UPDATED: 12:45 P.M.

The region will finally get a break from the heat on Thursday, but not before a round of severe thunderstorms barrels through today and tonight.

The National Weather Service has issued a severe thunderstorm watch for all of Massachusetts, including Sudbury, in effect until 9 p.m.

Residents can expect the formation of severe storms immediately, with storms becoming more numerous as the afternoon progresses.

Some storms will likely have damaging wind, large hail and torrential downpours.

The risk of these severe storms will diminish as the sun sets, but strong storms will still be a possibility with flash flooding a main concern.

In these storms, the NWS says locations may receive 2 to 3 inches of rain in a short period of time.

In Massachusetts, the greatest risk of severe weather will be south of the Mass Pike.

If you witness severe weather, tell us about it in the comments section. And if it's safe, download pictures to this article by clicking the Upload Photos and Videos button.

The NWS has also issued a heat advisory for the area in effect until 7 p.m.

Heat index values are expected to reach 100 to 104 as temperatures reach the low to mid 90s and dew points hitting 70.

With heat index values that high, heal illnesses are possible.