FXUS63 KIND 100456
AFDIND
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
1156 PM EST WED DEC 9 2009
.AVIATION...DISCUSSION FOR 10/06Z TAFS.
LIGHT SNOW SHOWERS AND FLURRIES CONTINUE ACROSS CENTRAL INDIANA
EARLY THIS MORNING AHEAD OF A WEAK UPPER LEVEL DISTURBANCE OVER
ILLINOIS. EXPECT SNOW SHOWERS WILL LINGER FOR ANOTHER FEW HOURS
UNTIL THE DISTURBANCE CAN PASS BY 07-08Z. MVFR CEILINGS WILL PERSIST
FOR THE REMAINDER OF THE OVERNIGHT...AND MAY DIP BRIEFLY BELOW
2000FT BETWEEN 08-12Z. WESTERLY WINDS WILL REMAIN GUSTY THROUGH
DAYBREAK.
HIGH PRESSURE WILL BUILD INTO THE REGION ON THURSDAY WITH
STRATOCUMULUS DECK MIXING OUT INTO A VFR CUMULUS FIELD BY MIDDAY.
CUMULUS WILL BE MOST EXTENSIVE AT KIND AND KLAF INTO THE AFTERNOON
HOURS BEFORE DRIER AIR AND SUBSIDENCE ALLOWS CLOUDS TO SCATTER LATE.
WESTERLY WIND GUSTS AT 25-30KTS WILL BE POSSIBLE ON THURSDAY BEFORE
DIMINISHING BY SUNSET AS THE SURFACE PRESSURE GRADIENT RELAXES.
SKIES WILL CLEAR THURSDAY NIGHT AS THE CENTER OF THE HIGH PRESSURE
MOVES OVER CENTRAL INDIANA.
&&
.UPDATE...
EXTREMELY INTENSE LOW PRESSURE CONTINUES TO MOVE AWAY FROM NORTHERN
MICHIGAN THIS EVENING. WESTERLY WINDS REMAIN GUSTY ACROSS CENTRAL
INDIANA...BUT HAVE BEGUN TO RELAX A BIT OVER THE LAST 2-3 HOURS.
SCATTERED LIGHT SNOW SHOWERS AND FLURRIES PERSISTED OVER THE REGION.
TEMPERATURES WERE MAINLY IN THE 20S.
UPDATE WILL FOCUS ON A FRESHENING OF THE NEAR TERM PERIOD OVERNIGHT
INCLUDING REMOVAL OF THE WIND ADVISORY AND A CLOSER LOOK AT BELOW
ZERO WIND CHILLS FOR THE FIRST TIME THIS SEASON. SNOW SHOWERS HAVE
LINGERED A BIT LONGER AND WITH A LITTLE MORE VIGOR THAN PREVIOUSLY
THOUGHT...AS WEAK RIPPLES OF ENERGY IN THE MID LEVELS PERTURBATE
THROUGH THE REGION ON THE BACK SIDE OF THE DEPARTING LOW PRESSURE.
INDY METRO WEBCAMS DURING RUSH HOUR SHOWED A SOLID DUSTING TO HALF
INCH OF SNOW COVER ON THE GROUND GENERALLY NORTH OF 38TH STREET WITH
LITTLE TO NOTHING ACROSS THE SOUTHERN HALF OF THE INDY METRO.
MAIN SHORT WAVE CURRENTLY LOCATED OVER WESTERN ILLINOIS THIS EVENING
WILL SHIFT EAST ACROSS THE FORECAST AREA BY 06Z. CONSIDERING
OBSERVATIONS ACROSS INDIANA AND ILLINOIS AND THE SUBTLE FORCING
AVAILABLE...THINK IT IS QUITE REASONABLE THAT SCATTERED FLURRIES OR
LIGHT SNOW SHOWERS WILL LINGER UNTIL THE SHORT WAVE TRAVERSES THE
FORECAST AREA. WILL HOLD ONTO SCATTERED SNOW SHOWERS MAINLY NORTH OF
THE METRO THROUGH MIDNIGHT...AS HIGHEST WINDS RESIDE IN THESE AREAS
AND RADAR RETURNS APPEAR TO BE A LITTLE STRONGER. ELSEWHERE...
SCATTERED FLURRIES WILL SUFFICE. THE SNOW SHOWER WHILE LIGHT WILL
LIKELY STILL CAUSE SLICK SPOTS ON AREA ROADWAYS AND OVERPASSES FOR
THE REMAINDER OF THE EVENING.
WINDS CONTINUE TO WEAKEN WITH MOST AREAS NOW EXPERIENCING GUSTS
BELOW ADVISORY CRITERIA. WITH LOW LEVEL JET DEPARTING TO THE
NORTHEAST OVER THE NEXT FEW HOURS...SHOULD CONTINUE TO SEE WIND
GUSTS DECREASE. HAVE GONE AHEAD AND DROPPED THE ADVISORY AS A
RESULT. HOWEVER WITH CONTINUED WIND GUSTS AT 25 TO 30 MPH OVERNIGHT
AND TEMPERATURES FALLING INTO THE TEENS...WIND CHILLS GENERALLY FROM
AROUND ZERO TO -10 WILL BE PREVALENT ACROSS THE FORECAST AREA. WILL
THEREFORE INTRODUCE A SPECIAL WEATHER STATEMENT TO ADDRESS THE FIRST
SIGNIFICANT WIND CHILLS OF THE SEASON.
REMAINDER OF THE FORECAST IN GREAT SHAPE. ZONES AND GRIDS OUT
SHORTLY.
&&
.DISCUSSION...
FORECAST FOCUS IS ON WINDS AND TEMPERATURES IN THE SHORT TERM.
AT 18Z A 975MB LOW WAS LOCATED ACROSS NORTHERN LOWER MICHIGAN.
SCATTERED SNOW SHOWERS WERE WRAPPING AROUND THIS LOW ACROSS THE
FORECAST AREA. DUE TO THE STRENGTH OF THE LOW...SURFACE WINDS WERE
STRONG ACROSS THE AREA...WITH GUSTS WELL OVER 40 MPH COMMON.
TEMPERATURES TO THE WEST AND SOUTHWEST OF INDIANA WERE IN THE TEENS
AND 20S.
MODELS ARE IN DECENT AGREEMENT OVERALL THROUGH THE FIRST FEW DAYS SO
WILL USE A BLEND. IN THE EXTENDED UNCERTAINTY INCREASES RAPIDLY WITH
GFS ENSEMBLE MOS SHOWING 4 TO 5 STANDARD DEVIATIONS FOR
TEMPERATURES. WITH NO REAL FAVORITE IN MODELS...WILL STICK CLOSE TO
HPC EXTENDED GUIDANCE FOR MOST ITEMS FROM DAY 4 /SUNDAY/ ON.
SURFACE LOW WILL CONTINUE TO SLOWLY PULL AWAY FROM THE AREA TONIGHT.
THIS WILL KEEP GUSTY WINDS AROUND DURING THE EVENING. BUFKIT SHOWS
35-40KT GUSTS MAINLY DURING THE EARLY EVENING HOURS ACROSS THE AREA.
THUS EXPECT WINDY CONDITIONS TO CONTINUE EARLY ON. ALTHOUGH WINDS
MAY DROP TO BELOW ADVISORY CRITERIA BEFORE 06Z...WOULD RATHER KEEP
ADVISORY AS IS AND LET EVENING SHIFT CANCEL EARLY THAN TRY TO PIN
DOWN TIMING NOW AND RISK CUTTING IT TOO EARLY. THUS WILL LEAVE
ADVISORY AS IS. EVEN THOUGH WINDS WILL BE BELOW CRITERIA...THEY WILL
STILL BE GUSTY.
NAM 2 METER /2M/ TEMPERATURES ARE DOING A PRETTY GOOD JOB THIS
AFTERNOON. THESE NUMBERS LOOK BETTER THAN THE WARMER MAV
TEMPERATURES FOR LOWS TONIGHT GIVEN UPSTREAM TEMPERATURES. MET LOW
TEMPERATURES ARE EVEN COOLER THAN NAM 2M READINGS. SINCE THE 2M
TEMPERATURES ARE DOING WELL...WILL GO CLOSER TO THESE NUMBERS FOR
LOWS. THESE ARE WELL BELOW AVERAGE AND MAINLY IN THE 10 TO 15 DEGREE
RANGE. COMBINED WITH THE AFOREMENTIONED WINDS...WIND CHILL
TEMPERATURES WILL BE BELOW ZERO FOR MUCH OF THE AREAS. WILL CONTINUE
TO HIGHLIGHT IN THE HWO.
A WEAK WAVE IN THE UPPER FLOW COULD PRODUCE SOME SCATTERED SNOW
SHOWERS ACROSS THE NORTHERN AREA THIS EVENING WITH FLURRIES POSSIBLE
MOST OTHER AREAS. NO ACCUMULATIONS ARE EXPECTED.
ON THURSDAY...BRISK AND COLD CONDITIONS WILL CONTINUE...WITH MAXIMUM
APPARENT TEMPERATURES ONLY REACHING ZERO ACROSS FAR NORTHERN
SECTIONS OF THE AREA. MAV TEMPERATURES LOOK TOO WARM GIVEN THE
STRENGTH OF THE COLD AIR...SO WENT CLOSER TO THE MET/NAM 2M NUMBERS
FOR HIGHS. CLOUDS WILL GIVE WAY TO SUN DURING THE MORNING.
TEMPERATURES THEN MODERATE INTO THE WEEKEND WITH HIGH PRESSURE IN
CONTROL. THE AREA MAY GET CLIPPED BY A SYSTEM MOVING ACROSS THE
SOUTHEAST USA ON SATURDAY NIGHT...SO INCLUDED SMALL POPS THEN. A
COLD FRONT WILL IMPACT THE AREA IN THE SUNDAY NIGHT INTO MONDAY
NIGHT TIME FRAME...SO CONTINUED LOW POPS THEN AS WELL.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
UPDATE...RYAN
PUBLIC...CS
AVIATION...RYAN
