Flash flooding paralyzes Boston morning commute

Driving the news: The Expressway fully closed at Exit 3 in Milton for several hours during the morning rush hour.

• Flash flood warnings went out to around 500,000 residents' buzzing phones about dangerous conditions until 11:15am.
• Multiple municipalities reported road closures and basement flooding. Some vehicles were stranded on highways when the waters hit.

By the numbers: Rainfall totals varied across the region, but areas south of Boston got hit hardest.

• Hingham got blasted with about 5.65 inches while Boston proper saw less than 1 inch.

Zoom in: The flooding came after, pardon the pun, a perfect storm of meteorological conditions: high humidity levels, slow-moving storm systems and a high tide around noon.

The bottom line: Highways reopened in the late morning and afternoon as the flood warning expired.