As our WCSH cameraman/audio operator/jack-of-all trades Gordon says, "St. Patrick's Day is the measuring stick for spring. Some years you are in shorts, others you are shoveling." (He would know, he's the most Irish guy I know. And, being from Boston, that's saying something)
Well if that's the case, and you measure spring by St. Patrick's Day, then this spring will be deemed chilly but bright. However, if you judge spring by the official start date (Wednesday) you may deem it to be entirely wintery. More on that later...
Today: With an upper level disturbance from last evening now offshore I see no reason we should develop anything more than a little high thin cloud cover through the day. Still, despite a good amount of sunshine, temperatures will struggle with highs in the mid 30s in most spots, some upper 30s over southern Maine.
Tonight: A clipper type storm system will sail to our south this evening but come close enough to take us from mostly clear to mostly cloudy by midnight. This will actual prove to be a positive though as it keeps overnight lows in the teens (still cold for mid-March) instead of allowing radiational cooling to take over and plummet temperatures further.
Sunday: High pressure in place over Canada will dominate our weather for St. Patrick's Day so look for mostly sunny and dry conditions. However, once again we will be quite chilly with highs this time around ranging from the upper 20s to around freezing. It will feel even colder due to a brisk northwest wind, so if you are going out bar hopping...I'd dress warmly.
Monday: Another pleasant but cool day with high pressure directly overhead this time. That will mean the winds settle down but temperatures remain in the low to mid 30s despite almost full sunshine.
As for our Tuesday/Wednesday storm: No big changes in my thinking here. The EURO continues to paint a VERY snowy picture with almost statewide 12"-15" amounts, signaling no changeover to rain even along the coastline. Meanwhile the GFS gives the coastline a good shot of snow (4'-5") before bringing in the warm air and pushing the rain/snow line back to the foothills. All told the GFS has flinched a bit more than the EURO as it has trended towards a slightly colder solution while the EURO has been consistent run after run. (In the world of car salesmen the EURO sticker was $20,000, the GFS countered with $15,000, the EURO "checked with his boss in the back" and came back with $19,999)
For what it's worth I still find the EURO overly cold given the track (over Boston and then over Portland) of the coastal low pressure system. I continue to like a blend solution that gives everyone snow to start on Tuesday morning, mixing with rain along the coastline by late afternoon/early evening but remaining mostly snow inland and ALL snow in the mountains. This would yield (roughly, it's still over 3 days out!) a 4-7" band along the coastline, 5-10" inland and 6-12" in the mountains.
I'm going to continue to watch the latest models runs today and see if there is a clearer trend as far as vertical temperature profiles and timing of that coastal low development (the two keys to this storm).
By the way the timing on this is snow starting early Tuesday morning and wrapping up early Wednesday over southern Maine and Wednesday afternoon over northern Maine. (Far northern Maine could be the jackpot from this storm with up to 16" in Caribou)