000
FXUS63 KIND 181705
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
1205 PM EST TUE NOV 18 2008

.AVIATION...DISCUSSION FOR 18/18Z TAFS

VFR CONDITIONS EXPECTED THIS TAF PERIOD.

ANY LINGERING LAKE EFFECT CLOUDS SHUD CONTINUE TO REMAIN EAST OF 
THE TAF SITES AND CONTINUE TO DIMINISH INTO THE EVENING HOURS AS THE 
UPPER RIDGE BUILDS ACRS THE AREA.

HIGH PRES OVR MO WL BUILD ACRS INDIANA DURG THE PERIOD. TIME 
SECTIONS AND FORECAST SOUNDINGS CONTINUE TO SHOW DRY LOWER LVLS. 
HOWEVER STRONGER WAA BEGINS TONIGHT AS H8 COLD POOL MOVES EAST. SOME 
SCT-BKN HIGHER CLOUDS WL BE EXPECTED...ESPECIALLY ACRS THE NRN 
AREAS...BUT CIGS WL STILL BE EASILY IN THE VFR RANGE.

&&

.DISCUSSION...
MAIN PROBLEM TODAY IS THE CHANCE OF SOME LAKE EFFECT SNOW NORTHWEST. 
INDIANA CONTINUES UNDER A STRONG FLOW FROM THE NORTH TO NORTHWEST. 
THE FETCH ACROSS LAKE MICHIGAN MAY BE STRONG ENOUGH TO BRING A 
CHANCE OF SNOW SHOWERS TO THE NORTH AND NORTHEAST PORTIONS OF THE 
CWA. THE NAM SNOW ACCUM HAS IT THERE. THE OTHER MODELS HOLD IT NORTH 
OF CWA. WITH SUCH OF STRONG FLOW WILL CONTINUE WITH THE CHC NW BUT 
SHOULD BE LIGHT ENOUGH SO THERE WILL BE LITTLE ACCUMULATION. OVER 
THE REST OF THE AREA THE MAIN CONCERN WILL BE TEMPERATURES. ALL 
MODELS WERE SEVERAL DEGREES TOO HIGH WITH MONDAYS TEMPS. 850 MB 
TEMPS DO NOT HAVE ANY WAA. SOME CLOUDS WILL ALSO DEVELOP WITH THE 
COLD AIR. DUE TO THIS WILL GO NEAR THE COLDER NGM TEMPS. TONIGHT THE 
FLOW SHIFTS TO THE WEST WHICH WILL END THE LAKE EFFECT SNOW IN THE 
CWA. AN AREA OF PVA MOVES THROUGH ALONG WITH SOME HIGH LEVEL 
MOISTURE. THE CAA WILL CONTINUE SO THE GFS LOOKS TOO WARM. WILL 
CONTINUE USING THE NGM TEMPS. ON WED A WEAK COLD FRONT MOVES TOWARD 
INDIANA. DUE TO LIMITED MOISTURE WILL JUST GO WITH AN INCREASE IN 
THE CLOUDS. THERE WILL BE WAA AHEAD OF THE FRONT. THE TENDENCY IS 
FOR GUIDANCE TO WARM THINGS UP TOO FAST WITH THESE SYSTEMS. WILL GO 
NEAR THE COOL NGM/ETA MAX TEMPS.THIS FRONT MOVES THROUGH WED NIGHT. 
DUE TO THE CONTINUING LACK OF MOISTURE WILL ONLY CONTINUE THE MOSTLY 
CLOUDY SKIES. THESE SHOULD HELP TO PREVENT TEMPS FROM FALLING AS 
MUCH AS PREVIOUS NIGHTS.  

THURSDAY THROUGH SATURDAY...PREFER THE ECMWF FOR THE EXTENDED 
PERIODS AS IT HAS EXHIBITED THE BEST CONTINUITY.  DRY AND BELOW 
NORMAL TEMPS ARE EXPECTED THROUGH THIS PERIOD.  NW FLOW ALOFT WILL 
ALLOW FOR ANOTHER SHORT WAVE TO DROP INTO THE STATE ON THURS NIGHT 
AND FRIDAY.  AT THIS TIME IT LOOKS LIKE THERE WILL BE LITTLE IMPACT 
ON CENTRAL INDIANA BUT COULD END UP ANOTHER LES EVENT FOR LAKE 
MICHIGAN AREAS.

SUNDAY AND MONDAY...WENT WITH THE ECMWF AGAIN AS IT DEVELOPS A LOW 
PRESSURE IN THE SOUTHERN PLAINS ON SUNDAY.  THIS WILL PUSH WARMER 
AIR INTO CENTRAL INDIANA ALTHOUGH AT THIS TIME IT STILL LOOKS TO BE 
BELOW NORMAL.  WARM ADVECTION RAIN WILL SPREAD THROUGH INDIANA ON 
SUNDAY AS THE LOW ADVANCES EAST.  AS THE UPPER SYSTEM AND SUBSEQUENT 
SURFACE LOW MOVE INTO THE STATE...RAIN WILL CONTINUE INTO MONDAY.  
AT THIS TIME IT LOOKS LIKE PRECIP TYPE WILL BE ALL RAIN WITH SOME 
RA/SN POSSIBLE AT THE TAIL END OF THE EVENT BUT ITS TOO FAR OUT TO 
DETERMINE THAT WITH ANY DEGREE OF CERTAINTY SO WILL STICK WITH RAIN.

&&

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

&&

$$

PUBLIC...SH
AVIATION...JP