NEAR TERM [Remainder of this afternoon and tonight]...
The 16 UTC regional surface analysis showed an outflow boundary
across central GA, associated with a fairly vigorous thunderstorm
complex. It appears that there will be enough of an interaction
between the cold pool associated with this storm complex and the
moderately unstable airmass in its path for scattered thunderstorms
to reach our forecast area later this afternoon and early evening.
The lower to mid tropospheric flow was weak, which would argue
against significant storm organization and/or updraft rotation.
However, sometime cold pools interacting with warm & humid boundary layers can be more organized than the large scale environment might suggest. Because the lower and mid tropospheric lapse rates were relatively steep, marginally severe hail and/or damaging wind gusts are possible, mainly in our GA zones.
Thunderstorms will gradually diminish after sunset, followed by
generally fair weather later tonight. Once again there may be areas
of low clouds and fog, especially west of the Apalachicola River and
in areas that get rain.
SHORT TERM [Monday through Tuesday Night]...
The consensus of numerical model guidance portrays an average mid-upper level shortwave ridge over much of our area in the Monday
and Tuesday time frame, with a west-to-east gradient in PWAT. The
lowest values will be situated over the western part of our area,
with the highest values in the east - closer to the influence of
the Atlantic Ocean.
The overall flow pattern through the depth of the troposphere should be fairly weak, so there shouldn`t be a larger-scale forcing mechanism for widespread convection. PoPs were concentrated in our Georgia and Florida Big Bend zones where deeper moisture will reside, with a diurnal trend to be maximized in the late afternoon.
Highs away from the coast will be around 90 degrees in general.
LONG TERM [Wednesday through Sunday]...
Chances for showers and thunderstorms are expected to be a little
more widespread in our area on Wednesday and Thursday as a low
amplitude mid-upper level trough ejects east from the Plains.
On Wednesday, our area will be situated right underneath highly
divergent flow aloft, and by Thursday a weak surface front should
be developing into our area; both situations favor at least a bit
of a focus for larger scale vertical motion.
Therefore, PoPs on Wednesday and Thursday were increased into the 30-40% range.
After that, a strong surface high builds south into the eastern US, and
the weak surface front shifts south into the Florida Peninsula. This should allow for some drier air to arrive and slightly lower PoPs closer to climatological normals. The temperature forecast is one of persistence, with highs maintaining close to 90.
AVIATION [through 18 UTC Monday]...
Clusters of thunderstorms have developed in north and central GA,
and appeared to be headed toward KABY (mid-late afternoon) and KVLD (late afternoon-early evening). Wind gusts of 35 KT and IFR Vis are possible with these storms as they translate quickly southeastward.
It`s unlikely that these storms will affect the other terminals.
Fog and low CIGS are possible early Monday morning, especially at KECP and KDHN.
Winds and seas should remain relatively calm through the work
Winds will be generally 10 knots or less, and seas 2 feet or less. There will be a chance for a few showers or storms, and winds could be briefly higher near storms. Storms would be most likely near the coast and in the late afternoon or evening hours.
Relative humidity values will remain above critical levels through
Tuesday with relatively light transport winds and deep mixing heights especially over Florida.
The airmass should remain sufficiently moist to preclude red flag conditions into the upcoming weekend.
Any rain through Friday would likely arrive in the form of scattered showers and thunderstorms, and average rainfall totals should be low enough to prevent any widespread flooding concerns or issues on mainstem rivers across the area.
PRELIMINARY POINT TEMPS/POPS...
Tallahassee 66 90 66 90 69 / 20 20 10 20 20
Panama City 70 85 69 85 71 / 10 10 10 10 10
Dothan 68 91 67 91 71 / 10 10 10 10 10
Albany 68 90 67 91 69 / 30 20 20 20 20
Valdosta 67 89 65 90 68 / 30 40 20 30 20
Cross City 66 88 64 89 67 / 20 30 20 30 20
Apalachicola 69 83 68 82 71 / 0 10 10 20 10