We've finally turned the corner on the recent wet weather pattern. Only widely scattered to isolated showers & storms will develop Fri. with cells inland west of I-95 & especially west of Highway 301. A light onshore east wind will keep afternoon temps. in the 80s at the beaches but low to mid 90s inland. Much the same for Sat. then a bit more moisture returns Sun.-Mon. bringing a little more shower & t'storm activity but long parts of Sun. & Labor Day will still be dry. Showers & storms will gradually increase again next week.
Nicholas Thompson sent a nice pic from Wed's. storms - a roll cloud/gust front in Jacksonville. The cause: cool, sinking air from a storm cloud's downdraft spreads out across the surface with the leading edge called a gust front. This outflow undercuts warm air being drawn into the storm's updraft. As the cool air lifts the warm moist air, water condenses creating a cloud which often rolls with the different winds above and below (wind shear).
"Isaac" is still rolling northeast & soon to the east & -- though weakening -- is still producing heavy rain. Kind of an intriguing possibility is that several forecast models show the mid & upper level disturbance from "Isaac" moving east into the Ohio Valley this weekend then back to the south next week reaching Florida about midweek(!). It's really just a curiosity as there will no longer be a surface reflection (low pressure) even if the upper air disturbance manages to get back to the Gulf or Atlantic. Surface development is unlikely (though it's wouldn't be impossible - remember "Ivan"? - see the 2nd map below. Depending on how much moisture is available, the disturbance could increase showers & t'storms some. So it'll be interesting to watch the Isaac's "leftovers".
Check out NASA's TRMM image below & click here for an animation & some narrative. The red colored areas equate to rainfall rates of nearly 3"/hour.
