465 
FXUS62 KJAX 031325
AFDJAX

Area Forecast Discussion
National Weather Service Jacksonville FL
925 AM EDT Fri Jun 3 2022

.UPDATE...

Mid and upper level dry air remains established this morning with
the latest RAOB showing near steady moisture levels through the 
atmospheric column, with PWAT ~1.3" (typical value for early June 
~1.5"). As of 9 AM, a slow-moving, weak frontal boundary has 
crossed the Ocmulgee River in southeast GA. This frontal zone 
will continue to slow and eventually stall; it will be the 
primary focus of convection this afternoon and evening across 
inland southeast GA. A secondary focus for convection will be 
along the Atlantic sea breeze where scattered showers may develop 
and perhaps an isolated storm as it reaches the St Johns river 
breeze this afternoon. Thunderstorm coverage will ramp up along 
the I-75 corridor early this evening as the Atlantic sea breeze 
collides with the GOMEX sea breeze. In addition to the enhanced surface
convergence along the sea breeze merger, weak upper lift will be 
offered by a subtle shortwave trough as it lifts northeastward out
of the GOMEX this evening. With the aforementioned dry air in 
place, storms that develop will be capable of strong wind gusts 
due to evaporative cooling enhancement (DCAPE 1000-1200 j/kg). 
Weak southwesterly steering flow will lead to slow storm motion 
this afternoon, around 5 mph. This may lead to localized heavy 
rainfall and nuisance ponding. 

Tonight, convection will wane but lingering showers and isolated
storm may continue through the late evening along the frontal
boundary as it slowly sags southward to the FL/GA border. Most
eyes will be on Potential Tropical Cyclone One, which may become
Tropical Storm Alex later today, as it approaches southern Florida
tonight. Associated moisture will increase across north-central 
FL as the system nears and showers along the northern fringe may 
advect from the Atlantic into coastal St Johns and Flagler 
counties near daybreak Saturday. Outside of higher risk of rip 
currents, local impacts are not expected with this system but a 
few southern zones may receive beneficial rain.

&&

.PREV DISCUSSION [748 AM EDT]...

.NEAR TERM [Through Tonight]...

Weak high pressure ridging axis extends over the area from the
western Atlantic waters WNW into the north central FL and west
along the gulf coast. A pocket of drier air is situated above 
the area with PWATs around 1.2 inches ahead of a cold front 
moving through the I-20 corridor of AL amd GA. Dewpoints range 
from the mid 60s over inland SE GA to the upper 60s along the SE 
GA coast and into interior NE FL near 70 along the NE FL coast and
north central FL areas, which is just a bit higher compared to 
yesterday morning at this time. Some cirrus is shifting slowly 
north from central FL into southern zones areas south of a 
Gainesville to Palatka to Saint Augustine line as high level winds
stream clouds well downstream of Potential Tropical Storm One 
that is well SW of the region near the Yucatan Peninsula slowly 
moving NE towards the southeastern Gulf of Mexico at this time. 
Mostly clear skies prevail for most of NE FL and SE GA with light 
southerly winds that are becoming a land breeze along the coast 
5-10 mph and less than 5 mph inland. Temperatures are a bit milder
than yesterday with low to mid 70s at most locations, with a few 
inland spots in the upper 60s. Some patchy, shallow ground fog may
develop inland over NE FL areas that received rainfall yesterday,
mainly west of Highway 301. 
 
Light westerly winds after sunrise will become southeasterly by 
the lunch hour over NE FL and the SE GA coast with light winds 
from the SW over GA areas ahead of the approaching cold front. 
Scattered showers and Thunderstorms will develop first over 
inland SE GA by early afternoon as the combination of lift along
the front, diurnal heating and strong instability coincide with
some pulse strong to severe storms that may create downburst wind 
gusts up to 40-60 mph as the presence of dry low and mid level air 
will yield high DCAPE values over 1,000 J/KG this afternoon. The
Atlantic seabreeze will move inland over NE FL and encounter the
Gulf coast seabreeze near I-75 with isolated to scattered storms
initiating during the mid to late afternoon time frame. A few 
strong storms may develop wind downburst wind gusts, but the 
potential for severe wind gusts will be less likely due to lower 
DCAPE values under 800 J/Kg south of I-10. Showers and storms will
linger after sunset along the frontal boundary over the Altamaha 
river basin of inland SE GA south and west into the Suwannee 
valley as the boundary sinks slowly into the area and shortwave 
energy moves in from the west. Highs will be hot today into the 
mid 90s along and west of I-95 with low 90s immediately east of 
I-95 and in the 85-90 range at the beaches. The mixing down of 
some drier air will limit heat index values to the same values as 
the air temperature, mid 90s or lower.

Tonight, skies will be partly to mostly cloudy from low and mid
level clouds associated with the periphery of Potential Tropical 
Storm One moving in from the south into north central FL and 
debris clouds and a few showers and storms lingering inland due 
to the frontal boundary. Also, rain showers associated with the 
northern fringe of Potential Tropical Cyclone One may begin to 
graze into extreme southeast zones from Flagler Beach westward 
into eastern Marion county just before sunrise, but amounts through
late tonight will be light. Light southeast winds will become 
NE over much of SE GA behind the front as it sinks to the FL/GA 
state line with light easterly winds over NE FL through dawn.
Lows will be milder in the mid 70s at the coast and around 70
inland.


.SHORT TERM [Saturday Through Sunday]...

Lingering frontal boundary will remain just north of the Florida 
/ Georgia border on Saturday. Meanwhile, Potential Tropical 
Cyclone One, currently northeast of the Yucatan will be tracking 
across the southern part of the Florida Peninsula Saturday and 
pushing northeast away from the state of Florida late Saturday 
night and Sunday morning. Timing and Development of this system 
still has some uncertainity. Showers and storms will increase in 
coverage during the day on Saturday as moisture increases across 
the region with PWATS increasing between 1.30 to 1.70 inches with 
much deeper moisture further down the peninsula to the right of 
the system. During Saturday afternoon and early evening, scattered
storms will be possible across SE GA and NE FL, and N Central FL 
could see scattered to numerous showers and storms. The highest 
chances for localized heavy rainfall will be primarily over 
eastern Marion and Flagler Counties where the tightest moisture 
gradient will reside. It is possible that 0.75 to 1.5 inches of 
24 hour rainfall can fall over north central Florida with some 
locally higher amounts depending on the ultimate track of the 
developing system. Winds are expected to shift from easterly in 
the early morning to east-northeasterly late Saturday morning as 
the low approaches, and winds will become breezy along the coast 
and adjacent Atlantic waters. The low pulls further away to the 
northeast Sunday with high pressure building over the mid Atlantic
with tailing trough lingering over southern FL which will keep 
some breezy or heightened winds over the offshore waters and our 
immediate coast with gradient relaxing inland. east coast sea 
breeze will push inland with isolated to widely scattered showers 
across SE GA and NE FL. With persistent onshore flow Sunday, rip 
current risk will be heightened this entire weekend. Highs this 
weekend will be mostly in the mid to upper 80s, with some maximums
near 90 over interior portions of SE GA and north central FL. 
Lows will be mainly in the upper 60s interior sections to mid 70s 
near the coast.


.LONG TERM [Monday Through Friday]...

Lighter winds Monday through the rest of the long term period 
will allow daily sea breezes to return each afternoon and evening.
Isolated to widely scattered showers will be possible area wide 
on Monday with east coast sea breeze. Isolated showers and storms
are expected in NE FL Tuesday and Wednesday with merging west
coast and east coast sea breeze. Storms should be limited with
riding building into the middle of next week. 

Coverage will increase again Thursday and Friday with isolated to
widely scattered showers area wide with a cold front boundary
moving toward and into the region.

An increasing trend in temperatures is expected through the long
term period with highs gradually increasing each day and reaching
the middle to upper 90s by Thursday and Friday. Low temperatures 
are expected to increase from the upper 60s and lower 70s Sunday 
night to the lower to middle 70s Thursday night.


.AVIATION...
[Through 12Z Saturday]

VFR conditions and light southwest winds will continue this 
morning as a weak, slow-moving front presses farther southeastward
toward the area. A gusty east coast seas breeze will press inland
late around noon, reaching the I-95 corridor (JAX) around 18z- 
19z. Vicinity showers and potentially a thunderstorm will be 
possible along the sea breeze as it pushes inland. The best 
thunderstorm potential will be early this evening at GNV as west 
and east coast sea breezes merge. Showers may linger along the 
stalling front in southeast GA but this activity is not likely to 
impact any TAF sites overnight. VFR conditions are likely to 
continue at all sites with the exception of GNV where IFR low 
stratus may develop toward sunrise Saturday. Potential Tropical 
Cyclone One will begin to move across south FL Saturday morning 
and as it does associated showers are possible at SGJ.


.MARINE...

A weak cold front will approach from the northwest today then
stall over the waters through Saturday as a tropical disturbance 
tracks east across the southern Gulf of Mexico. This tropical low
will cross the southern Florida peninsula late Saturday and depart
offshore of the south-central Florida Atlantic coast early Sunday. 
Local winds and seas will increase this weekend as the tropical 
system tracks to the south of the local waters and Small Craft 
Advisories may be needed Saturday night through Sunday. The low
will track farther offshore over the Atlantic Monday as high
pressure builds northeast of the region. The high will build east
of the local waters through mid-week with lingering troughs
northwest of the region. 

Rip Currents: Moderate risk at NE FL beaches and SE GA beaches 
today. A high end moderate risk is expected at all beaches
on Saturday as onshore flow increases at the coast.


.HYDROLOGY...

Based on the current track of Potential Tropical Cyclone One,
about 0.75 to 1.5 inches of 24 hour rainfall may fall over north 
central Florida areas with some locally higher amounts. Should 
the system track a little farther south, less rainfall may be
realized while a more northward shift may increase values up
a bit, but any flash flood concerns as of now appear to be 
minimal as the bulk of the system's rainfall falls generally 
south of our area over central and southern FL.

&&

.PRELIMINARY POINT TEMPS/POPS...

AMG  93  68  88  68  88 /  50  60  50  20  20 
SSI  90  75  86  74  86 /  20  20  50  30  30 
JAX  93  72  86  71  86 /  20  20  50  30  30 
SGJ  89  72  84  73  85 /  20  30  60  40  30 
GNV  92  69  86  69  89 /  50  40  50  30  30 
OCF  91  71  85  70  90 /  60  50  60  30  30 

&&

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