946 
FXUS62 KJAX 120008
AFDJAX

Area Forecast Discussion
National Weather Service Jacksonville FL
808 PM EDT Fri Jun 11 2021

.UPDATE...

There was an widely scattered to scattered convection this late
afternoon and early evening mainly northwest of U.S. Route 84 in
in interior southeast Georgia. Despite good near-surface moisture
recovery, mid level of the atmosphere was pretty dry, with the
isodrosotherm analysis and precipitable water value contours  
showing best moisture to the west of the region today. Currently,
there is convection over east central Georgia, with convective
outflow moving complex slowly south and east, but with loss of 
daytime heating, these thunderstorms should diminish as they 
approach the Altamaha River Basin Region per HRRR. 

With a moist southwest steering flow overnight there may isolated
to widely scattered shower or thunderstorms mainly from I-10 
northward into southeast Georgia during the pre-dawn hours with
main upper level trough axis over the mid Atlantic moves southeast
in concert with the deeper moisture over the region.

The aforementioned upper level trough and attendant backdoor front
will continue to move southeast into the region Saturday. 
Moisture associated with the trough and southwesterly flow will 
restore moisture to the area after a relatively dry day today, 
which will increase shower and storm chances across the area from 
the northwest to southeast on Saturday with scattered to numerous
showers and thunderstorms. Greater coverage expected by late 
afternoon into the early evening as both lift, instability and 
low-level moisture peak, particularly north of a line from
Jacksonville to Live Oak northward into southeast Georgia. The
greatest chance for isolated severe storms are across interior 
southeast GA and the Suwannee Valley where SPC has outlined a
marginal risk.

&&

.AVIATION...
[Through 00Z Sunday]

Mainly VFR conditions prevail through the period. There may be a
light shower with accompanying isold thunderstorms between 18z and
20z Saturday for area terminals north of I-10. Showers and 
thunderstorm chances pick up tomorrow particularly in the 
afternoon and evening for terminals north of I-10 between 20-24z.
Any TSRA could have VRB higher gusts or 3-4SM vsbys. Prevailing
winds Saturday will be out of the southwest, generally between 
8 and 12 knots. 

&&

.PREV DISCUSSION [358 PM EDT]...

.NEAR TERM [Through Tonight]...

Southwesterly winds have increased moisture across SE GA this
afternoon, which will continue scattered showers and storms 
through the night as an upper level trough moves southeastward 
across the area. A few strong storms may be possible this evening 
north of I-10 as upper level waves round the base of the trough.
Strong storm potential hazards could include brief heavy 
downpours, frequent lightning strikes, and wind gusts up to 50 
mph. Storm strength will be limited overnight with a lack of 
daytime heating and reduced instability, but will pick up again
Saturday. Low temperatures will be in the low-to-mid 70s across 
the area tonight, skies will be partly cloudy, and winds will be 
southwesterly.


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

A backdoor cold front will slowly approach the area from the 
northeast through the weekend as the upper level trough moves
to the southeast. Moisture associated with the trough and 
southwesterly flow will restore moisture to the area after a 
relatively dry day Friday, which will increase shower and storm 
chances across the area from the northwest to southeast on
Saturday. Ahead of the boundary and along the leading edge of the
trough, upper level divergence combined with instability caused 
by daytime heating will be sufficient enough to spawn a few 
stronger storms as the trough moves. Models suggest MUCAPE values
Saturday afternoon could reach upwards of 1000 J/kg and MLCAPE
could reach upward of 800 J/kg. Showers and storms will continue 
on Sunday as the base of the trough swings across NE FL. Sunday 
night showers and storm chances will decrease from north to south,
but scattered showers and thunderstorms will still be possible, 
mainly in NE FL.

Weekend high temperatures are expected to be cooler than Friday
due to clouds and rain but still warm. Saturday highs will be in 
the upper 80s and lower 90s with cooler temperatures inland. 
Sunday highs will also be in the upper 80s and lower 90s but with 
cooler temperatures at the coast.


.LONG TERM [Monday Through Friday]...

Another frontal boundary will move towards the region from the
northwest while weakening early next week. Several upper level
shortwaves will move along the boundary, which will continue rain
and storm chances each day. Towards mid-to-late next week the
boundary is expected to become stationary near the FL-GA border,
bringing drier air behind the front to SE GA. Stronger storms 
will be possible ahead of the boundary as it approaches the area.
High temperatures through the long term are expected to be in the
upper 80s and lower 90s, and lows are expected to be in the upper
60s and lower 70s.


.MARINE...

High pressure continues to sink south of the area as a slow moving 
backdoor cold front approaches the waters from the northeast with
associated low pressure currently positioned over the Carolinas. 
The pressure gradient between the low to the northeast and the 
high to the southwest will increase winds and waves tonight. Small
Craft will need to Exercise Caution in the nearshore and offshore
waters due to 15-20 kt southwesterly winds and 3-5 ft waves. The 
front will continue to slowly approach the area and increase 
chances for showers and thunderstorms through the weekend. 
Southwesterly flow will prevail Saturday, then shift to westerly 
Sunday as the front approaches the SE GA waters. By the middle of
next week a weakening frontal boundary will stall just north of 
the area waters, which will continue shower and thunderstorm 
chances each day. Southwesterly winds and 2-4 ft waves are 
expected to prevail Monday through Wednesday. 

Rip Currents: Moderate Risk today at all area beaches. Prevailing
offshore winds this weekend and decreasing wave heights will
result in a downward trend towards Low Risk at all area beaches.


.FIRE WEATHER...

Southwesterly winds have helped to recover moisture across SE GA
this afternoon, and will continue to increase moisture across the
area through the weekend. Tonight winds will decrease slightly and
scattered showers and thunderstorms will continue in SE GA. Breezy
west-southwesterly winds with gusts near 15 mph will prevail
Saturday. Winds are expected to decrease on Sunday, which will
lower dispersions. Shower and thunderstorm chances will increase
from northwest to southeast across the area Saturday and Sunday. A
stormy weather pattern is expected to continue into next week.

&&

.PRELIMINARY POINT TEMPS/POPS...

AMG  72  89  70  89  69 /  40  60  60  50  10 
SSI  76  90  75  88  75 /  30  60  70  50  20 
JAX  74  91  72  90  71 /  20  60  60  60  30 
SGJ  74  91  73  88  72 /  10  40  50  60  40 
GNV  72  90  71  89  70 /  10  50  50  70  40 
OCF  72  91  73  90  72 /  10  30  50  60  40 

&&

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