New England's First Decent Slug of Rain in a While is on the way

Yesterday's cold front will remain virtually stalled across southern New England today. This will likely keep unsettled weather around throughout the day with cloudy skies and scattered showers. The day won't be a washout anywhere, but multiple rounds of showers may pop up throughout the day with dry breaks in between. It will be much cooler than Tuesday as well on the other side of the boundary, but humid air will stick around.

The trough centered over the Great Lakes will dig deeper into the central United States later in the week. This will allow another surface low pressure to form over the Midwest and push northeast, toward New England. This system will likely lift to New England's west and north, acting as a frontal system for the region with a warm front moving in before a cold front. This system will act as New England's best chance for a widespread, soaking rainfall in a while.

There is certainly washout potential for New England on Thursday and Thursday night. With that said, the rainfall rates likely won't be constant through the entire duration of the storm. Multiple waves of rain and storms may bring an ebb and flow throughout the day. An initial round of scattered showers and downpours will likely move southwest to northeast across New England through the morning hours. A second main round of rain will likely push across the region through the afternoon and evening, with scattered showers in between.

Below: HRRR showing potential weather Thursday mid-morning (1st image) and Thursday mid-afternoon (2nd image):

The main slug of rainfall moving southwest to northeast Thursday afternoon will continue to steadily push through New England in the evening and into the overnight hours. By Thursday night, this rain will likely have pushed into the northern third of the region, including much of Maine. The system's cold front may ignite a line of showers and storms as it moves across southern and central New England during the overnight hours as well.

Below: HRRR showing potential weather heading into Thursday night:

With the system moving to the west of New England, it will be interior New England that will have the best chance at the highest amounts, mainly western Massachusetts and Connecticut. Overall, a plume of deep, Gulf moisture looks to continue to move up the east coast, funneled by a ridge of high pressure offshore, allowing for rounds of moderate to heavy rainfall. Again, this plume of moisture is what separates this system from the systems of the past few weeks that ended up drying up on arrival.

Below: GFS showing PWAT values (a measure of moisture in the atmosphere) Thursday evening:

Precipitable water (PWAT) values are expected to climb well over an inch, possibly pushing to near two inches. PWAT is a measure of moisture in the atmosphere. PWAT values well over an inch indicate a moisture-rich environment that is primed to allow for a good soaking (should a mode of forcing exist, which, in this case, is coming from the frontal system). A widespread 1-2 inches of rain is likely across the region.

Northernmost and southeastern-most areas will likely see the least, but still get a decent round of rain. It won't be a total drought-buster, but it will certainly help. It should be noted that the US drought monitor is updated weekly on Thursdays, but only factors in rainfall from the previous week through Tuesday morning. So most of the rainfall this week won't be factored into tomorrow's update, but rather, it will be in next week's update.

There is also a small chance for a few isolated strong to severe storms embedded within the rainfall. The main driver will be deep and effective shear with a low-level jet moving across the region. Naturally, this setup does not support a high amount of instability with thick clouds and multiple rounds of rainfall, and this will be the main limiting factor.

A warm front will put southern New England in the warm sector of the storm Thursday afternoon and evening, which will be the best time for any kind of severe weather to develop. Should instability manage to increase, this threat could increase, and the trends will be worth watching over the next 24 hours.

Below: Storm Prediction Center thunderstorm outlook for Thursday:

There remains uncertainty on how exactly this weekend will play out, but recent trends over the last 24 hours have been toward a drier Saturday. A secondary cold front will likely approach New England this weekend. The southwest flow ahead of this front will likely bring another warm-up, with some isolated to scattered afternoon showers possible. A sea breeze may bring a slight cool-down for Saturday, but Friday, Sunday and Monday are looking quite warm, with low 80s possible in the region's typical warm spots.