November 13, 1996, 03Z
surface data analysis
By late evening on November 12, 1996 (03z), the surface weather map looks
nondescript. The high pressure
from Illinois is making progress eastward
and, as seen in the isobaric field, the curvature of the pressure
anticyclonic flow is taking over in the western lower lakes through
southern lower Michigan.
| Unseasonably cold conditions continue in the
region, and there are some impressive local cold spots particularly near
Bradford, PA and over the state of West Virginia. Snow showers continue
near the lee side of the eastern lakes, but are coming to an end
downstream of Lake Michigan and Superior. The thermal trough near Lake
Michigan has "retrograded" westward somewhat and is positioned roughly
over this lake. This might be explained as a result of weakening
low-level air flow acting to reduce the "advection" of
the trough downstream - or - perhaps, the thermal trough is interacting
with synoptic scale disturbances or shortwaves pivoting through the
longwave trough in the Great Lakes.
The air flow near the surface in upper Michigan has veered to a more
westerly direction as the upper level trough and surface reflection are
starting to relax and pull out to the northeast. There is good
convergent flow at the east ends of Lake Erie and Ontario.
this night the heaviest snows fell in extreme NE Ohio and northeastward
to western New York and the east end of Lake Ontario in places like Oswego,
Motague, and further south towards Syracuse. Snows would continue
intermittently through Thursday in these areas, but the worst of the
storm had passed for much of the Great Lakes.
The Veteran's Day storm
was followed by a gradual warm up with rains falling early the next
week. Fears of a rapid warming and heavy rain - causing flooding - did
not materialize. There was some minor flooding observed in isolated
areas of the eastern lake snowbelts. Amazingly, much of the snow was
completely melted within a 7-10 period in NE Ohio.
Nov 12, 1996 19z
Data and Analysis