SO ANY RAINFALL WOULD BE LIGHT.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1127 AM CST THU FEB 18 2016

VERY WINDY PERIOD. BRISK SOUTHEASTERLY WINDS WILL TRANSITION TO
WESTERLY AFTER 04Z AS A COLD FRONT SHIFTS THROUGH THE AREA. WINDS
WILL INCREASE FURTHER AND BECOME GUSTY BEHIND THE FRONT. IF
SHOWERS DEVELOP WITH THE FRONTAL PASSAGE...POTENTIAL FOR WIND
GUSTS TO REACH HIGH WIND WARNING CRITERIA. FOR NOW...HAVE LOW
LEVEL WIND SHEAR MENTIONED. GUSTY CONDITIONS WILL PREVAIL
THROUGHOUT THE DAY ON FRIDAY. 


&&

.FSD WATCHES/WARNINGS/ADVISORIES...
SD...WIND ADVISORY FROM MIDNIGHT TONIGHT TO 6 PM CST FRIDAY FOR 
     SDZ038>040-052>056-058>062-064>071.

     HIGH WIND WARNING FROM MIDNIGHT TONIGHT TO NOON CST FRIDAY FOR 
     SDZ050-057-063.

     WIND ADVISORY FROM NOON TO 6 PM CST FRIDAY FOR SDZ050-057-063.

MN...WIND ADVISORY FROM 3 AM TO 6 PM CST FRIDAY FOR MNZ071-072-080-
     081-089-090-097-098.

IA...WIND ADVISORY FROM 3 AM TO 6 PM CST FRIDAY FOR IAZ001>003-
     012>014-020>022-031-032.

NE...WIND ADVISORY FROM MIDNIGHT TONIGHT TO 6 PM CST FRIDAY FOR 
     NEZ013-014.

&&

$$

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