FXUS63 KIND 101936
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
236 PM EST THU DEC 10 2009

.DISCUSSION...

FORECAST FOCUS IS ON TEMPERATURES EARLY THEN ON PRECIPITATION TYPE 
SATURDAY NIGHT.

AT 18Z LOW PRESSURE WAS ACROSS SOUTHEAST CANADA WHILE HIGH PRESSURE 
WAS ACROSS OKLAHOMA AND ARKANSAS. THE PRESSURE GRADIENT BETWEEN 
THESE TWO WAS KEEPING GUSTY WINDS ACROSS THE AREA. THE VERY COLD 
AIRMASS IN PLACE WAS PROVIDING TEMPERATURES MAINLY IN THE 10 TO 20 
DEGREE RANGE.

MODELS ARE IN DECENT AGREEMENT THUS RUN AND WILL USE A BLEND.

THE CUMULUS CLOUDS THAT ARE AROUND THE AREA NOW SHOULD DISSIPATE 
WITH LOSS OF HEATING LATE THIS AFTERNOON...LEAVING BEHIND MOSTLY 
CLEAR SKIES FOR TONIGHT. THE PRESSURE GRADIENT WILL KEEP WINDS 
AROUND 10 MPH MANY PLACES...BUT EVEN WITH THAT STILL EXPECT SOME 
COOLING TONIGHT GIVEN THE COLD DRY AIRMASS IN PLACE. GIVEN COLD 
CURRENT TEMPERATURES...BELIEVE THAT MAV MOS IS TOO WARM FOR LOWS 
TONIGHT. EVEN THE COOLER MET MOS LOOKS A BIT WARM ACROSS AREAS THAT 
ARE RUNNING COLDER THAN GUIDANCE NOW...MAINLY ACROSS THE NORTHEAST. 
THUS WILL GO AT OR A LITTLE BELOW MET NUMBERS TONIGHT.

TEMPERATURES WILL MODERATE ON FRIDAY AS CORE OF COLD AIR MOVES OFF 
TO THE EAST OF THE AREA. WEAK DECEMBER SUNSHINE WILL HELP BOOST THE 
TEMPERATURES...BUT EVEN WITH SUN THE MAV MOS LOOKS TOO 
WARM...ESPECIALLY GIVEN THE COLD START. WENT CLOSER TO THE COLDER 
MET NUMBERS FOR HIGHS.

SATURDAY WILL SEE INCREASING CLOUDINESS AND A LITTLE WARMER 
TEMPERATURES. AS A WARM FRONT MOVES ACROSS THE AREA SATURDAY 
NIGHT...MOISTURE AND ISENTROPIC LIFT INCREASE. LOOKS LIKE ENOUGH 
FORCING FOR SOME LOW CHANCE POPS. PROBLEM WILL BE PRECIPITATION 
TYPE. LOWEST LAYERS OF THE ATMOSPHERE WILL BE BELOW FREEZING ACROSS 
MUCH OF THE AREA WHILE LARGE LAYER ALOFT GOES ABOVE FREEZING AS WARM 
ADVECTION KICKS IN. BOTH NAM AND GFS BUFKIT SOUNDINGS SHOW A PERIOD 
OF LIGHT FREEZING RAIN IS POSSIBLE SATURDAY NIGHT BEFORE THE 
BOUNDARY LAYER WARMS TO ABOVE FREEZING. THUS WILL ADD TO THE 
FORECAST. GROUND TEMPERATURES WILL START OUT COLD AS WELL...AND THIS 
COULD HELP PROLONGATE THE FREEZING RAIN. AT ANY RATE...PRECIPITATION 
AMOUNTS LOOK TO BE LIGHT FOR THIS EVENT.

AT THE MOMENT BELIEVE THAT TEMPERATURES WILL BE WARM ENOUGH AFTER 
12Z SUNDAY FOR ANY LINGERING PRECIPITATION TO BE A COLD RAIN. 
TEMPERATURES WILL WARM UP ON MONDAY AHEAD OF ANOTHER POTENT COLD 
FRONT...SO CHANCES FOR RAIN LOOK TO BE THE WAY TO GO SUNDAY NIGHT 
AND MONDAY.

&&

.AVIATION...DISCUSSION FOR THE 10/18Z TAFS.

MAJOR WEATHER IMPACT FOR THIS TAF PACKAGE WILL BE WINDS. PRESSURE 
GRADIENT ACROSS THE SITES REMAINS STRONG BETWEEN POTENT LOW PRESSURE 
OVER QUEBEC AND AN ARCTIC HIGH OVER THE CENTRAL PLAINS. WINDS WILL 
GENERALLY REMAIN OUT OF THE WEST AT 15-20 KNOTS GUSTING TO AROUND 30 
KNOTS. GUSTS WILL CONTINUE THROUGH THIS AFTERNOON...WITH SURFACE 
WINDS NEAR OR ABOVE 10 KNOTS THROUGH THE OVERNIGHT...SAVE FOR BMG 
WHICH WILL DROP TO ABOUT 6 KNOTS AFTER 06Z. OTHERWISE...SKIES WILL 
REMAIN VFR AND VISIBILITIES UNRESTRICTED THROUGH THE PERIOD...WITH 
ONLY A SCATTERED CUMULUS DECK AROUND 3K FEET THIS AFTERNOON 
INTERRUPTING THE CLEAR SKIES.

&&

.IND WATCHES/WARNINGS/ADVISORIES...NONE. 

&&

$$

PUBLIC...CS 
AVIATION...NIELD