436
FXUS62 KMLB 010706
AFDMLB

Area Forecast Discussion
National Weather Service Melbourne FL
306 AM EDT Tue Jul 1 2025

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

.KEY MESSAGES...
Issued at 256 AM EDT Tue Jul 1 2025

- High chances of showers and lightning storms each day,
  especially Wednesday onward. Greatest coverage generally in the
  afternoon and evening, with higher than normal chances in the
  overnight.

- Rounds of showers and storms late week and into the weekend will
  increase the risk for minor flooding, especially for areas that
  receive locally high rainfall amounts multiple days in a row.

&&

.DISCUSSION...
Issued at 256 AM EDT Tue Jul 1 2025

Today-Tonight...The upper level low hanging out off our Atlantic
coast the last few days, and partially responsible for slightly
lower rain chances yesterday, departs eastward ahead of a
shortwave dropping into the southeast. A weakening ridge axis from
the subtropical high continues to extend towards the southern
counties, resulting in generally southerly winds across the area,
veering from southwesterly to the south, to southeasterly to the
north, again pushing along the east coast sea breeze on the
Treasure Coast, while to the north slowing development and
gradually pinning the boundary. Moisture increases from the south,
with PWATs around 2.0" reaching the Treasure Coast by the
afternoon. Showers and storms look to get going pretty quickly
down there as soon as the sea breeze develops, possibly as early
as the late morning, then generally pushing north and inland along
the sea breeze and outflow boundaries while increasing in
coverage. Highest coverage/chances across the interior in the late
afternoon and evening ahead of and long the sea breeze collision,
which looks to be skewed closer to the east coast up north and
farther inland down south from flow and convective evolution.
Greater instability returns, especially down south in the higher
moisture, with MUCAPE values 1,500-2,500 J/kg, but mid-level
warming (T500 increasing to M7-M6C) and shallow lapse rates
(around 5.5 C/km) paint a less supportive environment for strong
thunderstorms. That said, still some drier air aloft in places
which could enhance downdrafts, so primary storm threats continue
to be gusty winds to 50 mph, occasional to frequent cloud to
ground lightning, and locally heavy rainfall. Steering flow from
the S-SW at 10-15 kts should help keep showers and storms moving
along, but can`t rule out some training or slow/erratic motion on
boundary collisions, in which case a quick 1-3" of rainfall
leading to minor flooding would be possible. A Moderate risk for
dangerous rip currents continues at the beaches. Always swim near
a lifeguard, and never swim alone.

Wednesday-Friday...Wet. The ridge axis of the subtropical high
weakens and is shunted south in response to a shortwave associated
with a broad trough over the eastern US dropping into the
Southeast, with a weak trough axis looking to linger aloft through
the period. Surface flow becomes southwesterly, shifting the sea
breeze collision to the eastern side of the peninsula. A
weakening front sags into the Southeast north of Florida, which
combined with the southwesterly flow, causes moisture to surge
across Florida ahead of the front. PWATs increase to 2.0-2.2", at
or above the climatological 90th percentile and closing in on
daily max values for the time of year. All combined, multiple
rounds of showers and lightning storms are expected through the
period. While the sea breezes in the afternoon and evening will be
the focus for highest chances (60-80%) and coverage, most nights
continue at least a low (20-30%) chance for additional showers and
storms as the area remains weakly unstable. There is potential
for an area of low pressure to develop along the stalled frontal
boundary by the weekend, which the National Hurricane Center is
monitoring and currently has a low (20%) chance for gradual
tropical/subtropical development over the next 7 days. Heavy
rainfall will be the primary concern regardless of development, as
repeated rounds of showers and lightning storms increase/compound
concerns for flooding, especially locations that receive locally
high rainfall amounts over multiple days. The Weather Prediction
Center has highlighted portions of East Central Florida in a
Marginal Risk (level 1 of 4) for excessive rainfall each day, with
Thursday looking to have the highest chances. Gusty winds and
occasional to frequent cloud to ground lightning will be possible
with deeper convective. Cloud cover does help to bring
temperatures near to below normal in the U80s-90, resulting in
heat indices in the U90s-L100s.

Saturday-Monday...Some uncertainty remains in the extended range
of the forecast, dependent on if and how the low pressure system
develops, but pretty good agreement for the unsettle pattern and
flooding potential to continue through the weekend, with
conditions returning to a more typical summer pattern into next
week. Rain chances remain high Saturday and possibly Sunday, then
a gradual trend to closer to normal rain chances beyond the
weekend, though whether that`s early or mid week is unclear at
this time. An uptick in temperatures accompanies the decreasing
rain chances thanks to more opportunity for sunlight, but
generally remaining near to slightly above normal.

&&

.MARINE...
Issued at 256 AM EDT Tue Jul 1 2025

While winds and seas are generally favorable for boating as weak
high pressure remains in control through Thursday, multiple
rounds of showers and storms will pose a continuous risk for
marines through the week and into the weekend. A weakening ridge
axis from the subtropical high, located near central Florida
today, drops south of the area Wednesday and Thursday, shifting
flow from southerly today to southwesterly midweek. Winds back a
bit in the afternoon and evening behind the sea breeze, though
high cloud cover could result in a weak/late development. Seas 1-3
ft.

There is potential for a low pressure system to develop along a
stalled frontal boundary draped across North Florida by late week
and into the weekend, which the National Hurricane Center is
monitoring and currently has a low (20%) chance of tropical or
subtropical development over the next 7 days. Currently the
greatest impact from this system looks to be continued high
coverage of showers and lightning storms, but does decrease
confidence in the wind and seas forecast after Thursday, though
speeds and heights currently look to remain below cautionary
criteria.

&&

.AVIATION...
(06Z TAFs)
Issued at 150 AM EDT Tue Jul 1 2025

VFR CIGs will be common through the TAF period. Light and variable
winds through 12Z then South winds increase 6-9 knots, backing out
of the Southeast at coastal terminals around 10 knots by 16-17Z.
VCTS exists at coastal terminals starting at 18Z and inland
terminals at 19Z-20Z. Chose a 3-hr TEMPO (21Z-24Z) for MCO/SFB/ISM
with VCSH lingering aft 00Z.

&&

.PRELIMINARY POINT TEMPS/POPS...
DAB  89  73  89  74 /  60  50  70  40
MCO  91  73  89  75 /  70  50  70  30
MLB  88  73  90  75 /  60  40  70  40
VRB  89  71  90  72 /  60  40  70  40
LEE  89  74  87  75 /  70  40  70  30
SFB  91  74  90  75 /  70  50  70  30
ORL  91  75  89  75 /  70  50  70  30
FPR  88  71  90  74 /  60  40  70  40

&&

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

$$

DISCUSSION...Haley
AVIATION...Kelly