4:15pm EST Friday 2-24-12
New radar updates filtering in now and the situation is clear. Definite spin with the original low and secondary low forming as well. The low has stalled and so precip will hold off until after dark. Second low will intensify as it moves NE and bring more stable accumulations with dropping temps. Snow will end near dawn Saturday in most areas excluding the mountains where upslope snow showers will continue to crank Saturday
Coast south of Portland- Coating to 1″
Coast north of Portland – Bath excluding Yarmouth, Freeport and Falmouth 1-3″
5 Miles inland to 20 Miles inland including interior Casco Bay- 3-6″
20 miles inland to mountain zones 4-8″
Strong coastal low developing rapidly with cyclogenisis occurring near 40N 70W as the low moves NE.
Updates will continue to flow in as the weather continues to progress.
7:45 pm EST Thursday 2-23-12:
New forecasts coming in now and still trending cooler. This means that the secondary low will develop more quickly and reach a greater intensity before being driven off by approaching high pressure that will be building in for Saturday.
Low will approach the area tonight and snow will start at around 5:30am. Little accumulation before dawn but this thin layer will set the stage for more efficient accumulations with heavy snows later. Heavy snow will come with the 2nd low forming roughly 50 miles NE of Boston. This new low will start out fairly strong and will continue to deepen though cyclogenisis is not expected at this point. The new low will start to pull in sufficient cold air starting around 11:00. Warm air advection (which is warm air interacting with cold air usually overtaking it and produces precipitation) will be halted or significantly slowed by this point due to cool air being wrapped in by this point by the secondary low.
East winds brought on by the secondary low passing south of us will draw in warmer air along the coast and we will see a change to sleet possibly mixing with rain.
Snow amounts: Southern York County: 1-3″
Coast north of Portland to 20 miles inland: 3-5″
Inland and foothills: 4-6″
Snow will be falling today in NE as a warm front pushes north. The warm front will bring warm air and this will cause a mix at the coast and some light rain tomorrow. After that the forecast really becomes extremely unclear. Models like the idea of a coastal storm developing Friday or Saturday with an extremely large trough digging down through the eastern third of the country. Models have been backing off on that solution however there is a possibility to see a storm develop Monday.
Overview: Strong low pressure will move swiftly out the mouth of the St Laurence and has already pushed a cold front through overnight. Strong winds will develop behind the front bringing in cold air. Winds will gust to close to 50 mph out of the W or possibly WNW or NW. Tomorrow will feature clouding skies and a lot less wind. Thursday night will bring a clipper system to the area developing a coastal low in the southern Gulf Of Maine. These two systems will bring close to 6″ to the midcoast and Central Maine with 4-5″ along the coastal plain ( the waterline to around 10 miles inland) with 2-4″ in the mountains 3-5 is likely in the far north. Saturday will feature a second clipper system and coastal low so the results will be very similar to that of the Thursday night storm. Monday will feature yet another storm and since the models diverge and the storm is in the long range forecast details are uncertain but we do think that as of right now it looks like a wintry mix along the coast with more snow inland.
Details: Winds will pick up as the day goes on peaking at around 9am with 50+ mph gusts and sustained winds peaking at around the same time at 25-30 mph. This wind will bring in colder air and will set the stage for two systems which will affect the area Thursday and Saturday nights.These two systems will bring close to 6″ to the midcoast and Central Maine with 4-5″ along the coastal plain ( the waterline to around 10 miles inland) with 2-4″ in the mountains 3-5 is likely in the far north. After that we will find a quiet and cold end to the weekend. Monday however will be different with temps at the coast in the mid 30s so at this point it looks like a tricky forecast and a mix at the coast.
Mid Atlantic: Windy today but winds will calm as the day goes on and become cooler. This cooler air will set the stage for some flurries for Thursday night although the southern sections will not get too much precipitation in the next week with Thursday and Saturday nights being the only two times precipitation in the southern sections. The northern sections however will get some more prolonged snow showers Thursday and Saturday nights which could leave a coating to an inch on grassy surfaces.
Saturday 8:00 am
New England or Zone 1
Today will feature a chance of rain showers diminishing as the day goes on. Also Winds will be shifting to the north at about 5 mph.
Temperatures will be peaking in the lower 40s in southern sections and the upper to mid 30s inland.
NY South to DC East to VA Beach Or Zone 2
Clearing faster than Zone 1 however there is still a slight chance for a passing shower in the North of Zone 2 as a weak cold front moves through.
Southern areas ( Richmond to DC to Chesapeake bay to VA beach) will experience highs in the lower 60s and Northern regions (anything North of there in zone 2) will see highs in the 50s(upper 50s south and lower 50s north)