Scattered Storms to Develop for New England This Afternoon Before Great Weekend

An upper-level low will likely travel north of New England today, dragging its cold front across the region. This system will be slowed down by another system well offshore. This will allow for moisture to stream into New England ahead of the front and allow for a period of widespread showers and thunderstorms, bringing some beneficial rainfall.

This morning's round of showers will likely weaken and become more isolated as they push eastward. As the front pushes east through the day, showers will become more widespread and conditions will become more favorable for scattered thunderstorms. Areas east of the Connecticut River will have the best chance at more widespread afternoon activity, including thunderstorms, beginning in the early afternoon and continuing through the evening.

Below: FV3 showing potential weather this afternoon:

Friday will be an unsettled day all around, with the potential for multiple rounds of showers and thunderstorms. With that said, it will not be an all-day washout for anyone. Morning showers will mainly be limited to western New England and the more widespread afternoon activity will involve scattered thunderstorms rather than a shield of steady rain. It stills looks likely New England will see a widespread 0.25 to 0.75 inches of rainfall. Rain totals will likely end up highly varied from area to area given the scattered nature of thunderstorms.

A narrow ribbon of elevated moisture is expected to develop ahead of the front, and where this sets up in the afternoon will likely see the most rainfall out of this system. Maine is still in line to see the most widespread rainfall from these storms as storms will likely be most widespread across the state. Maine also has the best chance to see multiple rounds of storms. There is a chance for some storm training within this band of elevated moisture. This band is likely to set up in a line from eastern Massachusetts through southern New Hampshire and into interior Maine.

Storms may be able to re-develop in these areas and train as flow will be parallel to the cold front. This means thunderstorms could move over the same area for a couple hours this afternoon and evening. Should this develop, localized rainfall amounts of 1-3 inches would be possible, leading to isolated flash flooding. The Weather Prediction Center has placed this ribbon of moisture in the "marginal" category (level 1 of 4_ for excessive rainfall today. Flash flooding remains a low concern and this will be all beneficial in the long-term.

Below: WPC excessive rainfall outlook for today:

While shear will be modest in the afternoon, which is the main ingredient for storms to strengthen, not much else is working in favor of strong to severe storms. Instability will be low and moisture overall will be marginal. The overall setup will be rather similar to Wednesday with very cold air moving in aloft, so small hail and gusty winds will be possible, but both hail and wind will very likely remain below severe thresholds.

The upper-level low will likely remain parked just to New England's north for much of Saturday. The system's front may not clear eastern Maine until later Saturday morning. With the system parked just north of New England, scattered showers will likely continue into the day across the northern third of the region, with the most widespread activity across eastern Maine. High pressure will be trying to nudge back into New England in the wake of the frontal passage, aiding in conditions drying out Saturday for most.

Once this system clears out of New England's area by Sunday morning, sprawling surface high pressure will take hold. This will likely bring several days of very quiet, dry and seasonable weather through the middle of next week. A persistent dry, continental air mass over the region will keep 70s dominating for highs with minimal to no humidity. New England's next shot at more widespread rain likely won't come for at least another week. Early indications show another cold front with a low developing offshore next Friday (September 5).