Area Forecast Discussion
Issued by NWS Jacksonville, FL
FXUS62 KJAX 290604
Area Forecast Discussion
National Weather Service Jacksonville FL
204 AM EDT MON AUG 29 2016
...Continued High Rip Current Risk Along Area Beaches...
.NEAR TERM /Today Through Tonight/...
Radar has been showing scattered showers and isolated t-storms
over the coastal waters overnight...associated with a weak mid-
level circulation seen on water vapor animation well offshore of
se GA. System is forecast to move very little today, maintaining
threat of coastal showers/isolated t-storms. Model guidance
suggests some showers may move across coastal counties through the
morning... with scattered showers/isolated t-storms developing
further inland in the afternoon. Will reflect this in hourly POP
trends. High temps will range from the upper 80s near coast...
around 90 inland portion of coastal counties...lower 90s further
For tonight...showers diminish well inland...but model guidance
show increase in shower coverage over coastal waters after
midnight...with threat of scattered showers moving over coastal
counties. Low temps will be in the mid 70s inland... upper 70s
.SHORT TERM /Tuesday Through Wednesday Night/...
A mean layer trough axis extending northeast of TD #9 will pivoted
northward from central Florida Tue and then extend across or just
north of SE Ga Wed as the storm begins a north to northeast track
over the eastern Gulf of Mexico. Locally this will mean a
progressive increase in rain chances first across our southern NE
Florida zones Tuesday...then expanding farther northward across
the remainder of N Florida Wed on the southern side of the
aforementioned trough axis. Tue onshore flow will continue across
the area with waves of showers and isolated tstorms moving inland
from the Atlantic during the morning...with diurnal enhancement
inland across the remainder of NE Florida with less coverage
across SE Ga into the afternoon. By early Wed...offshore flow is
expected across our southern Florida zones on the southern edge of
northward progressing trough axis...while a drier northerly flow
over inland SE Ga and over our Suwannee River Valley zones. Rain
chances will overspread our Fl zones generally south of the I-10
corridor through the day Wed with once again diurnal enhancement.
Temperatures will remain above climo across SE Ga where drier and
more stable air will continue with max temps in the 90s...while
increased convection across NE Fl will keep max temps in the
mid/upper 80s. Low temperatures will generally moderate in the
.LONG TERM /Thursday Through Sunday/...
Forecast confidence with respect to the track of TD 9 has increased
given better model consistency advertising TD 9 (likely a tropical
storm by this time frame) tracking NE across the NE Gulf of Mexico
as a deepening 500 mb trough across the eastern CONUS picks up the
system. This scenario is pending that the system deepens enough
for this mid level trough to pick it up and steer it to the NNE.
Based on the latest NHC/WPC forecast...the potential for heavy
rainfall will overspread portions of NE Florida Thu through early
Fri as the system cross the northern Florida peninsula. This
would also be the most likely time period of tropical storm force
winds in convective squalls...including over the adjacent coastal
waters. Used the WPC QPF guidance which advertised up to 3 to 6
inches of rainfall overspreading the area with this system across
portions of NE Florida...with generally less than 2 inches across
SE Ga. Much of the local area will welcome this needed
rainfall...but high amounts in short duration could cause
temporary flooding problems. Also...depending on this storm`s
structure and eventual track...the NE side of the storm relative
to storm motion could overspread a portion of our Florida
zones...with is the more favored quadrant for tropical tornado
formation Thu into Thu night.
By Fri afternoon...a drier northerly flow will push southward
across the local area as the storm moves NE and offshore of the
GA/SC Atlantic coast with the trailing surface trough axis shunted
south of the local area Saturday as a backdoor cold front
bringing coastal showers inland. Surface high pressure over the
mid-Atlantic will extended a wedge axis across central Ga with a
deep layer cooler and drier northerly flow over the local CWA with
a 500 mb ridge building eastward across the Gulf coast region.
Thus...after a potentially unsettled Thu/Fri...a drier and cooler
pattern looks to be in store for the later half of the weekend
with dew pts in the mid/upper 60s by Sun/Mon.
Temperatures will range from highs only in the 80s Thu/Fri...with
some moderation to near climo values by the weekend. By early
next week...low temperatures in the mid/upper 60s will be possible
inland due to drier air over the local area.
.AVIATION...Generally expecting VFR conditions next 24
hours...but local MVFR conditions are possible in scattered SHRA
and isolated TSRA...with better chances for this for near-coast
TAF sites than well inland sites like KVQQ or KGNV. Easterly flow
pattern continues today...with occasional late morning-afternoon
gusts up to 18-20 kts.
.MARINE... With high pressure well north of the area and low
pressure well south will maintain moderate onshore flow pattern
over the waters through Wed. Model guidance keeps winds just below
exercise caution levels...but suggest increased seas due to
Closely monitoring progress of Trop. Depression #9 over far se
Gulf of Mexico. Latest guidance in fair agreement in suggesting
increased organization of system as it gradually moves northeast
from east-central Gulf to northern FL by early Fri...then offshore
of northeast FL late Fri into early Sat. Based on the latest
guidance from NHC...there is some potential for tropical storm
conditions over coastal waters Thu night and Fri.
Rip Currents...Will continue high rip current risk through Tuesday
due to easterly swell... moderate onshore flow...and early
afternoon low tides. Extreme caution is urged.
.PRELIMINARY POINT TEMPS/POPS...
AMG 91 73 91 72 / 40 10 30 20
SSI 88 77 86 77 / 30 30 40 40
JAX 90 75 87 75 / 30 30 50 40
SGJ 89 77 86 77 / 40 50 60 50
GNV 91 74 89 74 / 40 20 60 30
OCF 91 74 90 74 / 40 20 60 40
FL...High Rip Current Risk through Tuesday afternoon for Coastal
Duval-Coastal Nassau-Flagler-St. Johns.
GA...High Rip Current Risk through Tuesday afternoon for Coastal