FXUS63 KIND 050228
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
928 PM EST FRI DEC 4 2009

.UPDATE.
STRATOCUMULUS DECK MAKING SLOW PROGESS NORTH AND EAST ACROSS OUR 
NORTHWESTERN FORECAST AREA. ACARS SOUNDINGS REVEALING SLIGHT 
INVERSION AT 850 MILLIBARS WHICH COULD KEEP THE CLOUDS AROUND A 
LITTLE LONGER PERHAPS AFTER 06Z. HOWEVER...SATELLITE AND MODEL 
TRENDS FAVOR DECREASING CLOUD COVERAGE SOME THERE OVERNIGHT. WILL 
KEEP TEMPERATURES ABOUT THE SAME FOR OVERNIGHT LOWS GIVEN THE TRENDS 
BUT KEEP THEM UP LONGER UNDERNEATH THE LOW CLOUD DECK.

&&

.AVIATION...DISCUSSION FOR THE 05/00Z TAFS.

MAIN FEATURE OF NOTE FOR THIS SET OF TAFS IS THE MAINLY VFR STRATUS 
DECK CURRENTLY OVER ALL SITES. MODEL CROSS SECTIONS/SOUNDINGS AND 
TEXT GUIDANCE INDICATE SKIES SHOULD BE CLEARING QUICKLY...BUT THE 
DECK IS ONLY MAKING STEADILY SLOW PROCESS IN ERODING FROM THE SOUTH 
THIS EVENING. ACARS AIRCRAFT SOUNDINGS INDICATE THAT INCREASING 
SUBSIDENCE ALOFT COUPLED WITH CONTINUING NEAR SURFACE COLD ADVECTION 
IS MAINTAINING A TRAPPING INVERSION MUCH SHARPER THAN DEPICTED BY 
ANY GUIDANCE AROUND 850 MILLIBARS...THUS...FEEL THAT BROKEN CEILINGS 
WILL STAY AROUND THROUGH A GOOD PORTION OF THE NIGHT...BUT BE 
GENERALLY VFR...BEFORE BEGINNING TO SCATTER OUT DURING THE MORNING 
AS THERMAL TROUGH AXIS PASSES TO OUR EAST AND LOW LEVEL WARM 
ADVECTION BEGINS TO ERODE THE INVERSION. CU RULE BECOMES STEADILY 
MORE POSITIVE THROUGH THE DAY TOMORROW...SO FEEL THAT ONLY FEW-SCT 
CU AROUND 4K FEET WILL BE PRESENT DURING THE AFTERNOON...WITH AN 
OVERALL TREND TOWARD CLEARING.

WINDS WILL REMAIN BELOW 10 KNOTS DURING THE PERIOD.

&&

.PREV DISCUSSION... /ISSUED 225 PM EST FRI DEC 4 2009/ 

IMMEDIATE PROBLEM IS TEMPERATURES.

SO FAR WE ARE ONLY 30 DEGREES AT IND. CONSIDERING THIS AND UPSTREAM 
TEMPERATURES...AGREE WITH NORTH WEBESTER COLD AIR IS REALLY 
ENTRENCHED OVER OUR AREA. BECAUSE OF THIS LIKE COLDER MET THROUGH 
SUNDAY...ALTHOUGH WILL NUDGE TOWARD MAV. MAV IS FINALLY COLDER THAN 
MET SUNDAY NIGHT...AND WILL ALSO GO WITH THAT.

THE MODELS ALL AGREE ABOUT DRY WEATHER THROUGH SUNDAY THANKS TO 
RIDGE ALOFT. VARYING BETWEEN MOSTLY CLEAR TO PARTLY CLOUDY THROUGH 
THEN ACCORDING TO HOW MUCH DAYTIME STRATOCUMULUS WE GET AND HOW MANY 
MID TO HIGH CLOUDS CROSS AREA.

SUNDAY NIGHT INTO MONDAY...BOTH MODELS BRING IN A CHANCE OF 
PRECIPITATION AS WARM ADVECTION DEVELOPS. SEE NO REASON TO DOUBT 
THIS. IF PRECIPITATION DOES FALL...SUNDAY NIGHT LOOKS TO BE TOO COLD 
FOR ANYTHING BUT SNOW...BUT MONDAY COULD SEE SNOW OR RAIN.

AFTER MONDAY THINGS GET MORE EXCITING...BUT THAT FAR OUT IT IS TOO 
EARLY TO BE DEFINITIVE. AS MENTIONED ON CHAT MODELS DUE SEEM TO 
CONCUR WARM ADVECTION WILL BE SUFFICIENT TO KEEP US ABOVE FREEZING 
FROM TUESDAY THROUGH TUESDAY NIGHT. WITH ENORMOUS PRESSURE FALLS 
PROJECTED...WE MIGHT EVEN HAVE A LITTLE THUNDER TUESDAY NIGHT. 

&&

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

&&

$$

PUBLIC...KWIATKOWSKI
AVIATION...NIELD
.UPDATE...KOCH