FXUS63 KIND 281852
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
155 PM EST SAT NOV 28 2009

.DISCUSSION...A RIDGE OF HIGH PRESSURE WAS FOUND OVER EASTERN OHIO 
AND EASTERN KENTUCKY EARLY THIS AFTERNOON...QUICKLY MOVING EAST. LOW 
PRESSURE WAS FOUND OVER THE UP OF MICHIGAN AND A COLD FRONT WAS 
EXTENDING SW ACROSS WISCONSIN TO CENTRAL IOWA AND CENTRAL KANSAS. 
CURRENT RADAR MOSAICS SHOW NO PRECIPITATION ALONG THE FRONT. 

MAIN CHALLENGE TONIGHT WILL BE POPS ON SUNDAY AFTERNOON AND SUNDAY 
EVENING.

NAM AND GFS REMAIN IN PRETTY GOOD AGREEMENT AND WILL USE A BLEND.
TIME HEIGHT SECTIONS ACROSS THE AREA SHOW A DRY COLUMN TONIGHT WITH 
DECENT SUBSIDENCE. CURRENT DEWPOINTS ACROSS THE AREA ARE IN THE 
MIDDLE 30S. ALSO RADIATIONAL COOLING WON OUT LAST NIGHT. WITH CLEAR 
SKIES AND LIGHT WINDS EXPECTED TONIGHT WILL LEAN 1-2 DEGREES COOLER 
THAN MAVMOS FOR LOWS.

FORECAST SOUNDINGS BEGIN TO MOISTEN UP ON SUNDAY AS THE COLD FRONT 
APPROACHES FROM THE NW. STRONGER UPPER DYNAMICS ALSO APPROACH ON 
SUNDAY NIGHT. WEAK ISENTROPIC LIFT IS PRESENT...HOWEVER...LOWER 
LEVEL Q VECTOR CONVERGENCE APPEARS MUCH MORE 
FAVORABLE...PARTICULARLY DURING THE AFTERNOON. TIME HEIGHT SECTIONS 
SHOW BEST VERTICAL VELOCITY NEAR 00Z MON. QUICK DRYING APPEARS TO 
MOVE IN BEHIND THE FRONT ON SUNDAY NIGHT. GIVEN THE FAST FLOW 
ALOFT...THIS SHUD BE A QUICK HITTING SYSTEM. FEEL HIGHLY CONFIDENT 
THAT RAIN WILL OCCUR...BUT NOT VERY CONFIDENT AT ALL ON WHICH SIDE 
OF 00Z IT WILL OCCUR. HENCE WILL STICK CLOSE ON POPS DURING SUNDAY 
AFTERNOON AND SUNDAY EVENING. WILL RAISE POPS IN THE EVENING ACROSS 
THE SOUTHEAST AS PROXIMITY TO THE SYSTEM PROGRESSION SEEMS TO POINT 
TO BETTER CHANCES FOR RAIN THERE AFTER 00Z. GIVEN THE EXPECTED 
INCREASE IN CLOUDS WILL GO AT OR BELOW MAVMOS HIGHS ON SUNDAY. 
STRONG COLD AIR ADVECTION IN PLACE IN THE WAKE OF THE COLD FRONT 
WITH H8 TEMPS FALLING TO NEAR -4C BY 12Z MONDAY. GIVEN THIS WL ALSO 
GO AT OR BELOW MAVMOS FOR MONDAY MORNING LOWS.
 
DRY WEATHER WL REMAIN ON MONDAY AND MONDAY NIGHT AS A SURFACE RIDGE 
BUILDS IN QUICKLY BEHIND THE FRONT AND UPPER TROUGH DEPARTS TO THE 
EAST. THUS WILL AIR FOR A DECREASING CLOUDINESS TREND ALONG WITH 
TEMPS AT OR BELOW MAVMOS DUE TO COLD H8 TEMPS NEAR -4C.

AT THE MOMENT IT APPEARS A QUICK MOVING UPPER SYSTEM WILL PUSH OUT 
OF THE WESTERN GREAT LAKES ON TUESDAY...PERHAPS CLIPPING NORTHEAST 
PARTS OF CENTRAL INDIANA. EITHER WAY...WL INCLUDE MORE CLOUDS ON 
TUESDAY AND PERHAPS SOME LOW CHC POPS ACRS THE 
MUNCIE...ANDERSON...WINCHESTER AREAS.

AS FOR THE EXTENDED...ECMWF AND GFS THEN HINTING AT A STRONGER STORM 
COMING OUT OF THE SOUTHERN PLAINS ON WED THROUGH WED NIGHT. AT THIS 
TIME H7 STORM TRACK IS OVER CENTRAL INDIANA WITH THE SURFACE LOW 
TRAVERSING ACROSS KENTUCKY AND OHIO TO THE NORTHEAST. FORECAST 
SOUNDINGS INDICATE THAT TEMPS APPEAR COLD ENOUGH FOR SNOW ON 
WEDNESDAY NIGHT. STILL THIS IS  DAY5 AND MODEL CONTINUITY IS A MAJOR 
CONCERN. STILL SOME POPS ARE WARRANTED AT THIS POINT. BY THURSDAY 
AND FRIDAY...BROAD...COLD CYCLONIC FLOW APPEARS TO DEVELOP ACROSS 
THE EASTERN PARTS OF THE UNITED STATES. ALTHOUGH DEEP MOISTURE DOES 
NOT APPEAR TO BE PRESENT...A FEW FLURRIES OR LIGHT SNOW CANNOT BE 
RULED OUT GIVEN THE EXPECTED STRATUS AND PATTERN. HAVE TRENDED 
TEMPERATURES COOLER THAN GUIDANCE GIVEN THE EXPECTED FLOW. 

BY SATURDAY...UPPER LOW APPEARS TO MOVES WELL ENOUGH NORTHEAST THAT 
THE PRECIPITATION CHANCES SEEM TO BE LIMITED BUT COLD FLOW WILL 
REMAIN. ALL IN ALL A VERY INTERESTING PERIOD FOR THE END OF THE NEXT 
WORKWEEK...BUT CONFIDENCE IS LOW AS WE WOULD LIKE TO SEE MORE RUN TO 
RUN CONTINUITY.

&&

.AVIATION...DISCUSSION FOR 18Z TAFS 
VFR CONDITIONS WILL PREVAIL FOR MOST OF THE TAF PERIOD AS HIGH 
PRESSURE REMAINS OVER THE OHIO VALLEY. HOWEVER...THE RIDGE WILL 
START BREAKING DOWN BY THE END OF THE TAF PERIOD...AND MOISTURE WILL 
START FILTERING INTO TAF SITES AHEAD OF APPROACHING COLD FRONT. 
CEILINGS WILL START FALLING VERY EARLY TOMORROW MORNING...AND 
FORECAST SOUNDINGS ARE INDICATING MVFR CATEGORIES AS EARLY AS SUN 
12Z AT KLAF AND KHUF. HOWEVER...THE POSSIBLE CATEGORY CHANGE FALLS 
AT THE END OF TAF PERIOD...AND CONFIDENCE IS NOT HIGH AT THIS TIME. 
NEXT TAF PERIOD MAY HAVE TO MAKE NECESSARY ADJUSTMENTS.
&&

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

&&

$$

AVIATION...TDUD
PUBLIC...PUMA