FXUS63 KIND 271905
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
205 PM EST FRI NOV 27 2009

.DISCUSSION...A SURFACE RIDGE OF HIGH PRESSURE WAS FOUND ACROSS 
CENTRAL ILLINOIS EXTENDING NORTH TO WISCONSIN. LOW PRESSURE WAS 
CENTERED JUST EAST OF CAPE COD AND WAS KEEPING A COOL CYCLONIC FLOW 
ACROSS THE NORTHEAST PART OF THE COUNTRY. SATELLITE IMAGES SHOW THE 
CLOUDS ACROSS CENTRAL INDIANA BEGINNING TO WANE AS THE SFC FLOW 
BECOMES MORE ANTICYCLONIC AS THE RIDGE BUILDS EAST.

MAIN FORECAST CHALLENGE TDY WL BE TEMPS. 

NAM/GFS ARE IN PRETTY GOOD AGREEMENT AND WL USE A BLEND. SFC RIDGE 
EXPECTED TO BUILD ACRS INDIANA TONIGHT...CLEARING SKIES. HOWEVER 
300K ISENTROPIC SURFACE SHOWS DECENT UPGLIDE TONIGHT WITH ASSOCIATED 
WARM AIR ADVECTION. DEWPOINTS ARE EXPECTED TO BE IN THE MIDDLE AND 
UPPER 20S WITH CLEAR SKIES AND LIGHT SOUTH WINDS. WITH THESE 
COUNTERACTING FORCES OCCURRING...AND MAVMOS LOOKING VERY REASONABLE 
WL STICK CLOSE TO MAVMOS.

RIDGING WL BE BUILDING ACROSS INDIANA AND THE REGION ON SATURDAY. 
TIME HEIGHT SECTIONS SHOW A DRY COLUMN WITH SUBSIDENCE ALONG WITH A 
STRONGLY POSITIVE CU RULE. WITH PLENTY OF SUN AND H8 TEMPS STARTING 
OUT THE DAY NEAR 7C...WL LEAN TO THE WARMER SIDE OF MAVMOS FOR HIGHS.

ON SATURDAY NIGHT A COLD FRONT WILL BEGIN TO DROP OUT OF THE UPPER 
MIDWEST AND APPROACH INDIANA. INITIAL IMPACTS FROM THIS SYSTEM ON 
SATURDAY NIGHT WILL MAINLY JUST BE INCREASING CLOUDS...AS THE VERY 
DRY COLUMN WILL TAKE SOME TIME TO MOISTEN UP. WL AGAIN LEAN TOWARD 
THE WARMER SIDE OF THE MAVMOS GIVEN THESE TRENDS.

FORECAST SOUNDINGS FINALLY BEGIN TO SATURATE ON SUNDAY AS THE COLD 
FRONT PUSHES ACROSS INDIANA. LOWER LEVEL Q VECTORS SHOW GOOD 
CONVERGENCE AND THE 300K ISENTROPIC SURFACE ALSO SHOWS GOOD LIFT. WL 
TRY AND CONCENTRATE POPS TO MAINLY THE AFTERNOON HOURS AND 
CONFIDENCE IS GROWING SUCH THAT WE SHOULD BE ABLE TO RAISE MAVMOS 
POPS BY 10 TO 20 PERCENT. HOWEVER WITH EXPECTED CLOUDS AND 
PRECIPITATION WL GO AT OR BELOW MAVMOS TEMPS.

BEST CHANCES FOR RAIN WL BE ON SUNDAY NIGHT AS THE SURFACE FRONT 
PASSES ALONG WITH THE UPPER TROUGH. WL AGAIN RAISE POPS BY 10 
PERCENT BUT WILL STICK CLOSE ON THE TEMPS GIVEN THE MANY ELEMENTS IN 
PLAY INCLUDING RAIN CHANCES...CLOUDS AND COLD AIR ADVECTION.  

AS FOR THE EXTENDED...A SERIES OF FRONTAL SYSTEMS APPEAR TO PUSH 
ACROSS THE REGION LATE NEXT WEEK. MONDAY AND TUESDAY APPEAR TO START 
OUT THE WORKWEEK DRY AS HIGH PRES HIGH PRESSURE OVER THE SOUTHERN 
STATES KEEPS A MILD...QUICK AND WESTERLY PACIFIC FLOW ACROSS 
INDIANA. HOWEVER ON WEDNESDAY THE ECMWF AND GFS SUGGEST A STRONG 
COLD FRONT DROPPING OUT OF CANADA. AT THIS TIME MOISTURE WILL BE 
SUSPECT WITH THIS SYSTEM SINCE THE GULF NEVER REALLY OPENS 
UP...HOWEVER THE DYNAMICS SEEM STRONG ENOUGH THAT POPS STILL SEEM 
WARRANTED. 

ECMWF AND GFS ALSO SUGGESTING A STRONG LOW PUSHING OUT OF THE GULF 
ON THURSDAY AND PUSHING NORTHEAST ON FRIDAY...ALLOWING FOR A COLD 
CYCLONIC FLOW OF AIR ACROSS INDIANA. ECMWF EVEN HINTS AT H8 TEMPS 
NEAR -10C WHILE GFS IS LESS AGGRESSIVE WITH H8 TEMPS NEAR 0C. EITHER 
WAY A COLDER TREND APPEAR TOWARD THE END OF THE NEXT WORKWEEK...AND 
WITH CYCLONIC FLOW IN PLACE...TRAPPING OF STRATUS AND VERY LIGHT 
PRECIPITATION SEEMS QUITE REASONABLE.

&&

.AVIATION...DISCUSSION FOR THE 18Z TAFS.
  
SATELLITE IMAGERY IS STARTING TO SHOW SOME BREAKS IN THE CLOUD 
COVER. HOWEVER...ALL TAF SITES WILL REMAIN AT MVFR CATEGORY UNTIL 
MID AFTERNOON AND THEN BECOME VFR. THE THICKEST BAND OF CLOUDS IS 
CURRENTLY EXTENDING FROM LAFAYETTE TO BLOOMINGTON...BUT TERRE HAUTE 
IS SHOWING SIGNS OF CLEARING WITHIN THE NEXT FEW HOURS. OTHER THAN 
THAT...WINDS WILL GRADUALLY BACK TO THE SOUTHWEST EARLY TOMORROW 
MORNING. THEY WILL NOT BE A FACTOR THOUGH WITH SUSTAINED SPEEDS ONLY 
BETWEEN 5 AND10K TS. WINDS WILL GRADUALLY START INCREASING LATE 
TOMORROW MORNING.
&&

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

&&

$$

PUBLIC...PUMA
AVIATION...TDUD