It was a nice couple days of heat indices “only” in the upper 90s to low 100s, but we return to Advisory-level heat on Sunday as air temperatures in the mid-90s combine with dewpoints in the mid-to-upper 70s to yield heat indices 108-110°. Once again, you’ll want to be sure your outdoor activities involve frequent breaks in the shade with plenty of water.
Those outdoor activities may become disrupted as we get into the afternoon and evening hours as thunderstorms begin to fire along and ahead of the seabreeze. Coverage should increase as the evening goes on as a disturbance aloft swings by. Scattered to numerous showers and thunderstorms will be possible with some periods of locally heavy rain and cloud-to-ground lightning. A few stronger storms could produce sporadic damaging wind gusts, so be alert for possible severe weather warnings as well. Regardless of the severity of the storms, lightning makes every thunderstorm dangerous. If you can hear thunder, you’re close enough to be struck by lightning, so move those outdoor activities inside if a thunderstorm approaches your location. Most of the activity should disperse as we get later into Sunday night, though some could hang around with the energy aloft and an approaching front.
We’ll want to keep an eye on Monday for the potential for some flooding as slow-moving showers and storms should fire on that aforementioned front as it stalls out across the area. I’ll have more on that risk tomorrow as more data rolls in.
The weekend’s forecast will feature continued summer heat and humidity with showers and thunderstorms each afternoon.
We’ll start Saturday in the mid-to-upper 70s away from the coast, warming to the low to mid-90s in the afternoon. Dewpoints will be on the rebound after a slightly drier Friday, but heat indices should stay below the Heat Advisory threshold of 108° for one more day. That being said, it’ll still be plenty hot: it’ll feel like 103-105° at the height of the afternoon. The seabreeze will be the focal point for scattered thunderstorm development in the afternoon, with additional storms firing off outflow boundaries. Some of us may see a storm to cool us off, but others will not. High-resolution guidance is pointing at areas along and west of 17-A for the best chance for storms.
More widespread storms are possible Sunday ahead of another “cold” front that’ll be moving in from the north. Ahead of this front and before storms kick off, air temperatures could head into the mid-90s. This, combined with an increasingly humid airmass, could send heat indices toward the upper 100s and, after a couple days off, another Heat Advisory. Many of us should see relief, though, as showers and thunderstorms develop in the afternoon through the evening via the seabreeze, outflow boundaries, and the approaching front. A couple storms could be on the stronger side with damaging wind gusts the main concern as well, so be aware of that possibility.
