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000
FXUS63 KIND 121757
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
157 PM EDT WED MAR 12 2014

.UPDATE...
THE LONG TERM SECTION HAS BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 438 AM EDT WED MAR 12 2014

A STRONG LOW PRESSURE SYSTEM MOVING THROUGH THE OHIO
RIVER VALLEY WILL CHANGE RAIN TO SNOW OVER THE AREA TODAY AND BRING
STRONG WINDS TO CENTRAL INDIANA. BY TONIGHT THE SYSTEM WILL BE OUT
OF THE AREA AND HIGH PRESSURE WILL BRING QUIET WEATHER AND COLD
OVERNIGHT TEMPERATURES WITH IT. TEMPERATURES WILL BRIEFLY REBOUND
FRIDAY BUT THEN DROP BACK BELOW NORMAL FOR THE REMAINDER OF THE
FORECAST PERIOD.

&&

.NEAR TERM /REST OF TODAY/...
ISSUED AT 1031 AM EDT WED MAR 12 2014

RAIN-SNOW CHANGEOVER NOW GENERALLY SOUTH OF A BLOOMINGTON-
COLUMBUS LINE AS OF 14Z. TEMPS STEADILY FALLING INTO THE UPPER
20S/LOWER 30S OVER THE NORTHERN HALF OF THE FORECAST AREA WITH MID
30S STILL PREVALENT OVER THE SOUTH.

FORECAST IN EXCELLENT SHAPE...MAIN FOCUS FOR THE UPDATE IS TO ADJUST
TIMING OF DEPARTURE OF SNOW AND BETTER REFINE TEMP FALLS INTO THE
AFTERNOON AS THE COLD ADVECTION INTENSIFIES OVER THE REGION. RADAR
ANALYSIS SHOWING TWO DISTINCT AND DOMINANT SNOW BANDS ARCING
NORTHEAST TO SOUTHWEST OVER THE REGION WITH LIGHTER SNOW
SURROUNDING THE BANDS. FIRST BAND EXTENDING FROM RANDOLPH CO
SOUTHWEST TO NEAR COLUMBUS WITH THE SECOND BAND FROM KOKOMO
THROUGH HENDRICKS COUNTY TO NEAR BLOOMINGTON. WITHIN THESE
BANDS...SNOW IS HEAVIER AND FLAKE SIZE IS LARGER WITH VISIBILITIES
DROPPING TO 1/2-1SM COMMON. THE SECONDARY BAND IS POISED TO ROTATE
ACROSS THE INDY METRO BETWEEN 15-16Z AND MAY PROVIDE A BRIEF BURST
OF ACCUMULATION. STILL APPEARS SNOW WILL END FROM WEST TO EAST
ACROSS THE FORECAST AREA BETWEEN 16-18/19Z.

WITH THAT BEING SAID...APPEARS ACCUMS IN GENERAL WILL BE SLIGHTLY
LOWER THAN PREVIOUSLY THOUGHT AND HAVE DROPPED BACK TO 2-4 OVER
EXTREME NORTHERN COUNTIES WITH A GENERAL 1-2 ACROSS THE REMAINDER
OF THE WINTER WEATHER ADVISORY AREA. FOR THE INDY METRO...ONE INCH
OF SNOW MAY BE ABOUT THE BEST WE CAN DO. THE HEAVIER SNOWFALL
RATES WITHIN THE BANDS ARE ENOUGH TO OVERCOME THE WARMER
GROUND/ROAD TEMPS BUT WHERE SNOWFALL RATES ARE LIGHTER...SOME
DEGREE OF MELTING IS ONGOING DESPITE THE FALLING AIR TEMPS. COUPLE
OF REASONS FOR THIS...EVEN ON A CLOUDY RAW DAY LIKE THIS...SOLAR
RADIATION LEVELS IN MARCH ARE MUCH STRONGER THAN IN THE MIDDLE OF
WINTER. SECONDLY AND MAYBE MORE IMPORTANTLY...ROAD TEMPS CURRENTLY IN
THE MID 30S THANKS TO THE WARM TEMPS EXPERIENCED ON TUESDAY. IN
ADDITION...BLOWING SNOW LIKELY REDUCED SIGNIFICANTLY WITH THE
POSSIBLE EXCEPTION OF EXTREME NORTHERN COUNTIES AS SNOW IS HEAVY
AND WET.

EVEN WITH THE LOWER SNOW AMOUNTS...NASTY CONDITIONS PREVAIL WITH
THE STRONG WIND GUSTS AND WILL MAINTAIN WINTER WEATHER/WIND
ADVISORIES IN THEIR CURRENT FORMATS. PEAK GUSTS TO 45 MPH OR SO
REMAIN POSSIBLE FOR THE NEXT SEVERAL HOURS AS COLD ADVECTION
INTENSIFIES.

ZONE AND GRID UPDATES OUT.

&&

.SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/...

ISSUED AT 438 AM EDT WED MAR 12 2014

MODELS ARE IN PRETTY GOOD AGREEMENT AND GENERALLY USED A CONSENSUS
FOR THE SHORT TERM. HIGH PRESSURE WILL BUILD IN THE WAKE OF THE
FRONTAL PASSAGE AND MOVE ACROSS THE SOUTHEASTERN U.S. WEDNESDAY
NIGHT THROUGH FRIDAY. RELATIVELY COOL HIGHS EXPECTED ON THURSDAY
/UPPER 20S TO LOW 40S/ EVEN WITH FULL SUNSHINE AS TEMPERATURES WILL
START OUT COLD WITH WEDNESDAY NIGHT LOWS IN THE SINGLE DIGITS NORTH
TO TEENS SOUTH. ON THE BACK SIDE OF HIGH PRESSURE STARTING LATE
THURSDAY NIGHT AND INTO FRIDAY SHOULD SEE WARM ADVECTION AND THIS
WILL ALLOW TEMPERATURES TO CLIMB BACK INTO THE 50S FOR HIGHS ON
FRIDAY. FRIDAY NIGHT LOW PRESSURE PASSING NORTH OF THE GREAT LAKES
WILL DRAG A COLD FRONT THROUGH CENTRAL INDIANA. FORCING WITH THE
FRONT IS FAIRLY WEAK AND UPPER FORCING STAYS WELL NORTH OF THE AREA.
THUS TRENDED POPS DOWN TO SLIGHT CHANCE ACROSS MOST OF THE AREA
WITH A LOW CHANCE IN THE NORTH AND EAST. THIS SET OF MODEL RUNS
BRINGS COLD AIR IN A LITTLE FASTER THAN PREVIOUS RUNS SO CHANGED
OVER TO A MIX OF RAIN AND SNOW IN THE NORTH AFTER 6Z.

&&

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...

ISSUED AT 149 PM EDT WED MAR 12 2014

HIGH VARIABILITY AND LOW CONFIDENCE DURING THIS PERIOD AS MODELS
SUGGEST SEVERAL WEAKER SYSTEMS PASSING THROUGH THE AREA ALBEIT
WITH LIMITED MOISTURE. GFS PUSHES SOME UPPER SUPPORT AND A WEAK
TROUGH THROUGH THE AREA ON MONDAY...HOWEVER MOISTURE REMAINS
LIMITED AND CONFIDENCE IS LOW AS THE ECMWF PUSHES BETTER SUPPORT
THROUGH DEEP SOUTH.

A WARMING TREND IS NOTED THROUGH THE PERIOD AS STRONG WARM AIR
ADVECTION IS SEEN IN THE GFS ON TUE THROUGH WEDNESDAY. A THERMAL
RIDGE ACTUALLY BUILD ACROSS ILLINOIS AND INDIANA WITH 850MB TEMPS
RISING TOWARD 11C. THIS SHOULD PRODUCE SOME TEMPS AT OR ABOVE NORMALS.
HAVE INCLUDED A CHC FOR RAIN ON WEDNESDAY AS A GFS SUGGEST A COLD
FRONTAL PASSAGE...STILL VERY LOW CONFIDENCE.


&&

.AVIATION /DISCUSSION FOR THE 121800Z TAFS/...

ISSUED AT 1250 PM EDT WED MAR 12 2014

RADAR RETURNS OVER THE AREA SHOW RETURNS DIMINISHING AND QUICKLY
MOVING EAST...EXITING THE AREA. AS SNOW WAS EXITING CEILINGS WERE
BECOMING MVFR. THUS AS THE BACK EDGE OF THE CLOUD SHIELD WITH THE
DEPARTING LOW PASSES ACROSS THE AREA...EXPECT MVFR CEILINGS TO
PERSIST THE NEXT 6 HOURS.

HIGH PRESSURE IS THEN EXPECTED TO BUILD ACROSS THE AREA TONIGHT
AND SUBSIDENCE RETURNS. FORECAST SOUNDINGS INDICATE A DRY
COLUMN...THUS WILL TREND TOWARD VFR OVERNIGHT.

SOME GOOD WARM AIR ADVECTION IS EXPECTED ON THURSDAY AND THIS
SHOULD RESULT IN SOME HIGH CLOUDS ACROSS THE AREA....BUT STILL
VFR CONDITIONS.


&&

.IND WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 4 PM EDT THIS AFTERNOON FOR INZ021-028>031-
035>049-051>057-060>065-067>072.

WINTER WEATHER ADVISORY UNTIL 4 PM EDT THIS AFTERNOON FOR INZ021-
028>031-035>049.

&&

$$

SYNOPSIS...CP
NEAR TERM...RYAN
SHORT TERM...CP
LONG TERM....PUMA
AVIATION...JP

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