Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Tallahassee Florida
424 PM EDT Friday Aug 28 2015
Near term [through tonight]...
Despite drier air to our west leftover on the dry side of a
retreating front, strong 1000-700 mb south-southeasterly flow will
bring low level moisture to the region. Plenty of instability is on
tap with mid level lapse rates of 7 c/km and SBCAPE of 2500-3000
j/kg. Scattered showers and thunderstorms are likely this afternoon
and evening. With moisture and instability available, some of the
thunderstorms will be strong to severe storms with gusty winds and
small hail being the main threat. As night continues, pops begin to
decrease over land and increase over the water. Lows will be near
normal in the low to mid 70s.
Short term [saturday through Sunday night]...
In the upper levels, there will be weak troughing to the west and
weak ridging to the east. In the low levels, southerly/easterly
flow will bring increased moisture. Therefore, rain chances will
be relatively high this weekend with scattered showers and
thunderstorms. Pops around 60 percent are expected for the entire
region on Saturday, particularly in the afternoon/evening hours.
Highs on Saturday will be in the upper 80s with heat indices in
the low to mid 90s.
On Sunday, low level moisture will decrease in the western part of
the region. Pops will be around 30 percent in the west and 50
percent in the central and eastern parts of the region. Highs on
Sunday will be around 90 with heat indices in the mid to upper 90s.
Long term [monday through friday]...
Upper level features are forecast to be weak in the extended
period. In the lower levels, ts Erika could begin to affect the
region as early as Tuesday morning. The official NHC forecast for
Erika has the entire Florida Peninsula, the eastern Gulf and the
open waters of the Atlantic east of Florida in the error Cone.
There is still a great deal of uncertainty with Erika's track. If
Erika tracks farther east and remains over open Atlantic waters,
it will not impact the region. If Erika tracks farther west into
the Gulf it could become more of a threat to the Florida
Panhandle. If Erika tracks through the center of The Cone, it may
move up the Florida Peninsula as a weak ts. If Erika moves up the
Florida Peninsula, Big Bend Florida and most of the Georgia
counties will see increased rain chances and possibly heavy rain.
If Erika moves into the region from the Gulf, the whole area will
see increased rain chances with heavy rain likely, especially on
Tuesday and Wednesday. Due to the uncertainty of Erika's track,
the extended forecast also has a great deal of uncertainty. Expect
highs around 90 with heat indices around 100 degrees at times.
[through 18z saturday]
VFR conditions should prevail outside of thunderstorms this
afternoon and evening. Storms are most likely to directly effect
vld and aby, with MVFR-IFR cigs/vsbys and gusty winds possible.
Storms may linger into the evening, clearing out by around 03z. An
early start will be possible tomorrow in North Florida with storms
beginning to develop around 15z.
Light winds and low seas are expected through the weekend. After
that, it will depend on Erika's track. No matter the track, at
least a slight increase in winds and possibly seas should be
expected starting next week.
An increase in low level moisture and rain chances for the next
few days will preclude any fire weather concerns.
With a transition to a wetter pattern beginning today, expect
average rainfall amounts on the order of 1-1.5" over the next
three days. This will have little impact on area rivers. Next
week, the potential for some very heavy rain exists depending on
Erika's track. At this time, models suggest the possibility for
5-7" over a 48 hour period with Erika. Should the track shift
west, these amounts could spread into the southeast Big Bend and
south-central Georgia. Interests along the Suwannee River are
urged to pay close attention to rainfall forecasts over the next
Preliminary point temps/pops...
Tallahassee 75 88 72 90 73 / 40 60 30 50 30
Panama City 75 86 74 88 75 / 40 60 30 30 20
Dothan 71 85 69 90 70 / 40 60 20 30 20
Albany 73 87 71 89 71 / 40 60 30 40 20
Valdosta 73 88 72 90 72 / 40 60 30 50 30
Cross City 74 90 72 90 73 / 40 60 30 50 30
Apalachicola 76 86 75 87 76 / 60 60 30 30 20