Forecast Problems?
•Horizontal displacement of heavy lake effect snow squalls up to 350 km down wind of Lake Ontario •Intensity of lake effect snow band (rate of snowfall) •Impacts of strong low level winds on snowfall accumulations
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How far inland will band produce heavy snowfall rates with reduced vis?
Products to issue (mention in zones, then issued nowcast, heard about traffic accidents issued SPS, then received reports of 4 to 5 inches of snow issued lake effect snow advisory
Timing of heaviest snowfall associated with lake effect along the sfc boundary
How quickly the heaviest snow band moves across our forecast area?
The impacts of mountains and valleys (upslope/downslope )flow and enhancement due to funneling of bands
Strong low level winds>20 knots can lead to snow crystal fragmentation
Sustained Surface winds >18 knots can move ice crystals at the sfc, which fractures the crystal and causes compaction and decreases accumulation. Roebber/Schultz