Heathrow, Florida Weather Forecast Discussion

652
FXUS62 KMLB 121928
AFDMLB
Area Forecast Discussion
National Weather Service Melbourne FL
328 PM EDT Fri Sep 12 2025
...New KEY MESSAGES, DISCUSSION, MARINE...
.KEY MESSAGES...
Issued at 317 PM EDT Fri Sep 12 2025
- Lingering high moisture will continue above normal rain chances
  and potential for locally heavy rainfall and minor flooding this
  afternoon and tonight.
- Gusty to breezy conditions are expected across much the area
  this weekend, especially along the Volusia coast where windy
  conditions are possible.
- A High Risk for rip currents remains at area beaches today and
  may persist into the weekend.
&&
.DISCUSSION...
Issued at 317 PM EDT Fri Sep 12 2025
Rest of Today-Tonight...Bit of a sloppy mess across portions of
East Central Florida this afternoon. While the very slow frontal
boundary has pushed well to our south as an upper level trough
approaches Florida, high moisture associated with the front
continues to linger across the area, especially down south where
PWATs push over 2.1", and to a lesser extend up north where any
drier filtering in is being offset by low-level moisture provided
by freshening onshore flow, which is producing some gusty
conditions at times across the northern counties, and breezy
conditions along the northern coast. Scattered showers and a
couple lightning storms are parading southwestward, which looks to
continue well into the evening. Westerly to southwesterly flow
aloft opposing the low-level flow is producing some banding of
showers, increasing the potential for heavy rainfall impacts, but
the highest chances for minor/nuisance flooding will be along the
coastal corridor from coastal convergence, and across the southern
counties where coverage will be highest from the higher moisture.
Locally high rainfall amounts of 2-4" will be possible with any
slower moving or persistent banding of heavy showers and storms,
continuing the potential for minor flooding of roadways and poor
drainage areas. Any areas that have already seen heavy rainfall
the past few days could see more impactful flooding. A Marginal
Risk (level 1 of 4) for excessive rainfall continues from the
southern counties up to the northern coastal corridor, which
continues through the overnight as onshore moving bands of showers
that could get hung up at the coast remain possible. With
instability generally lacking lightning storms capable of
occasional cloud to ground lightning and gusty winds to 45 mph
will be isolated at best. Breezy/gusty conditions linger into
evening before letting up. Slightly below normal afternoon highs
top out in the M80s.
The Weekend...It`s been a hot minute since we`ve seen this much
flip-flopping from models in the 24-48 forecast window. A sharp
trough aloft digging down the eastern seaboard and pushing well
south of Florida stalls, with increasing confidence a cutoff low
will develop in the base of the trough near the Southeast
Seaboard. Still some slight differences in timing and location
between the various models, and run to run within model suites. In
the latest guidance, the ECM closes off the upper low by Sunday
morning near the NE FL/SE GA coast, while the GFS doesn`t close
the low for another 24-hours and closer to the Carolina coast.
This will impact timing and location of the attendant surface
low`s development, resulting in slight variations where, when, and
how much the pressure gradient tightens between this feature and
surface high pressure over the eastern US. This then has
implications on forecast winds (especially over the Volusia
coast/Atlantic waters), as well as where bands of higher/lower
moisture will track. Looks like breezy and gusty conditions in the
afternoons after the sea breeze develops are a given for the
Volusia coast, as are gusty conditions across much of the area,
but whether we see windy conditions in Volusia and breezy
conditions elsewhere is still uncertain, as guidance has gone back
and forth between the two scenarios over the last 24 hours. While
the guidance driving this forecast package (06Z models)
technically brought winds down a little, opted to err on the
cautious side and stay closer to the 75th quartile of guidance,
which is more consistent with the previous forecast. This calls
for northerly winds 5-10 mph in the mornings to shift
northeasterly and increase to 10-15 mph with gusts 20-25 mph
across the northern inland counties, as well as the coast south of
the Cape, and 15-20 mph with gusts approaching 30 mph along the
Volusia and northern Brevard coasts and inland a bit in the
afternoons. These winds linger into the late evening, before
easing a bit overnight.
Gradual drying is expected as the trough ushers out the front and
associated higher moisture, but the stout onshore flow will
continue to provide sufficient low-level moisture to support
scattered onshore moving showers in the afternoons and evenings
(possibly numerous Saturday), as well as the coastal corridor
during the overnight hours. This activity once again looks to be
mostly low-topped showers, but isolated lightning storms will be
possible as the unsettled upper level environment (minus the drier
air) become more favorable. Afternoon highs in the M-U80s.
High astronomical tides will continue to cause wave runup to near
the dune line during the early afternoon high tides through the
weekend, and potential for coastal flood impacts along the
northern coast could increase if the low develops sooner and
closer to ECFL. A High Risk of life-threatening rip currents also
continues today and may linger into the weekend.
Next Week (Modified Previous Discussion)...There remains some
differences in the model guidance into next week with how upper
level/surface features evolve. The GFS is back to developing a
cutoff low but offshore the Mid-Atlantic seaboard, with the ECMWF
at least being a little more consistent still developing its
cutoff low over the Southeast, but meandering northward this
time. Both models continue to show some weak surface low pressure
development off the Southeast seaboard, with the ECMWF keeping
this low a little closer to our coast and the GFS going back
further to the northeast. However, overall forecast trends into
next week indicate lowering rain chances through at least early in
the week to around 30-40% as drier air continues to build into
the region under lower level N/NE flow. Rain chances then look to
gradually rise into mid to late week as low level flow gradually
veers to the E/SE allowing moisture to increase once again. Highs
continue in the mid to upper 80s through the week, with lows
mostly in the low to mid 70s.
&&
.MARINE...
Issued at 317 PM EDT Fri Sep 12 2025
Today-Tuesday (Modified Previous Discussion)...While the front has
finally shifted south of the area, moisture lingering over the
Florida and the local Atlantic waters will continue higher
coverage of showers and storms across the coastal waters over the
next couple days, with coverage gradually then decreasing into
early next week. N/NE winds will continue over the coastal waters,
and will produce poor boating conditions at times, mainly north
of the Cape, as they increase to 15-20 knots each afternoon and
evening through the weekend. There is potential for winds just the
Volusia coast to increase to over 20 kts at times as a weak area
of low pressure gradually develops off the Southeast seaboard.
Small craft are strongly urged to exercise caution here. Seas 3-5
ft increase to around 6 ft at times in the Gulf Stream and Volusia
waters this weekend.
&&
.AVIATION...
(18Z TAFs)
Issued at 149 PM EDT Fri Sep 12 2025
Another day of high coverage and multiple rounds of showers and
storms across the area. VFR conditions prevailing outside of
convection. However, VIS/CIG reductions in heavier showers and
storms are possible. Thus, TEMPOs have been included for most
terminals, with the exception of LEE/TIX/MLB, given the current
radar presentation. This will need to be monitored through the
afternoon. Coverage of showers and storms is forecast to diminish
towards sunset. But, they will remain possible along the coast
overnight, occasionally drifting onshore from the local Atlantic
waters. Northeast winds 10-15 kts, with gusts up to 20-25 kts,
especially along the coast and near DAB. Similar conditions are
forecast across the area Saturday.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB  73  84  72  84 /  60  60  40  50
MCO  72  87  71  87 /  30  40  20  40
MLB  74  86  73  86 /  40  50  30  40
VRB  72  87  72  87 /  50  50  30  30
LEE  71  86  70  86 /  10  20  10  30
SFB  72  86  71  86 /  30  50  20  40
ORL  72  86  72  86 /  30  40  20  40
FPR  72  86  71  87 /  50  50  30  30
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...None.
AM...None.
&&
$$
DISCUSSION...Haley
AVIATION...Leahy

NWS MLB Office Area Forecast Discussion