Port Saint John, Florida Weather Forecast Discussion

494
FXUS62 KMLB 050758
AFDMLB
Area Forecast Discussion
National Weather Service Melbourne FL
358 AM EDT Sun Oct 5 2025
...New KEY MESSAGES, DISCUSSION, MARINE...
.KEY MESSAGES...
Issued at 330 AM EDT Sun Oct 5 2025
- Dangerous beach and marine conditions will continue this
  upcoming week, including minor coastal flooding, life-
  threatening rip currents, and breaking waves of 5 to 7 feet with
  minor to moderate beach erosion especially near times of high
  tide.
- Scattered to numerous fast-moving showers off the Atlantic will
  support locally heavy rainfall where banding features can
  develop. Localized flooding will be a concern through Monday.
&&
.DISCUSSION...
Issued at 330 AM EDT Sun Oct 5 2025
Today-Mon...Breezy/gusty easterly flow will continue across ECFL
around high pressure located along the NE US coast. Increasing
moisture (PWATs climbing near 2" today) will support fast moving
showers pushing onshore and well inland. Brief downpours will
accompany many showers and more prolonged heavy rain will be
possible where coastal convergence sets up banding segments and
produces a quick 1-3 inches. But most areas will see less than 1"
today.
On Mon, PWATs increase further to 2-2.25" with indications of some
mid level support which should lead to an increase in rainfall
coverage and intensity. Increased moisture transport off the Atlc
(and well inland) will produce a risk of excessive rainfall and
have extended the Flood Watch for the coastal counties through 8
pm Monday. Heavy rain will also occur over portions of the
interior but soils are much wetter closer to the coast which will
increase the risk for flooding.
With the brisk onshore flow not letting up, this prolonged period
of dangerous beach and marine conditions will continue the next
few days. High Surf Advisories, High Rip risk, and Coastal Flood
Advisories have been extended through Tuesday. High tides are
running 1-3 feet above normal and this higher water level will
continue to affect locations along the intracoastal waters as
well. We are also monitoring points along the St. Johns River
where heavy rainfall could lead to additional river flooding. The
river has already reached Moderate Flood Stage at Astor and is
forecast to reach Action Stage at Geneva in a day or two.
Tue-Sat...Some drier air is forecast to move in Tuesday or
Wednesday as the surface high now over the western Atlantic
continue to push further out to sea. Another strong surface high
is forecast to develop over the northern US, following quickly
behind the previous high as it moves towards the Northeast, with a
weaken cold front and associated ribbon of moisture stuck between
the two. There is decreasing confidence when or if this moisture
will make it to Florida, with the latest model guidance calling
for it to fall short, which has brought rain chances for the
latter half of the week down. Winds finally relent a little, but
not enough to alleviate coastal flooding/beach erosion concerns as
the arrival of this month`s set of high astronomical tides has
the potential to continue these impacts. Beach conditions are also
likely to remain poor to hazardous, as are marine conditions over
the Atlantic waters.
&&
.MARINE...
Issued at 330 AM EDT Sun Oct 5 2025
Solid Small Craft Advisory (SCA) conditions continue over the
local Atlc waters as tight pressure gradient around sfc high along
the eastern seaboard supports ENE winds at 17-25 knots with
frequent gusts to 30 kts. These winds and long period swell have
built seas 7-11 feet and these very hazardous conditions will
persist for some days. The SCA has been extended for all the
waters through Tue and further extensions appear likely esp for
the offshore waters later into the week. Onshore flow is forecast
to persist for the foreseeable future with pressure gradient
supporting 15-20 knots so poor to hazardous boating conditions are
forecast. High coverage of showers and isolated storms containing
heavy rain and cloud to water lightning through Mon night. Some
drying is forecast to move in from the northeast mid-week.
&&
.AVIATION...
(06Z TAFs)
Issued at 210 AM EDT Sun Oct 5 2025
A persistent pattern of onshore-moving showers continues. VCSH is
maintained along the coast from TIX southward through early this
morning. Forecasted coverage is then expected to increase more
areawide after 13Z/14Z with VCSH extending across the interior.
Periods of prevailing light showers will be possible from MLB
southward, resulting in MVFR VIS/CIG reductions through the
afternoon. Across the interior, TEMPOs have been added at MCO/ISM
(16Z/18Z) where models suggest a period of heavier downpours.
Additional TEMPOs may be needed as confidence increases in time,
and will reevaluate with the 12Z TAF package issuance. Breezy
east winds are forecast with gusts increasing to 20-25 kts by mid
morning and into the afternoon.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB  84  75  84  75 /  60  50  70  50
MCO  86  75  86  75 /  60  30  70  40
MLB  85  76  85  77 /  60  60  70  60
VRB  85  76  85  76 /  60  50  70  60
LEE  86  74  86  74 /  50  20  60  30
SFB  85  75  85  75 /  60  40  70  40
ORL  85  76  85  75 /  60  30  70  40
FPR  85  76  85  76 /  60  50  70  60
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...Flood Watch through Monday evening for FLZ041-141-154-159-164-
     247-254-259-264-347-447-547-647-747.
Coastal Flood Advisory until 5 PM EDT Tuesday for FLZ141-154-159-
     164-347-447-647-747.
High Surf Advisory until 5 PM EDT Tuesday for FLZ141-154-159-164-
     347-447-647-747.
AM...Small Craft Advisory until 5 PM EDT Tuesday for AMZ550-552-555-
     570-572-575.
&&
$$
DISCUSSION...Kelly
AVIATION...Law

NWS MLB Office Area Forecast Discussion