Lake Effect Thunder-Snows Over the Eastern Great Lakes Robert Hamilton NWS Buffalo, NY Scott Steiger, Ph D SUNY Oswego, NY

Less than 1/10 of 1% of snowfall in the continental United States is accompanied by thunder and lightning. Curran and Pearson 1971

Lake Effect Storms Over the Eastern Great Lakes Surprisingly Efficient in Producing Lightning 20% 80%

Make Up of Data Set… Use of Spotter Reports from Dense Snow Spotter Network NLDN

130 Events 10 Years

Ice particles -40 C Supercooled droplets start To Nucleate around -10c -20 C 0 C -10 C Droplets form by Condensation in Updraft Graupel Forms Through Riming

Parameters Affecting Lake Effect Thundersnow  Height of -10C.53 X  Lake Surface Temp.48 X  Height of Lake Induced EL.45 X  Lake Induced CAPE.28 X  Fetch (Lk Erie).46 X  Shear…Band Type.93 X Correlation Coefficient (r) t test significance

Height of -10C Birch Parameters Affecting Lake Effect Thundersnow Dove …Moderate Correlation …84% Difference Between Ltg and Non-Ltg Events …Supported by Previous Studies by Schultz, Moore and Michimoto

Height of the Lake Induced Equilibrium Level On Average…Lake Induced EL 37% higher for TSSN events

Lake Induced CAPE

Open Water Lake Temperature

Long Fetch Across the Axis of the Lake

Finally….is the presence of lightning aided by close proximity charge concentrations between clouds?

Houston Environmental Aerosol Thunderstorm (HEAT) Project….2005 Update (Richard Orville, et al)

Project EAGLLES “Eastern Great Lakes Lake Effect Snow” Headed up by Hobart and William Smith College and the University of Illinois

Lightning Non-Lightning Likely Chance Not Expected (Ft)

Questions….

What have I found…reaffirmed. Ltg No Ltg Difference Avg Lake Temp 44.3 F 38.2 F 16% Avg 850mb Temp % Hgt of -10 Level 4000 ft 2169 ft 84% Htg of -20 Level ft 8400 ft 22% Thickness of Den Zone 3250 ft 3300 ft Negligible Lake Induced CAPE 525 j/kg 400 j/kg 30% Lake Induced Equilibrium Hgt 12,132 ft 8866 ft 37% 10 years worth of data…..nearly 130 events Basically no difference in events in regards to the thickness of -10 to -20 zone. 6.1k ft Lake Induced Li %