The Beginning
Of The Event - Dec 22nd
Visible
satellite image at 1645GMT 12/22/98
There
are many different scale interactions here. One band is eminating
from the Straits of Mackinac on Lake Huron. Multiple bands
fuse into one distinct band on Lake Erie, with another weaker band at the
northeast corner of Lake Erie, possibly formed by the concave-shaped bay
north of Long Point. On Lake Ontario, a band along the south shore
of the lake curves inland near Fair Haven. This may be a result of
the band impinging on the "downwind channel" created by the band coming
from Lake Huron.
Buffalo
radar at 1700GMT 12/22/98
The
radar mathes up quite well with satellite imagery and clearly shows the
precipitation "echoes" associated with the cloudbands. You can see
the "possible" interaction of the Lake Huron band with the "bending" at
the east end of the Lake Ontario band.
The
End of the Event - Dec 25th
Visible
satellite image at 1715GMT December 25th
It's
pretty easy to pick out the lake cloudbands here. An area of clouds
over central Lake Erie consolidates into an organized band as it gets east
of Long Point, Ontario. Long Point is another "small scale"
feature that helps to define the intricate structure of lake effect snowbands.
Finally, if you look closely at the west end of Lake Erie, the water wll
be a bit lighter shade of gray. This is ice cover developing at the
shallow end of the lake.
Buffalo
radar at 1732GMT - Dec 25th
The
Buffalo radar is in "clear air" mode in this image. This mode allows
us to see weaker echoes such as the snowflakes associated with lake effect
events. The "dry" snowflakes return much less energy to the radar
than something like a big raindrop, but the National Weather Service Doppler
radars provide the technology to "see" such events quite well.