MESOSCALE DISCUSSION 0039
   NWS STORM PREDICTION CENTER NORMAN OK
   0236 PM CST THU JAN 20 2011
   
   AREAS AFFECTED...PORTIONS OF THE MIDDLE OHIO VALLEY REGION
   
   CONCERNING...HEAVY SNOW 
   
   VALID 202036Z - 202330Z
   
   BANDS OF MODERATE TO HEAVY SNOW WILL OVERSPREAD PORTIONS OF THE
   MIDDLE OHIO VALLEY REGION THROUGH LATE AFTERNOON...WITH RATES UP TO
   1 INCH PER HOUR EXPECTED.
   
   LATEST OBSERVATIONS INDICATE THAT A BAND OF MODERATE SNOW IS
   DEVELOPING ALONG THE INTERSTATE 71 CORRIDOR FROM CNTRL OHIO INTO
   NWRN KY....WITH AREAS OF LIGHTER SNOW ACROSS S-CNTRL OHIO. THIS
   ACTIVITY IS BEING DRIVEN BY DEEP-LAYER ASCENT AHEAD OF A TROUGH
   SWINGING THROUGH THE GREAT LAKES AND OHIO VALLEY REGION. SNOWFALL
   RATES ARE FORECAST TO INCREASE THROUGH THE REMAINDER OF THE
   AFTERNOON AS THE STRONG ASCENT PROGRESSES EASTWARD WHILE BEING
   AUGMENTED BY INCREASING 700-MB FRONTOGENESIS. FORECAST SOUNDINGS
   THROUGH LATE AFTERNOON INDICATE THAT THE ASCENT WILL COINCIDE WITH
   RELATIVELY DEEP AND SATURATED DENDRITIC GROWTH ZONES TO PROMOTE
   EFFICIENT SNOW GROWTH. ADDITIONALLY...MODEL GUIDANCE SUGGESTS THE
   DEVELOPMENT OF WEAK SLANTWISE INSTABILITY BY 00Z ACROSS PORTIONS OF
   EASTERN OHIO...WHICH WILL FURTHER SUPPORT MESOSCALE BANDING AS THE
   ACTIVITY SHIFTS EASTWARD. AS SUCH...BANDS OF MODERATE TO HEAVY SNOW
   ARE FORECAST TO AFFECT THE DISCUSSION AREA THROUGH LATE
   AFTERNOON...WITH RATES UP TO ONE INCH PER HOUR EXPECTED.
   
   ..COHEN/GARNER.. 01/20/2011
   
   
   ATTN...WFO...PBZ...RLX...CLE...JKL...ILN...LMK...
   
   LAT...LON   38698505 39328448 40118315 40488161 39748072 38728152
               38218314 38208425 38698505