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Area Forecast Discussion (AFD)

Issued by Jacksonville, FL (JAX)

FXUS62 KJAX 160839

Area Forecast Discussion
National Weather Service Jacksonville FL
439 AM EDT Mon Sep 16 2019


As TC Humberto slowly pulls away from the area and prevailing 
winds become more northerly, drier conditions expected today but 
still a low chance of coastal showers for the coastal counties 
through the better portion of the day. Due to more sun, max temps 
will push through the lower 90s inland and upper 80s at the 
coast. Winds not as high over the eastern zones as prior days as 
gradient weakens but expecting breezy conditions of 15-20 mph with
a few gusts to 30 mph. Winds generally 10-15 mph further inland 
today. Becoming mostly clear for most areas tonight with lows a 
bit lower due to lower dewpoints. Any shower activity will likely 
remain over the coastal waters as deep moisture continues to shift
eastward with TC Humberto. Main local hazard is the surf and rip 
current problem today and will likely be a hazardous issue the
rest of the week.


Hurricane Humberto will continue to slowly move off to the
northeast, keeping low level winds slightly elevated on Tuesday, 
particularly along the coast. A much drier air mass will push into
SE GA & NE FL on Tuesday, with PW values falling below 1.5" 
across the area and minimum surface RH values around 35% in inland
portions of the area. It will be drier, but not cooler. Afternoon
temperatures will peak in the mid 90s on Tuesday and overnight, 
temperatures will stay in the low-mid 70s. Low level flow will 
become more easterly on Wednesday, bringing a return flow of 
moisture at least near the surface. This will also mean a return 
of scattered showers and isolated thunderstorms. Temperatures will
be slightly cooler, with highs in the low 90s and overnight lows 
in the mid 60s across inland SE GA, upper 60s to low 70s 
everywhere else.


By Thursday, the area will be situated under the eastern periphery of
the mid and upper levels ridges and on the southeast side of the 
low level ridge. This deep layer ridging will slowly build 
eastward through the weekend. On Sunday, a +PV anomaly will swing 
through the upper level trough to our northwest, amplifying it as 
it moves into the Great Lakes Region. This will develop a cold 
front that will sweep towards the southeastern US on Monday. The 
upper level anomaly driving this system is poised to lift off to 
the northeast Monday night, however, so this front will likely 
stall out and dissipate to the north of our area. Persistent low 
to mid level easterly flow from this pattern is more likely to 
bring scattered showers and isolated storms to the area than the 
front at this time. Still, temperatures will be cooler over the 
weekend and early next week with highs mostly in the upper 80s and
lows in the mid-upper 60s.



Sct-broken cumulus will continue to affect the coastal TAFs through
the mid morning hours, with periods of MVFR cigs expected. Further
inland for GNV, more scattered cumulus deck expected today. A low 
chance of a brief shower that may cause some MVFR vsby into midday
but otherwise rain chances are much lower today than the prior 
couple of days. Expecting more prevailing VFR after mid afternoon 
as drier air filters into the area. However, SGJ may continue to 
see sct-broken cumulus mid afternoon into the late evening hours 
as northerly flow brings in stratocu off the warm Atlantic waters.
North to northeast winds will increase again to about 15G22kt 
after sunrise...decreasing to near 10 kt or less this evening. 



Winds and seas remain rough and hazardous and based on latest 
data and guidance have extended advisories a bit longer. Winds at 
SAUF1 were 22 kt and seas at St Augustine buoy were 7-8 ft. Most 
of the wave energy is composed of strong swells in the 8 to 11 
sec period range. While winds may relax a bit tonight and Tuesday,
seas will remain hazardous for small boaters. Then, as a backdoor
front/trough pushes through on Wed, winds and seas will pick up 
again. Swells from Humberto should also continue to affect area 
waters through late this week.

Rip Currents: High Risk of rip currents and high surf expected to
continue across area beaches. Latest readings show seas of 6 to
near 8 feet which suggests surf may be 5-7 ft for for northeast 
FL beaches and a bit lower for southeast GA. 

Coastal flood statement issued this morning for elevated water 
levels at several sites with at least a couple of locations 
flirting with minor flooding criteria. These higher levels were 
noted at Satsuma and Bings Landing. The elevated water levels may 
continue to occur for a good portion of this week, due to the 
prevailing northerly-northeast winds and recent full moon. For 
most part looks like majority of water measuring stations remain 
below minor flooding in the near term period.



Hurricane Humberto will slowly move northeastward away from the
area, but its proximity to us will mean the continuation of 
breezy conditions. Elevated winds will lead to high dispersions in
NE FL & SE GA today and Tuesday. Drier air will work its way into
the area on Tuesday, with RH values dropping to around 35% over 
inland portions of our area. Red flag conditions are not 
anticipated for the next several days.


AMG  92  69  95  71 /   0   0   0   0 
SSI  89  75  90  76 /  20   0   0  10 
JAX  90  73  92  74 /  20   0   0  10 
SGJ  87  75  88  75 /  30  10   0  10 
GNV  91  70  94  70 /  10   0   0   0 
OCF  92  72  94  71 /  10   0   0   0 


FL...High Rip Current Risk through late tonight for Coastal Duval-
     Coastal Flagler-Coastal Nassau-Coastal St. Johns.

     High Surf Advisory until 4 AM EDT Tuesday for Coastal Duval-
     Coastal Flagler-Coastal Nassau-Coastal St. Johns.

GA...High Rip Current Risk through late tonight for Coastal Camden-
     Coastal Glynn.

AM...Small Craft Advisory until 4 AM EDT Wednesday 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 until 4 AM EDT Tuesday for Coastal waters 
     from Altamaha Sound to Fernandina Beach FL out 20 NM-
     Coastal waters from Fernandina Beach to St. Augustine FL 
     out 20 NM-Coastal waters from St. Augustine to Flagler 
     Beach FL out 20 NM.