Scientific Forecaster Discussion
fxus62 ktae 290024
Area forecast discussion
National Weather Service Tallahassee Florida
824 PM EDT Tue Mar 28 2017
No significant changes to the previous forecast below appear
[through 00z thursday] mostly clear skies along with mainly calm
winds and abundant low level moisture are expected to allow areas
of fog and low ceilings to develop again tonight. In general, IFR
or lower conditions are expected at the taf sites. Visibilities
and ceilings will improve in the morning by 14z.
Previous discussion [357 PM edt]...
Near term [through tonight]...
The weak front that is situated north of the County Warning Area that has helped to
initiate convection will weaken tonight and push off to the east,
while remaining north of the County Warning Area. This, combined with the loss of
daytime heating, will work to diminish convection and thus kept pops
below 20 percent for after 00z. The main impact tonight will be
areas of fog, with patchy dense fog, generally from 06z to 14z. Lows
will be above normal with lows in the mid 60s.
Short term [wednesday through Thursday night]...
Areas of fog will dissipate shortly after sunrise Wednesday, with
mainly dry conditions expected through the afternoon and night
under an upper level ridge. However, enough instability and
moisture will be present across SW Georgia to justify slight
chances of thunderstorms during peak heating times in the late
afternoon and evening. A sharp upper level trough will move into the
Mississippi Valley region on Thursday afternoon/night, with
moisture and instability increasing ahead of this feature. On
Thursday night, a line of showers and thunderstorms will likely
move into our western areas. Pops across the Florida Panhandle and southeast
Alabama range from 60-80 percent Thursday night, and models are
showing heavy rainfall potential during this time with quantitative precipitation forecast amounts
ranging from 1-3" across our western areas. A few strong to
severe thunderstorms cannot be ruled out as 0-6 km bulk shear
values increase to 50 kts, but marginal instability (cape
generally 1000 j/kg or less, highest near the Gulf coast) could
limit severe potential. Very warm days will continue, with inland
highs in the mid-upper 80s and upper 70s along the coast. Lows
will range from the upper 50s to mid 60s.
Long term [friday through tuesday]...
The powerful shortwave trough mentioned in the short term
discussion will move eastward across our area on Friday morning
and afternoon, with a cold front at the surface also moving from
west to east across our area during the day. Showers and
thunderstorms will remain likely as a result, mainly along and
east of the front from the Florida Big Bend into SW Georgia. A few strong
to severe storms will remain possible, with ample bulk shear and
cape values around 1000 j/kg just ahead of the front. Dry air will
move into our area behind the front during the weekend, although
generally clear skies will allow temperatures to warm into the
low-mid 80s each day.
Another powerful upper trough and potent surface low are likely
to move just northwest of our area on Monday, and a strong mid-
level jet could push into our region behind the trough on Tuesday.
Instability looks decent with SBCAPE up to 1500-2000 j/kg
possible each day, and bulk shear of around 40 kts is possible so
scattered strong to severe storms cannot be ruled out. Also,
periods of heavy rain are possible with deep layer moisture moving
into our area (pwat values up to 2" at times). Both the GFS and
European model (ecmwf) show widespread quantitative precipitation forecast amounts of 1-2" with locally higher
totals across our area, mainly Monday and Monday night. A lot of
uncertainty still remains since the event is nearly a week out,
but strong to severe storms and localized flooding appear
possible during this time.
Light winds and seas are expected through Thursday, but could
reach advisory levels Thursday night through Friday as a front
and a line of showers and thunderstorms move through the
northeastern Gulf. Winds and seas will decrease late Friday and
remain fairly light through the weekend.
Red flag conditions are not expected for the next several days with
relative humidity values remaining above critical levels.
Showers and storms could produce heavy rainfall on Thursday night
and early Friday, and a second round of storms/heavy rain is
possible early next week. Flooding is not expected from Thursday
to Friday with thunderstorms likely moving quickly across our
area, but cannot be ruled out early next week with additional
periods of heavy rain.
Preliminary point temps/pops...
Tallahassee 59 85 58 85 63 / 0 0 0 10 40
Panama City 63 77 62 77 66 / 10 0 0 0 80
Dothan 61 85 59 85 63 / 10 10 0 10 70
Albany 62 86 61 87 64 / 10 20 20 20 40
Valdosta 59 86 59 86 62 / 0 10 10 40 20
Cross City 56 85 57 85 61 / 0 0 0 10 20
Apalachicola 61 76 62 77 66 / 10 0 0 0 60