FXUS63 KIND 160431
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
1131 PM EST TUE DEC 15 2009

.AVIATION...DISCUSSION FOR 16/06Z TAFS

VFR EXPECTED THROUGH THE PERIOD.

HIGH PRESSURE WILL MOVE ACROSS THE AREA ON WEDNESDAY...SHIFTING THE 
WINDS FROM NORTHWEST OVERNIGHT TO LIGHT SOUTHWEST BY WEDNESDAY 
AFTERNOON. EXPECT ONLY SOME SCATTERED MID AND HIGH LEVEL CLOUDS. IND 
MAY SEE A BROKEN MID LEVEL DECK CLOSER TO THE END OF THE 30 HOUR 
PERIOD.

&&

.UPDATE...FOR THE REST OF TONIGHT

NO SIGNIFICANT CHANGES MADE. 

&&

.DISCUSSION...ACROSS THE FORECAST AREA THIS COLD DECEMBER 
DAY...TEMPERATURES WERE IN THE MID 20S TO NEAR 30 UNDER CLOUDY SKIES 
THAT WERE CLEARING RAPIDLY FROM THE NORTHWEST. DEWPOINTS WERE IN THE 
MID TEENS TO MID 20S...WITH SINGLE DIGIT DEWPOINTS NEARLY ON OUR 
DOORSTEP. WINDS WERE BLUSTERY OUT OF THE WEST NORTHWEST ABOUT 10-15 
MPH...GUSTING TO 20-25 MPH AT TIMES. REGIONAL 88D MOSAICS SHOWED 
ONLY LAKE EFFECT SHOWERS ACROSS FAR NORTHERN INDIANA AND MICHIGAN 
AND A SCANT FEW FLURRIES BARELY DETECTED AT TIMES NEARER THIS AREA.

FORECAST CHALLENGE OF THE DAY WILL BE TEMPERATURES.

MORNING MODEL RUNS WERE IN DECENT AGREEMENT IN THE SHORT TERM...AND 
DIFFERENCES WERE NOT SIGNIFICANT ENOUGH TO IMPACT FINAL FORECAST. 
STRONG ARCTIC HIGH CENTERED OVER MID MISSOURI VALLEY WILL PUSH 
EASTWARD OVER THE NEXT 24-48 HOURS BEFORE RETREATING TO THE EAST 
NORTHEAST LATE IN THE WEEK. THIS WILL GIVE US AN EXTENDED PERIOD OF 
GENERALLY CLEAR SKIES THROUGH TOMORROW NIGHT...BEFORE UPPER LEVEL 
IMPULSE IMPACTING THE PACIFIC NORTHWEST TODAY CRESTS THE WEST COAST 
RIDGE AND BEGINS TO DROP INTO THE GREAT LAKES REGION FOR THE END OF 
THE WEEK. ONLY SHORT TERM IMPACT OF THESE CHANGES WILL BE A GRADUAL 
INCREASE IN CLOUDS THURSDAY INTO FRIDAY AND BEYOND.

FOR TEMPERATURES...BASED ON STRONG CAA CONTINUING THIS EVENING AND 
UPSTREAM MINS OUTSIDE THE SNOWPACK WHICH MANAGED MID TEENS EVEN 
UNDER CLOUDY SKIES AND BREEZY CONDITIONS...HAVE CUT ALL MOS BY AT 
LEAST 3-5 DEGREES...ESPECIALLY OVER WESTERN AND NORTHWESTERN 
FORECAST AREA...WHERE WINDS WILL GO CALM AND SKIES WILL CLEAR 
EARLIEST. FOR TOMORROW HIGHS...THE COOL MET LOOKS BETTER BASED ON 
TEMPS UPSTREAM NEARER THE HIGH CENTER...WHICH WILL BE PASSING 
THROUGH TOMORROW. COOL MET IS AGAIN BEST TOMORROW NIGHT...AS 
RADIATIONAL COOLING CONDITIONS SHOULD BE EXCELLENT WITH CLEAR 
SKIES...LIGHT WINDS...AND A DRY COLUMN. FOR THURSDAY...CUT MOS 
SLIGHTLY AS ONLY WEAK WAA BEGINS...WHICH SHOULD NOT PORTEND AN 8-10 
DEGREE DAY TO DAY JUMP AS DEPICTED BY GUIDANCE.

IN THE EXTENDED...LONG RANGE MODELS AGREE IN PRINCIPLE ON LARGE 
SCALE TROUGHING AFFECTING THE GREAT LAKES AND MIDWEST ONCE AGAIN 
BEGINNING FRIDAY AND CONTINUING INTO NEXT WEEK. CONSISTENCY WITH 
RESPECT TO TIMING/INTENSITY/EXACT LOCATION OF IMPULSES AND 
ASSOCIATED SURFACE FEATURES/SENSIBLE WEATHER LEAVES MUCH TO BE 
DESIRED. WE SHOULD SEE ONE OR MORE SHOTS OF SNOW THIS WEEKEND AND 
PERHAPS EARLY NEXT WEEK...BUT IT IS A RELATIVE GUESSING GAME AS TO 
EXACTLY WHEN AT THE MOMENT...THUS...WHEN LONGER RANGE GUIDANCE POPS 
ARE AT THEIR PEAK...HAVE INSERTED A LOW CHANCE OF 
SNOW...OTHERWISE...HAVE KEPT THE FORECAST DRY...AS SLIGHT 
CHANCE/BELOW CLIMATOLOGY POPS IN THE EXTENDED DO NOT HAVE MUCH 
SIGNIFICANCE. WHAT CAN BE SURMISED IS THAT TEMPERATURES WILL ONCE 
AGAIN DIP WELL BELOW NORMAL.

&&

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

&&

$$

UPDATE...JH
PUBLIC...NIELD
AVIATION...CS