Powerful Pacific Storm to Continue Impacting Northern California; Heavy Snow in the Appalachians and Portions of the Northeast

A strong atmospheric river will continue to impact northern California with heavy rain and life-threatening flooding through Friday. Unsettled weather is expected across much of the Northeast and Great Lakes over the next few days, including the likelihood of heavy snow in the central Appalachians and higher elevations of northeastern Pennsylvania and southern New York. Read More >

WINTER STORM SUMMARY FOR
JANUARY 21, 2012 EVENT

Synopsis

A weak low pressure system developed across the lower Tennessee Valley on Friday January 20th and moved eastward Friday night. The low crossed our area on Saturday January 21st before moving off to our northeast and exiting the region Saturday night.

Watches/Warnings/Advisories

A Winter Storm Watch was issued at 318pm on Thursday January 19th for Sussex County in New Jersey and Carbon and Monroe Counties in Pennsylvania. At 346am on Friday January 20th, the following counties were added to the Watch: Warren and Morris in New Jersey; Lehigh and Northampton in Pennsylvania. Also at this time a Winter Weather Advisory was issued for the following counties: New Castle in Delaware; Cecil in Maryland; Burlington, Camden, Gloucester, Hunterdon, Mercer, Middlesex, Monmouth, Ocean, Salem and Somerset in New Jersey; Berks, Bucks, Chester, Delaware, Montgomery and Philadelphia in Pennsylvania. At 320pm on Friday January 20th all of the areas in the Winter Storm Watch were changed to a Winter Weather Advisory. At 446pm on Saturday January 21st the Winter Weather Advisory was cancelled for all areas.

Precipitation/Temperatures/Winds

Precipitation began as snow across the region just after midnight on the night of January 20th. A changeover to freezing rain began just after 3am across the southern areas as warmer air wedged in above the surface and then continue to changeover as the warm air moved northward. Periods of mixed precipitation (freezing rain, snow, sleet) occurred Saturday morning, with a complete changeover to freezing rain and drizzle by the late morning hours. Areas across the far north and in higher elevations remained all snow through the event, while the southern most and coastal areas changed over to plain rain.

Event total snow amounts were largely in the 2-4 inch range, with 4-6 inches across the higher elevations. Areas along the coast and across extreme southern New Jersey, Delaware and Maryland saw less than 2 inches. There was also up to 0.20 inches of ice accumulation reported.

Significant Impacts/Aspects

No major impacts were noted with this storm other than the usual traffic accidents associated with inclement weather.

Notes

Information contained in this summary is preliminary. More complete and/or detailed information may be contained in subsequent monthly NOAA storm data publications.

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