FXUS63 KIND 111821
AFDIND
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
120 PM EST FRI DEC 11 2009
.DISCUSSION...
MAIN CHALLENGE TO THE FORECAST WILL BE PRECIPITATION TYPE SATURDAY
NIGHT IN OVERRUNNING/WAA SETUP.
SURFACE HIGH PRESSURE WAS CENTERED ACROSS THE TENNESSEE VALLEY THIS
AFTERNOON WITH ITS INFLUENCE ACROSS THE OHIO VALLEY ALLOWING FOR
SUNNY SKIES ACROSS CENTRAL INDIANA EARLY THIS AFTERNOON WHICH HAS
ALLOWED TEMPERATURES TO WARM TO AROUND 30 DEGREES. WEAK PRESSURE
GRADIENT HAS ALSO ALLOWED FOR MUCH LIGHTER WINDS THAN YESTERDAY.
UPPER PATTERN FEATURED FAST NORTHWEST FLOW ACROSS THE OHIO VALLEY.
MODELS ARE IN GOOD AGREEMENT ON KEEPING SKIES CLEAR TONIGHT WITH AN
INCREASE IN MID AND UPPER CLOUDS ON SATURDAY IN THE FAST PACFIC
FLOW. WITH CLEAR SKIES TONIGHT BUT LIGHT SOUTH FLOW...LOOKS LIKE A
COMBO BETWEEN THE WARMER NAM AND COOLER GFS. TOMORROW...WITH WARM
AIR ADVECTION KICKING IN STRONG...BUT INCREASE IN CLOUDS...PREFER A
COMBO BETWEEN THE WARMER GFS AND COOLER NAM.
MODELS ARE NOW TRENDING WARMER SATURDAY NIGHT AND SOUNDINGS AND
BUFKIT SUGGEST PREDOMINATELY A RAIN EVENT SATURDAY NIGHT. MODELS AND
300K LVL ISENTROPIC ANALYSIS ALSO ALL SUGGEST THE RAIN WILL SPREAD
QUICKLY NORTHEAST AFTER 00Z SUNDAY WITH THE BEST CHANCE BEING FROM
03-09Z. SOUNDINGS DO INDICATE POTENTIAL FOR THE PRECIPITATION TO
BRIEFLY START AS SNOW DUE TO EVAPORATIVE COOLING AS THE LOWER LEVELS
START OUT DRY. HOWEVER...DO NOT THINK THIS WILL LAST LONG ENOUGH TO
MENTION AS STRONG WARM AIR ADVECTION COMMENCES AND THE SOUNDINGS
WARM DRAMATICALLY BY 06Z SUNDAY. WILL ALSO MOVE POPS INTO THE LIKELY
CATEGORY AS ALL THE MODELS ARE TRENDING TOWARDS MORE COVERAGE. THE
MODELS ARE ALSO TRENDING QUICKER TO MOVE THE RAIN OUT...SO WILL NOW
ONLY GO WITH A SMALL CHANCE OF RAIN SUNDAY MORNING ACROSS ROUGHLY
THE EASTERN HALF.
WILL KEEP SMALL POPS GOING MONDAY AND MONDAY NIGHT AS A COLD FRONT
MOVES THROUGH. CONTINUE TO LIKE RAIN WITH POSSIBLE MIX MONDAY NIGHT
AS THE COLDER AIR MOVES IN. REST OF THE FORECAST LOOKS DRY AND
COLDER AS CANADIAN HIGH PRESSURE BUILDS IN ONCE AGAIN.
&&
.AVIATION...DISCUSSION FOR THE 11/18Z TAFS.
VFR THROUGH THE PERIOD AS VERY STRONG HIGH PRESSURE PASSES TO THE
SOUTH OF THE SITES. ONLY CHANGE GROUPS ARE FOR DIURNAL WIND SPEED
CHANGES AND DIRECTIONAL SHIFTS AS THE HIGH PROGRESSES EASTWARD.
CROSS SECTIONS SHOW SOME MIDLEVEL MOISTURE WORKING INTO THE AREA
LATE IN THE PERIOD...AND HAVE ADDED SCT080 LATE TO ACCOUNT FOR THIS.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC...KOCH
AVIATION...NIELD
