Skip Navigation Links weather.gov 
NOAA logo-Select to go to the NOAA homepage NOAA's National Weather Service   Select to go to the NWS homepage
Storm Prediction Center
navigation bar left  
  navigation bar end cap


 
USA.gov is the U.S. Government's official Web portal to all Federal, state and local government Web resources and services.

Mesoscale Discussion 1930
< Previous MD         Next MD >
MD 1930 graphic

   MESOSCALE DISCUSSION 1930
   NWS STORM PREDICTION CENTER NORMAN OK
   0133 PM CST THU NOV 20 2014

   AREAS AFFECTED...PORTIONS OF JEFFERSON...LEWIS...AND OSWEGO COUNTIES
   IN NEW YORK

   CONCERNING...HEAVY SNOW 

   VALID 201933Z - 210000Z

   SUMMARY...A QUASI-STATIONARY CONVECTIVE BAND CONTINUES TO BECOME
   ESTABLISHED OVER AND IN THE LEE OF LAKE ONTARIO AND WILL LIKELY
   PERSIST DURING AT LEAST THE NEXT 2-3 HOURS...PRODUCING SNOWFALL
   RATES OF 2-4 INCHES PER HOUR.

   DISCUSSION...VIS IMAGERY AND SFC OBSERVATIONS SUGGEST THAT
   CONVERGENCE ALONG THE LONG AXIS OF LAKE ONTARIO CONTINUES TO GIVE
   WAY TO A DEEPENING CONVECTIVE BAND. DEEP UNIDIRECTIONAL WSWLY/WLY
   WIND FIELDS WILL CONTINUE TO MAXIMIZE OVER-LAKE FETCH
   LENGTH...PROMOTING CONTINUED GROWTH OF THE LAKE-ENHANCED CONVECTIVE
   BOUNDARY LAYER. RAP SOUNDINGS SUGGEST MARGINAL BUOYANCY EXTENDING
   SUFFICIENTLY DEEP FOR CHARGE SEPARATION AND PERHAPS AN ISOLATED
   THUNDERSTORM OR TWO -- AS HAS BEEN RECENTLY OBSERVED PER LIGHTNING
   DATA -- WHICH WOULD BE ASSOCIATED WITH THE HIGHEST SNOWFALL RATES TO
   4 INCHES PER HOUR. UPSLOPE FLOW ON THE WRN SLOPES OF THE TUG HILL
   REGION WILL ALSO FAVOR LOCALIZED INSTANCES OF SIMILAR RATES.
   OTHERWISE...2-3-INCH-PER-HOUR SNOWFALL RATES WILL BE LIKELY WITH THE
   CORE OF THE CONVECTIVE BAND...WHICH SHOULD REMAIN QUASI-STEADY STATE
   OVER THE REGION DURING THE NEXT 2-3 HOURS.

   LARGER-SCALE VEERING OF THE LOW-LEVEL FLOW AND SOLITARY-BAND
   DISRUPTION...AS ADDRESSED IN RECENTLY ISSUED MCD 1929...CASTS
   UNCERTAINTY REGARDING THE EVENTUAL EVOLUTION OF SNOWFALL INVOF THE E
   END OF LAKE ONTARIO LATER THIS AFTERNOON INTO THE EVENING. WHILE IT
   IS POSSIBLE THAT THE LAKE-ONTARIO CONVECTIVE BAND COULD
   RE-ORIENT/DIMINISH...MORE SUBSTANTIAL VEERING COULD BE RELEGATED TO
   PREDOMINANTLY LAKE ERIE INTO THE EARLY EVENING -- IN WHICH CASE
   HEAVY SNOW WOULD PERSIST ACROSS THE LAKE ONTARIO VICINITY FOR
   SEVERAL MORE HOURS.

   ..COHEN/GOSS.. 11/20/2014


   ATTN...WFO...BUF...

   LAT...LON   43817623 43997580 44067537 43947524 43637559 43617610
               43817623 

Top/All Mesoscale Discussions/Forecast Products/Home
Weather Topics:
Watches, Mesoscale Discussions, Outlooks, Fire Weather, All Products, Contact Us

NOAA / National Weather Service
National Centers for Environmental Prediction
Storm Prediction Center
120 David L. Boren Blvd.
Norman, OK 73072 U.S.A.
spc.feedback@noaa.gov
Page last modified: November 21, 2014
Disclaimer
Information Quality
Help
Glossary
Privacy Policy
Freedom of Information Act (FOIA)
About Us
Career Opportunities