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000
FXUS63 KIND 052028
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
328 PM EST THU DEC 5 2013

.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 1258 PM EST THU DEC 5 2013

AN ACTIVE WEATHER PATTERN IS EXPECTED THE NEXT 24 HOURS AS WINTRY
WEATHER RETURNS TO CENTRAL INDIANA. A COLD FRONT HAS PUSHED
SOUTHEAST OF CENTRAL INDIANA...ALLOWING MUCH COLDER AIR TO PUSH IN
TO THE AREA. A FLOW OF MOIST AIR ALOFT ALONG WITH SEVERAL UPPER
LEVEL WEATHER DISTURBANCES ARE EXPECTED TO PUSH IN TO
CENTRAL INDIANA TONIGHT AND AGAIN ON FRIDAY. THIS WILL RESULT IN
ACCUMULATING SNOW TONIGHT AND FRIDAY FOR MOST OF CENTRAL
INDIANA...AND THE FIRST REAL BIG SNOW OF THE SEASON.

HIGH PRESSURE IS EXPECTED TO BUILD ACROSS THE AREA FRIDAY
NIGHT...ENDING THE SNOW. HOWEVER VERY COLD...ARCTIC AIR WILL ARRIVE
IN INDIANA...WITH TEMPERATURES WELL BELOW NORMAL THOUGH THE WEEKEND.

ANOTHER PASSING STORM SYSTEM MAY BRING SOME LIGHT SNOW OR FREEZING
PRECIPITATION TO AREA ON SUNDAY THROUGH MONDAY. YET ANOTHER SHOT
OF ARCTIC AIR IS THEN EXPECTED TO ARRIVE ON FOR THE MIDDLE OF NEXT
WEEK AND HIGH TEMPERATURES WILL ONLY BE IN THE TEENS.

&&

.NEAR TERM /TONIGHT/...

ISSUED AT 1258 PM EST THU DEC 5 2013

RADAR THIS AFTERNOON SHOWS A SURGE OF MOISTURE OVER SOUTHERN
ILLINOIS STREAMING NORTHEAST TOWARD CENTRAL INDIANA. SURFACE
ANALYSIS EARLY THIS AFTERNOON SHOWS COLD HIGH PRESSURE IN PLACE
ACROSS THE CENTRAL PLAINS AND A COLD FRONT EAST OF INDIANA...OVER
CENTRAL OHIO...EASTERN KENTUCKY AND CENTRAL TENNESSEE. COLD WEST
TO NORTHWEST SURFACE FLOW WAS IN PLACE ACROSS CENTRAL INDIANA.
SURFACE TEMPS WERE FALLING THIS AFTERNOON ACROSS THE NORTHWEST
PARTS OF THE STATE AND BARELY RISING ACROSS SOUTH. THE WATER VAPOR
IMAGERY IS IMPORTANT TODAY. IT SHOWS A PLUME OF MOISTURE STREAMING
ACROSS MEXICO INTO THE AMERICAN SOUTHWEST AND THEN NORTHEAST INTO
THE GREAT LAKES AND OHIO VALLEY. THIS STREAM OF MOISTURE WILL BE
OUR SOURCE FOR PRECIP OVER THE NEXT 24-36 HOURS.

FORECAST SOUNDINGS ACROSS THE AREA LEAN TOWARD A FREEZING RAIN
PRECIP TYPE LATE THIS AFTERNOON AND THIS EVENING ACROSS SOUTHERN
PARTS OF CENTRAL INDIANA. PRECIPITATBLE WATER VALUES AROUND 0.8
INDICATE PLENTY OF MOISTURE AVAILABLE FOR THIS SYSTEM. COLDER AIR
IS EXPECTED TO ARRIVE ACROSS THE ENTIRE FORECAST AREA AFTER 06Z AS
ALL FORECAST SOUNDINGS FALL BELOW FREEZING...CHANGING THE PRECIP
TYPE TO ALL SNOW REGION WIDE.

THUS HAVE TRENDED FORECASTS TOWARD 100 POPS...WITH BEST CHANCES
FOR FREEZING PRECIP ACROSS SOUTHERN PARTS OF THE FORECAST AREA
THIS EVENING. ALSO GIVEN THE EXPECTED PATH OF THE BAND OF
MOISTURE...SOUTHERN INDIANA IS IN THE MOST FAVORABLE POSITION FOR
HEAVIER SNOW AMOUNTS. AS FOR TEMPS...GIVEN THE COLD AIR ADVECTION
BUT EXPECTED PRECIPITATION...HAVE TRENDED LOWS AT OR ABOVE MAVMOS.

&&

.SHORT TERM /FRIDAY THROUGH SATURDAY/...

ISSUED AT 1258 PM EST THU DEC 5 2013

SNOW IS EXPECTED ON FRIDAY. FORECAST SOUNDINGS AND TIME HEIGHT
SECTIONS CONTINUE TO SUGGEST A SATURATED COLUMN THROUGH THE DAY
WITH SOUNDINGS ENTIRELY BELOW FREEZING. FLOW ALOFT CONTINUES TO
SUGGEST THE MOIST SOUTHERN JET OF MOISTURE STREAMING IN TO THE
OHIO VALLEY. EMBEDDED SHORT WAVE ARE EXPECTED TO PROVIDE MORE
FORCING FOR ONGOING SNOW. TIME HEIGHT SECTIONS SHOW ANOTHER ROUND
OF GOOD VV DURING THE AFTERNOON HOURS. PRECIPITABLE WATER VIA
FORECAST SOUNDINGS SHOW A CONTINUOUS STREAM OF MOISTURE ACROSS THE
AREA WITH VALUES AROUND 0.60-0.80 FROM 12Z THROUGH 18Z AND AFTER
BEFORE TRAILING OFF AFTER 00Z SAT. THUS PLENTY OF MOISTURE APPEARS
AVAILABLE.

FRONTOGENESIS FORCING APPEARS VERY FAVORABLE FOR THIS
EVENT...AGAIN SHOWING A PERIOD STRONG FORCING MID DAY FRIDAY. THUS
WITH HIGH MOISTURE AND VERY GOOD FORCING EXPECT BANDS OF SNOW
ACROSS THE AREA ON FRIDAY. AGAIN...HEAVIEST AMOUNTS WILL BE ACROSS
THE SOUTHERN PARTS OF FORECAST AREA...WITH LIGHTER AMOUNTS NORTHWEST.
WITH ONGOING PRECIP EXPECTED ON FRIDAY HAVE TRENDED TEMPS COOLER
THAN MAV...STEADY IN THE UPPER 20S.

ON FRIDAY NIGHT...DEEP MOISTURE IS LOST IN THE FORECAST SOUNDINGS
AS BEST FORCING IS LOST AND THE SOUTHERN STREAM SHIFTS EAST. HIGH
PRESSURE OVER THE CENTRAL PLAINS CONTINUES TO BUILD ACROSS THE
REGION A COLD SURFACE RIDGE BUILDS ACROSS CENTRAL ILLINOIS AND
CENTRAL INDIANA. THUS WILL TREND TOWARD A BECOMING PARTLY CLOUDY
SKY. A FEW LINGERING SNOW SHOWERS OR FLURRIES WILL BE POSSIBLE
ACROSS THE EAST AS FRIDAY/S SYSTEM DEPARTS.

HIGH PRESSURE WILL PROVIDE COLD BUT DRY WEATHER FOR SATURDAY.
FORECAST SOUNDINGS REMAIN QUITE DRY. THUS WILL TREND TOWARD A
PARTLY CLOUDY SKY. AS FOR TEMPS DURING THIS PERIOD...GIVEN THE
EXPECTED FRESH SNOW AND COLD AIR IN PLACE WILL TREND HIGHS AND
LOWS COOLER THAN MAVMOS.

&&

.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
ISSUED AT 252 PM EST THU DEC 5 2013

MAIN ISSUE IN THE LONG TERM IS ANOTHER WINTER SYSTEM POSSIBLY
IMPACTING THE AREA EARLY SUNDAY INTO SUNDAY NIGHT. MODELS APPEAR
THEY MAY BE TRENDING SLIGHTLY COOLER MAINLY DURING THE DAY ON
SUNDAY. PRECIP MAY SNEAK INTO THE SOUTHERN FORECAST AREA AROUND
DAYBREAK SUNDAY IN THE FORM OF SNOW...WITH LIGHT SNOW POTENTIALLY
ACROSS MUCH OF THE AREA SUNDAY MORNING. PRECIP MAY TRANSITION TO A
MIX OF SLEET AND SNOW WITH SOME FREEZING RAIN POSSIBLE ACROSS THE
SOUTHWEST SUNDAY AFTERNOON. THIS MIX POTENTIAL WILL EXPAND A BIT
FURTHER NORTHWEST SUNDAY EVENING BEFORE COLD AIR AGAIN OVERTAKES THE
AREA AND MOST PRECIP LATE SUNDAY NIGHT CHANGES BACK TO SNOW...WITH
THE EXCEPTION OF A LIGHT MIX POSSIBLE IN THE EAST.

AMOUNTS WITH THIS SYSTEM...WHILE STILL QUITE UNCERTAIN BEING SO FAR
OUT...APPEAR VERY LIGHT ACROSS MOST OF THE FORECAST AREA. ACROSS THE
SOUTHEASTERN HALF OF THE AREA...FROM VINCENNES TO INDIANAPOLIS AND
MUNCIE SOUTHEASTWARD...1-3 INCHES OF SNOW/SLEET APPEAR POSSIBLE WITH
POTENTIAL FOR A FEW HUNDREDTHS OF FREEZING RAIN. SNOW/SLEET
ACCUMULATIONS OF UP TO 4 INCHES APPEAR POSSIBLE ACROSS THE FAR
SOUTHEASTERN FORECAST AREA...IN THE NORTH VERNON AREA.

ONCE THIS SYSTEM EXITS...DRY WEATHER WILL DOMINATE THE REMAINDER OF
THE FORECAST PERIOD...AND TEMPS WILL TURN SHARPLY COLDER. HIGHS MAY
NOT GET OUT OF THE TEENS AT TIMES NEXT WEEK. ALLBLEND HANDLED THE
OUTER PERIODS WELL AND FEW CHANGES WERE REQUIRED.

&&

.AVIATION /DISCUSSION FOR THE 05/21Z IND TAF UPDATE/...
ISSUED AT 328 PM EST THU DEC 5 2013

SPEED UP TEMPO FREEZING RAIN...SLEET AND SNOW MIX BASED ON
OBSERVATION TRENDS.

PREVIOUS DISCUSSION FOLLOWS...

POOR FLYING CONDITIONS TO DEVELOP ACROSS MOST OF THE SITES AND
PERSIST THROUGH THE PERIOD.

SOME SHOWERY PRECIPITATION HAS ALREADY DEVELOPED AND IS MOVING
THROUGH THE AREA. DEPENDING ON LOCATION THIS APPEARS TO BE -RA/-FZRA
MIXED WITH SLEET. THIS SHOULD BE THE PREDOMINANT PRECIPITATION TYPE
THROUGH EARLY EVENING AT IND/HUF AND THROUGH LATE EVENING AT BMG.
LAF WILL LIKELY BE COLD ENOUGH WITHIN THE FIRST FEW HOURS OF THE
PERIOD FOR MOST ANYTHING THAT OCCURS THERE TO FALL AS SNOW.

PRECIPITATION WILL INCREASE IN COVERAGE AND INTENSITY OVERNIGHT AND
GRADUALLY CHANGE TO ALL SNOW. THIS TRANSITION APPEARS LIKELY TO
OCCUR BY 01-02Z AT HUF/IND...WITH A MORE PROLONGED MIXING PERIOD AT
BMG. HOWEVER...EVEN BMG SHOULD BE ALL SNOW BY LATE TONIGHT.

A SECOND WAVE WILL MOVE INTO THE AREA NEAR THE END OF THE TAF PERIOD
FOR MOST SITES...MID MORNING TOMORROW...AND CONTINUE INTO THE
AFTERNOON. THIS WILL LIKELY CAUSE WIDESPREAD IFR CONDITIONS OR WORSE
IN MODERATE SNOW.

LAF WILL ESCAPE THE WORST OF THE CONDITIONS AND IS LIKELY TO REMAIN
MVFR THROUGH MUCH OF THE PERIOD.

WINDS WILL GRADUALLY BECOME NORTHERLY DURING THE PERIOD...WITH
SPEEDS LIKELY DECREASING SLIGHTLY THROUGH TONIGHT.


&&

.IND WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING FROM 10 PM THIS EVENING TO MIDNIGHT EST
FRIDAY NIGHT FOR INZ037-039>042-044>049-051>057-060>065-067>072.

WINTER WEATHER ADVISORY UNTIL MIDNIGHT EST FRIDAY NIGHT FOR
INZ021-028>031-035-036-038-043.

&&

$$

SYNOPSIS...PUMA
NEAR TERM...PUMA
SHORT TERM...PUMA
LONG TERM....NIELD
AVIATION...NIELD/MK

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