Surface weather map at 1pm today from NWS/NCEP/HPCStrong northwesterly winds, gusting as high as 33 mph locally and 36 mph in Baltimore, are knocking the afternoon temperatures back to the upper 30s after a mid-day high of 42 in the Washington DC metro area. The winds are due to a deepening low pressure area just north of Maine. The instability in this flow is also producing very widely scattered snow showers on radar, although it is hard to find any stations in the local area actually reporting precipitation.
The snow-lovers, of course, are putting their hopes on the system after the next one. The models are developing a low in the Southeast which has the possibility of bringing the area's first significant winter event on Monday. Since this is still nearly 72 hours away, there is plenty of opportunity for the forecast flip-flop follies. For what it's worth, the early model run this afternoon (the "NAM") has a much weaker system further south on Monday than the other major model (the "GFS") from this morning. One thing for certain, however, is that there will be lots of
media hype. Kids, do your homework! Stay tuned to CapitalWeather.com through the weekend, and we will keep you informed.
Tonight and TomorrowTonight will be mostly clear with lows in the low to mid 20s. Tomorrow will be partly cloudy with increasing clouds late in the day, highs in the low 40s.
December HurricaneWhile extremely rare, December hurricanes are not unique, so it's only fitting that the record-breaking season of 2005 should have one. The National Hurricane Center reports that this is only the 5th such hurricane to form since 1851; the most recent was Lili in 1984. Epsilon acquired enough delta (change) to its v (velocity) in order to become a minimal hurricane this morning, and it is maintaining that strength in the advisory just issued. This is in spite of moving northeastward over cooler central Atlantic waters. It is still expected to weaken and lose tropical characteristics in the next couple of days, but it is likely to keep its identity as a circulation over the next 5 days.
Current Changes and Climate Image from CNN.comWhen I linked to Der Spiegel on Wednesday, my college German was too rusty to realize the article was about a significant new study published in the journal Nature yesterday. The paper,
"Slowing of the Atlantic meridional overturning circulation at 25° N", is available only by subscription, but the
abstract and an
editor's summary are available online. The gist of the reported result, although based on limited data, is that the Atlantic "conveyor belt" circulation which moves warm tropical water northward has weakened by about a third since 1957. Since this has some of the flavor of the "Day After Tomorrow" doomsday scenario, there is a definite risk of hyping the conclusions. Here are some press reports on the subject:
The RealClimate blog has a more
scientific analysis.