003 
FXUS62 KJAX 111843
AFDJAX

Area Forecast Discussion
National Weather Service Jacksonville FL
243 PM EDT Wed Sep 11 2019

.NEAR TERM /Through Thursday Night/...

An upper level low over north central Florida will move
southwestward into the northeastern Gulf tonight, and then slowly
westward into the central Gulf by Friday morning. Cool 500mb temps
around -8 to -9C on the 12Z sounding were warming and will be 
around -7.5 to -8C by 00Z tonight as the upper low moves away from
the region. Mid/upper level temps will then continue to warm to
around -6.5C overnight tonight and through the day on Thursday. 
The fast east northeasterly flow and lack of convergence will 
lead to only low rain chances from streamer showers this afternoon
moving inland from the Atlantic coast. If an isolated thunderstorm
is able to form, it could become strong across the interior with 
gusty winds. A few coastal showers are possible overnight. Low
temperatures will be in the low 70s across the interior and the 
mid to upper 70s at the coast due to the continuing onshore flow. 

Strong mid/upper level high pressure will remain centered over the
Tennessee Valley through Thursday night. Surface high pressure 
will also remain across the Southeast through the period, with 
east northeasterly onshore flow. A tropical wave across the 
eastern Bahamas will slowly push west northwestward through Friday 
morning to the western Bahamas. Breezy onshore flow is expected at 
the beaches due to the strengthening pressure gradient between the 
high to the north and the low pressure to the southeast. Moisture 
levels will remain near normal through Thursday across northeast 
Florida in the 1.4-1.6 inch range, and the same across southeast 
Georgia today through Thursday morning. A drier pocket of air is 
forecast to rotate southwestward across southeast Georgia late 
Thursday afternoon and into the overnight hours, with precipitable 
water values dropping to around 1 inch. Rain chances will remain 
generally in the 20-30% range through Thursday night, with 
streamer showers pushing onshore Thursday, and a few showers are
possible for the northeast Florida beaches Thursday night. Highs 
on Thursday will be in the upper 80s to lower 90s inland and the 
mid 80s at the beaches. Overnight lows will be in the low 70s 
across the interior and the upper 70s at the beaches once again. 

.SHORT TERM /Friday Through Saturday Night/...

Mid/upper level high pressure over the Southeast on Friday is 
forecast to slowly shift eastward to the coast of the Carolinas by
Saturday morning and then into the western Atlantic Saturday 
night. A tropical wave is forecast to move across the western 
Bahamas and towards south Florida on Friday, and then could 
potentially develop into a tropical cyclone near the southeast 
Florida coast. The models have been slowing down the movement of 
this system, which means the deeper tropical moisture is now not 
expected to arrive across northeast Florida until Saturday. Some 
of the guidance that is slower or shows a slightly deeper low 
pressure area brings the system further northwestward up the 
Florida peninsula, including the ECMWF. A couple outliers even 
show the system moving to the east of the Florida Peninsula, like
the UKMET. The trend has been to slow the system down and to be
further east over the past 24 hours, and this will be something 
to watch as we head into the weekend. The current consensus is for
an area of low pressure or tropical wave to track across southern
Florida this weekend and into the eastern Gulf of Mexico. 

Isolated to scattered showers and embedded storms are expected for 
north central Florida on Friday, with decreasing rain chances 
northward. Mainly dry conditions are expected for southeast 
Georgia, especially across the interior. Deep tropical moisture 
will then spread over the entire region Saturday, with numerous to 
widespread showers and embedded storms. 

.LONG TERM /Sunday Through Wednesday/...

An area of low pressure is forecast to move towards the north 
central Gulf coast or Florida Panhandle on Sunday, and deep 
tropical moisture is forecast to continue across the area. How 
much rainfall will depend on the ultimate track and strength of 
the tropical wave currently near 75W. For now, high rain chances 
are expected Sunday and Monday. High pressure is then forecast to 
build across the area Tuesday into the middle of the week, with 
rain chances returning to normal. 
&&

.AVIATION...
Onshore flow at 10-15 knots this afternoon will impact all TAF
sites with gusty E-NE winds and brief MVFR showers at times, so
for now have kept as VCSH and will update as needed for more
intense shower or even the slight chance for a thunderstorm, but
storm chances too low to include 6-8 hour long VCTS groups.
Diurnal shower activity will fade over inland areas with VFR conds
at GNV/VQQ with tempo MVFR fog towards sunrise, while coastal
shower chance will remain overnight at Atlc TAF sites and have
kept VCSH at CRG/SSI/SGJ along with slightly better chances of
MVFR CIGS in the 2500-3000 ft range towards morning. E-NE winds
increase into the 10-15G15-20 knot range after 13-14z on Thu with
MVFR CIGS expected along the coastal TAFs that will push inland in
the 3000-3500 ft range for inland TAFs by the 14-15z time frame
and with brief showers possible again have kept VCSH for all TAF
sites.

&&

.MARINE...
High pressure will dominate north of the waters while a tropical 
wave crosses the Bahamas and south Florida through the weekend. 
Winds will increase to near exercise caution levels Thursday as 
the pressure gradient tightens as the low approaches the Bahamas. 
As the low passes to the south of the local waters Friday through
Sunday, combined seas will near advisory levels due to building 
swells within the outer waters. Rain potential increases Fri-Sun 
due to tropical moisture overspreading the waters. 

Rip Currents: Extended period of at least moderate risk of rip
currents this week due to persistent onshore flow. 

&&

.PRELIMINARY POINT TEMPS/POPS...
AMG  70  92  70  91 /   0   0   0   0 
SSI  76  87  77  86 /  10  20  10  10 
JAX  74  89  76  87 /  10  30  10  20 
SGJ  76  86  76  86 /  30  30  20  30 
GNV  71  90  73  88 /  10  20  10  20 
OCF  72  91  73  89 /  10  20  10  30 

&&

.JAX WATCHES/WARNINGS/ADVISORIES...
FL...None.
GA...None.
AM...None.
&&

$$

Kennedy/Hess/Bricker