Area Forecast Discussion
Issued by NWS Jacksonville, FL

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FXUS62 KJAX 232023
AFDJAX

Area Forecast Discussion
National Weather Service Jacksonville FL
423 PM EDT Sat Sep 23 2017

...HIGH SURF AT THE NORTHEAST FLORIDA BEACHES THROUGH MONDAY...
...HIGH RIP CURRENT RISK CONTINUES AT AREA BEACHES THROUGH AT
LEAST MONDAY...

.NEAR TERM /Through Sunday/...
Overview: The near term pattern begins with an upper trough
digging across the intermountain west, a ridge over the Ohio
Valley, the remnants of Jose east of the northeastern conus, an
upper low over the western Florida Panhandle and the northeast
Gulf, and Hurricane Maria east/northeast of the Bahamas. The upper
trough and upper ridge will push slowly eastward, the remnants of
Jose will drift southeastward, the upper low over the
northeastern Gulf will continue to slowly retrograde westward, and
Hurricane Maria will move slowly northward through Sunday.

Rest of today and tonight: Breezy east northeasterly flow will
prevail through the afternoon, with showers/storms pushing across
the interior. However, coastal showers and embedded storms will
remain possible into the late afternoon. Storms will dissipate in
the evening, with dry conditions expected after midnight.
Overnight lows will be in the upper 60s to lower 70s inland and
the mid 70s along the coast.

Sunday: Drier mid level air will begin to move into the region on
Sunday, rotating around Hurricane Maria. This will lead to much
lower rain chances. Only isolated to widely scattered
showers/storms are expected on Sunday. An isolated coastal shower
is possible in the morning, followed by isolated to widely
scattered showers/storms across the west and southwestern portion
of the region Sunday afternoon. Afternoon highs will be in the low
to mid 80s along the coast and the upper 80s inland.

.SHORT TERM /Sunday night through Tuesday night/...
Hurricane Maria will make its closest approach to our coast on
Sunday evening, passing just under 500 miles offshore. Low level
flow will shift from northeasterly to northerly overnight, which
will funnel a dry and subsident air mass on the western periphery
of Maria into our region. Some high cloudiness may linger over our
area Sunday night, but skies will trend towards fair by Monday
morning and will likely stay fair through at least midweek. Breezy
north-northeasterly winds will continue on Sunday night and
Monday for locations east of Interstate 95, with winds shifting to
northwesterly on Monday afternoon at inland locations in northeast
and north central Florida. Lows Sunday night will only fall to the
mid and upper 70s at area beaches due to the breezy onshore wind,
with inland locations decoupling and falling into the upper 60s.
Highs on Monday will climb to the upper 80s/near 90 inland and the
mid 80s at the beaches. Clear skies, light winds and the dry air
mass in place on Monday and Tuesday nights will allow lows to fall
to the mid and upper 60s at inland locations, with lower 70s at
the coast. Plentiful sunshine and low humidity values will boost
highs to near 90 inland, with a late afternoon sea breeze keeping
coastal highs in the mid to upper 80s.

.LONG TERM /Wednesday through Saturday/...
Hurricane Maria will slow its forward progress off the Carolina
coast on Wednesday and Thursday, keeping our region within a dry
and subsident north-northwesterly flow pattern. The dry air mass
and plenty of sunshine will allow highs to climb into the lower
90s at inland locations, which is just under record high
territory at our climate sites. Sea breezes will be pinned and
late to form, allowing coastal highs to climb to near 90 on
Wednesday and Thursday. Lows will continue to fall to the
mid/upper 60s inland and the lower 70s at the coast.

Long-term guidance remains in disagreement on Friday and Saturday
as a pair of cold fronts approach our region from the northwest.
Models indicate that a shortwave trough diving southward from
Hudson Bay will sharpen and be the impetus to finally accelerate
Hurricane Maria northeastward away from the North Carolina Outer
Banks, and this feature will also transport deeper moisture
northward from the Caribbean and eastern Gulf of Mexico over our
region. The 12Z operational GFS is faster with this moisture
return than the operational 12Z ECMWF, and thus model blends
depict chances for isolated convection as early as Friday
afternoon. Scattered showers and thunderstorms appear to be most
probable on Saturday ahead of the amplifying trough aloft/surface
cold front. Seasonably hot weather will continue on Friday ahead
of the front, with inland highs in the lower 90s and upper 80s at
the coast. Highs on Saturday should remain in the 80s with
increasing clouds and rain chances.

&&

.AVIATION...
Showers/storms will continue to push across the interior this
afternoon, affecting KGNV. East northeast winds 10-15 knots will
prevail through the afternoon, with winds diminishing overnight.
Patchy fog is possible tonight across the interior. Otherwise, VFR
conditions are expected. East northeast winds will increase again
to 10-15 knots on Sunday.

&&

.MARINE...
Hurricane Maria will move slowly northward through the weekend,
which will bring increasing swells to the regional waters. East
northeast winds will also be 15 to 20 knots. Seas in the near
shore waters will build to 6-9 feet from tonight through  Monday
night. 6 to 9 foot waves offshore will peak in the 9-12 foot range
late tonight through Monday. SCA level seas are likely to persist
for much of next week in the offshore waters due to large swells
from Maria, which is expected to turn northeastward by late next
week. Maria will pass our latitude on Monday well to our east,
allowing winds to shift to a northerly and then northwesterly
direction with decreasing speeds by late Monday and Tuesday.

Rip Currents: High risk of rip currents through Monday due to
increasing swells from Hurricane Maria. High Surf Advisory in
effect late tonight through Monday morning for surf 7 feet or
higher along the coast of northeast Florida. Beach erosion will
become an increasing concern during times of high tide through
early next week.

&&

.HYDROLOGY...
A Coastal Flood Advisory remains in place through the Sunday night
high tide cycle for the St. Johns River basin, as minor flooding
continues during each high tide cycle from Jacksonville southward
to Palatka. Further south, flooding approaches moderate levels
into the Welaka and Ocklawaha River basins. Strengthening onshore
winds may keep the risk of minor to moderate flooding in place
during times of high tide through early next week.

Moderate flooding continues along portions of the Santa Fe and St.
Mary`s Rivers, with minor flooding along the Satilla River east of
Waycross and portions of the Upper Suwannee River north of I-10.

&&

.PRELIMINARY POINT TEMPS/POPS...
AMG  69  87  67  88 /  10  10   0   0
SSI  75  84  75  85 /  10  20   0  10
JAX  73  86  70  88 /  20  20   0  10
SGJ  74  84  77  85 /  30  20  10  10
GNV  70  86  69  90 /  20  20   0  10
OCF  71  89  70  90 /  20  30   0  10

&&

.JAX WATCHES/WARNINGS/ADVISORIES...
FL...High Rip Current Risk through Monday evening for Coastal Duval-
     Coastal Nassau-Flagler-St. Johns.

     Coastal Flood Advisory until 6 AM EDT Monday for Clay-Coastal
     Duval-Flagler-Inland Duval-Putnam-St. Johns.

     High Surf Advisory from 11 PM this evening to 5 AM EDT Monday
     for Coastal Duval-Flagler-St. Johns.

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

AM...Small Craft Advisory until 5 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-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.

&&

$$

Kennedy/Nelson/Corless


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