Friday, February 16, 2007 Forecast

There are a two events in the next week that we need to talk about. The first one is the clipper this Sunday that I had mentioned before. The second is potential coastal storm next Thursday.

Today through Saturday will be very nice days. Temperatures will be a little cold today but will rebound significantly into the 20's tomorrow and for Saturday. Clipper system pulls through on Sunday bringing a chance of snow showers. This could dump an inch or maybe two inches before the snow ends Sunday Night. Im going to throw in the towel on the possibility of any redevelopment of the low because at this point, even if it happened, the low would track too far east.

Colder and drier weather follows behind the storm for Monday and Monday Night, before high pressure scoots off the coasta allowing another warm up on Tuesday. Temperatures will climb to the upper 20's on Tuesday, and continue to around 30 on Wednesday and low 30s on Thursday. Skies through Wednesday will be partly cloudy.

Thursday (2/22): our next potentially major winter storm. Currently the only model actually going with this storm is the Euro, but with its past history this winter, I wouldnt blow it off. All the other models either dont develop the southern low or send it well south of the region.
Temperatures will be an issue with this storm for sure. We couldnt even come out with all snow for Bliz07, so with temperatures around freezing, we may have to worry about icing more than anything. Closer to the coast will probably be rain.

Ensemble forecasts for the AO have a consensus for near neutral by the 19th. However, then they split up with some taking the AO into the positives, and others dropping it negative again. This will decide on whether cold intrusions continue. The NAO is remaining neutral through the next two weeks, and so blocking will be minimal at best but at least we will not have a powerful PacJet racing through. The PNA is what will destroy the trough and the cold in the east. Ensembles have a general consensus for a negative PNA by the 19th. This will ultimately shift the western ridge into the midwest, stopping all arctic flow into the upper plains. The ridge will not make it all the way east because of a continued neutral to neg AO, but will be enough to allow SE ridge build in and slightly warmer temperatures (nearing average) for the last week of February.
As for storminess, an overall increase in precipitation will occur through the end of February and into March as the southern jetstream lifts further north and we enter the path of the storms. As for snow, the warmer temperatures will make it harder to come by, but as long as the 850mb temps are cold, 8:1 to 12:1 ratio snow events are possible through March. There is a general outlook for storminess for the March 3rd through the 5th. I'll give more details on this threat later today.