Weather for New England and the Northeast

Area Forecast Discussion
National Weather Service Gray ME
222 PM EDT Tuesday, June 16, 2026

**What Has Changed**

Another Coastal Flood Statement has been issued for Portland and points south for tonight's high tide cycle.

**Key Messages**

1. High astronomical tides continue into the middle of the week with minor flooding possible around the times of high tide.

2. Expect slightly warmer temperatures on Wednesday with some isolated to scattered showers and thunderstorms during the afternoon, mainly over the mountains.

3. A strong storm system crosses the region on Thursday, likely bringing a soaking rainfall along with the potential for a few strong to severe storms in the afternoon.

4. The weather pattern remains unsettled Friday into the weekend with daily chances for afternoon showers and a few storms.

**Synopsis**

**Key Message 1 Description**

High astronomical tides will continue through the middle of the week. Wave action is not expected to be a significant issue until later in the week, and by then the tides will gradually be decreasing. Water levels are expected to run about 0.5 feet above normal again late tonight into early Wednesday morning, prompting another Coastal Flood Statement for Portland and locations southward where minor flooding is possible.

One more especially high tide cycle is possible late Wednesday night into early Thursday morning as this elevated water level remains in place. Current projections suggest tides should stay just below minor flood stage during that period.

**Key Message 2 Description**

A ridge of high pressure aloft, known as upper level ridging, will build into the region tonight and Wednesday, allowing temperatures to warm. Afternoon highs Wednesday will range from the upper 60s and lower 70s across northern areas to the upper 70s and lower 80s across southern areas and the coastline.

Later Wednesday afternoon, a weak disturbance in the upper atmosphere, known as a shortwave, will move through the region. This will bring a 20 to 40 percent chance of showers and perhaps an isolated thunderstorm. Most of this activity is expected to remain over the higher terrain and should fade after sunset as daytime heating decreases.

A strong upper level storm system and larger scale trough of low pressure will approach Wednesday night. The next round of precipitation may begin reaching southwestern New Hampshire late at night. Overnight lows will generally range from the upper 40s to middle 50s.

**Key Message 3 Description**

A strong area of low pressure, more typical of spring or fall than mid June, will move through the St. Lawrence River Valley on Thursday while dragging a cold front toward New England.

A widespread soaking rainfall is expected to spread across the region Thursday morning as a warm front lifts northward. Before the rain arrives, areas of fog may become locally dense during part of the morning commute, especially along the western Maine coast and nearby inland areas.

Thursday afternoon remains somewhat uncertain. The extent of onshore winds, rainfall, and low cloud cover will determine how much instability develops ahead of the cold front. At this time, western Maine appears likely to remain more stable due to cool marine air, while southern New Hampshire has a better chance of warming into the warm sector, the area of warmer and more humid air ahead of the cold front.

Some forecast guidance suggests atmospheric instability could reach around 500 joules per kilogram of surface based CAPE (Convective Available Potential Energy), a measure of how much fuel is available for thunderstorms. Strong wind shear, which is the change in wind speed and direction with height, will also be present.

If enough instability develops, a few storms could become strong to severe, producing damaging wind gusts and possibly even an isolated tornado. Because instability remains uncertain, forecasters continue to agree with the Storm Prediction Center Marginal Risk, Level 1 out of 5.

Heavy rainfall is also a concern. The atmosphere will contain abundant moisture, measured by high precipitable water values, and strong lifting mechanisms will be present. As a result, parts of the region remain under a Marginal Risk for excessive rainfall.

Two areas of gusty winds bear watching outside of thunderstorms. Locations that enter the warm sector could experience wind gusts of 30 to 40 mph. Along the coastline, a strong low level jet, a ribbon of fast moving winds a few thousand feet above the ground, could also contribute to gusty conditions.

Some patchy fog may develop Thursday night if winds become light enough. Otherwise, skies should gradually clear behind the cold front.

**Key Message 4 Description**

From Friday through the weekend, a broad area of low pressure aloft will remain over northern New England. This pattern will support rising air, periodic disturbances rotating through the atmosphere, and increasing afternoon instability.

As a result, expect fair weather clouds to develop each day along with scattered afternoon and early evening showers and a few thunderstorms. The highest chances will generally be across the mountains.

Forecast soundings indicate that some of the stronger storms could produce small hail.

Friday and Saturday will also be somewhat breezy. High temperatures will generally reach the 70s and 80s on Friday, then mainly the 70s during the weekend.

Looking ahead to early next week, forecast models are in reasonable agreement that another upper level disturbance will move through the Great Lakes region. This could lead to the development of a surface low pressure system as it approaches New England, bringing another opportunity for more widespread precipitation. However, the exact track and timing remain uncertain at this point.