671
FXUS62 KMLB 031850
AFDMLB

Area Forecast Discussion
National Weather Service Melbourne FL
250 PM EDT Thu Sep 3 2026

...New KEY MESSAGES, DISCUSSION, MARINE...

.KEY MESSAGES...
Issued at 250 PM EDT Thu Sep 3 2026

- Locally heavy to excessive rainfall leading to flooding issues
  will be the main threat from storms this afternoon and early
  evening. Other storm threats will be gusty winds to around 40
  mph and occasional to frequent cloud to ground lightning.

- A wet weather pattern will persist across East Central Florida
  into the weekend. The main storm hazard through late week will
  continue to be the potential for locally heavy rainfall that
  could lead to mostly minor flooding.

- Muggy conditions and seasonably hot temperatures in the upper
  80s to low 90s will continue the next couple days, then
  temperatures increase a couple degrees going into the weekend.
  Peak afternoon heat indices remain in the triple digits.

&&

.DISCUSSION...
Issued at 250 PM EDT Thu Sep 3 2026

Currently-Tonight...Showers and storms have been developing near
to south of a line from Orlando to Melbourne along the east coast
sea breeze and a differential heating boundary created from debris
cloud cover over northern portions of east central FL. Showers
and storms will continue to increase, especially from near the
Orlando metro area southward through Osceola, Okeechobee counties
and the Treasure Coast from outflow collisions and the advancing
east coast sea breeze. 10Z sounding at the Cape this morning
showed a very saturated airmass, with a PW value of 2.5" (a record
for the day based off SPC sounding climatology), as well as warm
temps aloft (around -4C at 500mb). DCAPE also remains rather low
(around 400-500 J/kg) on SPC Mesoscale Analysis. Therefore threat
for any stronger wind gusts remains low, but gusts up to 30 to 40
mph and occasional to frequent lightning will still occur. The
deep tropical moisture in place will keep locally heavy to
excessive rainfall the main threat from storms or heavier showers
today. Quick rainfall accumulations of 1-3 inches will be very
easy to occur from any storms through this afternoon/evening,
leading to mostly minor flooding of roadways and poor drainage
areas. However, there remains a low (5-10% chance) for totals of
4+ inches, which may lead to isolated instances of flash flooding.
A Marginal Risk for Excessive Rainfall (Level 1 of 4) remains in
place across east central Florida for today.

Convection should begin to diminish past sunset with the loss of
daytime heating, but a few storms with lingering areas of debris
cloud cover rainfall may persist through the evening hours. Drier
conditions expected overnight, with low level flow becoming more
southerly, which should keep most convection that develops over the
waters offshore. Warm and very muggy overnight, with lows in the mid
to upper 70s for most locations.

Friday-Saturday...PW values forecast to actually decrease some, but
still remain high around 2.0-2.2" through late week and into early
weekend, as ridge axis of high pressure across the west Atlantic
settles southward across the area. With the continued moist airmass
in place and weak steering flow, locally heavy rainfall around 2-4"
and mostly minor flooding will continue to be a threat from slow
moving or persistent storms and heavier showers. The Weather
Prediction Center maintains a Marginal (level 1 of 4) Risk for
excessive rainfall through at least Friday. Scattered to numerous
showers and storms will develop each day, with increasing coverage
from late morning into the afternoon. Low level flow will become
more southerly Friday, with boundary collisions favored well
inland. Flow then turns south-southwesterly Saturday, shifting
the sea breeze collision a little farther east across east central
Florida. Rain chances range from 50-70 percent, with highest
chances across the interior tomorrow and 70 percent areawide on
Saturday. Temperatures increase a tad, but still near to just
slightly above normal, with highs in the low 90s and some mid 90s
possible across the interior. Peak heat index values will reach
100-107F ahead of any storms. Overnight conditions will remain
warm and humid with lows in the 70s.

Sunday-Wednesday...(Previous Discussion) The trough over the eastern
seaboard and western Atlantic is forecast to reach just offshore the
Southeast seaboard Sunday or so, ushering a weakening front into the
Deep South, and possibly reaching Florida Monday or Tuesday. There
remains some uncertainty how far south the boundary will make it,
and more uncertainty where weak disturbances may develop on the
boundary as it stalls. Both impact whether East Central Florida
remains in the subtropical soup or if some drier air will finally
reach the area, what kinda of support there is for convection, and
what flow regime we end up in. Given the uncertainty the official
forecast trends towards the ensembles and blends, which call for
broad stroked rain chances to remain above normal, but do decrease a
bit towards mid-next week. Seasonable temperatures stay on the
hotter side through the weekend, then tick down a degree or two for
the work week.

&&

.MARINE...
Issued at 250 PM EDT Thu Sep 3 2026

Tonight-Tuesday...Main hazard for boaters will continue to be above
normal coverage of showers and storms, especially during the
overnight and morning hours. However, a weak W/SW steering flow may
allow for some offshore moving storms in the afternoon and evening
from Friday and into the weekend. Otherwise, boating conditions are
forecast to remain mostly favorable.

Ridge axis of high pressure over the west Atlantic, currently north
of the area, will shift gradually south across the waters through
Saturday, and then will shift south of the area by late weekend into
early next week. Winds are forecast out of the S/SE through
Saturday, before becoming offshore Sunday into Monday. However, the
east coast sea breeze will still form into the afternoon on both of
these days, with winds turning onshore behind this boundary into the
afternoon/evening. A relatively light predominant onshore flow looks
to then redevelop into Tue as high pressure builds down toward the
Mid-Atlantic coast. Wind speeds are forecast to generally remain
below 15 knots, with seas 2-3 feet through Friday, falling to 1-2
feet into the weekend through Monday. Wave heights may then build
slightly through Tuesday, up to 2-4 feet.

&&

.AVIATION...
(18Z TAFs)
Issued at 155 PM EDT Thu Sep 3 2026

Mainly a light east wind flow this afternoon, enhanced slightly by
the Atlc sea breeze at coastal terminals up to 12 knots.
Considerable clouds across northern sections is delaying heating
but better heating south of MCO is generating SCT-NMRS SHRA with
embedded TSRA. The sea breeze will spark addl convection near the
Treasure coast so have upgraded them to a TEMPO to start the 18Z
TAF package as storm motion is toward the coast. Additional TSRA
will develop later this afternoon assocd with boundary collisions
over the interior and better heating as high clouds thin. So
maintained MVFR TEMPOs for MCO/SFB. Activity is forecast to
gradually diminish beyond 00Z, with light SE winds areawide. CAMs
not showing much coastal shower activity for the overnight. On
Fri, convective initiation looks a little later than today. Did
insert VCTS for MCO aft 18Z Fri.

&&

.PRELIMINARY POINT TEMPS/POPS...
DAB  76  90  75  91 /  20  50  30  70
MCO  76  93  76  93 /  40  60  40  70
MLB  77  91  76  91 /  30  50  20  70
VRB  75  90  75  90 /  30  50  20  70
LEE  76  92  76  92 /  40  70  40  70
SFB  76  93  76  93 /  30  60  40  70
ORL  77  93  77  93 /  40  60  40  70
FPR  75  90  75  90 /  30  50  20  70

&&

.MLB WATCHES/WARNINGS/ADVISORIES...
FL...None.
AM...None.
&&

$$

DISCUSSION...Weitlich
AVIATION...Kelly