FXUS63 KFSD 300933
AFDFSD
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NATIONAL WEATHER SERVICE SIOUX FALLS SD
330 AM CST MON NOV 30 2009
.DISCUSSION...
A RELATIVELY BENIGN PATTERN IN STORE FOR MUCH OF THE UPCOMING
WEEK...WITH ABOVE NORMAL TEMPERATURES FOR THE BEGINNING OF THE
PERIOD AND THEN COOLING DOWN TO NEAR TO SLIGHTLY BELOW NORMAL BY
MIDWEEK. PRESENTLY SEEING A FEW WAA MID CLOUDS ACROSS THE NORTHERN
PLAINS THIS MORNING...THOUGH MODELS HAVE BEEN OVERDOING THE AMOUNT
OF CLOUDS...SO DO NOT THINK WE WILL SEE MUCH IN THE WAY OF CLOUDS
THIS MORNING. COULD SEE AN INCREASE IN HIGH CLOUDS THIS AFTERNOON AS
CIRRUS CURRENTLY OVER THE WESTERN HIGH PLAINS PUSHES TO THE EAST.
OTHERWISE...LOOKS TO BE A MUCH WARMER DAY THAN YESTERDAY AS THE
AIRMASS MODERATES...THOUGH MIXING WILL NOT BE THAT GREAT WITH AN
INVERSION IN PLACE ACROSS THE AREA...BUT EXPECTING HIGHS IN THE
LOWER TO MID 50S WEST TO MID AND UPPER 40S EAST. WILL BE A LITTLE
BREEZY THIS AFTERNOON IN A TIGHTENING GRADIENT AS LOW PRESSURE
SWINGS ACROSS THE UPPER MIDWEST...AND 925 MB WINDS CRANK UP TO
AROUND 25 TO 30 KT...THOUGH WITH LIMITED MIXING HIGHER WINDS WILL BE
SOMEWHAT ELEVATION DEPENDENT.
WINDS WILL DROP OFF TONIGHT...AND WITH CLEARING SKIES WILL BE
ANOTHER GOOD RADIATIONAL NIGHT WITH LOW LYING AREAS DROPPING OFF THE
MOST. LOWS ARE LOOKING TO BE GENERALLY IN THE MID AND UPPER 20S
ACROSS THE CWA.
COLD FRONT STILL ON TRACK TO PUSH THROUGH THE CWA ON
TUESDAY...THOUGH EXACT TIMING SOMEWHAT IN QUESTION WITH MODELS
DIFFERING A BIT. GFS/ECMWF OFFER A SLIGHTLY FASTER SOLUTION THAN THE
NAM...AND THIS COULD MAKE A DIFFERENCE IN TEMPERATURES ON TUESDAY
AFTERNOON. IF THE SLOWER SOLUTION WERE TO VERIFY...COULD BE A LITTLE
WARMER IN OUR EAST THAN CURRENTLY FORECASTED WITH PREFRONTAL MIXING.
ONE CAVEAT TO THIS WOULD BE THE AMOUNT OF HIGH CLOUDINESS PRESENT
OVER THE AREA...WHICH MAY KEEP TEMPERATURES FROM REACHING THEIR FULL
POTENTIAL. RIGHT NOW...HAVE HIGHS A COUPLE OF DEGREES EITHER SIDE OF
50...WITH WARMEST READINGS IN OUR SOUTHEAST.
MUCH COOLER AIR WILL BEGIN TO FILTER INTO THE REGION ON TUESDAY
NIGHT BEHIND THE FRONT...WITH NORTHWESTERLY WINDS PICKING UP WITH
THE FRONTAL PASSAGE. WEDNESDAY IS LOOKING TO BE A RAW DAY AS THE
UPPER/MID LEVEL LOW PRESSURE SWINGS ACROSS THE UPPER MIDWEST...WITH
A GOOD BIT OF CLOUDINESS...GUSTY NORTHWEST WINDS...AND HIGHS ONLY IN
THE LOWER TO MID 30S WITH 925 MB TEMPS AROUND -4 TO -6 C. ENERGY
MOVING AROUND THE BACKSIDE OF THE TROUGH MAY CREATE ENOUGH LIFT TO
KICK OFF A FEW FLURRIES ON WEDNESDAY NIGHT INTO EARLY THURSDAY IN
OUR EAST. STAYED ON THE WARMER SIDE OF GUIDANCE ON WEDNESDAY NIGHT
WITH CLOUDS/WINDS...THOUGH STILL LOOKS TO DROP BACK INTO THE MID AND
UPPER TEENS. THURSDAY LOOKS TO BE THE COLDEST DAY OF THE WEEK AS LOW
LEVEL CAA CONTINUES...AND HIGHS WILL ONLY REACH THE MID TO UPPER
20S. /JM
&&
.AVIATION...
VFR THRU 00Z TUES.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
$$