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Area Forecast Discussion (AFD)

Issued by Jacksonville, FL (JAX)

FXUS62 KJAX 190827

Area Forecast Discussion
National Weather Service Jacksonville FL
427 AM EDT Thu Sep 19 2019

.NEAR TERM (Today and Tonight)...

A surface cold front stretches across the spine of the FL
Peninsula this morning, with our area sitting on the drier and
cooler side. At 08Z, temperatures were in the upper 60s to low
70s, with dew points in the mid 60s, but temperatures are expected
to drop a little more before sunrise. In the wake of the front,
northeast winds will increase again today. Winds will be around
10-15 mph over inland portions of the area, 15-20 mph along the
coast. In addition to just being windy today, this strong onshore
flow could bring scattered showers to the area this afternoon,
mostly along the coastline. Noticeably cooler temperatures are
also expected today, with highs in the low-mid 80s. Likewise,
overnight temperatures should be mostly in the mid-upper 60s. 

.SHORT TERM...(Fri and Sat)...
Strong mid level ridge from the nrn Gulf Coast to the deep south will
slowly build over the region through this period. Sfc high pressure
around 1028 mb over VA and MD will slowly sink southward to SC 
and NC while weakening and allow local pressure gradient to relax 
a bit. Model sounding and cross section show plentiful low level 
moisture during the period and a strong subsidence inversion 
around 5000-7000 ft. Anticipate a low chance of showers due to low
level convergence both Friday and Saturday, with lessening 
chances Sat evening as the gradient loosens and moisture depth 
decreases. Best chances showers will be Friday, around 20-40 
percent for the coastal areas and only 10-15 percent well inland. 
Saturday, will taper Pops back to 10-20 percent for all areas.

Highs will be kept to the lower 80s near the coast, and mid 80s
further inland. Relatively cooler overnight lows in the lower 
60s for inland southeast GA and mid 60s inland northeast FL to 
upper 60s and lower 70s for rest of area. Sat, increased
thicknesses, and some decrease in moisture will allow for better
insolation and warmer temps with highs mid 80s coast and upper 
80s inland. Anticipate breezy easterly winds Friday around 15-20 
mph coastal areas and 10-15 mph inland...and generally 10-15 mph 
on Saturday most areas. Mostly clear skies Saturday night and 
decrease low level moisture will allow for min temps again in the 
lower to mid 60s inland, though lower 70s along the coast, as 
easterly winds will persist there.

.LONG TERM...(Sun-Wed)...

Deep layer ridge will persist over the area Sunday and Monday with 
a dry and subsident air-mass in place. Mostly clear to partly 
cloudy skies expected. For Tue and Wed, a weak front will move 
into the southeast states as a shortwave pushes across the nrn 
U.S. and Great Lakes. Westerly flow and ridge aloft will bring 
warmer temps during the extended period. Highs are currently 
forecast to reach mid 90s inland zones for Tue and Wed. Overall, 
minimal rain chances Tue and Wed and for most part our area 
remains dry. 



Patchy MVFR vsbys are possible again this morning should clear out
shortly after sunrise. Strong northeast winds expected today in
the wake of a cold front, with the strongest winds along the
coast. Gusts to 25-30 knots will be possible. With strong onshore
flow, scattered showers will be possible again this afternoon,
with the highest chances near the coastline. 



With northeast flow increasing again in the wake of a backdoor
cold front, seas will begin to build again today. Winds of 20 to
25 knots are expected with gusts to 30 knots. This onshore flow
will persist for the next several days, but wind speeds will
gradually fall through the weekend. Waves will also gradually fall
behind the wind speeds, but waves of 7 feet or greater may linger
into early next week for our offshore waters. A small craft
advisory remains in effect through at least Saturday.

Rip Currents: Strong northeast flow today will result in surf 
heights building to 7-8 ft along the FL coastline, 5-6 ft along
the GA coastline. Elevated breaker heights will persist through 
at least Saturday night. A High Surf Advisory has continues for 
the northeast Florida beaches through Saturday evening. Pounding 
surf will likely result in minor beach erosion during times of 
high tide at area beaches into the weekend. A High Risk of deadly 
Rip Currents will continue through the weekend at all area 



Scattered showers are possible today and tomorrow, but overall QPF
remains low- less than an inch across the area. Northeast flow
will increase again today, keeping water levels elevated within
the St. Johns River basin and along the Intracoastal Waterway in
northeast and north central Florida during times of high tide.
Water levels of 1-1.5 feet above astronomical high tide will
likely continue through the weekend. A coastal flood statement is
in effect. Otherwise, there are no flooding concerns.


AMG  84  64  85  64 /   0   0  20  10 
SSI  81  72  82  72 /  30  30  30  20 
JAX  83  70  85  69 /  50  40  30  20 
SGJ  83  72  84  73 /  50  50  20  10 
GNV  85  67  87  67 /  30  10  20  10 
OCF  87  69  89  68 /  20  20  20  10 


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

     High Surf Advisory until 4 PM EDT Saturday 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 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-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.