Radar returns and cold weather

[powderfreak]

Anyone know if the extremely cold air over the northeast can produce snowfall rates higher than one would assume based on radar echo returns? There are reports of moderate snow (>.5mi visibility) in areas of +8 to +16 DBZ returns (Dunkirk, NY) and light snow with visibility of >1mi at Buffalo, NY but again in only +8 to +12 DBZ returns. Binghamton, NY has visibilities of >2mi in only -4 to +4 DBZ returns.

I noticed this during the last cold outbreak a few days ago that many areas with very cold temps were reporting light snow and restricted visibilities in areas where the radar was showing next to no precipitation.

Are the temps really that cold and the snow that light and fluffy that they are tricking the radar? Heavy snow in +16 DBZ returns is pretty cool if you ask me. Just imagine what a usual snowstorm with returns of +30 to +40 DBZ's would produce in this airmass.

[JCT777]

When it is this cold, snow that seems fairly unimpressive on radar will accumulate a lot faster than if temps are closer to freezing. Snow to liquid ratios with temps below 20 degrees are often 15:1 to 20:1, and possibly higher.

[powderfreak]

Makes sense. How about temps in the -5 to +10 range? Anyone see any 40 to 1 ratios with this thing?

-Scott

[JCT777]

Anyone see any 40 to 1 ratios with this thing?

Possibly along the northern fringe, but 30:1 would be a safer estimate.