000
FXUS63 KIND 111413
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
1013 AM EDT TUE MAR 11 2014

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

&&

.SYNOPSIS...
ISSUED AT 423 AM EDT TUE MAR 11 2014

A WARM SPRINGLIKE DAY WILL GIVE WAY TO A STRONG SYSTEM
THAT WILL BRING RAIN AND THEN SNOW TO THE AREA TONIGHT AND
WEDNESDAY. STRONG WINDS WITH THE SYSTEM WILL BE IN PLACE ON
WEDNESDAY AS WELL. QUIET WEATHER WITH THE EXCEPTION OF SLIGHT RAIN
CHANCES FRIDAY NIGHT UNTIL SUNDAY WHEN ANOTHER STORM SYSTEM ARRIVES
BRINGING CHANCES FOR MIXED PRECIPITATION THROUGH MONDAY.

&&

.NEAR TERM /TODAY/...

ISSUED AT 423 AM EDT TUE MAR 11 2014

QUIET DAY BEFORE THE STORM ARRIVES UNDER WARM ADVECTION. SHOULD SEE
SOME CLOUDS FROM ADVECTION BUT THESE WILL DO LITTLE TO LIMIT WARMING
AS 850 MB TEMPERATURES CLIMB TO AROUND 10C. LOOK FOR HIGHS IN THE
60S TO AROUND 70.

&&

.SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...

ISSUED AT 423 AM EDT TUE MAR 11 2014

FORECAST FOCUS IS ON STORM SYSTEM TONIGHT THROUGH WEDNESDAY. NAM IS
A NORTHERN OUTLIER WITH THE LOW TRACK SO GENERALLY DISREGARDED IT.
FAIRLY SIMILAR FEATURES SEEN IN GFS AND 12Z ECMWF SO GENERALLY
AVERAGED THEM...BUT DISCUSSION WILL FOCUS ON SPECIFICS SEEN IN THE
GFS.

AT 6Z GFS SHOWS STRONG FRONTOGENESIS ACROSS THE CENTRAL AND SOUTHERN
COUNTIES WITH TEMPERATURE PROFILES WELL ABOVE FREEZING AND A
SOUTHWESTERLY LLJET OF AROUND 50 KTS. DECENT ISENTROPIC LIFT FROM 0
TO 6Z WITH THIS FEATURE. WITH ELEVATED INSTABILITY AVAILABLE
CONTINUED WITH MENTION OF SLIGHT CHANCE FOR THUNDER.

850-700 LAYER FRONTOGENESIS IS PHENOMENAL ACROSS THE NORTHERN HALF
OR SO OF THE AREA AT 12Z ACCORDING TO THE GFS /OVER 50 AND OVER 100
OVER THE FAR NORTHERN COUNTIES/. Q VECTOR CONVERGENCE ALOFT OVER 30
FOR THE ENTIRE AREA AND OVER 50 ACROSS THE NORTHERN HALF OR SO. OF
NOTE IN THE CROSS SECTION THOUGH IS THAT THE AREA OF NEGATIVE EPV
/ENHANCED INSTABILITY/ IS SHOWING UP JUST BELOW A DECENT INTRUSION
OF DRY AIR ALOFT WHICH COULD BE FALSELY ENHANCING THE POTENTIAL
INSTABILITY. DRY AIR RUSHING IN ALOFT COULD ALSO CUT DOWN ON
DENDRITIC GROWTH THEREBY CUTTING DOWN ON SNOW AMOUNTS.

SHORTWAVE SHOWING UP AS PRESSURE ADVECTION ON A PV SURFACE MOVES
THROUGH BETWEEN 12 AND 18Z WEDS. AT THIS POINT LOOKS LIKE SYSTEM
WILL BE ZIPPING THROUGH THE AREA AND MAJORITY OF PRECIP COULD BE
COMING TO AN END ACROSS MUCH OF THE AREA BY AROUND 18Z.

AS FAR AS PRECIPITATION TYPE IS CONCERNED...FORECAST SOUNDINGS SHOW
THERMAL PROFILES OF ALL RAIN ACROSS THE ENTIRE AREA THROUGH 6Z.
BETWEEN 6Z AND 9Z COLDER AIR STARTS TO MOVE IN FROM THE
NORTHWEST...BUT LOOKS LIKE A SHORT-LIVED WARM LAYER REMAINS ALOFT
WHICH COULD ALLOW FOR SOME BRIEF SLEET BEFORE CHANGING OVER TO SNOW.
BY 15Z SOUNDINGS SHOW ALL SNOW EVEN SOUTH OF THE AREA SO HAVE THE
ENTIRE AREA SNOW STARTING THEN. IN BETWEEN 9 AND 15Z SHOULD SEE SNOW
MOVE IN FROM THE NORTHWEST AND SEE A SIMILAR TRANSITION FROM
NORTHWEST TO SOUTHEAST OF RAIN TO A MIX OF RAIN/BRIEF SLEET/SNOW TO
SNOW.

AS FAR AS SNOW AMOUNTS ARE CONCERNED...LOOKS LIKE THE NORTHERN
COUNTIES COULD SEE 3-5 INCHES...WITH AROUND 2 OR SO CENTRAL AND
TRACE TO 1 IN THE SOUTH. WITH THE STRONG FORCING IN THE NORTH
COULDN/T RULE OUT 6 INCHES SOMEWHERE...BUT WITH THE WARM GROUND TO
START OUT AND THE DRY AIR MOVING IN QUICKLY ALOFT TO SHUT THINGS
DON/T EXPECT TO SEE THAT WIDESPREAD EVEN IN THE NORTHERN COUNTIES.
WENT WITH A WINTER WEATHER ADVISORY FOR THE NORTHERN COUNTIES WITH
THE ANTICIPATED SNOW AMOUNTS.

ANOTHER BIG CONCERN WILL BE THE WIND WITH THIS SYSTEM. A TIGHT
PRESSURE GRADIENT DEVELOPS ACROSS THE AREA AS THE LOW MOVES THROUGH.
COULD SEE WIND GUSTS AROUND 40 MPH. COMBINING THESE WITH ANY SNOW
COULD LEAD TO SOME PRETTY SERIOUS VISIBILITY ISSUES...ESPECIALLY IN
THE NORTHERN COUNTIES WHICH COULD SEE A PERIOD OF MODERATE TO HEAVY
SNOW. FOR NOW WILL KEEP THE WINTER WEATHER ADVISORY CONFINED TO THE
NORTHERN COUNTIES WITH THE HEAVIEST SNOW BUT COULD SEE THE POTENTIAL
FOR EXPANDING IT SOUTHWARD IF CHANGEOVER TO ALL SNOW OCCURS FASTER
THAN CURRENTLY FORECAST.

HIGH PRESSURE BUILDS IN WEDNESDAY NIGHT AND DRY THEN THROUGH
THURSDAY NIGHT WITH TEMPERATURES REMAINING BELOW NORMAL.

&&

.LONG TERM /FRIDAY THROUGH MONDAY NIGHT/...

ISSUED AT 427 AM EDT TUE MAR 11 2014

DRY CONDITIONS CAN BE EXPECTED ON FRIDAY WITH ZONAL FLOW ALOFT.
HOWEVER...A WEAK COLD FRONT WILL TRAVERSE CENTRAL INDIANA ON FRIDAY
NIGHT.  MOISTURE APPEARS TO STILL BE LIMITED WITH THIS FRONT...AND
LATEST INITIALIZATION ONLY PULLS IN SLIGHT CHANCE POPS FOR RAIN.
FURTHER OUT...A LARGE RIDGE OF HIGH PRESSURE ESTABLISHES ITSELF OVER
THE WESTERN U.S. WITH A BROAD CUT-OFF LOW OVER EASTERN
ONTARIO/WESTERN QUEBEC.  THIS PATTERN WILL BE CONDUCIVE TO PRECIP
CHANCES AS WEAK WAVES ROTATE AROUND THAT CUT-OFF LOW.  THE BEST
CHANCES WILL BE ON SUNDAY AND MONDAY WITH A PLETHORA OF PRECIP TYPES
RANGING FROM RAIN...SNOW...TO A MIX OF RAIN/SNOW.  SLIGHTLY COLDER
AIR WILL ACCOMPANY THIS PATTERN WITH HIGHS FALLING BACK INTO THE 30S
AND 40S FOR THE SECOND HALF OF THE EXTENDED PERIOD.

&&

.AVIATION /DISCUSSION FOR THE 111500Z TAF UPDATE/...
ISSUED AT 1013 AM EDT TUE MAR 11 2014

FORECAST IN GREAT SHAPE WITH ONLY MINOR ADJUSTMENTS NEEDED BAED ON
CURRENT OBS. STILL MVFR VISIBILITIES AT KHUF BUT EXPECT THEM TO
IMPROVE TO VFR WITHIN THE HUR AS MIXING INCREASES.

12Z DISCUSSION FOLLOWS.

KLAF AND KHUF ARE CURRENTLY EXPERIENCING VLIFR/LIFR FOG AND WILL
CONTINUE TO THROUGH MID MORNING. AT THAT TIME...ALL TAF SITES
SHOULD BE UNDER VFR CONDITIONS THROUGH THIS AFTERNOON. CONDITIONS
WILL QUICKLY START TO DETERIORATE TO MVFR/IFR CATEGORY THIS
EVENING AS PRECIP ENTERS THE AREA. THE INITIAL PRECIP ONSET WILL
BE IN THE FORM OF RAIN...BUT THAT WILL TRANSITION TO ICE PELLETS
AFTER WED 09Z...AND THEN FINALLY TO ALL SNOW AROUND WED 15Z. WINDS
WILL BE RATHER LIGHT AND VARIABLE AT THE BEGINNING OF TAF
PERIOD...BUT ARE EXPECTED TO BECOME NORTHERLY AND STRONG LATE
TONIGHT. SUSTAINED SPEEDS WILL BE AS HIGH AS 15 TO 25 KTS WITH
GUSTS UP TO 35 KTS.

&&

.IND WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 4 AM TO 4 PM EDT WEDNESDAY FOR
INZ021-028>031-035-038-040>042.

&&

$$

SYNOPSIS...CP
NEAR TERM...CP
SHORT TERM...CP
LONG TERM....TDUD
AVIATION...TDUD/RYAN

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