FXUS63 KIND 101719
AFDIND
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
1218 PM EST THU DEC 10 2009
.AVIATION...DISCUSSION FOR THE 10/18Z TAFS.
MAJOR WEATHER IMPACT FOR THIS TAF PACKAGE WILL BE WINDS. PRESSURE
GRADIENT ACROSS THE SITES REMAINS STRONG BETWEEN POTENT LOW PRESSURE
OVER QUEBEC AND AN ARCTIC HIGH OVER THE CENTRAL PLAINS. WINDS WILL
GENERALLY REMAIN OUT OF THE WEST AT 15-20 KNOTS GUSTING TO AROUND 30
KNOTS. GUSTS WILL CONTINUE THROUGH THIS AFTERNOON...WITH SURFACE
WINDS NEAR OR ABOVE 10 KNOTS THROUGH THE OVERNIGHT...SAVE FOR BMG
WHICH WILL DROP TO ABOUT 6 KNOTS AFTER 06Z. OTHERWISE...SKIES WILL
REMAIN VFR AND VISIBILITIES UNRESTRICTED THROUGH THE PERIOD...WITH
ONLY A SCATTERED CUMULUS DECK AROUND 3K FEET THIS AFTERNOON
INTERRUPTING THE CLEAR SKIES.
&&
.UPDATE...
FORECAST IS ON TRACK. MAINLY JUST TWEAKED HOURLY TEMPERATURES/WINDS
BUT FOR THE MOST PART LEFT HIGH TEMPERATURES ALONE. AJDUSTED SKY
COVER A BIT AS WELL...BUT AGAIN NO MAJOR CHANGES MADE.
&&
.DISCUSSION...
SNOW SHOWERS HAVE PRETTY MUCH ENDED ACROSS CENTRAL INDIANA AS THE
LOW PRESSURE SYSTEM IMPACTING THE AREA MOVED TO THE NORTHEAST. IR
SATELLITE IMAGERY IS DISPLAYING A COLD FRONT ALONG THE EASTERN
SEABOARD EXTENDING TO THE GULF OF MEXICO. THE LARGE PLUME OF
MOISTURE ASSOCIATED WITH THE SYSTEM HAS MOVED INTO CANADA. IN ITS
WAKE...BITTER COLD AND BREEZY CONDITIONS HAVE SETTLED INTO THE
MIDWEST. ELSEWHERE...HIGH PRESSURE IS BUILDING ACROSS THE WESTERN
TWO THIRDS OF THE COUNTRY.
THE MAIN CHALLENGE FOR THE SHORT TERM FORECAST IS THE TEMPERATURES.
THERE WILL BE NO POPS UNTIL SATURDAY.
BASICALLY...THE GFS CONTINUES TO BE TOO WARM WITH THIS COLD AIR
MASS. EVEN WITH AMPLE SUNSHINE TODAY...DO NOT FEEL IT WILL BE
ENOUGH FOR TEMPERATURES TO TOP OFF IN THE LOW 20S TODAY...WHICH IS
WHAT THE GFS IS SUGGESTING. THE NAM/GEM CONTINUE TO HAVE THE BEST
HANDLE ON THE COLD AIR MASS. AS A RESULT...STUCK CLOSE TO THOSE
MODELS AND WENT WITH HIGHS IN THE TEENS. TONIGHT...GFS COMES INTO
AGREEMENT WITH OTHER MODELS...SO CONFIDENCE IS HIGH. RADIATIONAL
COOLING WILL HELP TO BRING LOWS DOWN INTO THE TEENS...AND WITH A
DECENT PRESSURE GRADIENT...WINDS WILL STILL BE BREEZY CAUSING
WIND CHILLS WELL BELOW ZERO.
FRIDAY/FRIDAY NIGHT...A WARMING TREND BEGINS AS WINDS SHIFT TO THE
SOUTHWEST. THIS IS WHERE THE GEM FALLS OUT OF AGREEMENT WITH THE
GFS/NAM. LIKED THE WARMER TEMPERATURES OF THE GFS/NAM AS WARM AIR
ADVECTION SURGES INTO SOUTHERN INDIANA. THE LARGEST CHANGE IN THE
FORECAST WAS TO SATURDAY NIGHT/S LOWS. MADE A SIGNIFICANT INCREASE
IN TEMPERATURES FROM MID 20S TO MID 30S AS WARM AIR REACHES THE
UPPER LEVELS. TIME SECTIONS INDICATING TEMPERATURES JUST BELOW
FREEZING AT H850...WHICH IS A DRASTIC INCREASE FROM THE SUBZERO
TEMPERATURES OF THE LAST FEW DAYS. CONFIDENCE DECREASES ON
SATURDAY/SATURDAY NIGHT AS CLOUDS MOVE INTO THE REGION AHEAD OF
THE NEXT SYSTEM. CONTINUED TO TREND ON THE WARM SIDE...BUT THIS
MAY HAVE TO ADJUSTED.
AS FAR AS POPS...WENT WITH 20S ACROSS FORECAST AREA FOR NOW ON
SATURDAY AS NEXT SYSTEM MOVES CLOSER TO THE REGION.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
UPDATE...CS
PUBLIC...TDUD
AVIATION...NIELD
