3 pm update: A flash flood warning has been issued for southern Middlesex, Suffolk, central Norfolk, north central Plymouth, and eastern Worcester counties.
2 pm update: Severe thunderstorms have developed along a cold front this afternoon. Storm motion eastward will continue through the afternoon and evening and bring the threat of strong storms to the Boston area by 3 pm.
So far, we've had gusts 60+ mph and quarter size hail reports—both criteria for a severe thunderstorm. The weather will be slow to clear up as more storms linger back through western Mass.
Improvements will likely arrive this evening around 7 pm in Boston. The threat for strong storms and downpours will continue across southeastern Mass into the evening.
noon update: A line of showers stretched from NW Mass into southern New Hampshire by noon.
This cold front, today's storm trigger, is a slow mover. That means central Mass storms early-mid afternoon may not reach the Boston area until 5 pm latest. A safe bet would be to expect storms around 3 pm. There's the slight chance of a storm at the end of the Red Sox 1 o'clock game. Most likely, I expect thunderstorms between the two Red Sox games today. We could see them linger into the early part of the 7 o'clock game, but rain/storm chances will steadily fall through the evening in Boston.
The storms will stick around south of the Mass Pike into the evening. This is where the greatest threat for severe weather and flooding exists this evening and tonight with so much available moisture.
Lightning and slow-moving heavy rain will be the main concern with afternoon storms. Some wind damage is possible in the area, but it's the downpour potential that will steal the headline today. Cities or towns where storms get stuck may see 1" or rain… That's a lot on top of the 8"+ we've had this June and may lead to locally flooded streets with slow drainage.
Some lingering clouds and a light shower may linger into the morning across southeastern Mass. Sunshine will overspread the region from west to east and take full hold of southern New England by afternoon. Humidity levels will be lower tomorrow with highs in the mid 70s—a wonderful outdoor day!