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000
FXUS63 KIWX 101000
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
500 AM EST WED FEB 10 2010

.SHORT TERM...
TODAY THROUGH THURSDAY NIGHT...FAIRLY COMPLICATED SCENARIO TO
START OFF EARLY THIS MORNING...WITH A POST FRONTAL TROF E/W ACROSS
THE CENTRAL FORECAST AREA. MODERATE TO OCNLY HEAVY SNOW HAD
FALLEN ALONG THIS CONVERGENCE AREA EARLIER. THE MAIN DEFORMATION
ZONE WAS TO THE NORTH...WITH THE SOUTHERN FRINGE DRIFTING BACK
SOUTH INTO THE FORECAST AREA. VERY IMPRESSIVE SINGLE BAND OVER
LAKE MICHIGAN WAS JUST STARTING TO PIVOT EAST OVER FAR SOUTH LAKE
MICHIGAN. THIS BAND HAD PRODUCED SNOWFALL RATES UP TO 3 INCHES PER
HOUR IN THE CHICAGO AREA. ALTHOUGH DELTA T VALES NOT THAT
IMPRESSIVE...THE LAKE EFFECT SNOW SHOWERS WERE BEING ENHANCED BY
SYNOPTIC LIFT AND HAD A VERY LONG FETCH ACROSS THE MAIN AXIS OF
LAKE MICHIGAN. HAVE MADE SOME ADJUSTMENTS TO SNOW AMOUNTS BASED ON
THE LATEST OBS...RADAR AND THE LOCAL WRF/ARW. THE SYNOPTIC SCALE
LIFT SHOULD DECREASE TODAY...SO EXPECT AN OVERALL DECREASE IN
SNOW/SNOW SHOWER ACTIVITY. HOWEVER...LAKE EFFECT SNOW SHOWERS
SHOULD STILL BE ABLE TO PRODUCE RATES UP TO 2 INCHES PER HOUR AS
DELTA T VALUES REMAIN NEAR 13. HAVE KEPT THE WINTER STORM WARNING
IN EFFECT GIVEN SOME LIGHTER SNOW MOVING BACK INTO THE AREA FROM
THE NORTH AND THE LAKE EFFECT SNOW SHOWERS TRANSLATING INTO THE
AREA. WINDS SHOULD INCREASE TODAY AND BECOME BRISK WITH BLOWING
AND DRIFTING SNOW MAKING SOME ROADS IMPASSIBLE.

&&

.LONG TERM...
QUIET START TO THIS PD AS EAST COAST BOMB WRAPS UP NEAR NEW
FOUNDLAND SWD OF HIGH LAT BLOCK SOUTH OF ICELAND. MID LVL TROUGH
ELONGATED W/SWWD LOOKS LIKE IT WILL FORCE FOLLOWING NRN STREAM SW
DROPPING SWD OUT OF WRN HUDSON BAY WELL SOUTH OF CWA SAT NIGHT/SUN
AND THEN INTENSIFY RAPIDLY THROUGH THE MID ATLANTIC (SNOWSTORM
NUMBER 3?) BY MON. WILL STAND PAT THOUGH W/IMPLIED TIMING IN GRIDS
FOR NOW PER DIFFS NOTED AMG GFS ENSEMBLES W/DEPTH AND TIMING OF
AMPLIFYING NRN BRANCH SW AND EXTEND POPS THROUGH SUN NIGHT AS A HEDGE
TWD SLWR HPC PREFERRED CONSENSUS MIDWAY BTWN THE GFS/ECMWF ALTHOUGH
XPC CONTD ERRATIC MODELING OF THIS SMALL SCALE FTR UNTIL IT GETS
FULLY SAMPLED IN THE CANADIAN RAOB NETWORK.

OTHERWISE CONTD COLD W/STEEPENING NW FLW ALOFT THROUGH THE PD
W/TEMPS CONTG WELL BLO NORMAL.

&&

.AVIATION...
THE MAIN DEFORMATION ZONE WAS NORTH OF THE SBN AND FWA
TERMINALS. A BAND OF MODERATE TO HEAVY SNOW HAD DEVELOPED BETWEEN
SBN AND FWA ALONG A LOW LEVEL CONVERGENCE AREA OF A LOW LEVEL
TROF. THE POST FRONTAL TROF WILL LINGER INTO EARLY THIS
MORNING...BUT WINDS WILL INCREASE ONCE THE SFC LOW MOVES EAST AND
WEAKENS. FOR THE TAFS...HAVE KEPT BLOWING SNOW WITH CONDITIONS A
LITTLE LOWER AT SBN WITH LAKE ENHANCED SNOW MOVING INTO THE AREA.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WINTER STORM WARNING UNTIL 7 PM EST /6 PM CST/ THIS EVENING FOR
     INZ003>009-012>018-020-022>027-032>034.

MI...WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR MIZ077>081.

OH...WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR OHZ001-002-
     004-005-015-016-024-025.

LM...GALE WARNING UNTIL 11 PM EST THIS EVENING FOR LMZ043-046.

&&

$$

SHORT TERM...SKIPPER
LONG TERM...T
AVIATION...SKIPPER