Preview of NWS' New Version of Forecast
This preview is not operational and should not be used for support decisions.

Area Forecast Discussion (AFD)

Issued by Jacksonville, FL (JAX)

FXUS62 KJAX 180828

Area Forecast Discussion
National Weather Service Jacksonville FL
428 AM EDT Wed Sep 18 2019

A regional 06Z surface analysis shows a weak cold front draped 
across southern GA this morning, just north of our CWA. This front
is poised to push further south, bringing scattered showers and 
isolated thunderstorms to the area today, along with gusty 
northeast winds, particularly along the coast. The front will 
likely exit the area overnight, with a fairly quick drop off in 
precipitation in the evening/overnight hours. Highs today will be 
in the upper 80s to low 90s. Lows will be noticeably cooler 
tonight in the wake of the front, dipping into the mid 60s in SE 
GA, upper 60s in NE FL, and low 70s along the coastline. 

Fairly strong high pressure system over the Mid Atlantic with ridge
southwest into the southeast states will produce tight pressure gradient
on Thursday with windy conditions at the coast and a risk of isolated to 
scattered showers, mainly south half of the area. Outside chance of a 
thunderstorm over the coastal waters. Max temps will be in the 80s, 
with winds and coastal clouds keeping the ern zones in the lower 80s, 
Mid 80s will be inland. Thursday night...breezy winds will persist 
just above the sfc with partly cloudy skies and risk of a few showers 
again. Drier and somewhat cooler air will allow temps to fall into
the lower to mid 60s inland, but lower 70s along the coastal areas. 

Friday...east to northeast flow persists through at least 500 mb and 
moisture will be confined below an inversion around 800 mb. Still can't 
rule out isolated to scattered showers again given low level 
convergence and more than ample  moisture in the low levels. 
Showers should be confined mainly to the eastern zones. Friday night...
similar pattern will exist with a low chance of showers mainly confined
to the coastal counties, with subtle decrease in moisture working in 
from the northeast around the high pressure system. Lows in the lower
to mid 60s over inland southeast GA...lower 70s coast.

The pattern over the area favors generally dry and warm conditions with 
deep layer high pressure over the area during the weekend. Based on the GFS,
PWATs are basically an inch or less Sat and Sun. By early next 
week, ridge aloft gets shunted further south into the Gulf of Mexico. 
Some moisture may increase by Tue as mean layer winds shift to the 
southwest and west ahead of the next frontal boundary. For local wx...
easterly flow continues over the area Sat and Sun and breezy at times 
over eastern zones and can't rule out a couple of stray showers so 
leaned toward rain chances only about 10-15 percent for the northeast FL
coastal counties. For Mon-Tue, rain chances will likely be kept
at less than 15 percent. Trend in the guidance is warmer max 
temps during the period with highs mid 80s to near 90 Sat and Sun, then
upper 80s to lower 90s Mon and Tue, with some mid 90s possible northwest
zones on Tue.


Patchy MVFR vsbys are possible this morning, most likely near VQQ.
These vsbys restrictions, if they develop, should clear out
shortly after sunrise. Northeast winds will pick up in the late
morning-early afternoon hours, particularly at sites near the
coast. Scattered showers and isolated thunderstorms are forecast
to develop across the area this afternoon. These storms will
likely bring MVFR cigs, but storms and reduced cigs should scatter
out around 01Z.


Seas had remained elevated from strong swell from Humberto earlier
in the week and though they have lowered slightly, they will
increase again through tomorrow. A cold front will sneak from the
northeast over our offshore and coastal waters today, bringing a
return of strong northeast flow to fuel this increase in wave
heights. Advisory conditions are expected to continue through the
remainder of the week. Showers and isolated thunderstorms will
also return with today's cold front, mostly during the daytime

Rip Currents: The high risk of rip currents continues today and
for the next several days.


Chances for showers and isolated thunderstorms return to the
forecast today thanks to a backdoor cold front, but overall QPF
remains low- less than an inch across the area. Persistent
northeast flow is leading to elevated water levels along the St.
Johns, Tolomato, and Matanzas Rivers during high tides. This will
continue through tonight. A coastal flood statement is in effect 
for these elevated water levels along the St. Johns, Tolomato, 
and Matanzas Rivers. Otherwise, there are no flooding concerns.


AMG  88  65  84  62 /  40  20   0  10 
SSI  84  72  81  71 /  50  20  30  30 
JAX  87  71  83  69 /  40  20  30  30 
SGJ  86  72  82  72 /  40  30  40  20 
GNV  91  69  85  66 /  50  30  20  10 
OCF  92  69  86  67 /  50  30  20  10 


FL...High Rip Current Risk through Saturday evening for Coastal Duval-
     Coastal Flagler-Coastal Nassau-Coastal St. Johns.

GA...High Rip Current Risk through Saturday evening for Coastal 
     Camden-Coastal Glynn.

AM...Small Craft Advisory until 9 PM EDT Saturday 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-
     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.