Area Forecast Discussion
Issued by NWS Northern Indiana

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000
FXUS63 KIWX 242058
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
358 PM EST WED DEC 24 2014

.SYNOPSIS...
ISSUED AT 1017 AM EST WED DEC 24 2014

THE LOW HAS MOVED UP FROM THE SOUTH AND IS CURRENTLY IN THE
EASTERN PORTION OF THE REGION. THIS LOW WILL CONTINUE TO MOVE
NORTHWARD AND BE NORTH OF THE GREAT LAKES BY EARLY CHRISTMAS
MORNING. AS THE LOW PULLS AWAY AND TEMPERATURES DROP...THE RAIN
WILL CHANGE OVER TO SNOW...WHICH WILL END CHRISTMAS MORNING. HIGH
TEMPERATURES TODAY WILL RANGE FROM THE LOWER 40S IN THE WESTERN
PORTION OF THE REGION TO THE UPPER 50S IN THE EASTERN PORTION.
LOWS TONIGHT WILL BE IN THE LOWER 30S.

&&

.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 358 PM EST WED DEC 24 2014

HAVE CANCELLED THE WINTER WEATHER ADVISORY FOR WEST AREAS EARLIER
AND HAVE ALSO CANCELLED THE WIND ADVISORY FOR NW OHIO. A PAIR OF
DEEPENING SFC LOWS WAS OVER WEST OHIO AND MOVING NORTH. A LARGE AREA
OF PRECIPITATION ASSOCIATED WITH THIS SYSTEM IN THE DEFORMATION ZONE
HAD MOVED INTO NORTHERN INDIANA AND WILL MOVE OUT OF THE AREA EARLY
TONIGHT AS THE LOW MOVES NORTH. JUST NOT ENOUGH COLD AIR WITH THIS
SYSTEM FOR A DEFINITE CHANGEOVER TO SNOW... ALTHOUGH INCREASING LIFT
HAS BEEN ALLOWING A RAIN AND SNOW MIX IN THE STRONGER BANDS.
SOME LIGHT ACCUMULATIONS ON GRASSY AREAS ARE POSSIBLE... HOWEVER...
HAZARDOUS WINTER WEATHER CONDITIONS ARE NO LONGER EXPECTED. THE COLD
FRONT HAS PASSED THROUGH NW OHIO BY MID AFTERNOON. THE THERMAL
GRADIENT BEHIND THE FRONT WAS AS RELATIVELY WEAK AND STRONG WINDS
WERE NO LONGER EXPECTED OVER THIS AREA.


&&

.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 358 PM EST WED DEC 24 2014

TEMPERATURES ARE QUICK TO WARM AGAIN FOR THE EARLY PORTION OF THE
LONG TERM PERIOD AS WEAK RIDGING BUILDS ACROSS THE AREA. A FRONTAL
WAVE WILL MOVE THROUGH ON SATURDAY AND SATURDAY NIGHT WITH MOSTLY
RAIN EXPECTED. THE GEM IS SLOWER TO OPEN THIS WAVE ACROSS THE FOUR
CORNERS REGION AND RESULTS IN THE SYSTEM MOVING THROUGH AROUND 12
HOURS LATER THAN THE EURO AND GFS. THESE TIMING REASONS DO INSTILL A
DEGREE OF UNCERTAINTY IN REGARDS TO THIS EVENT...SO ELECTED TO
ADJUST SPOTTY LIKELY POPS FROM THE SUPERBLEND DOWN TO HIGH CHANCE
UNTIL CONFIDENCE WRT TIMING INCREASES. AS COLD AIR ADVECTS IN BEHIND
THIS SYSTEM...RAIN MAY MIX WITH SNOW BRIEFLY...BUT LITTLE TO NO
ACCUMULATION IS EXPECTED.

BEYOND THIS SYSTEM...MODELS CONTINUE TO STRUGGLE WITH THE HANDLING
OF EACH SHORTWAVE IN THE PROGRESSIVE FLOW ACROSS THE EASTERN
CONUS...SO DID NOT MAKE ANY APPRECIABLE CHANGES TO SUPERBLEND POP
INITIALIZATION. CONFIDENCE IS GROWING THAT A COLDER THAN NORMAL
PATTERN MAY DEVELOP NEAR NEW YEARS AND LAST INTO THE FIRST PART OF
2015 AS NORTHWEST FLOW DEVELOPS IN THE GREAT LAKES REGION.

GEM AND ECMWF BOTH HINT AT A SNOWSTORM IN THE MID ATLANTIC/OHIO
VALEY REGION DURING THIS TRANSITION PERIOD WHILE THE GFS PINCHES OFF
OFF THE WAVE OF INTEREST ACROSS THE 4 CORNERS REGION TO BE EJECTED
AT A LATER DATE. CONSIDERING HOW ATROCIOUSLY THE MODELS HANDLED THE
SYSTEM MOVING THROUGH TODAY...AM CAUTIOUS TO PICK A PREFERRED
SOLUTION. WILL STICK WITH LOW CONFIDENCE OF A STORM SYSTEM IN THE
MID ATLANTIC/OHIO VALLEY REGION SOMETIME NEXT WEEK THAT WE WILL NEED
TO CLOSELY MONITOR FOR ANY NORTHERLY TENDENCIES IN THE TRACK.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1251 PM EST WED DEC 24 2014

A DEEPENING SFC LOW WAS NEAR THE OHIO RIVER AND MOVING NORTH. A
LARGE AREA OF PRECIPITATION ASSOCIATED WITH THIS SYSTEM WILL
SPREAD NORTH OVER NORTHERN INDIANA. MOVED BACK THE CHANGEOVER TO
SNOW AND WENT MORE OPTIMISTIC WITH CIGS AND VSBYS. JUST NOT
ENOUGH COLD AIR WITH THIS SYSTEM FOR A DEFINATE CHANGEOVER...
ALTHOUGH INCREASING LIFT SHOULD ALLOW AT LEAST A RAIN/SNOW MIX AT
SBN BY THIS EVENING. CONDITIONS SHOULD IMPROVE OVERNIGHT TO MVFR
AS WINDS BACK TO THE WEST AND SOUTHWEST.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 4 PM EST THURSDAY FOR LMZ043-046.

&&

$$

SYNOPSIS...LOTHAMER
SHORT TERM...SKIPPER
LONG TERM...BENTLEY
AVIATION...SKIPPER


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