488
FXUS62 KMLB 301837
AFDMLB

Area Forecast Discussion
National Weather Service Melbourne FL
237 PM EDT Sat Aug 30 2025

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

.KEY MESSAGES...
Issued at 230 PM EDT Sat Aug 30 2025

- Persistent troughing over the eastern U.S. will enhance coverage
  of afternoon and evening showers and lightning storms through at
  least early next week

- A low risk of excessive rainfall exists each day through at
  least mid week, particularly in areas that see several rounds
  of heavy rain in storms

- A moderate rip current risk continues at local beaches;
  beachgoers should be aware of offshore moving storms this
  afternoon and evening

&&

.DISCUSSION...
Issued at 230 PM EDT Sat Aug 30 2025

Today-Tonight... Upper level trough centered across the eastern US,
and extending over the Florida peninsula, remains in place. At the
surface a stationary front sits just to our north, with deep
moisture pooling near the boundary across the ECFL (PW values around
1.8-2.0"). Locally, the pressure gradient will remain relatively
weak, with westerly flow dominating throughout the entire
atmospheric column. The east coast sea breeze is forecast to form
this afternoon and remain pinned along the coast.

Higher than normal rain chances are once again forecast this
afternoon and evening as deep moisture and westerly flow enhance the
summertime convective pattern. Model guidance is in good agreement
that the highest coverage for storms today will be across east FL
due to that dominate westerly wind. However, due to high clouds
streaming overhead, which could disrupt daytime heating, some
uncertainty in the evolution of convection remains. Have maintained
50-70 percent PoPs today, with the highest coverage occurring along
and to the east of the St. Johns River as well as across the
Treasure Coast, where boundary interactions along the sea breeze
will likely take place. Main storm hazards will be frequent
lightning strikes, gusty winds or 40-50 mph, and locally heavy
rainfall of 1 to 3 inches. There is a low risk for excessive
rainfall today, particularly in areas that see repeated rounds of
storms. A secondary storm hazard will be the potential for a brief
weak rotation and or funnel clouds where stronger boundary collisions
occur. Any lingering activity will diminish or push offshore by
midnight, with mostly dry conditions forecast overnight.

Seasonably warm today due to the high clouds and higher rain
chances. Afternoon highs will be in the upper 80s to low 90s with
heat indices of 98-103 degrees. Beachgoers should keep an eye on the
western sky this afternoon as storms are forecast to push into the
Atlantic this afternoon and evening. Muggy conditions overnight,
with lows in the low to mid 70s.

Sunday...(Modified Previous Discussion) Broad troughing remains in
place over the eastern U.S., albeit slightly weaker as the primary
upper low shifts into the Canadian Maritimes. Guidance indicates the
front will nudge a little closer to the area as both deterministic
and ensemble members suggest a broad, weak low developing over the
Atlantic. Deep moisture pooling along and to the south of this
feature, combined with continued westerly flow aloft, support above
normal precipitation chances. Maintained a high chance (70-80%) for
rain and lightning storms for now, though future iterations of the
forecast may be able to introduce a north-to-south gradient
depending on where the front settles. There is a low excessive
rainfall threat, particularly in areas that see repeated rounds of
storms. These higher than normal rain chances will help to keep
temperatures seasonably warm, with afternoon highs in the upper 80s
to low 90s. Muggy conditions persist overnight, with lows in the low
to mid 70s.

Monday-Friday...(Modified Previous Discussion) Ensemble guidance
remains in good agreement through the end of next week, with an
unusually strong signal for continued troughing over the eastern
half of the United States. The "big picture" suggests a continuation
of higher-than-usual rain chances through at least the middle of the
week. The placement of the surface boundary and its attendant
moisture pool, along with several shortwaves rounding the base of
the trough, will dictate which areas see the greatest chances for
storms through at least Wednesday. Have maintained a broad 60-70%
PoPs focused on the afternoon and evening for now through Wednesday.
A low excessive rainfall threat continues each day through at least
Wednesday, particularly in areas that see repeated rounds of storms.

Toward the end of the forecast period, guidance indicates a sharp
polar trough emanating from Canada may provide enough forcing to
shift the local surface boundary southward. At the very least, this
would lead to a sharp north-to-south gradient of precipitation
chances, which the NBM is beginning to show in the extended. For
now, have maintained 50-60% PoPs focused in the afternoon and
evening late week into early weekend.

&&

.MARINE...
Issued at 230 PM EDT Sat Aug 30 2025

Today... (Modified Previous Discussion) Westerly flow at or below 10
knots today will turn onshore this afternoon behind the Atlantic sea
breeze. Afternoon storms are expected to develop over the mainland
and push back toward the coast. Seas 1 - 3 feet.

Sunday-Thursday...(Modified Previous Discussion) A surface boundary
is forecast to meander over the local waters early next week,
resulting in a slight surge of north to northeast winds (up to 15
knots). Seas will gradually deteriorate into Labor Day, increasing
up to 3 to 6 feet offshore (highest north). Higher coverage of
storms is forecast during the evening and early overnight hours as
inland storms push offshore.


&&

.AVIATION...
(18Z TAFs)
Issued at 138 PM EDT Sat Aug 30 2025

Today`s convective setup nearly identical to yesterday, as deep
westerly flow favors the west coast sea breeze, propelling storm
activity to the eastern half of the peninsula. As of 18Z, scattered
showers and isolated thunderstorms have already produced MVFR
impacts at KLEE with the cluster of storms shifting towards KSFB at
the current time. The east coast sea breeze remains pinned along the
coast, so a large collision over all coastal terminals is expected
after 20Z this afternoon. Treasure Coast terminals will once again
be the last to see storms, occurring past 22Z today. Variable winds
overnight becoming west after 15Z tomorrow ahead of yet another
round of afternoon storms in this active and wet pattern. VFR
outside of convection.

&&

.PRELIMINARY POINT TEMPS/POPS...
DAB  73  87  75  85 /  40  80  40  70
MCO  75  90  74  88 /  30  80  30  70
MLB  75  88  74  87 /  40  80  50  70
VRB  73  89  73  88 /  40  80  50  70
LEE  74  88  74  87 /  30  80  20  70
SFB  75  89  74  87 /  30  80  30  70
ORL  75  89  75  88 /  30  80  30  70
FPR  72  90  72  89 /  40  80  50  70

&&

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

$$

DISCUSSION...Watson
AVIATION...Schaper