Area Forecast Discussion
Issued by NWS
FXUS62 KTAE 211856
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TALLAHASSEE FL
256 PM EDT Mon Apr 21 2014
.Near Term [Through Today]...
A weakening broad upper level trough will move from the lower
Mississippi Valley across the southeastern US tonight, with an
increase in mid and high level cloudiness. Overnight lows will be
seasonable with readings in the mid to upper 50s. With an increase
in clouds that will suppress radiational cooling, do not expect much
in the way of fog to develop. Any showers will hold off until later
in the day Tuesday.
.Short Term [Tonight Through Wednesday]...
Tuesday...The fairly progressive large scale mid/upper level
pattern starts the day marked by trough over Wrn most states...
ridge Ewd to Wrn Gulf states...and a weak positively tilted H5
shortwave trough over Ern states bringing increasing mid moisture.
At surface...low over PENN/Ontario border with weak back door cold
front Swwd thru MS/AL/LA to begin the day. By sundown...trough
axis has pivoted to Ern seaboard while cold front...absent upper
support...begins to weaken...slow down and then become quasi-stnry
lying more WSW to ENE along S/Cntrl AL/GA. The latest guidance
shows only marginal instability with weak lapse rates...meager
shear and forcing. However PWATS increase to around 1.4 inches NW
to 1.1. inches SE CWFA and there should be enough cape to support
at least isold Tstms south of front and over our CWFA in the aftn.
50-10% NW-SE POP gradient with highest POPs and QPF (AOB 0.16
inches) SE AL and adjacent SW GA. Highs in the low 80s.
Tuesday Night...The trough moves into the Atlc with upstream ridging
overspreading the Gulf region. Both the GFS and ECMWF show the front
stalling near the FL-GA border Tuesday night into Wednesday. With
loss of heating and exiting trough...POPs decrease to slight chance
possibility of Shwrs/isold Tstms. With winds remaining above calm...
this scenario will favor low clouds but some fog is likely and fog
and CAM/SREF guidance implies both ample low stratus and at least
patchy fog but will hold off on inserting into GRIDS that far out.
Expect mild temperatures...lows around 60.
Wednesday...Ridging with rising heights and subsidence builds in
to dominate local region. Front begins to wash out across or just
south of our Srn CWFA with decreasing cloud cover. Expect highs in
the low to mid 80s.
.Long Term [Wednesday Night Through Monday]...
The large scale Srn stream pattern commences fairly progressive with
near zonal flow over Wrn states...weak trough over Cntrl states and
weak ridging over Ern states. On Friday...ridging moves offshore
leaving near zonal flow over SE region reflected in uni-directional
flow on model soundings. Flow shifts to weak WNW flow into Sat. On
Sun into Mon...upstream amplified ridging builds Ewd into Gulf
region. At surface...ridge becomes established over Nrn Gulf
on Thurs thru Fri night. Then...a low well to the north of CWFA
brings a trailing weak front to our area on Sat where it likely
stalls by Sat eve providing a small chance of convection. Sheared
out front then lifts back Nwd on Sun. This will place local area in
warm sector allowing for a weak seabreeze to develop Sat-Mon.
Next cold front moves into SE on Mon yielding a modest increase on
precipitation across mainly NW half of CWA on Mon. With local area
in warm sector...temperatures are expected to be slightly above
climo with inland highs in the low to mid 80s and under the sea
breeze influence...somewhat cooler at the coast.
[Through 18Z Tuesday] VFR conditions with increasing high clouds
after 06Z. A weak front will approach the southeast on Tuesday with
a gradual lowering of ceilings after 18Z.
The pressure gradient will be relatively weak through Wednesday, so
winds and seas are expected to remain below 15 KT. There will be a
slight increase in winds and choppiness near the coast each
afternoon due to the daily sea breeze development.
Red Flag conditions are not expected through the remainder of the
Most of our area rivers are above normal stage with many in flood
stage. The Choctawhatchee at Bruce is forecast to reach major flood
stage Tuesday morning with several others in moderate flood stage. Most
area rivers will crest soon or have already crested. The exception
is the Suwannee River which will rise slowly for the remainder of
the week. QPF amounts for tomorrow are expected to be less than
0.25 inch and will not have major impacts on river levels.
The most up-to-date river forecast information can always be found
on our AHPS page (below).
.Preliminary Point Temps/PoPs...
Tallahassee 55 82 59 83 58 / 0 20 10 10 0
Panama City 60 76 62 79 62 / 0 20 10 10 0
Dothan 58 81 59 82 57 / 0 40 20 10 0
Albany 57 82 58 82 56 / 0 40 30 0 0
Valdosta 55 82 59 84 57 / 0 20 20 10 0
Cross City 54 81 57 83 58 / 0 10 10 10 0
Apalachicola 58 75 62 77 62 / 0 10 10 0 0