1. By Rick Garuckas Andrew Calvi, Dillon Ulrich, and Andrew Janiszeski
BFB Lake Effect Snow
By Rick Garuckas Andrew Calvi, Dillon Ulrich, and
Andrew Janiszeski

2. Parameters To Look At Wind direction at surface and 850 mb.
Lack of directional shear.
Moisture
Lifting mechanisms.
Temp from surface to 850 mb.

3. Importance of Looking at Surface and 850 mb Temps.
Typically want 13 degrees C difference from surface to 850 mb.
Larger temp difference increases potential for heavy snow.
Too little temp difference will not produce a decent band.
If you have moist environment you can still get a lake response even if temp difference is slightly below 13 degrees C.

4. Winds Ideal wind speeds of 10 to 25 kts in boundary layer.
Above 40 kts, the band will start to get ripped apart.
Below 10 kts, snowfall will be right along shoreline due to land breeze dominance.
Typically want 30 degrees or less of directional shear within boundary layer.

5. Types of Wind Directions (degrees)
240: northern Jefferson County
250: central Jefferson County (Watertown)
260: southern Jefferson/northern Lewis Counties
270: extreme southern Jefferson, northern Oswego, western and central Lewis Counties (heart of the Tug Hill)
280: Central Oswego County (Oswego)
290: southern Oswego/northern Cayuga Counties (Fulton)
300: western Oswego, no. Cayuga, eastern Wayne, northern Onondaga Counties
310: Multiple bands-Oswego, Cayuga, Wayne, Onondaga, Madison, (Syracuse)

6. Lake to Lake Connections
Georgian Bay Connection(300 degrees)
Lake Huron Connection (280 degrees)
Occasional Lake Superior-Lake Huron-Lake Ontario Connection (280 degrees)
Hudson Bay Connection (340 degrees)

7. Moisture Typically need 70% or more moisture in boundary layer.
Moisture from Lake to Lake Connections enhance snowfall.

8. Sources of Lift/Convergence
Orographic lift.
Frictional Convergence.
Thermal Convergence.
Land Breeze.

9. Preparing Your Forecast
Current Obs of course!
1. Satellite and KSYR radar since this radar sees lake effect better.
Look at 500 mb to see where trough axis is.
Look at 850 mb and surface wind speeds.
Check position of short waves.
Check moisture fields.
Check temps at surface and 850 mb.
Check soundings (ie look for capping layer).

10. Useful Websites/Tools
(accuweatherpro)
Penn State Ewall.
SPC mesoanalysis.
Bufkit
GLERL
NCEP HRRR