January 19-21 1978
This was the last in a tri-fecta
of winter storms over a seven day stretch that produced a full winter
weather spectrum in the northeastern United
States. Snowfall amounts averaged
between 10 to 16 inches across the state of West
Virginia, while from Philadelphia
northeast a foot and a half or greater was common. The highest
snowfall reported was across western Maryland
and the northern West Virginia
mountains, where nearly 30 inches of snow occurred. In terms of
societal impacts, this was the most crippling snowstorm in the northeast
since 1969, not to mention one of the highest snow producing nor'easters
to affect West Virginia.
High pressure built east from the northern plains on
the evening of the 18th to northern Maine by the morning of the 20th.
The anticyclone hung tough retreating into the Canadian Maritimes on
the evening of the 20th. Its stay was long enough to trap
cold air east of the Appalachians and keep sub-freezing temperature
across much of West Virginia.
The surface low responsible for this winter precipitation originated
in the northern Gulf of Mexico during
the day of the 19th then rapidly strengthened as it moved
up the eastern seaboard on the 20th. The bulk of the
snow fell between 6Z and 18Z on the 20th. While the surface
low was in southern New England, wrap around upslope snow showers continued
across West Virginia for a good part
of the 21st before winding down as high pressure built east
from the Midwest.
The 850mb charts illustrated a closed low off southeastern
Louisiana at 12Z on the
19th. The low then tracked northeast reaching east
central Alabama by 00Z on the 20th.
The low continued its movement northeast tracking east of the Appalachians, while it strengthened slightly. With the cyclone
track on the lee side of the Appalachians
and boundary layer cold air advection under a northerly wind component,
850mb temperatures never surpassed 0C for the event. This thermal
structure and the placement on the northeast quadrant of the 850mb low,
led to a period of heavy snowfall across West
Virginia. Strong cyclonic flow as the
low continued into southern New England,
kept the upslope snow in place through the 21st. The cyclone
did not undergo explosive cyclogenesis as
the greatest change in geopotential heights
was a decease of 60 meters in 12 hours. Much like previous
nor'easters that affected West
Virginia, there was no closed 500mb low present
with this storm either. Initially a trough of low pressure crossed
New England, while a second trough associated with the surface low ejected
out of the Gulf Coast region and up the eastern seaboard.
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