Lessons Learned from
Case 1
Based on climatology, upper low pressure tracking southeast out of the
Great Lakes rarely produces widespread heavy snow in the Carolinas and
Virginia (Albright and Cobb, 1996), unless it tracks through the Carolinas.
The upper deformation zone, in combination with Atlantic moisture, produced
the heavy snow in extreme eastern North Carolina (another case is documented
in Albright and Cobb 1995).
The west/east-oriented jet streaks within the southern semicircle of
the upper low limited the low-level thermal and moisture advection, as
no moisture from the Gulf of Mexico was entrained into the system.
The limited low-level thermal and moisture advection resulted in more
southeastward displacement of the area of heavy snow.
The progressive northern stream upper ridge provided enhanced upper
confluence in southeastern Canada, resulting in deeper cold advection and
deep layer drying into Virginia.
Evolution of the upper and surface ridges are often overlooked, and
must be evaluated for consideration of low-level cooling and drying, which
can significantly reduce snow amounts.
Next