MESOSCALE DISCUSSION 0013
   NWS STORM PREDICTION CENTER NORMAN OK
   1136 AM CST TUE JAN 06 2004
   
   AREAS AFFECTED...LEE OF LAKE ONTARIO
   
   CONCERNING...HEAVY SNOW 
   
   VALID 061736Z - 062130Z
   
   A SINGLE W-E LAKE EFFECT SNOW BAND IS EXPECTED TO DEVELOP OVER LAKE
   ONTARIO DURING THE NEXT 2-4 HOURS...RESULTING IN INCREASING SNOWFALL
   RATES ACROSS THE COUNTIES OF OSWEGO...SRN JEFFERSON AND SRN LEWIS BY
   OR AFTER 21Z.  GIVEN THE LIKELIHOOD OF A SINGLE BAND WITH STEEP
   LOW-LEVEL LAPSE RATES...SNOWFALL RATES UP TO 2-3 INCH PER HOUR CAN
   BE EXPECTED INTO THE EVENING.
   
   SATELLITE IMAGERY SHOWS A CIRCULATION CENTER MOVING EWD ACROSS LAKE
   ONTARIO AND WAS LOCATED OVER THE NORTH CENTRAL PORTION OF THE LAKE
   AS OF 17Z.  BACKED LOW-LEVEL SWLY WINDS WITH DIRECTIONAL SHEAR FROM
   THE SURFACE TO 3 KM IN ADVANCE OF THIS FEATURE WILL CONTINUE TO
   TEMPORARILY DISORGANIZE THE CURRENT BAND OF SNOW IN LEE OF LAKE
   ONTARIO.  MEANWHILE...AREA VADS INDICATE LOW-LEVEL WINDS VEERING TO
   THE WEST WITH THE PASSAGE OF THE CIRCULATION CENTER AND SURFACE
   TROUGH WHICH EXTENDED SSELY TO BETWEEN ITH AND BGM AT 17Z.  BUF
   RADAR SHOWS 1-3 NARROW BANDS DEVELOPING ATTM OVER LAKE ONTARIO ALONG
   AND WEST OF THE CIRCULATION CENTER...WHICH IS EVIDENT OF THE
   DEEPENING WLY WINDS.
   
   RADAR/SATELLITE TRENDS INDICATE THE CIRCULATION CENTER WILL MOVE
   EAST OF LAKE ONTARIO BY 20Z...WITH WLY LOWER TROPOSPHERIC WINDS
   RESULTING IN THE DEVELOPMENT OF A SINGLE BAND BY MID-LATE AFTERNOON
   ALONG THE LONG AXIS OF LAKE ONTARIO.  ARCTIC AIR WILL SPREAD EWD
   ACROSS THE WARM /4-5C/ ICE-FREE LAKE WATERS STEEPENING SFC-3 KM
   LAPSE RATES TO NEAR 9 C/KM.  THIS WILL ENHANCE THE CONVECTIVE NATURE
   WITH HIGH SNOWFALL RATES.  IN ADDITION...WLY WINDS WILL INCREASE TO
   20-30 KT BY LATE THIS AFTERNOON... SUPPORTING WHITEOUT CONDITIONS.
   
   ..PETERS.. 01/06/2004
   
   
   ATTN...WFO...BGM...BUF...
   
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