Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Tallahassee Florida
135 PM EDT Tuesday Jul 26 2016
Aviation [through 18z wednesday]...
Expect mostly VFR conditions, but with scattered MVFR ceilings
present this afternoon along with scattered showers and isolated
thunderstorms. Winds will be mostly from the south-southwest through
the period. Some of our local hi-res guidance suggests that IFR
visibilities may be possible tomorrow morning just northwest of dhn
Previous discussion [1254 PM edt]...
Near term [through today]...
Current surface analysis shows a trough stretching from our western
Gulf zones northwestward to the central Gulf Coast. This feature,
along with an upper trough moving through the same area, will
enhance development of showers and thunderstorms across our western
Gulf zones and coastal Florida Panhandle locations overnight through the
morning. Elsewhere, dry conditions are expected with light and
variable winds inland through the early morning hours.
Relatively strong southerly flow (for this time of year) east of the
aforementioned trough will bring precipitable water values near/greater than 2"
from the northeastern Gulf into the Florida Panhandle throughout the
morning, and into the remainder of our area by the afternoon hours.
This copious amount of moisture, combined with forcing from the sea
breeze and moderate instability, will result in greater than normal
coverage of scattered showers and thunderstorms. Showers and storms
will be most likely in the Florida Panhandle in the morning, spreading
into southeast Alabama and far southwestern Georgia by the afternoon.
Slightly less moisture will exist in our eastern locations, but
still expect ample moisture and instability to be present, so 40-60%
pops were placed across most of the Florida Big Bend region and SW
Georgia during the afternoon and early evening. Early thunderstorm
development will likely keep highs in the upper 80s to lower 90s
across our western and central areas, with some mid-upper 90s
possible in parts of SW Georgia where clouds/storms will be slower
Short term [tonight through thursday]...
Pattern wise, an upper level ridge is centered over the Atlantic near
the Georgia coast and persists through Thursday while at
the surface, the County Warning Area remains in southerly flow on the western
side of the Bermuda high.
A few showers and thunderstorms are expected to persist into tonight
from the more active pattern expected today. The most likely area
for this will be across the far western portions of the County Warning Area where precipitable water
values remain above 2 inches for the first half of tonight. Will see
a decrease in precipitable water values after this. So although the County Warning Area remains in
southerly flow, the drier air expected for Wednesday and Thursday
will help to limit convective activity and thus forecast is for
isolated to low end chance pops each day. For Wednesday night, precipitable water
values drop below 1.5 inches and thus expect any storms that do form
Wednesday to be quickly shut off Wednesday night.
High temperatures will range from the low to mid 90s inland with the
upper 80s to lower 90s along the coast. This will result in heat
indices up to the low 100s, however a few areas will seem a
little less oppressive with values only in the mid 90s.
Long term [thursday night through tuesday]...
Upper level high pressure off the Georgia coast flattens Friday
with the center moving further east into the Atlantic and it
eventually weakens next week as a trough slides across the
northeast. Pws begin to increase on Friday and this will allow US
to return to a more typical summertime pattern in terms of pops
through the long term with daytime values mainly in the 20-30
percent range. High temperatures will continue in the low to mid
90s, resulting in heat indices in the low to mid 100s.
Moderate southerly flow of 15-20 knots across the western waters
will allow for 2-4 foot waves and some up to 5 feet through this
evening. Given this will include a small craft exercise caution
headline for the waters west of Apalachicola. After this, winds
will subside to around 10 knots or less through into next week and
this will result in seas mainly 1-2 feet.
No fire weather concerns are anticipated during the next several
days due to light winds and relative humidity values well above critical
Rain is expected today across the area, particularly across the
western half of the County Warning Area. While overall rainfall amounts will be
less than an inch and do not raise hydrology concerns, isolated
higher amounts are possible and thus will have to monitor for
localized ponding of water and flooding. After tonight, will
return to a more typical summertime pattern.
Preliminary point temps/pops...
Tallahassee 75 96 75 97 75 / 10 20 0 20 0
Panama City 79 91 79 90 80 / 30 10 0 20 10
Dothan 74 94 73 95 74 / 20 30 0 10 10
Albany 74 97 74 97 74 / 10 20 10 10 10
Valdosta 73 97 73 97 74 / 10 20 10 10 0
Cross City 73 96 74 96 75 / 20 20 10 20 10
Apalachicola 78 91 78 90 79 / 20 10 0 20 10
Florida...high rip current risk until 8 PM EDT /7 PM CDT/ this evening for
coastal Bay-coastal Franklin-coastal Gulf-south Walton.