Spring Fever...
We just missed a record today in Boston the high was 59 set one minute before 4PM the record of 61 set back in 1981 still stands. Of course the near record warmth was interesting today but what I found most interesting was the temp drop that occurred between 4PM and 5PM...59 to 42 in one hour!!! Similar temp drops were occurring all over Southern New England and they weren't just happening at the coast. In fact, the wind was out of the East at only 5mph...a feeble seabreeze, one that could not be solely responsible for the chill down that was happening in towns like Bedford and Nashua and Fitchburg miles away from the ocean. So if the cold wasn't being advected in from any direction (most stations were reporting calm wind) then the source had to be either from above the ground or from what's on the ground...snow. The Blue Hill Observatory is the key...current temp 600 feet up is 50 degrees so it's actually warmer AGL (above ground level)...thus the snow is the source. Without any wind and mixing, it is acting like a refrigerator and cooling the air near the ground, that air gets trapped under the warm air and has no place to go...it will keep cooling to its dew point in spots later tonight and areas of fog will form. Pretty cool right?!?!?!
We get another warm one tomorrow but with limited sun highs likely won't reach the lofty levels of today...mid to upper 50s. A coldfront will move through later in the afternoon with a few showers but more importantly colder air for the weekend. The cold will be in place when the next system works in from the west but the question is will it be able to hold and right now it doesn't look that way. With no blocking high to the north warm air advection preceding the system should successfully usher in some warmth.
