New England weather this week: Gradually improving

This week will start off unsettled, wet and cool, but conditions will gradually improve through the week.

MONDAY

A slow moving cold front that helped bring areas of southwest Connecticut nearly a foot of rain yesterday will finally cross New England this afternoon and evening. This will create a generally unsettled day ahead of the cold front, with scattered showers and thunderstorms developing. Showers and storms will be isolated this morning before becoming more numerous heading into the afternoon. The main line of storms associated with the front will move through New England later in the afternoon and evening.

HRRR showing potential weather early this evening:

Photo byHRRR/Tropical Tidbits

With the atmosphere remaining moisture-rich ahead of the front, along with the extremely saturated soils in places, there is a continued risk of flash flooding. While a widespread quarter inch to one inch of rain is likely today, areas that get under a thunderstorm will see more. Any area that sees multiple thunderstorms today could see multiple inches of rain. As usual, exactly where these storms hit is hard to say until they actually start forming. It goes without saying that areas that have seen 8+ inches in the last 24 hours are at a high risk.

Photo byNew England Storm Center

The threshold for flash flooding to occur in many areas of western New England has dropped to 1.5-2 inches of rain in three hours. Six hour flash flood thresholds have dropped to 2 inches and locally lower in areas that saw significant flooding yesterday. With thunderstorm development possible today, those numbers are dangerously low. The best news is that, unlike yesterday, storms will generally be moving along rather than sitting in place.

Photo byNortheast River Forecast Center

While the threat of additional flooding is by far the greatest risk today, there is a low threat for some of the storms to turn severe. While some ingredients are in place for severe storms, instability will be a major limiting factor. The greatest threat in any storm that becomes stronger will be damaging winds gusts and small hail.

Photo byNew England Storm Center

Thunderstorms should weaken quickly this evening once the sun sets, which will limit both the flood and severe weather potential for areas farther east in New England, where the cold front will cross after dark.

TUESDAY & WEDNESDAY

Some lingering showers will be possible Tuesday morning as the front pushes offshore. In addition, a weak area of low pressure will likely drop down from Canada, continuing the chance for showers on Tuesday and Wednesday afternoon, mainly in the mountains. This disturbance will bring plenty of clouds for both Tuesday and Wednesday for all of New England. Drier air will help keep any shower coverage during this time on the low side.

The main story will be the cool, fall-like air mass that will set up across New England post-frontal crossing. Highs may struggle to reach the 70s in many areas of New England, with everyone likely failing to reach the mid-70s. Humidity will also nose-dive during this time as well.

Photo byNew England Storm Center

THURSDAY & FRIDAY

By Thursday, the low pressure that dropped into New England on Tuesday will likely have wobbled its way north, near New Brunswick. This will keep shower chances around for northern Maine and northern New Hampshire on Thursday, but high pressure building to the west of New England should allow for drier, sunnier times for everyone else with temperatures beginning a warming trend.

Photo byNew England Storm Center

On Friday, this low should continue to exit New England with high pressure looking to take control of the region. This expansive high pressure is currently on track to set up to the southwest of New England, which should support a continued warming trend through the weekend. Temperatures are currently looking to get back to seasonable levels by Friday. All of this will be contingent on the upper low departing on time.

WEEKEND

Heading into this upcoming weekend, the ridge of high pressure looks to keep control over New England with dry and warm conditions. After a cool week, the weekend is currently favored to see temperatures climb back to more summery levels, with 80s dominating for much of the region. For now, there's not much to say about this upcoming weekend, which is certainly a good thing in the weather department.

Weather map for Saturday (August 24):

Photo byWeather Prediction Center

BEYOND

For those not looking forward to a fall-like week in the middle of August, the warm-up expected at the end of this week is supported by the Climate Prediction Center's 6-10 day outlook. This outlook features New England with up to a 70% chance of above average temperatures heading toward the start of September. We did mention that a cool-down in the middle of August may be followed by a warm-up to end the month in our monthly outlook published at the beginning of this month.

Photo byClimate Prediction Center