February 14- 17th 1958
This storm developed over the southern Rockies then tracked
along the Gulf Coast
states before ejecting northeast up the eastern seaboard. Precipitation
started on the night of February 15th and persisted through
the 16th. Two surface anticyclones kept the atmosphere cold
enough for snow. One high pressure slipped off the mid Atlantic coast
the night of the 14th, while the next brought a reinforced
shot of cold air as it moved across southern Ontario
into New England February 16th
and 17th. The track of the low just inland along the eastern
United States is
a favorable track for heavy snow in the West Virginia Mountains,
especially if a strong upper level system crosses. Highest snowfall
totals were over a foot in the northern and central mountains with greater
than six inches across the southern mountains. Of course, lower layers
of the atmosphere need to be below freezing, but that was not an issue
since surface temperatures resided in the 20s.
The upper level pattern initially consisted
of an intense cyclone exiting New England, with another low progressing
across the southern plains of Canada. A ridge was present in the
western United States
and a trough positioned in the central part of the country. The aforementioned
low in south central Canada
strengthened as it interacted with lower heights in the central U.S
becoming closed off when it reached lower Michigan
on the 16th. Strong upper level winds and cyclonic vorticity
advection downwind of the trough axis strengthened the surface low as
it moved east across Georgia.
The surface low continued an eastward movement into the Atlantic
Ocean and further intensified. The upper low deepened to
504dm across eastern Pennsylvania at 00Z on the 17th.
The 850mb
analysis illustrated a deep trough over the central United
States with a closed low across Louisiana
at 12Z on the 15th of February. The 850mb low traversed the
Gulf Coast
states and then intensified as it moved north across eastern sections
of North Carolina and Virginia.
Temperatures across West Virginia stayed below 0C at 850mb for
the entire event. With the cyclone deepening, strong cyclonic flow cooled
temperatures between -10C to -15C. Two criteria forecasters key on for
moderate to heavy snow prediction are areas where forcing lies between
the -2C to -8C isotherm at 850mb.
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