Area Forecast Discussion
Issued by NWS Jacksonville, FL
FXUS62 KJAX 220739
Area Forecast Discussion
National Weather Service Jacksonville FL
239 AM EST Wed Feb 22 2017
...WIDESPREAD SHOWERS WITH ISOLATED STORMS POSSIBLE THROUGH
.NEAR TERM (Through tonight)...
There is good agreement between the GFS and ECMWF that a closed low
across the lower Miss Valley will move southeast across the Gulf of
Mexico and be positioned across south Fl by early Thu morning.
There will be a slug of moisture and lift to the north of the low of
which the northern fringes of it will be over the area during the
day Wednesday and continuing into Wednesday night. With bulk of
deepest moisture and lift south of the area...total rainfall amounts
continue looking not too impressive ranging from near an inch across
the far south to around a quarter of an inch across inland southeast
Ga. There may be a few amounts over an inch along the coast (as
suggested by the GFS) depending on any setups of convergent bands
which will be monitored closely. There may also be a few brief
isolated storms given weak instability in combination with forcing
to the north of the low. However...the best chance of storms appears
to be south of the area and across the coastal waters.
.SHORT TERM (Thursday through Friday night)...Upper level cutoff
low and surface low pressure system will move into the Atlantic.
Some wrap around onshore moisture will keep a chance for scattered
showers along the northeast Florida coast. A few rumbles of thunder
are possible too as around 500 J/kg of CAPE could be realized if
cloud cover breaks. As the upper low and surface low depart into
the Atlantic, onshore flow will continue and upper level ridging
will build briefly across Florida. Temperatures along the coast
will likely remain in the 70s, while further inland most locations
will be in the low 80s.
.LONG TERM (Saturday through Tuesday)...Upper level ridging will be
short-lived as heights begin falling Saturday in response to a large
upper level shortwave trough crossing the Great Lakes. At the
surface, a cold front trailing from a rapidly moving low pressure
system in the Great Lakes region will graze our southeastern Georgia
zones, and there may be just enough moisture to squeeze out a few
showers, but this front could pass mainly as just an increase in
clouds in that area. The front will continue moving through the
area, and enough cold air advection is expected to put a temporary
end to our above normal temperatures as surface high pressure
settles in and near normal conditions are expected. Saturday
night`s lows will be in the 40s and highs on Sunday will be mostly
in the upper 60s. Zonal flow sets up across the Southeast and high
pressure remains in place until it moves offshore sometimes Monday.
Dry conditions will continue, and above normal temperatures will
return for the start of the next workweek as upper level ridging
.AVIATION....Cigs will gradually lower this morning with prevailing
MVFR cigs expected with rain becoming predominant during the morning
and continuing through the day. Isolated thunder possible over ne Fl
but will leave out of TAFs due to low probability.
.MARINE...Low pressure system will move southeast across the Gulf
today and then offshore the south Fl coast on Thursday. The gradient
will tighten between the low to the south and a persistent high
across the western Atlantic. Onshore winds/seas will be on the
increase today reaching advisory levels mainly for the Ne Fl waters
beginning tonight and continuing into Friday morning. A Small Craft
Advisory has been posted for the offshore Ne Fl legs beginning
tonight and for the nearshore Ne Fl legs on Thursday. A cold front
will move across the waters late Saturday with Advisory conditions
possible Saturday night.
Rip Currents: Moderate risk both today and Thursday.
.PRELIMINARY POINT TEMPS/POPS...
AMG 74 60 78 57 / 60 30 10 0
SSI 69 62 72 60 / 70 50 30 10
JAX 74 62 76 60 / 80 60 40 10
SGJ 73 64 75 63 / 80 70 50 20
GNV 73 62 79 60 / 80 50 30 0
OCF 73 62 78 60 / 80 60 40 0
AM...Small Craft Advisory from 4 AM Thursday to 4 PM EST Friday for
Waters from Altamaha Sound GA to Fernandina Beach FL from
20 to 60 NM-Waters from Fernandina Beach to St. Augustine
FL from 20 to 60 NM-Waters from St. Augustine to Flagler
Beach FL from 20 to 60 NM.
Small Craft Advisory from 1 PM Thursday to 5 AM EST Friday for
Coastal waters from Fernandina Beach to St. Augustine FL
out 20 NM-Coastal waters from St. Augustine to Flagler
Beach FL out 20 NM.