Area Forecast Discussion
Issued by NWS Northern Indiana

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000
FXUS63 KIWX 242348
AFDIWX

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

.SYNOPSIS...
ISSUED AT 642 PM EST WED DEC 24 2014

LOW PRESSURE WILL LIFT QUICKLY UP THROUGH SOUTHEAST CANADA TONIGHT
WITH RAIN AND SNOW SHOWERS ENDING ACROSS THE AREA THIS EVENING. 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
VALLEY 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 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 642 PM EST WED DEC 24 2014

GIVEN SFC LYR STILL WELL ABV FREEZING AND WKNG HYDROMETEOR
PRODUCTION WITHIN BROAD SCALE COMMA HEAD WILL DROP ALL MENTION OF
SNOW ACCUMULATION FOR THIS EVENING AS DEEPENING CYCLONE LIFTS
OUT THROUGH SE CANADA. HWVR EXPANSIVE LOW CLD MASS WILL PERSIST IN
WAKE OF THIS SYS W/MVFR CIGS CONTG THROUGH MOST THE TAF VALID
PD...ALTHOUGH SOME SUBSIDENCE INDUCED CLRG MAY DVLP LT PD. OTRWS
GUSTY WRLY GRADIENT FLW THIS EVENING IN CONCERT W/SHALLOW LL CAA
WING WILL WKN OVERNIGHT.

&&

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

&&

$$

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


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