It is like the weather pattern has turned on the atmospheric hose! April was dry with a minor drought developing. Since May 8th, the tables have turned and we have seen up to 7-9″ of rain! Tropical storm Andrea water logged the region with 4-6″ of south of the MA Pike. And now, another slug of soaking rain to move through with additional 1-2+”. Bye Bye drought! Flood Watch has been posted through Tuesday Night because of the high water table currently in place. Most small rivers and streams will be vulnerable to more flooding. Excessive water will lead to the potential for more street and poor drainage flooding in any downpours.
A warm humid air mass is surging up the Atlantic seaboard with a trough directing a strong SW flow right up into New England. There is currently a cool dome of air across the region. This warm humid air to the south is lifting up over the cooler air in the form of an approaching warm front which is moving towards us this evening. Showers have been turning into a steadier rain. We will be tracking strong to severe thunderstorms in the mid-Atlantic states which will be shifting northward into New England tonight. These storms will weaken upon their arrival, but heavy downpours with rumbles of thunder are possible late tonight through the early morning hours which could drop rainfall rates up to 1″ an hour and help to create this localized flooding while most are asleep.
With a low to our west, the warm front will begin to push into SNE Tuesday where it will stall. The heaviest rain will be quickly be ending early tomorrow and lifting north and pulling off the coast. Still expect damp drizzly conditions with a few left over showers for the AM commute. The trend will be for drier weather to develop by the late morning into the midday with a few breaks of sun possible. CT may get into the warm humid sector and climb into the 70′s behind the warm front, while most of us will remain in the 60′s. A cold front will sweep through tomorrow afternoon with the low tracking through the region. This may trigger another round of thunderstorms for the mid-late afternoon which will track from west to east. Any breaks of midday sun will increase our risk for strong storms to develop. If clouds hold, it will be cooler and more stable…so less of a risk.
The upper low will still be over us on Wednesday…so expect plenty of clouds to linger with breezy WNW winds in place. Brighter skies should be found in western new England. Wednesday will be an overall drier day, but still just enough instability in place for a few scattered showers with highs in the lwr 70′s
In case you have not noticed, the atmosphere is in a bit of a blocking pattern. A large area of high pressure in the Atlantic is helping the Jetstream to buckle with a persistent trough in the northeast with several shortwaves which continue to spill into this trough keeping a very active weather pattern going with seasonable cool temps for the week ahead. Another vigorous short wave will track from California, over a ridge in the Midwest and head back down into the trough across the Northeast for the end of the week.
This will be a wave of low pressure which will track south of New England. yesterday, it looked like it would track far enough away from us to keep rain out of the forecast for the end of the week. The latest information shows this low track closer to New England. A low will from in the Midwest, and track east through Pennsylvania and off the coast of New Jersey. Once off the coast it should become a stronger low. This low will likely be se of Nantucket early Friday. After some sunshine Thursday morning… It appears we will have to watch for another round of rain late Thursday-Thursday night into Friday morning. Gusty winds and larger swells may become an issue depending on the strength and track of the low. This could also come with another heavy swath of rain which could lead to more flooding in southern New England with a few more inches of water to fall. Still plenty of questions still to be answered this far out. Nothing is certain yet. Luckily this will be a fast moving low…so the heavy rain and wind should be quickly departing Friday.
Another shortwave will dive down for James Bay bringing with it cooler dry air. This will reinforce the trough across New England all weekend with a seasonally cool air mass in the middle 70′s. At this point the weekend looks dry and pleasant with a mix of sun and clouds. After this week….it will be a welcome break.