A storm will bring damaging winds, heavy rain and warm air to Boston midweek

A strong storm system will bring significant weather impacts to Boston Tuesday night into Wednesday. Heavy rains, gusty winds and a wave of unusual warmth will blow through New England before cooler air returns. Here’s what you need to know:

Heavy rain and risk of flooding

Boston will see about 2 inches of rain late Tuesday through Wednesday evening. Much of the area will see 2 to 3 inches of rainfall, with local amounts of around 4 inches possible.

While this causes water levels to rise and helps alleviate drought conditions, it also increases the risk of urban flooding and poor drainage, particularly in areas where leaves clog stormwater drains.

If you travel, be prepared for backwater and limited visibility during the heaviest rains. You may even hear a few rumbles of thunder during some of the heaviest rains.

In terms of timing, a few isolated showers are possible on Tuesday evening, turning into more consistent pockets of rain after midnight. Rain will continue to fall on Wednesday, falling steadily and at times heavily before easing around midnight or just after midnight.

Damaging gusts of wind

The storm will bring a strong low-level jet across eastern Massachusetts, producing southerly wind gusts of 50 to 60 miles per hour. Winds will increase throughout the morning on Wednesday, with gusts above 40 on Cape Cod to begin and increasing to 40 to 50 mph gusts throughout the afternoon.

The strongest wind will blow on Wednesday evening between 4 p.m. and 9 p.m., coinciding with heavy rain. Gusts over 50 mph are most likely in Boston and surrounding cities during this time. Isolated gusts of 60 to 70 mph are possible, with the threat greatest in the southeastern part of the state, Cape Cod and Cape Ann. Isolated wind damage, fallen tree branches and power outages are likely.

Before the storm, secure loose outdoor items, especially light Christmas decorations.

Unusual warmth

A surge of warm air will accompany the system, pushing high temperatures in Boston into the low 60s on Wednesday – a stark contrast to the recent cold. Although December is particularly warm, it will not reach the record high of 68 degrees set in 1911.

Despite the warmth, rain and wind will dominate the day, so dress for wet weather. Maybe you skip the umbrella and opt for the raincoat because of the strong winds.

Cooler, drier air returns

As the storm subsides, temperatures will drop significantly. However, due to the persistent southerly flow, there is no risk of ice or frost from Wednesday night into Thursday.

Highs on Thursday will be in the low 40s, with brisk northwest winds gusting up to 30 mph keeping the air cool.