338
FXUS62 KMLB 172355
AFDMLB

Area Forecast Discussion
National Weather Service Melbourne FL
755 PM EDT Tue Sep 17 2024

...New AVIATION...

.AVIATION...
(00Z TAFs)
Issued at 746 PM EDT Tue Sep 17 2024

Extended VCTS through 03Z-04Z at KMLB-KSUA for TSRA/SHRA flaring
up on outflow boundaries near the stalled frontal boundary west
of the terminals. Short-fused AMDs for +TSRA impacts possible as
this activity shifts eastward and offshore, especially KVRB-KFPR.
Overnight fog or stratus generally not expected, but there is a
small chance for VIS reductions at KLEE between 09Z-14Z, though
too low for mention in the TAFs. Typical diurnal seabreeze pattern
and near normal afternoon SHRA/TSRA chances expected again
Wednesday.

&&

.PREVIOUS DISCUSSION...
Issued at 410 PM EDT Tue Sep 17 2024

- Marginal Risk for severe storms this afternoon and early this
evening, from Orlando/Titusville southward

- High astronomical tides promote elevated water levels this
week, Coastal Flood Advisory continues

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

Now-Tonight...A stream of mid level cloud cover has shifted slightly
north this afternoon to encompass areas near and south of Cape
Canaveral. Farther north along and west of Interstate 95, the
east coast sea breeze is weakly visible on satellite and radar,
slowly moving inland. Temperatures are climbing into the mid and
upper 80s with a spot or two closing in on the 90 degree mark. GOES-
derived PW, RAP analysis, and the 15z XMR sounding all depict
some drier air entering the mix, especially from 600mb on up. ML LI
is around -6 to -7 with nearly all inhibition depleted and MLCAPE on
the order of 1500-2500 J/kg. Low level lapse rates should continue
to gradually steepen as the surface layer warms this afternoon,
though preceding cloud cover across the south could have somewhat of
an impact on the magnitude of this occurring. Also, modest mid
level lapse rates may temper storm strength a bit more than
previously forecast.

Nonetheless, CAMs still suggest shower and lightning storm
development will begin in the next 1 to 3 hours. Outflow from the
initial activity and the east coast breeze will aid in additional
development farther north and west through late afternoon and early
evening, particularly from Sanford/Titusville southward where
greater moisture availability is focused. Stronger updrafts, coupled
with 25 kt of bulk shear, drier mid level air, and DCAPE around
1000+ J/kg, have the potential to produce strong to damaging wind
gusts. These occurrences should remain isolated in nature, hence
the Marginal Risk (1 out of 5 risk) for severe storms from the
Storm Prediction Center. Activity is forecast to gradually
diminish through midnight, while also drifting toward the Atlantic
coast. Temperatures are expected to settle into the 70s later
tonight, especially north of the Treasure Coast where additional
clearing is forecast.

Wednesday-Thursday...Surface winds remain light through the middle
part of the week, with some form of a westerly directional
component. Shower and storm chances remain similar each afternoon
(40-55 PoP) with a general focus on the southern half of the area,
where there is greater moisture to work with. Mid level troughing
will allow weak impulses of energy to swing across the state, aiding
somewhat in daytime convective development. Gusty winds, lightning
strikes, and brief heavy downpours are the main threats that will
accompany any storms. High temperatures are forecast to remain in
the low 90s each day with overnight lows ranging through the 70s.
Minor coastal flooding concerns are expected to continue, focused
around each high tide cycle.

Friday-Monday...Mid level ridging builds east from the western Gulf
this weekend, allowing onshore surface winds to resume. A surface
front is expected to settle across the Florida Straits, focusing the
greatest moisture south of the forecast area. Still, PoPs around 25-
35 percent were maintained to account for sea breeze driven
isolated/scattered diurnal convection. Highs will stay in the upper
80s to low 90s with overnight temps in the 70s to near 80 degrees at
the coast.

&&

.MARINE...
Issued at 410 PM EDT Tue Sep 17 2024

Now-Tonight...Improving boating conditions are expected with seas
decreasing to around 3-5 ft late tonight. Winds remain light,
becoming offshore overnight around 5 kt. Isolated showers and
lightning storms are possible, capable of producing gusty winds and
locally higher seas.

Wednesday-Saturday...Light offshore flow becomes onshore behind the
east coast breeze each afternoon through Thursday, before more
persistent ENE wind resumes Friday into next weekend. Seas are
forecast to be favorable for boating, around 2-4 ft. Daily rain and
lightning storm chances will continue, especially Wed-Thu.

&&

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

&&

.MLB WATCHES/WARNINGS/ADVISORIES...
FL...Coastal Flood Advisory until 2 PM EDT Thursday for FLZ141-154-
     159-164-347-447-647-747.

AM...None.
&&

$$

DISCUSSION...Schaper
AVIATION...Haley