09/08 – Brantly’s “Scattered Showers” Tuesday Afternoon Forecast
Tuesday and Wednesday, an extension of a large and deep layer high pressure system over the Atlantic will develop over the interior southeast U.S. into the lower Mississippi Valley on Thursday, and this should block any additional transport of moisture into the central Gulf coast region, and could suppress the amount of convection. For now, the models and current forecast keeps rain chances in the isolated range north and scattered range south.
The cutoff low over the central Rockies is expected to gradually open into a potent shortwave trough that will move across the northern Plains late Friday and Friday night and the upper Mississippi Valley Saturday. The southern portion of the trough will not be anywhere near the Gulf coast, however the lower Mississippi Valley ridge will be suppressed and positioned more to the north and east again.
There is no longer any push of drier air with a frontal boundary expected, but rather more moisture from easterlies and inverted trough features from Florida and the eastern Gulf coast into the central Gulf coast region over the weekend and early next week. This will mean typical September heat and humidity and daily rain chances from daytime heating driven showers and thunderstorms.