Gale Warning 7, NWS Jacksonville, FL

Area Forecast Discussion
National Weather Service Jacksonville FL
135 AM EDT Sat Sep 19 2020

.AVIATION...
[Through 06Z Sunday]

Widespread MVFR CIGS about to overspread all TAF sites from the
coast to inland over the next 4-6 hours with MVFR VSBYS already
being reported at SSI in light showers that will impact CRG/SGJ
within the next couple of hours, then push inland to JAX/VQQ by
12z then GNV by 15z. NE winds will steadily increase to 15-20
knots with gusts to 25-30 knots at SGJ/SSI/CRG with gusts of 20-25
knots at JAX/VQQ/GNV by the 15-18z time frame. Heavy rainfall will
begin to impact SGJ by the 15z time frame with embedded storms
possible from 18z-03z time frame and have included VCTS for now.

&&

.PREV DISCUSSION [728 PM EDT]...

.NEAR TERM [Through Tonight]...

The northeast flow pattern will intensify Tonight as high pressure
builds to the north, and an inverted trough builds over the western
Atlantic. Cloud coverage will increase through the night, as
isolated to scattered showers become more common. The best chance
for these showers will be along the coastal counties. Winds will
pick up overnight along the coast, becoming noticeably gusty at
area beaches by dawn. The showers that come ashore overnight will
also produce briefly higher wind gusts. Lows will generally be in
the upper 60s to around 70 inland, and in the lower to middle 70s
coastal.

.SHORT TERM [Saturday Through Sunday Night]...

Expansive high pressure will strengthen as it shifts west from
the Great Lakes region to New England. This will enhance the
northeasterly flow across the region, leading to breezy to gusty
conditions across the area; coastal areas will be on gustier side
with respect to gradient winds. Additionally, scattered to
numerous showers and isolated storms are expected to move onshore,
primarily affecting the coastal areas, each afternoon.
Northeasterly steering flow may result in multiple waves of heavy
rain along the northeast Florida coast/beaches this
weekend...localized flooding will be a concern.

As a drier, cooler airmass upstream slowly jostles its way south,
a noticeable plunge in temps will occur, with readings between
8-10 degrees below mid-September normals. By Sunday, high temps
across most of the area will be in the low to upper 70s with
morning low falling into the low to mid 60s across southeast
Georgia and the upper 60s to lower 70s across northeast Florida.

.LONG TERM [Monday Through Friday]...

Surface high will remain centered over New England through
Monday before repositioning and stacking under broad ridging
aloft. Prolonged strong northeasterly winds (and associated
coastal hazards) will likely remain through Monday but may start
to back off on Tuesday as winds veer to the east as the surface
high scoots to the southeast. Meanwhile, dry north-northeasterly
low to mid-level flow will scour moisture to our south, eliminating
chances for most of the area with the exception of low-end chances
along the coastal northeast Florida. Shower and storm chances
will remain at bay through at least Wednesday before the influence
of TS Beta lift a tropical airmass northward back over the area on
Thursday. Unseasonably cool, Fall-like temps will continue
through the middle of next week before trending back towards
normal.

.MARINE...

High pressure will strengthen over the Great Lakes through this
evening and will wedge into the southeastern states tomorrow,
with an abrupt north to northeasterly wind surge entering the
southeast Georgia waters just after midnight tonight and then
overspreading the northeast Florida waters during the predawn and
early morning hours on Saturday. Have posted a Gale Watch to
replace small craft advisories by late morning Saturday into
Monday as well as a high surf advisory for surf heights increasing
to 6 to 9 feet along the coast. Strong high pressure will then
build over New England tomorrow night and Sunday, maintaining
strong northeasterly winds across our waters through Monday night,
with widespread showers and a few thunderstorms expected. High
pressure will then weaken over the Appalachians on Tuesday as a
Tropical Cyclone approaches Deep South Texas.

Rip Currents: High Risk of Rip currents through Monday for NE FL
and SE GA due to the NE winds surging onshore through the weekend.

.HYDROLOGY...

The strong NE onshore flow will push bands of showers and isolated
storms into the St Johns and Flagler coastal areas on Saturday
and Sunday with rainfall totals of 2-3 inches expected. Localized
flooding is expected which will be exacerbated during times of
high tide along the coast and in urban areas. However, a flash
flood watch does not appear needed at this time.

&&

.PRELIMINARY POINT TEMPS/POPS...

AMG  78  60  76  57  75 /  10  10   0   0   0
SSI  78  68  78  68  77 /  30  30  10  10  10
JAX  80  69  80  69  79 /  60  50  30  10  20
SGJ  82  74  82  73  81 /  90  80  60  20  30
GNV  82  70  81  68  82 /  60  60  20  10  10
OCF  85  72  83  70  83 /  80  70  30  10  10

&&

.JAX WATCHES/WARNINGS/ADVISORIES...
FL...High Rip Current Risk from 6 AM EDT this morning through Monday
     afternoon for Coastal Duval-Coastal Flagler-Coastal Nassau-
     Coastal St. Johns.

     Coastal Flood Watch from this evening through Monday afternoon
     for Coastal Duval-Coastal Flagler-Coastal Nassau-Coastal
     St. Johns.

     High Surf Advisory from 5 PM this afternoon to 6 PM EDT Monday
     for Coastal Duval-Coastal Flagler-Coastal Nassau-Coastal
     St. Johns.

     Coastal Flood Advisory from 9 AM this morning to 8 PM EDT this
     evening for Coastal Duval-Coastal Flagler-Coastal Nassau-
     Coastal St. Johns.

     Coastal Flood Advisory from 9 AM this morning to 6 PM EDT Monday
     for Clay-Inland Duval-Inland Flagler-Inland St. Johns-
     Putnam.

GA...High Rip Current Risk from 6 AM EDT this morning through Monday
     afternoon for Coastal Camden-Coastal Glynn.

     Coastal Flood Watch from this evening through Monday afternoon
     for Coastal Camden-Coastal Glynn.

     High Surf Advisory from 5 PM this afternoon to 6 PM EDT Monday
     for Coastal Camden-Coastal Glynn.

     Coastal Flood Advisory from 9 AM this morning to 8 PM EDT this
     evening for Coastal Camden-Coastal Glynn.

AM...Small Craft Advisory until noon EDT today 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 Fernandina Beach to St. Augustine FL from 20 to
     60 NM-Waters from St. Augustine to Flagler Beach FL from 20
     to 60 NM.

     Gale Warning from 4 PM this afternoon to 6 PM EDT Monday 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 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 noon EDT today for Coastal waters
     from Altamaha Sound to Fernandina Beach FL out 20 NM-Waters
     from Altamaha Sound GA to Fernandina Beach FL from 20 to 60
     NM.

     Gale Warning from noon today to 6 PM EDT Monday for Coastal
     waters from Altamaha Sound to Fernandina Beach FL out 20 NM-
     Waters from Altamaha Sound GA to Fernandina Beach FL from
     20 to 60 NM.

&&