Area Forecast Discussion
Issued by NWS
FXUS62 KTAE 030517
Area Forecast Discussion
National Weather Service Tallahassee FL
1217 AM EST Sat Dec 3 2016
.AVIATION [Through 06Z Sunday]...
VFR conditions will persist through the entire period, with a broken
to overcast high cloud deck expected at all terminals. Winds will
generally be out of the northeast and light, peaking around 6-8
kts during Saturday afternoon and evening. Some gusts from 10 to
15 kts are possible, mainly at DHN and ECP.
.PREV DISCUSSION [913 PM EST]...
.NEAR TERM [Through Tonight]...
The 6 pm regional surface analysis showed an area of high pressure
across much of the Southeast, and a developing warm front in the
western Gulf of Mexico. Vapor imagery and upper air data showed a
deep trough over the Rockies. Moist, southwest winds aloft were
advecting high-level moisture ahead of this trough over the Gulf
Coast region, and this increase in clouds overnight will prevent
low temperatures from reaching the 30s in our forecast area. The
afternoon forecast package is on track and no changes were
.SHORT TERM [Saturday Through Sunday Night]...
Conditions will begin to transition from calm and dry to active once
again through the day Saturday. Weak upper level shortwave ridging
is expected to move across the area, with surface high pressure
lifting northward out of the area Saturday into Sunday. This will
allow deep layer moisture to stream into the area ahead of a potent
eastward moving upper level shortwave trough and associated
developing surface low off of the eastern Texas Gulf Coast. The
latest guidance continues to indicate PWATS rising above 1.50" by
Sunday afternoon, with values continuing to rise through Sunday
night. Forcing in the form of a warm front lifting northward across
the area is expected, with isentropic lifting north of the front
expected to enhance shower and embedded thunderstorm development. As
a result, widespread showers and storms are expected across most of
the tri-state region Sunday into Sunday night, with the potential
for heavy rainfall across the Florida Panhandle, southeastern
Alabama and portions of southwestern Georgia (as noted by the WPC
day 3 excessive rainfall outlook). Temperatures will run above
seasonal normals once again through the period as a result of the
warm frontal passage, with highs in the low to mid 70s and lows in
the low to mid 50s Saturday morning and low to mid 60s Sunday
morning with widespread cloud cover in place.
.LONG TERM [Monday Through Friday]...
The heavy rain threat will continue into the work week, as the
aforementioned warm front continues to push northward through the
area. Some model guidance continues to forecast PWATS approaching
the 2" mark by Monday across the area, threatening the previous
December record of 2.05" set in 2015. The system to the west of
the area will rapidly lift northeastward through the day Monday,
with the trailing cold front advancing eastward toward the area
Monday evening/night. Given the moisture and shear in place ahead
of the advancing front, there remains the possibility of some
strong storms across parts of the area Monday night into Tuesday
morning ahead of the cold front. As mentioned in yesterday`s AFD,
the limiting factor at this time looks to be instability, as
widespread shower and embedded thunderstorm activity ahead of the
front is expected to limit the potential for adequate
destabilization. Expect temperatures to remain mild Monday and
Tuesday, with highs in the mid to upper 70s and lows in the mid to
The cold front is expected to clear the region Tuesday afternoon,
limiting moisture and yielding quiet conditions for Wednesday.
Temperatures will be slightly cooler for mid week, but still mild
with highs in the upper 60s to low 70s and lows in the mid to
upper 40s. A slight chance for showers could return to the region
ahead of a potent cold front at the end of the period. It should
be noted that the latest model guidance is generally in poor
agreement regarding the timing of the next system, but it has
consistently looked capable of providing a true taste of winter
across the region by the end of the week, with temperatures
cooling to highs in the 50s and lows in the 30s.
Easterly winds will increase to 20 to 25 knots tonight and remain
elevated through the weekend, yielding seas of 5 to 7 feet with
locally higher amounts offshore. As a result, a small craft advisory
has been issued for late tonight through Sunday afternoon. Choppy
conditions are expected to continue into next week. Widespread
showers and thunderstorms are expected Sunday through Tuesday.
Surface high pressure will shift northeast as a low pressure system
takes shape across the central United States. This will allow east
to eventual southeast winds this weekend into early next week which
will draw in higher moisture content and higher relative humidity
values. Also, rain chances will increase late in the weekend through
mid week next week as the low pressure system moves across the
southern United States. On Saturday, afternoon relative humidity
values will fall into the upper 20 percent range across much of
southwest Georgia and the Florida Big Bend but winds and ERC values
preclude a red flag warning. Relative humidity values will be much
higher Sunday through mid week.
Widespread showers and thunderstorms are expected to spread across
the region Sunday through Tuesday, with the current forecast showing
widespread totals generally ranging from 1 to 3 inches across the
region. Widespread higher accumulation ranges are not out of the
question, and forecast changes should be monitored closely with each
issuance. The highest totals at this time are currently forecast
across the Florida Panhandle, southeastern Alabama, and southwestern
Georgia. While it is too early to identify a flooding threat with
confidence, it is worth noting that WPC has the aforementioned areas
outlooked in a marginal risk for excessive rainfall Sunday and
Monday. Will continue to monitor closely and fine tune the forecast
over the weekend.
.PRELIMINARY POINT TEMPS/POPS...
Tallahassee 71 54 74 66 76 / 0 0 10 40 60
Panama City 68 58 73 67 75 / 0 10 30 50 70
Dothan 65 51 68 60 72 / 10 20 40 70 70
Albany 67 51 68 59 70 / 0 10 40 70 70
Valdosta 69 51 74 63 75 / 0 0 10 30 50
Cross City 72 53 78 63 78 / 0 0 0 10 30
Apalachicola 68 60 72 68 74 / 0 10 10 40 60
GM...Small Craft Advisory until 2 PM EST Sunday for Coastal Waters
From Ochlockonee River to Apalachicola Fl out to 20 Nm-
Coastal waters from Apalachicola to Destin FL out 20 NM-
Waters from Suwannee River to Apalachicola FL from 20 to 60
NM-Waters from Apalachicola to Destin FL from 20 to 60 NM.