FXUS63 KIND 011706
AFDIND
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
1200 PM EST TUE DEC 1 2009
.AVIATION...
MAIN PROBLEM FOR AVIATION WILL NOT OCCUR UNTIL THE EXTENDED PORTION
OF THE IND TAF. TAFS WILL BEGIN THE HIGH PRESSURE EXTENDING FROM THE
EAST COAST INTO INDIANA. VERY DRY AIR IS ASSOCIATED WITH THIS
SYSTEM. THIS WILL GIVE EITHER CLEAR SKIES OR INCREASING HIGH CLOUDS.
ON WEDNESDAY STRONG LOW PRESSURE WILL MOVE FROM THE GULF COAST
STATES INTO KENTUCKY BY 00Z. THE MAIN DIFFERENCE BETWEEN PREVIOUS
MODEL RUN AND LATEST IS HOW QUICK IT BRINGS IN COLDER AIR. THE
LATEST RUN IS NOT AS COLD AS THE PREVIOUS RUN. WILL JUST BRING IN
SOME RAIN SHOWERS WITH MVFR CEILINGS INTO THE IND TAF AFTER 18Z.
&&
.UPDATE...
TEMPERATURES INCREASING A BIT FASTER THAN HOURLIES WERE
INDICATING...SMOOTHED THAT OUT. OTHERWISE...HIGH PRESSURE
CONTINUES TO BRING CLEAR SKIES TO CENTRAL INDIANA.
&&
.PREV DISCUSSION... /ISSUED 528 AM EST TUE DEC 1 2009/
AVIATION...
VFR CONDITIONS EXPECTED THROUGH THE PERIOD WITH ONLY SOME CIRRUS
AROUND. SOUTHWEST WINDS WILL GENERALLY BE AT OR ABOVE 10KT DURING
THE DAYTIME HOURS TODAY...WITH GUSTS AROUND 15-20KT POSSIBLE. AFTER
00Z OR SO WINDS WILL DIMINISH SOME AND BEGIN TO BACK...REACHING
SOUTHEAST TO EAST BY 12Z WED.
DISCUSSION...
SATELLITE INDICATED CLEAR SKIES WERE THE RULE ACROSS THE MID
MISSISSIPPI VALLEY...OHIO VALLEY AND INDIANA. A BROAD AREA OF HIGH
PRESSURE WAS CENTERED OVER WESTERN TENNESSEE. WATER VAPOR IR
INDICATED AN UPPER LOW OVER EASTERN CANADA AND JUST SOUTH OF NEW
MEXICO AND A STRONG SHORT WAVE JUST NORTH OF MONTANA.
MAIN FOCUS WILL BE PRECIPITATION CHANCES...TIMING AND TYPE WEDNESDAY
INTO THURSDAY.
FOR TODAY...CLEAR WILL BE THE RULE AS THE SURFACE HIGH OVER WESTERN
TENNESSEE TRACKS TOWARDS THE CAROLINAS. WILL GO ON THE HIGH END OF
MOS TEMPERATURES TODAY WITH PLENTY OF SUNSHINE AND WARM ADVECTION.
MODEL CONSENSUS STILL DEVELOPS A SURFACE OVER THE WESTERN GULF LATER
TODAY AND THEN MOVE IT NORTH NORTH EAST INTO THE OHIO VALLEY BY 00Z
THURSDAY AND TO NEAR BUFFALO BY 12Z THURSDAY. THE OPERATIONAL GFS IS
STILL THE FARTHEST EAST WITH THE SURFACE LOW TRACK TAKING IT ACROSS
FAR EASTERN KENTUCKY WHILE THE NAM IS THE FARTHEST WEST TRACKING IT
ACROSS SOUTHEAST INDIANA AND WESTERN OHIO. THE CANADIAN...EUROPEAN
AND UK MODELS ARE CLOSER TO THE NAM SCENARIO...BUT JUST A TAD EAST
OF THE NAM. MOST OF THE GFS ENSEMBLE MEMBERS ARE WEST OF THE
OPERATIONAL GFS. A MODEL BLEND SEEMS REASONABLE AND WILL GO NEAR OR
JUST SLIGHTLY WEST OF THE SREF.
THE MODELS ARE A LITTLE FASTER IN BRINGING PRECIPITATION OUR WAY.
WILL START RAIN A LITTLE SOONER THAN PREVIOUS FORECAST...BUT NOT
QUITE AS FAST AS CURRENT MODELS AS I HAVE SEEN MANY TIMES THEM BEING
A BIT FAST WITH SYSTEMS MOVING OUT OF THE SOUTHWEST. THE SHORT WAVE
MOVING OUT OF SOUTHWEST CANADA AMPLIFIES INTO A MAJOR UPPER LOW AS
IT MOVES INTO THE UPPER MIDWEST AND THE UPPER LOW OVER THE SOUTHWEST
IS EJECTED ACROSS THE OHIO VALLEY.
TONIGHT WILL START OUT CLEAR...THEN CLOUDS MOVING IN LATE TONIGHT.
WILL GO CLOSE TO MOS TEMPERATURES. ON WEDNESDAY WILL UNDERCUT MOS
TEMPERATURES A LITTLE AS PRECIPITATION MOVES IN. NAM SURFACE
TEMPERATURES ONLY MAX OUT IN THE 40S AND EVAPORATIONAL COOLING FROM
PRECIPITATION WILL KEEP TEMPERATURES A LITTLE COOLER.
PRECIPITATION WILL START OUT AS RAIN AND CHANGE OVER TO SNOW BY 06Z
THURSDAY OVER WESTERN SECTIONS AND IN THE EAST BY 09Z-10Z. SNOW
AMOUNTS UP TO AN INCH ARE POSSIBLE ACROSS OUR NORTHWEST WHERE CHANGE
OVER OCCURS QUICKER. MOST OTHER AREAS WILL BE A HALF INCH OR LESS
WITH THE GROUND BEING WARM AND TEMPERATURES BARELY REACHING
FREEZING.
ONLY MINOR CHANGES MADE THURSDAY INTO FRIDAY. SCATTERED VERY LIGHT
SNOW SHOWERS OR FLURRIES WILL BE THE RULE THURSDAY AND WILL KEEP A
CHANCE OF FLURRIES THURSDAY NIGHT AND FRIDAY MAINLY NORTH. THE
COLDEST AIR SO FAR THIS SEASON WILL MOVE ACROSS OUR AREA THURSDAY
INTO SATURDAY. PREVIOUS FORECAST UNDERCUT MOS TEMPERATURES A LITTLE
AND THIS STILL LOOKS GOOD.
FINALLY FAIR WEATHER WILL BE THE RULE THIS WEEKEND AS HIGH PRESSURE
MOVES ACROSS OUR REGION. MODELS HINT THAT ANOTHER SYSTEM FROM THE
SOUTHWEST MAY AFFECT OUR WEATHER BY THE MIDDLE OF NEXT WEEK.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC...JH
AVIATION...SH
UPDATE...TDUD
