A strong cold front will move through the area late Thursday. Ahead of it, muggy and hot conditions will produce the instability needed to fire up scattered storms.
The best chance of storms through early afternoon will be across northwestern Virginia. The Richmond metro area will see the best chance of storms after about 4 or 5 p.m.
The muggy air will allow any shower or storm to unleash very heavy downpours. A few isolated storms may produce damaging wind gusts. The threat for stronger storms will end by midnight as the cold front reaches the coast.
Humidity levels will drop a bit on Friday, but it will turn more humid over the weekend into early next week. During this period, highs will reach or exceed 90°.