National Weather Service United States Department of Commerce

January 11-14th 1964

 

A 1044mb high pressure system built south into the Dakota's on the 11th and then drifted slowly south into the central plains. Meanwhile a second, but weaker surface anticyclone developed in southern Ontario and slid east across northern New England. With this double barrel high structure, cold air was entrenched across much of the mid-Atlantic and Ohio Valleys. The surface low, which initially started in the front range of the Rockies, marched east across the southern plains and lower Mississippi River Valley. The low curved north similar to 850mb and 500mb circulations due to a highly amplified trough. The surface low occluded off the southeastern coast of Virginia then trudged northeast up the eastern seaboard into New England. Cyclogensis then occurred around Charleston, SC, although there were hints that a weak circulation developed in the northern Gulf of Mexico. The surface low intensified as it interacted with the Gulf Stream off the South Carolina. The lowest pressure reported was 982mb at 12Z on the 13th just off the Maryland shoreline. The occluded low tracked west of the Appalachians on the 12th and 13th, which was the culprit for the heavy snow that fell across West Virginia. Much of the state experienced greater than six inches of snow with highest amounts of 12 inches in the mountains. Reference the table on the previous page for a snowfall map for this event.

 

Upper level analysis depicted a 500mb shortwave that dove south from the northern plains into Oklahoma. The associated upper low became cutoff across Oklahoma by 00Z on the 12th. The closed 500mb low strengthened as it moved northeast up the Ohio Valley on the 13th. The low went from 534dm over northeast Oklahoma to 516dm during the evening of the 13th. With the track of the upper low, West Virginia was situated just left of the upper low track, a favored location to experience heavy snowfall.

 

At 850mb, the circulation mirrored the 500mb pattern as it commenced as an open wave and strengthened rapidly across the southern plains. It became closed off over Kansas at 00Z January 12th. The 850mb low track was similar to the 500mb track as the low passed over the mountain state. Even though the low tracked from central Kentucky to Charleston, WV, to Philadelphia, PA, warm air was unable to intrude with a cold airmass already in place. Temperatures initially were -5C, however as the low tracked over central West Virginia, they warmed to almost 0C in southern West Virginia. The northern part of the state hovered around -5C for the duration of the event. With the low passing to the west, southerly winds brought an area of warm air into the coalfields, although rainfall was observed only for a short period.

 

The following indicators were satisfied that could assist forecasters to accurately predict snow amounts.

1. The 850mb low moved northeast

2. West Virginia was 1.5 degrees latitude to the left of the 850mb low track

3. -5C isotherm bisected the area of heavy snow.

 

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