Heat advisory extended as daily thunderstorm threat stretches into weekend

BOSTON - The National Weather Service has extended the heat advisory for central and eastern Massachusetts through Wednesday.

Heat advisory Massachusetts

The advisory now stretches all the way to the coastline to include Boston and the North and South Shores. It's now scheduled to end at 8 p.m. Wednesday, a day later than originally expected.

Again, if you are not in the shaded areas that does NOT mean that you won't experience some periods of high heat and humidity. The National Weather Service is simply highlighting the areas most at risk for heat indices between 95 and 100 degrees.

Air quality alert Massachusetts

In addition to the heat advisory, parts of eastern Massachusetts are also under an air quality alert through Tuesday night. This is posted due to higher levels of ozone being detected at ground level and is mainly a concern for sensitive groups such as the elderly, children and those with respiratory issues.

You can expect more heat and humidity through the remainder of the week and less chances for storms.

Heat wave, but no record heat

We will likely reach or exceed 90 degrees in parts of the Boston area each and every day through Friday. You need three consecutive days above 90 for an official heat wave.

The temperatures will not reach record levels, staying mainly in the low 90s, but combined with a persistently and oppressively humid airmass, each day will have "feels-like" temperatures nearing 100, especially in and just to the northwest of Boston.

Beryl path

The main reason for extending the heat advisory and the hotter forecast later this week is that it now appears the remnants of Beryl won't have much impact on southern New England.

The center track of what is left of Beryl will move through the upper Midwest and into Canada later this week, several hundred miles away from our area.

Therefore, the shield of rain will remain quite a far distance away, tracking through upper New York state and northernmost New England.

In the Boston area there will be a daily, isolated threat for a few showers or thunderstorms but nothing widespread or long-lasting. We cannot completely rule out a thunderstorm each and every day through Saturday, but no day is expected to be a washout.

We will hone in on the timing of any showers or thunderstorms for Friday and the weekend as we get closer. Stay with WBZ-TV, WBZ.com and CBS News Boston for frequent updates.