NEAR TERM [Through Tonight]...
Currently, an upper trough stretches down the spine of the
Appalachians and then westward along the central Gulf Coast.
At the surface, a cold front is analyzed from near Atlanta across
central Alabama to just north of New Orleans.
These features, combined with a deep feed of tropical moisture ahead of the front, are generating multiple bands of showers and thunderstorms across the tri-state area.
The front will sag southward through the overnight hours, with a weak wave developing over southern Georgia. This will keep the rain chances high through the night, especially across the southeastern two-thirds of the forecast area.
The far northwestern areas may see the rain taper off towards sunrise behind the boundary. Heavy rain will continue to be a threat overnight. Due to the pre-existing wet conditions over the Panhandle, this area will have the greatest threat for flash flooding. However, minor flooding of urban and low-lying areas will be possible throughout the forecast area overnight.
SHORT TERM [Sunday Through Monday Night]...
Through Monday, very broad and rather insignificant east-west
oriented upper level troughing will gradually wash out as a high
amplitude ridge moves east out of the Southern Plains.
In the lower levels, the aforementioned surface front will pass through
the Tri-State area tomorrow, and then stall over the northern Gulf of Mexico through Monday.
The surface front is essentially getting all its bang from low level forcing, and that is expected to continue on Sunday as the front continues eastward. Thus, rain chances will remain high once again. This will be especially true across north Florida, nearer to what will likely be a low-level PV induced low in the northern Gulf. Although widespread severe weather is not anticipated, there is a non-zero threat for an isolated tornado resulting from what could be a marginally strong low-level jet.
By Monday, the front will most likely remain confined to the northern Gulf. This will temporarily dry things out, with only isolated to scattered showers and thunderstorms expected over land.
Temperatures will remain below average through Monday due to the
abundant cloud cover in the afternoons. Overnight, temperatures
should fall into the middle 60s across southeast Alabama and south
Georgia in an area of weak cold air advection behind the front.
LONG TERM [Tuesday through Saturday]...
The extended range forecast continues to have significant
differences both model run to model run and between models as
It appears as though the aforementioned front will drift back to the north on Tuesday bringing an increased chance for rain over land areas. Just how far north this front will go is still unclear, but for now keep it mainly confined to north Florida.
On Wednesday, differences in position of an approaching upper
shortwave between the GFS and ECMWF would suggest either a rather insignificant passage or a return to widespread showers and storms.
Regardless of how that eventually turns out, there is fair agreement that we will dry out to finish off the week. Temperatures are forecast to remain near or slightly below average through the period.
AVIATION [Beginning 19Z Saturday]...
Prevailing rain with occasional TSRA is in the forecast much of the
forecast period at all terminals. Cigs will gradually lower through
the night as well as a front approaches the region. The western
terminals may see an end to the rainfall after 12z Sunday.
Cautionary level winds are expected ahead of a passing cold front
through Sunday night. Thereafter, a stretch of easterly winds just
slightly below cautionary levels is forecast. Seas should peak
around 5 feet with the front, then subside to 2 to 3 feet for the
following several days.
A moist airmass will remain in place across the region into early
next week, with no fire weather concerns anticipated.
There have been some rather impressive rain rates this afternoon
in some of the strongest storms, though thus far the storms have
thankfully been fairly progressive.
Through the remainder of the event (through ~ Tuesday) expect widespread averages across southeast Alabama and southern Georgia to be between 1-2 inches, while 2 to 4 inches will be more common across north Florida.
As mentioned previously high rain rates will be possible, thus any
slow movement or training could produce total amounts 2 to 3 times
as much as the averages in localized areas.
As far as area rivers are concerned the average rainfall amounts shouldn`t cause too much of a problem, it would be locally heavier storms that could cause sharp rises to area water systems.
PRELIMINARY POINT TEMPS/POPS...
Tallahassee 72 79 70 87 70 / 80 70 40 40 40
Panama City 73 80 70 87 72 / 80 80 40 40 40
Dothan 68 82 66 85 66 / 70 40 20 30 40
Albany 71 82 67 82 64 / 70 60 20 30 30
Valdosta 70 77 69 84 67 / 80 70 50 30 40
Cross City 72 80 72 87 70 / 80 80 60 40 50
Apalachicola 75 79 71 85 74 / 80 80 70 40 40
FL...Flash Flood Watch through Sunday morning for the Florida
Panhandle west of the Apalachicola River.
High Rip Current Risk through tonight for Bay and Walton county beaches.