FXUS63 KIND 102322
AFDIND
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
622 PM EST THU DEC 10 2009
.AVIATION...DISCUSSION FOR 11/00Z TAFS.
VFR CONDITIONS EXPECTED THROUGH THE PERIOD. CUMULUS HAD DISSIPATED
WITH THE LOSS OF DAYLIGHT...WITH CLEAR SKIES THE RULE ACROSS CENTRAL
INDIANA. OUTSIDE OF A FEW ADDITIONAL WIND GUSTS EXCEEDING 20KTS
EARLY THIS EVENING...WINDS WILL CONTINUE TO SLACKEN BACK TO A
SUSTAINED 10-15KTS FOR MUCH OF THE NIGHT. HIGH PRESSURE EXPANDS
ACROSS THE OHIO VALLEY TONIGHT AND FRIDAY WITH DRY WEATHER. MAY SEE
A FEW CIRRUS PASS ACROSS THE SOUTHERN PART OF THE FORECAST AREA
FRIDAY MORNING...OTHERWISE SKIES WILL REMAIN CLEAR ALL DAY FRIDAY.
SOUTHWEST WINDS OF 10-15KTS WILL CONTINUE FRIDAY...WITH THE
POSSIBILITY FOR SOME BRIEF GUSTS TO AROUND 20KTS AT KLAF DURING THE
AFTERNOON.
&&
.DISCUSSION...
FORECAST FOCUS IS ON TEMPERATURES EARLY THEN ON PRECIPITATION TYPE
SATURDAY NIGHT.
AT 18Z LOW PRESSURE WAS ACROSS SOUTHEAST CANADA WHILE HIGH PRESSURE
WAS ACROSS OKLAHOMA AND ARKANSAS. THE PRESSURE GRADIENT BETWEEN
THESE TWO WAS KEEPING GUSTY WINDS ACROSS THE AREA. THE VERY COLD
AIRMASS IN PLACE WAS PROVIDING TEMPERATURES MAINLY IN THE 10 TO 20
DEGREE RANGE.
MODELS ARE IN DECENT AGREEMENT THUS RUN AND WILL USE A BLEND.
THE CUMULUS CLOUDS THAT ARE AROUND THE AREA NOW SHOULD DISSIPATE
WITH LOSS OF HEATING LATE THIS AFTERNOON...LEAVING BEHIND MOSTLY
CLEAR SKIES FOR TONIGHT. THE PRESSURE GRADIENT WILL KEEP WINDS
AROUND 10 MPH MANY PLACES...BUT EVEN WITH THAT STILL EXPECT SOME
COOLING TONIGHT GIVEN THE COLD DRY AIRMASS IN PLACE. GIVEN COLD
CURRENT TEMPERATURES...BELIEVE THAT MAV MOS IS TOO WARM FOR LOWS
TONIGHT. EVEN THE COOLER MET MOS LOOKS A BIT WARM ACROSS AREAS THAT
ARE RUNNING COLDER THAN GUIDANCE NOW...MAINLY ACROSS THE NORTHEAST.
THUS WILL GO AT OR A LITTLE BELOW MET NUMBERS TONIGHT.
TEMPERATURES WILL MODERATE ON FRIDAY AS CORE OF COLD AIR MOVES OFF
TO THE EAST OF THE AREA. WEAK DECEMBER SUNSHINE WILL HELP BOOST THE
TEMPERATURES...BUT EVEN WITH SUN THE MAV MOS LOOKS TOO
WARM...ESPECIALLY GIVEN THE COLD START. WENT CLOSER TO THE COLDER
MET NUMBERS FOR HIGHS.
SATURDAY WILL SEE INCREASING CLOUDINESS AND A LITTLE WARMER
TEMPERATURES. AS A WARM FRONT MOVES ACROSS THE AREA SATURDAY
NIGHT...MOISTURE AND ISENTROPIC LIFT INCREASE. LOOKS LIKE ENOUGH
FORCING FOR SOME LOW CHANCE POPS. PROBLEM WILL BE PRECIPITATION
TYPE. LOWEST LAYERS OF THE ATMOSPHERE WILL BE BELOW FREEZING ACROSS
MUCH OF THE AREA WHILE LARGE LAYER ALOFT GOES ABOVE FREEZING AS WARM
ADVECTION KICKS IN. BOTH NAM AND GFS BUFKIT SOUNDINGS SHOW A PERIOD
OF LIGHT FREEZING RAIN IS POSSIBLE SATURDAY NIGHT BEFORE THE
BOUNDARY LAYER WARMS TO ABOVE FREEZING. THUS WILL ADD TO THE
FORECAST. GROUND TEMPERATURES WILL START OUT COLD AS WELL...AND THIS
COULD HELP PROLONGATE THE FREEZING RAIN. AT ANY RATE...PRECIPITATION
AMOUNTS LOOK TO BE LIGHT FOR THIS EVENT.
AT THE MOMENT BELIEVE THAT TEMPERATURES WILL BE WARM ENOUGH AFTER
12Z SUNDAY FOR ANY LINGERING PRECIPITATION TO BE A COLD RAIN.
TEMPERATURES WILL WARM UP ON MONDAY AHEAD OF ANOTHER POTENT COLD
FRONT...SO CHANCES FOR RAIN LOOK TO BE THE WAY TO GO SUNDAY NIGHT
AND MONDAY.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC...CS
AVIATION...RYAN
