Good morning everyone, Attached is our updated weather briefing regarding the upcoming heatwave. We are now confident that the heatwave begins on Sunday for some locations, especially in the Connecticut River and Merrimack valleys. We have attached the following: 1. Maximum heat index/apparent temperature values for Sunday through Tuesday. 2. One-pager briefing. Our next update will be by 6 AM Sunday unless there are major changes to the forecast. Thank you, Rodney Chai and Hayden Frank If you have any questions or would like more information, don't hesitate to contact us via this email address, on NWSChat <https://nwschat.weather.gov/>, or at the following: National Weather Service Boston/Norton, MA 46 Commerce Way Norton, MA 02766 508.622.3280 Website <http://www.weather.gov/boston> | Facebook <http://www.facebook.com/NWSBoston> | Twitter <http://www.twitter.com/NWSBoston>