718 
FXUS62 KJAX 082030
AFDJAX

Area Forecast Discussion
National Weather Service Jacksonville FL
430 PM EDT Mon Jun 8 2020

...RIVER FLOODING THIS WEEK NE FLORIDA...

.NEAR TERM [Through Tonight]...

Drier mid level air has reduced coverage of convection this 
afternoon from west to east across the forecast area, but has 
increased downdraft wind potential with DCAPE analyzed over 600 
J/kg across our eastern zones to over 1000 J/kg generally near the
I-75 corridor. The main convective hazards will continue to be 
localized heavy rainfall where boundaries merge over already 
saturated ground across NE FL as well as gusty downburst winds, 
even in just shower activity. Low level shear much weaker than 
past couple of days so rotating cells not as large of a threat. 
Mostly dry conditions will develop this evening as deeper 
convection presses offshore of the Atlantic coast and drier 
mid/upper level air pivots across the area from the GOMEX bringing
partially clearing skies tonight. Next wave of showers and isolated
storms will begin to creep inland from the Gulf Coast region toward
sunrise, otherwise mostly dry conditions after midnight. 

Muggy nighttime conditions due to high moisture over the area 
with low temperatures trending above normal in the low/mid 70s. 

.SHORT TERM [Tuesday Through Wednesday Night]...

Above normal rain chances will continue as high atmospheric
moisture lingers over the area under WSW steering flow as the mean
layer 1000-700 mb ridge builds across the Florida peninsula. Tue
morning shower/tstorm activity will advance inland from the Gulf
Coast region as a short wave trough and weak surface trough axis
pivot northward from the eastern GOMEX. Morning shower and tstorm
activity will move across SE GA into the early afternoon, while
convection begins across NE FL along the sea breezes, with
activity maximized in the afternoon/early evening across NE FL
near the St Johns River basin where boundary collisions occur. Wed
expect a more 'typical' sea breeze regime with peak in precip
across the interior during the afternoon as boundaries collide.
Weak upper level dynamics and warm temperatures aloft under a
building mid level ridge across the FL peninsula will limit severe
weather potential, however, locally heavy, potentially flooding
rainfall will be possible. Precip will tend to drift eastward into
the early evening each day and gradually fade in coverage through
midnight. 

A general 'warming' trend in temperatures with less persistent 
cloud cover and a building mid level ridge over FL with high 
trending near normal values in the upper 80s to near 90 inland, 
mid 80s coast. Muggy low temperatures will trend above normal in 
the low/mid 70s. 

.LONG TERM [Thursday Through Monday]...

A surface front will stall across the region and linger into the
weekend as an upper level trough deepens across the eastern CONUS.
Locally heavy rainfall will continue to be a hazard Thu with weak
steering flow over the area and continuation of high moisture
fueling showers/storms that form along both Gulf/Atlantic coast
sea breezes and also across inland SE GA near the approaching
surface front. Fri into Mon drier mid level air advects over NE FL
from the east which favors a downward trend in rain chances and a
more dominant east coast sea breeze that will bring morning
coastal showers/tstorms, then shift the focus for stronger
afternoon/evening storms inland toward I-75 corridor and across
interior SE GA. Although the drier air will favor lower rain
chances compared to last weekend, strong to severe storm potential
will increase this period as the upper levels destabilize under
the deepening upper level trough. 

Temperatures will trend near normal values. 

&&

.AVIATION...
[Through 18Z Tuesday]

Showers and thunderstorms will be widespread this afternoon except
at GNV, with activity moving northeastward around 20 knots and 
overspreading the northeast FL terminals and SSI after 18Z. An 
isolated shower or thunderstorm may impact the GNV terminal, but 
confidence was too low to include anything more than vicinity 
coverage. Brief IFR conditions and wind gusts to 30 knots can be 
expected with convection through 00Z. Outside of thunderstorm 
activity, southerly surface winds will prevail except at the 
coastal terminals, where the Atlantic sea breeze boundary shifting
winds at SGJ to east-southeasterly around 10 knots and the rest 
of the Duval County terminals and SSI after 19Z. Thunderstorm 
activity should dissipate by 01Z, with fog possible after midnight
at GNV and VQQ as surface winds diminish.

&&

.MARINE...

An extended period with no headlines expected into the weekend 
with light southerly winds generally 10 kts or less and combined 
seas 3 ft or less through Thu. High pressure offshore of the 
Atlantic coast will strengthen across south Florida through 
Wednesday with weak surface troughs remaining west of the local 
waters. A surface front will approach from the west Thursday and 
then stall and meander across the region Friday and Saturday with 
prevailing winds transitioning to ESE. Daily shower and 
thunderstorm potential, mainly during the afternoon and evening. 

Rip Currents: Low risk today and tomorrow. Elevated rip current
risk Fri into weekend as onshore flow develops. 

&&

.FIRE WEATHER...

Elevated rain chances continue through mid-week with high 
moisture across the region and warm SSW winds. Winds will 
transition SSE near the Atlantic coast in the afternoons with the 
sea breeze. Thunderstorms will be more numerous during the 
afternoon and early evening, gradually weakening after sunset. The
potential for locally heavy rainfall on saturated ground will 
make areas across Northeast Florida more flood prone this week. 
Due to weak winds, low daytime dispersion is expected Tuesday and 
Wednesday across parts of Northeast Florida, especially near the 
St. Johns River basin. 

&&

.HYDROLOGY...

The North Fork at Black Creek and the St. Marys at Trader's Hill
were in minor flood, with the crest gradually leveling off and
starting to decline early this afternoon. Locations along the
Suwannee River including Suwannee Springs and White Springs were
on track to reach or come very close to minor flood mid-week. The
Santa Fe basin is also expected to have several locations rise
precariously close to minor flood mid week. Although a widespread
persistent heavy rainfall event is not expected this week,
scattered to numerous showers and t'storms will bring the
potential for localized heavy rain, so further water rise is
certainly possible across these more vulnerable basins across NE
Florida. 

&&

.PRELIMINARY POINT TEMPS/POPS...

AMG  72  89  71  89  72 /  20  60  40  70  30 
SSI  76  87  75  86  75 /  40  40  30  50  20 
JAX  73  89  73  90  73 /  40  50  30  60  10 
SGJ  74  88  73  87  73 /  40  50  30  50  10 
GNV  74  88  72  89  71 /  30  60  30  70  10 
OCF  74  88  72  89  72 /  20  60  30  70  20 

&&

.JAX WATCHES/WARNINGS/ADVISORIES...
FL...None.
GA...None.
AM...None.
&&