854
FXUS62 KMLB 211843
AFDMLB

Area Forecast Discussion
National Weather Service Melbourne FL
243 PM EDT Sat Sep 21 2024

...New DISCUSSION, MARINE...

.DISCUSSION...
Issued at 204 PM EDT Sat Sep 21 2024

...Onshore winds and a northeasterly swell will promote a Moderate
to High Risk of life-threatening rip currents at Central Florida`s
Atlantic beaches...

...Minor coastal flooding remains possible, particularly during the
late morning high tides through this weekend. Low-lying streets,
yards, and docks along the barrier islands and Intracoastal Waterway
may experience minor flooding...

...There remains a medium chance (60%) for tropical development in
the northwest Caribbean or southern Gulf of Mexico next week. It is
too early to determine if and what impacts this may bring to East
Central Florida. Continue to monitor the forecast for updates...

Current-Tonight...Already some earlier excitement with a funnel
cloud reported by Air Traffic Control from Daytona Beach Airport,
associated with a cloud line over the intracoastal. Troughiness
aloft will continue to weaken as it slides south/east and further
out into the western Atlc. Mid-level high pressure over ERN Texas
will expand across the GoMex and FL peninsula with rising heights
and warmer temperatures at H500. Expect NERLY winds at the surface
to average 10-15 mph with higher afternoon gusts; we may see some
coastal locations average 15-20 mph this afternoon for wind speeds.
A diffuse sea breeze boundary will push inland and provide a
focus for convection. Only modest deep layer moisture is present
and our precip chances will remain below normal with 20pct
north/west of I-4 and highest up to 40pct across the Space and
Treasure coasts. Storm motion will be fairly slow and out of the
north to northeast. Lightning strikes, heavy downpours, and gusty
winds locally will be the main threats. Activity diminishes this
evening, though will retain a small PoP along the coast overnight
for ISOLD low-topped convection chances. Overnight mins generally
in the L-M70s while conditions remain humid.

There will remain a HIGH risk for numerous, strong, life-threatening
rip currents at the beaches along Volusia and north Brevard coasts,
while a Moderate risk continues southward through Martin County.

Additionally, minor coastal flooding remains a concern during high
tide. After this morning`s high tide, there will be a secondary peak
in the late evening.

Sun-Sun Night...The aforementioned mid-level high pressure ridging
continues to spread its influence across the Gulf and FL peninsula.
Some warming aloft will also occur. At the surface, weak high
pressure will exist across the region. Light morning winds will
transition to NERLY as a diffuse sea breeze develops and moves
inland during the afternoon. PWATs will remain modest with highest
PoPs (~30pct) generally Orlando southward. The limited
instability with subsidence will limit shower and storm chances
overall. Convective activity diminishes in the evening, though
will retain a small PoP along the coast for any onshore moving
showers. Afternoon highs in the U80s with a few L90s possible
across the interior. Peak afternoon heat indices top out anywhere
from 97-103F. Overnight lows in the 70s with conditions muggy.

             ***Autumn begins at 8:43 am ET on Sunday***

.Previous Extended Forecast Discussion...

Mon-Wed...Quiet early autumn weather as we head back to work and
school. Deep-layer ridging continues to build as drier air drifts
overhead. H5 T`s soar to a very suppressive -3 or -4C as H5 heights
reach 591 dam in the grand ensemble mean by early Wednesday.

Bottom line, shower/storm chances lessen to 10-20% from Orlando
northward and 20-30% to the south each day. Surface high pressure
drifting into the Atlantic will deliver breezy easterly winds.
Expect partly to mostly sunny skies with highs in the upper 80s to
low 90s.

Thu-Sat...The weather during this timeframe will be almost entirely
dictated by the ultimate evolution and movement of lower pressures
and rich tropical moisture rising from the Caribbean into the Gulf.
Most ensemble members show a disturbance making it into the southern
Gulf of Mexico by Wednesday or Thursday. After that time,
significant uncertainty remains, which is expected at this stage.
Guidance on potential tropical development may take several days to
resolve, due to the initial absence of a trackable feature and the
evolving upper air pattern over North America. The depth and
position of a trough over the Midwest still look to be the ultimate
variables as to when and whether this disturbance gets a kick
north/northeastward.

The National Hurricane Center has increased the chance of tropical
development in the southern Gulf to 60%. It remains too early to
determine local impacts. We continue to advertise an increase in
rain/storm chances (40-60%) from Thursday into next weekend,
which is supported by the expected uptick in tropical moisture
over the state.

We are now in peak hurricane season. Check weather.gov/mlb and
hurricanes.gov for the latest updates, and take the time to check
on your hurricane preparedness kits and plans.

&&

.MARINE...
Issued at 204 PM EDT Sat Sep 21 2024

Tonight thru mid next week...High pressure to the north will
continue to provide for a light to moderate NNE/NE flow that will
veer more ENE- E Sun overnight into early-mid next week. Speeds
commonly 8-15 kts. Seas near shore 3-4 ft building to 4-5 ft over
the Gulf Stream/offshore into next week. ISOLD to WDLY SCT
(10-30pct) showers and lightning storms remain in the forecast.

&&

.AVIATION...
(18Z TAFs)
Issued at 120 PM EDT Sat Sep 21 2024

VFR conditions forecast through the period at all terminals.
Spotty shower coverage across east central Florida today, as NE
flow remains in place. Winds at the terminals may become gusty
this afternoon, with gusts up to 20 knots possible. VCSH through
00Z across the interior terminals, and continuing overnight at
the coastal terminals. Winds will become lighter at 5 to 10 knots,
remaining out of the NE overnight. Similar set up for tomorrow,
with spotty shower coverage and persistent NE flow. VCSH after 16Z
across the interior terminals and persisting along the coastal
terminals.

&&

.HYDROLOGY...The Saint Johns River at Astor is forecast to
remain in Moderate Flood stage into early next week. Farther
upstream, the Saint Johns at Deland and Sanford will remain near
or slightly above Action Stage.

&&

.PRELIMINARY POINT TEMPS/POPS...
DAB  74  88  74  89 /  20  20   0  10
MCO  73  91  74  91 /  10  30  10  20
MLB  75  89  76  88 /  20  30  20  20
VRB  73  89  75  89 /  20  30  30  30
LEE  73  91  73  92 /   0  20   0  10
SFB  73  89  73  90 /  10  30   0  10
ORL  74  91  75  92 /  10  30   0  10
FPR  73  89  74  89 /  20  30  30  30

&&

.MLB WATCHES/WARNINGS/ADVISORIES...
FL...Coastal Flood Advisory until 2 PM EDT Sunday for FLZ141-154-159-
     164-347-447-647-747.

AM...None.
&&

$$

DISCUSSION...Sedlock
AVIATION...Tollefsen