WINTER STORM SUMMARY FOR
DECEMBER 05, 2009 TO DECEMBER 5, 2009 EVENT

Synopsis

The first winter storm of the year occurred on Saturday, December 5th. On Friday, December 4th, an area of low pressure developed in the Gulf of Mexico, then made its way toward the southeast coast of the US. This low pressure eventually began to move north along the eastern seaboard, while strengthening during the day Saturday. As the low pressure made its way northward, light rain began falling across much of the area early in the morning on Saturday. However, as the low pressure system continued northward, cooler air began to wrap around the system, which eventually began to create a mixture of rain and snow by the late morning hours and into the early afternoon. By the mid-afternoon hours, the rain and snow mixture had changed to all snow for the areas along and north of the I-95 corridor, and remained so through the evening hours. Areas to the south experienced a period of all snow, before mixing back with rain once again during the evening hours. All precipitation eventually came to an end before midnight as the low pressure system moved further away from the area to the northeast.

Watches/Warnings/Advisories

A Winter Weather Advisory was issued at 325 am for the following areas: Warren, Hunterdon, Morris, Somerset, Middlesex, Western Monmouth, Mercer, Salem, Gloucester, Camden, and Northwestern Burlington counties in New Jersey; Berks, Lehigh, Northampton, Chester, Montgomery, Bucks, Delaware, and Philadelphia counties in Pennsylvania; New Castle county in Delaware; and Cecil and Kent counties in Maryland. At 12:45 pm, a Winter Weather Advisory was issued for the following areas: Sussex county, New Jersey; Carbon and Monroe counties in Pennsylvania; and Queen Annes county in Maryland. The Winter Weather Advisory was canceled at 1040 pm.

Precipitation/Temperatures/Winds

Liquid equivalent precipitation amounts averaged around one half to three quarters of an inch, with some higher amounts of around an inch closer to the coast, and some amounts around one quarter of an inch for some areas north and west of Philadelphia. Snowfall had a wide range as well. Areas along and south of the I-95 corridor experienced around an inch or less, with some areas like Philadelphia International receiving only a trace of snowfall. Snowfall amounts rose quickly and varied farther north and west of Philadelphia. There was a very narrow band of 1 to 2 inches of snowfall, but an extensive area of 2 to 4 inches extending from Chester county Pennsylvania, through Morris county New Jersey and points further north. There was even a small area near the borders of Berks, Lehigh, Bucks, and Montgomery that received isolated amounts of 6 inches or greater. Some of the higher elevations in Monroe county Pennsylvania and Sussex county New Jersey received even more snow, around 7 to 8 inches. Temperatures were in the low to mid 30s for much of the event, even with the snow falling. At times temperatures fell close to 30 degrees during periods of heavy snow, and eventually dropped into the 20s for many areas, overnight as skies cleared out toward morning. Winds were not much of a problem for this event, but there were some gusts around 25 to 30 mph.

Significant Impacts/Aspects

No major impacts or problems were reported other than the usual slippery roads and traffic accidents that comes with wintry precipitation.

Notes

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