FXUS63 KIND 251756
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
1257 PM EST FRI DEC 25 2009

.DISCUSSION...

BIGGEST PROBLEM IS TEMPERATURES. 

MAV LOOKS HIGH TO ME FOR MOST OF FORECAST PERIOD. MET LOOKS BETTER 
BUT STILL NEEDS TO BE CUT. 

LOOKING AT TEMPERATURES UPSTREAM DONT SEE 30S UNTIL YOU GET TO 
ARKANSAS AND ITS SUNNY THERE. ABOVE 30 WILL BE CHALLENGING TOMORROW 
SINCE WE ARE APT TO BE CLOUDY. 

SECOND REASON I DONT LIKE MOS TEMPS IS THE MODELS CONCUR WITH 
THICKNESSES PLUNGING OVER INDIANA BEGINNING OVERNIGHT. MAV TEMPS 
DONT SEEM TO PICK UP ON THIS VERY WELL AND MET DOES NOT AFTER 
TONIGHT....BUT ITS CONSISTENT WITH THE COLD TEMPERATURES THAT SEEM 
TO BE HEADING TOWARD THIS. 

BOTTOM LINE IS I CAN LIVE WITH MET TONIGHT...BUT AFTER THAT I WILL 
CUT IT ABOUT 3 DEGREES INTO MONDAY. 

AT LEAST IT WILL BE COLD ENOUGH SO ANY PRECIPITATION WILL BE SNOW. 
MODELS AGREE WE WILL BE IN DRY SLOT MOST OF TONIGHT WITH MOISTURE 
INCREASING AT MID LEVELS BUT BOUNDARY LAYER STAYING DRY TOWARD. I 
EXPECT FLURRIES FLURRIES DEVELOPING IN MOIST LAYER AND MAKING IT TO 
SURFACE...BUT AGREE WITH GUIDANCE ABOUT LOW CHANCE OF MEASURABLE.

SATURDAY COULD BE GOOD FOR SNOW SHOWERS WITH CYCLONIC FLOW OVR 
LAKES...UNSTABLE BOUNDARY LAYER...AND SOME Q VECTOR DIVERGENCE 
ALOFT. SOME PLACES WILL TRACE OUT...OTHERS WILL MEASURE...BUT THINK 
MOST REPRESENTATIVE FCST WILL BE SNOW SHOWERS LIKELY.

MODELS AGREE FAIRLY WELL ABOUT PRIMARY FIELDS SATURDAY NIGHT THROUGH 
SUNDAY. TO THE EXTENT THEY DIFFER LIKED GFS WHICH WAS MUCH CLOSER TO 
SREF. FOR THE MOST PART ACCEPT MAV POPS SATURDAY NIGHT INTO 
MONDAY...BUT WILL BUMP UP TO 50 PERCENT SUNDAY WITH MODELS SHOWING 
FAIRLY GOOD QVECTOR DIVERGENCE ALOFT. 

BUFKIT SUPPORTS SOME GUSTS SATURDAY WHICH MAKES SENSE AS COLD 
ADVECTION ALOFT PROMOTES DOWNWARD MIXING. CLOUDY TO MOSTLY CLOUDY 
THROUGH SUNDAY NIGHT UNDER CYCLONIC FLOW. MAY GET SOME BREAKS MONDAY 
AS HIGH STARTS TO BUILD IN. 

&&

.AVIATION...DISCUSSION FOR 18Z TAFS
AVIATION CONDITIONS WILL BE MVFR THROUGH THE TAF PERIOD. THROUGH 12Z 
SATURDAY VERY STRONG LOW PRESSURE WILL ROTATE AROUND IOWA. AFTER 12Z 
IT WILL BEGIN TO MOVE THROUGH THE GREAT LAKES. MUCH COLDER AIR WAS 
WRAPPING AROUND THE LOW. THIS AIR WILL MOVE INTO INDIANA DURING THE 
AFTERNOON. LIGHT RAIN SHOWERS WILL QUICKLY CHANGE TO LIGHT SNOW 
SHOWERS. THESE WILL NOT DECREASE CONDITIONS BELOW MVFR WITH ONLY 
MINOR ACCUMULATION. THE STRONGEST WINDS WILL BE WEST OF THE LOW. 
DURING THE AFTERNOON SOME GUSTS IN INDIANA COULD REACH 30 KTS BUT 
WILL DECREASE TO 25 KTS AFTER 00Z. WINDS ALOFT WILL ONLY INCREASE TO 
30 KTS AT 3 THOUSAND FEET OUT OF THE SOUTH SO ANY LOW LEVEL WIND 
SHEAR WILL BE MINOR. WITH THE SYSTEMS MOVING LITTLE THROUGH HE TAF 
PERIOD THERE WILL BE ONLY MINOR CHANGES IN CONDITIONS. 

&&

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

&&

$$

PUBLIC...KWIATKOWSKI
AVIATION...HAINES