Area Forecast Discussion
Issued by NWS Jacksonville, FL

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FXUS62 KJAX 181844

Area Forecast Discussion
National Weather Service Jacksonville FL
244 PM EDT Fri Aug 18 2017

.NEAR TERM...through Saturday...

The region will be between a trough dipping into SE GA and a
ridge of high pressure to the Southeast through Tonight.
Convection will continue this afternoon, with best coverage over
NE FL, due to moist flow from the gulf. With fairly light flow,
locally heavy rainfall will be expected. A drier flow over SE GA,
will limit convective potential there this afternoon. Clearing
skies will be expected Overnight.

The trough will weaken on Saturday, with the high pressure ridge
building to the East. This pattern will lead to a more
Southeasterly flow over the coastal waters Saturday afternoon,
helping to push the East coast sea breeze further inland. The flow
will remain fairly light, so locally heavy rainfall will again be

Near to slightly above normal temperatures are expected this

.SHORT TERM...Sun & Mon...

Pattern shift as prevailing flow transitions to SSE early next
week as mean layer 1000-500 mb ridge axis and surface Bermuda
Ridge axis lift north of the local forecast area. The diffuse
surface front will linger across the area Sun, then lift northward
into Mon. High moisture content with PWAT values near 2 inches
will continue across the area which will fuel scattered mainly
afternoon evening scattered showers and tstorms. Convection will
fire along the stronger east coast sea breeze front by early
afternoon and along and south of the diffuse surface front.
Rainfall will then progress and develop farther inland toward the
I-75 corridor through the afternoon and evening. Rainfall will
gradually decrease in coverage and intensity each evening through
midnight, with a chance of showers/isolated tstorms near the
Atlantic coast overnight under the onshore flow.

Temperatures will near to above normal Sun for highs with values
in the low to mid 90s inland to upper 80s Atlantic coast. Muggy
overnight conditions will continue with minimum temperatures will
range in the 70s.

Monday trended a few degrees lower than consensus guidance for
maximum temperatures due to timing of the solar eclipse. At this
time advertised high temperatures near 90 well inland to mid/upper
80s coast. Also lowered hourly temperatures down several degrees
between 1-4 pm. It is highly possible that where cloud breaks
occur, temperatures could cool as low as 15 degrees than a normal.
It is also highly possible that cloud cover and convection could
limit local eclipse viewing. A better chance of less cloud cover
during the afternoon will be toward the Atlantic coast trailing
the Atlantic coast sea breeze.

.LONG TERM...Tue through Fri...

Tue & Wed...Lower rain chances as the mean layer ridge axis
begins to settle back south and extend across the local forecast
area as a trough axis begins to deepen across the mid-West. Light
steering flow under the ridge will enable both the Gulf and
Atlantic coast sea breeze to develop and drift inland with the
main convective concern locally heavy rainfall. Temperatures will
trend near to above normal.

Thu & Fri...Elevated rain chances return as the ridge axis
settles south of the forecast area and the trough axis deepens
across the southeast region. Steering flow will transition back to
the SW as the surface front settles toward south Georgia late Thu
into Fri. The front combined with the daily sea breezes and
increasing upper level dynamics and instability will bring higher
rain chances to the forecast area each day, especially Fri when
the front is expected to be across the local area. Locally heavy
rainfall will continue to be the main convective hazard, but a few
strong to severe storms will be possible this period as well due
to cooler temperatures aloft under the deepening upper level



Convection will dissipate late this afternoon, with restrictions
and gusty winds possible in and near storms. Clearing is expected
Tonight. Convection is expected to develop once again Saturday



The region will be between high pressure to the Southeast and
a trough to the North Today. High pressure will be to the East
over the weekend, then to the Northeast early next week.

Rip Currents: Low risk today and Saturday.



Low daytime dispersions across NE Florida today and again
Saturday due to light transport winds and elevated rain chances.


AMG  75  94  74  94 /  10  40  20  40
SSI  79  92  79  89 /  10  30  20  40
JAX  75  93  76  92 /  10  40  40  30
SGJ  77  93  78  89 /  10  30  20  20
GNV  75  93  75  92 /  20  60  40  50
OCF  74  93  75  91 /  20  60  40  50




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