517
FXUS62 KMLB 161936
AFDMLB

Area Forecast Discussion
National Weather Service Melbourne FL
336 PM EDT Mon Sep 16 2024

...New DISCUSSION, MARINE, HYDROLOGY...

.DISCUSSION...
Issued at 336 PM EDT Mon Sep 16 2024

Key Messages...

- Poor to hazardous boating and surf conditions will continue
  tonight into Tuesday

- Saint Johns River at Astor forecast to remain in Moderate Flood
  through this week

- High astronomical tides will promote elevated water levels into
  this week, and a Coastal Flood Advisory continues through at
  least Tuesday night

Currently-Tonight...Low pressure northeast of FL (Potential Tropical
Cyclone 8) will push onshore the South Carolina coast into tonight,
with frontal boundary associated with this system remaining across
the southern half of central FL. Isolated to scattered showers and
storms will continue to develop across the region through mid to
late afternoon as moisture continues to increase and a passing
disturbance in the mid levels aids in destabilization and lift. With
a continued west-southwest steering flow some of this activity may
be able to push back toward the east central FL coast and offshore
into this evening, especially near to south of the Cape. Still can`t
rule out isolated stronger storms with frequent lightning, gusty
winds to 40-50 mph and locally heavy rainfall the main threats. Dry
conditions should largely prevail past midnight, and there will
again be the potential for patchy fog, especially across the
interior. Lows will fall into the low to mid 70s.

High astronomical tides will continue to produce elevated water
levels through this week. Minor coastal flooding will be possible
during the high tide cycles, with the next of these occurring
between 7-8PM tonight. A Coastal Flood Advisory continues currently
through Tuesday evenings high tide cycle, but additional extensions
in this advisory may be needed through the week.

Tuesday...Frontal boundary will linger across the central Florida
peninsula into tomorrow as it lifts slowly northward. Moisture
continues to gradually increase, with PW values around 1.8-1.9"
across the entire region. This should again allow scattered
showers and storms to develop into the afternoon and evening (PoPs
40-50%), with a westerly steering flow continuing to shift
convection eastward across the area and offshore. Lingering drier
air aloft and cool temps at 500mb around -7C may still allow for
isolated stronger storms to form, producing frequent lightning
strikes, gusty winds to 40-50 mph and locally heavy rainfall.
Highs will be in the upper 80s/low 90s with humid conditions
producing peak heat index values 98-104. Lows will continue to
range in the low to mid 70s.

Wednesday-Sunday...(Modified Previous Discussion) Mid level low
pressure across the southeast U.S. becomes absorbed into an open
trough late week. A series of 500mb vorticity pulses will move
across the peninsula through the period. The surface boundary across
north Florida shifts back southward across the area Thursday, moving
into south Florida. A drier airmass builds behind the boundary while
moisture piles up to its south. Coverage of showers and storms
remains mostly scattered through the extended period with PoPs
generally between 30-50 percent, except up to 60 percent across
Okeechobee County and the southern Treasure Coast on Wednesday. High
temperatures in the low 90s cool into the upper 80s by the weekend.

&&

.MARINE...
Issued at 336 PM EDT Mon Sep 16 2024

Tonight...Poor to hazardous boating conditions continue over the
coastal waters from elevated swells from PTC8. Will allow the
Small Craft Advisory (SCA) over the nearshore waters, north of
Sebastian Inlet to drop off early at 4 PM, as seas at buoys
41009/41070 have remained around 6 feet. However, lingering seas
up to 7-8 feet are still forecast offshore, so will maintain SCA
headlines through late tonight for the 20-60nm offshore zones.
Nearshore, will keep exercise caution headlines for seas up to 6
feet. Winds will be relatively light and somewhat variable with
weak frontal boundary across the area, and speeds will generally
range around 5-10 knots.

Isolated to scattered showers and storms will still be possible
over the waters.

Tuesday-Friday...(Modified Previous Discussion) Seas subside
Tuesday, settling around 3-4 ft Wednesday afternoon. Variable
winds continue into late week while remaining 10 kts or less.
Scattered showers and lighting storms are forecast each day.

&&

.HYDROLOGY...
Issued at 336 PM EDT Mon Sep 16 2024

The Saint Johns River near Astor is forecast to remain in Moderate
Flood stage (around 3.2-3.4 ft) through this week. The potential
exists for small additional rises if locally heavy rainfall develops
over the river basin.

Southward, additional heavy rainfall across the Saint Johns River
basin has caused a steady rise in river levels with the forecast
point at Deland forecast to remain in Action Stage and the point at
Sanford forecast to reach Action Stage tonight into Tuesday. Geneva
Above Lake Harney is forecast to remain just below Action Stage
through Tuesday, with a rise to Action Stage possible mid to late
week. Additional heavy rain could cause further rises, so interests
along the river should monitor for forecast updates.

&&

.AVIATION...
(18Z TAFs)
Issued at 222 PM EDT Mon Sep 16 2024

Primarily VFR conditions are forecast outside of showers/storms.
MVFR conditions are forecast at KLEE after 06z for BR and visibility
to 4miles into the early AM. TAFs begin with VCTS between 18-20Z
at KSUA and TAF sites N of KMLB. Isolated to scattered showers/lightning
storms are forecast to develop into the PM and end by 00-02Z. Light
and variable winds are forecast to become onshore into the PM

&&

.PRELIMINARY POINT TEMPS/POPS...
DAB  73  89  73  90 /  20  40  20  40
MCO  74  91  73  92 /  20  50  10  50
MLB  76  90  74  90 /  40  50  40  50
VRB  76  90  73  91 /  30  50  40  50
LEE  73  90  73  91 /  20  40  10  40
SFB  73  90  73  91 /  20  50  10  50
ORL  75  91  74  92 /  20  50  10  50
FPR  76  90  73  90 /  30  50  40  60

&&

.MLB WATCHES/WARNINGS/ADVISORIES...
FL...Coastal Flood Advisory until midnight EDT Tuesday night for
     FLZ141-154-159-164-347-447-647-747.

AM...Small Craft Advisory until 4 PM EDT this afternoon for AMZ550-
     552.

     Small Craft Advisory until 4 AM EDT Tuesday for AMZ570-572-575.

&&

$$

DISCUSSION...Weitlich
AVIATION...Fehling