Update, Tuesday 12 PM: A Flash Flood Watch has been issued for the following counties: Jackson, Calhoun, Gulf, Holmes, Washington, Bay, Walton, Okaloosa, Santa Rosa, and Escambia. Several rounds of strong thuderstorms are expected over these areas Tuesday afternoon, followed by a squall line of storms Tuesday night. Several inches of rain could be produced by these storms, with local accumulations between 6-8" possible from the strongest storms.
The severe weather threat is expected to increase across the Florida Panhandle Tuesday as a deepening low pressure system migrates eastward into the Tennessee River Valley dragging a cold front to the south.
Throughout the day Monday an unseasonably humid air mass spread northward from the Gulf of Mexico creating an unstable environment prime for thunderstorm development. A few scattered storms passed through the Florida Panhandle but the majority of the severe threat remained to the north of the Sunshine State. However, another round of scattered storms, some of which could be severe is expected to arrive into western parts of the Florida Panhandle Tuesday.
Atmospheric shear, a key ingredient required for the formation of thunderstorms, is anticipated to be minimal Tuesday morning but quickly increase to become more favorable for storm development in the afternoon as the cold front approaches from the west. Storms will start out scattered throughout the first part of the day with weather models indicating storms to combine and form a squall line ahead of the cold front. This squall line is expected to move into western portions of the Florida Panhandle Tuesday afternoon and evening before slowly moving eastward overnight into Wednesday as it approaches central areas of the Panhandle.
The Storm Prediction Center has issued a Slight Risk (hazard level 2 out of 5) for northwestern locations of the Florida Panhandle with a Marginal Risk (level 1 out of 5) to the south and east from Pensacola through Panama City Beach. This is expected to change as the event draws closer.
A few thunderstorms could be strong to severe producing damaging straight line winds, small hail and isolated tornadoes. Isolated flash flooding will also be a concern for areas that pick up an abundant amount of rainfall.
The threat is expected to continue eastward overnight into Wednesday into parts of the central Panhandle and the Big Bend where a Marginal Risk is currently forecast. Weather models continue to indicated that the threat for severe weather could lessen for Wednesday as the cold front approaches. However, a few storms could still reach severe levels as they move towards the Peninsula.
Upon the passage of the cold front, cooler and drier air will penetrate into the region bringing relief to the summer-like temperatures which have been spreading across the Sunshine State.