894
FXUS62 KJAX 092309
AFDJAX

Area Forecast Discussion
National Weather Service Jacksonville FL
709 PM EDT Thu May 9 2024

...New AVIATION...

.NEAR TERM...
(through Tonight)
Issued at 335 PM EDT Thu May 9 2024

Strong to severe thunderstorms associated with the southeastward
moving MCS will continue to impact southeast GA through late
afternoon, with activity expected to cross the FL/GA border in the
5 PM - 7 PM time frame. This MCS will continue racing
southeastward early evening hours, with weakening likely as the
line pushes across the Interstate 10 corridor towards sunset as
it encounters the drier and more stable air mass that remains in
place across north central FL. Damaging straight line wind gusts
of 50-70 mph will be the primary threat for locations north of
I-10, but a few isolated incidents of hail and tornadoes cannot be
ruled out across southeast GA through late afternoon. The Storm
Prediction Center has maintained an Enhanced Risk (level 3 out of
5) for severe thunderstorms across southeast GA, where a 10%
probability of downburst wind gusts in excess of 74 mph exists, in
addition to 5% probabilities for tornadoes along with enhanced
probabilities for large hail. A Slight Risk was maintained for
locations along and south of I-10 into the early evening hours.

The longwave trough will continue to dig southeastward across the
Tennessee and Ohio Valleys tonight, with strengthening westerly
flow to the south of this feature propelling another shortwave
trough and associated MCS across the Deep South during the
overnight and predawn hours. The prior weakening MCS will push
across north central and coastal northeast FL during the early to
mid evening hours, with a break in between MCSs expected through
the overnight hours. Short-term, high resolution guidance is in
relatively good agreement in positioning this next MCS and
associated strong to severe thunderstorm threat at the doorstep of
the Ocmulgee/Alapaha/Suwannee Rivers around sunrise on Friday,
with this activity then sweeping eastward across our area through
the morning hours. Breezy west- southwesterly boundary layer flow
in advance of this upstream MCS is expected to advect a stratus
layer across the Suwannee Valley and inland southeast GA
overnight, with these low clouds possibly crossing the I-95
corridor around sunrise. Cloud cover and warm air advection
downstream of the approaching cold front should keep lows in the
70-75 degree range overnight.

&&

.SHORT TERM...
(Friday through Saturday night)
Issued at 335 PM EDT Thu May 9 2024

Upper shortwave trough and associated MCS will move across the
region Friday morning bringing strong to severe thunderstorms to
the Ocmulgee/Alapaha/Suwannee River basins around sunrise on
Friday. This activity will then sweep eastward across our area
through the late-morning hours before shifting offshore. There
remains uncertainty with the next round of potentially severe
weather. If the morning MCS clears the area early enough, the
airmass may be able to recover ahead of the approaching cold front
from the northwest Friday afternoon into evening. Storms will
redevelop ahead of the front but the severity of them will be
determined by the airmass recovery. Regardless, damaging straight-
line winds will be the main threat along with the potential for
hail and isolated tornadoes. The cold front and associated
convection is expected to exit to the south Friday evening with a
drier airmass clearing the skies in its wake. Sunny skies and
around normal temperatures in the 80s are anticipated for Saturday
with lows dipping into the upper 50s and 60s.

&&

.LONG TERM...
(Sunday through next Thursday)
Issued at 335 PM EDT Thu May 9 2024

Warm and dry conditions on Sunday quickly give way to a wet and
unsettled pattern for next week as upper shortwaves parade across
the region. A wave of low pressure will move eastward across the
northern Gulf lifting a stationary front across southern FL up the
peninsula Monday into Tuesday as a warm front. As the warm front
lifts across the region, a moist and unstable airmass will become
established which will support an increasing thunderstorm
potential throughout next week. High temperatures will generally
be around normal in the 80s and then trend upward on Wednesday.

&&

.AVIATION...
(00Z TAFS)
Issued at 709 PM EDT Thu May 9 2024

Difficult TAF forecast for this package given the uncertainty in
thunderstorm activity timing Friday. For now, have placed VCTS
beginning in the morning, with PROB30 groups in the afternoon
hours for the TAF sites. Tonight, low ceilings will move in
affecting all the sites around 07-09Z, clearing near sunrise.
Showers and isolated thunderstorms will linger this evening for a
few more hours near SSI especially.

&&

.MARINE...
Issued at 335 PM EDT Thu May 9 2024

A squall line of strong to severe thunderstorms will traverse the
Georgia waters during the mid to late afternoon hours today, with
this line reaching the northeast Florida waters during the late
afternoon and early evening hours. This squall line is expected to
weaken after sunset as it approaches the waters from St. Augustine
southward. Strong to severe thunderstorms will be capable of
producing damaging wind gusts, hail, and frequent lightning
strikes. Outside of thunderstorm activity, seas of 3-5 feet will
prevail both near shore and offshore through tonight. Otherwise,
a cold front will enter the southeastern states tonight and will
progress southeastward across our local waters on Friday afternoon
and evening.

Additional rounds of strong to severe thunderstorms will be
possible after sunrise and again during the afternoon hours ahead
of this front. Winds will shift to northwesterly in the wake of
the frontal passage on Friday night and Saturday morning, with
weak high pressure the expected to build eastward from the Ozarks
on Saturday night, reaching the coastal Carolina region by Monday
afternoon. This weather pattern will result in onshore wind
development on Sunday afternoon, with onshore winds then
strengthening on Monday night ahead of an approaching warm front.
Showers and thunderstorms will overspread our local waters by late
Monday night as this warm front lifts northeastward across our
area.

Rip Currents: Gusty offshore winds should result in a low risk at
all area beaches on Friday and Saturday.

&&

.PRELIMINARY POINT TEMPS/POPS...
AMG  70  82  60  81 /  40  90  10   0
SSI  72  83  64  80 /  30  90  20   0
JAX  72  86  64  84 /  40  80  30   0
SGJ  73  90  67  83 /  40  70  30  10
GNV  73  88  64  87 /  20  60  30  10
OCF  73  89  68  89 /  10  40  30  10

&&

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

$$