February 16-22, 2007 Idea: Winter Retreats from the Southern

[donsutherland1]

Following a possible moderate to significant storm in the eastern U.S. around mid-month, the pattern could begin to relax afterward. Such relaxation would likely mean a draining of the cold from the southern half of the U.S. Farther north and east, the colder air is likely to hold on. Late in the period, a renewed surge of colder air across the northern half of the United States is possible. However, by that time, winter’s worst cold—both in terms of actual temperatures and departures from normal—will be in the past.

Nonetheless through much of the February 16-22 period, the southern branch of the jet stream could remain fairly active. This could provide precipitation opportunities across the southern tier states and then in the eastern United States. Southern New England and possibly the northern Mid-Atlantic region could see one or more opportunities for snowfall.

My confidence in the above ideas is less than usual on account of some data being unavailable due to CDC website issues.

Finally, beyond this period, there is much uncertainty as to whether a stronger cold regime could redevelop. Such a regime would depend on the development of a strong block. The absence, so far, of such blocking during the winter and less than impressive ensemble guidance likely suggests that from this far out, odds may lean against the development of such a block. If so, there may be the prospect of the commencement of a more pronounced warming beyond the timeframe of this discussion, even if its duration is not lengthy. For now, there is still ample time to assess that situation before reaching any firm conclusions, and a colder, though not extreme, idea is still plausible.

My thinking for the average temperature anomalies during the 2/16-22 period is as follows:

Average Regional Temperature Anomalies (2/16-22):
Northeast: Somewhat below normal to near normal
Mid-Atlantic: Near normal
Southeast: Near normal
Great Lakes: Near normal to somewhat above normal
Northern Plains: Near normal to somewhat above normal
Central Plains: Near normal to somewhat above normal
Southern Plains: Near normal to somewhat above normal
Pacific Northwest: Near normal to somewhat above normal
Southwest/Rest of West Coast: Above normal

For the major cities from Washington, DC to Boston, the 2/16-22 period is likely to feature:

- Nights generally in the 20s, especially in Boston New York City, and Philadelphia, and 20s and 30s in Washington, DC
- Days mainly in the 30s in Boston and 30s and 40s in New York City, Philadelphia and Washington, DC.
- One day with a high temperature at or above 50° in Washington, DC

In the Southeast, Atlanta will likely see highs generally in the 50s with some 60s possible. Lows should generally be in the 30s and 40s. Elsewhere, Burlington will likely see highs mainly in the 20s and 30s. Lows should be in the teens.

[hcaeb]

Don,
What is your opinion of a major snow/ice storm for NC around the 12-13th of this month?

[Stephanie]

I can handle those temps!