Monday, December 28, 2009

 Snowy & Wet For Auld Lang Syne

10:30 PM 12-30 Update # 2: As the Stormcast Team surmised from a variety of nowcast data, including radar and upper level charts, the situation is trending colder than anticipated by NWS and Accuweather.  The surface low is producing snow in the NC and VA foothills, and the coastal surface high is drifting eastward too slowly, permitting precip has already begun to over-run at upper levels. This suggests much of the I-95 corridor from Washington to Philadelphia and their metro interior area may see more snow than sleet or freezing rain, due in part to evaporative cooling as precip falls into air with low dewpoints. Snowfall totals below were adjusted slightly to reflect this.

2:30 PM 12-30 Update # 1: Winter Weather Advisories from 4AM - 1PM for western Virginia, central and western Maryland into south-central Pennsylvania

11:00 AM WEDNESDAY 12-30-09  Stormcasters Mr. B and PasadenaMatt with an update on the New Year's Storm: A "play in three acts" from Thursday to Saturday for Mid-Atlantic/Northeast

ACT 1 ~ THE SNOW: By 6AM Thu, light snow is accumulating.
8 AM Becomes steady along I-95 corridor, central/western MD and PA. 3" or more from Towson, MD north / west into southern PA. Up to 2" in Baltimore/Washington metro areas toward Philadelphia in the morning hours (snow & sleet combined).
12 PM Mixes with sleet and freezing rain in the Baltimore-Washington region. Higher elevations of southern / eastern PA may see 4" or more before changeover.
4 PM to Ball Drop All precip over to rain for New Year's Eve celebrations along I-95. Areas west of I-81 should remain snow or occasionally mix with rain/sleet.

ACT 2 ~ THE SWITCH: New Year's Day, rain changes back to snow as the secondary low moves off the New England coast. Some wind-driven "wrap-around" snow is possible across eastern Mid-Atlantic ; Western MD and Shenandoah Valley may see a prolonged period of snow into the weekend enhanced by lake-effect. 

ACT 3 ~ THE SECONDARY Saturday into Sunday, cold northwest winds arrive as the low departs. Coastal New Jersey, Long Island, and coastal southern New England stay rain the longest, ending as snow Saturday morning. Blizzard conditions are possible along Downeast Maine and the Interior Friday night into Sunday. Surrounding states may also receive heavy snowfall rates well into Saturday.

SUMMARY: Unless you are heading to the ski resorts, it is not shaping up to be a rockin' New Year's Eve for "First Night" celebrations across the Eastern U.S. If you want a winter wonderland while pounding the glades up yonder, then pack today and leave tonight. We would if we were you.  Stormcasters: Mr. B, PasadenaMatt | Editor: Mr. Foot | Advisor: Mr. Andy of Southern York Co., PA

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