999
FXUS62 KMLB 201425
AFDMLB

Area Forecast Discussion
National Weather Service Melbourne FL
1025 AM EDT Mon May 20 2024

...New UPDATE, MARINE...

.UPDATE...
Issued at 1025 AM EDT Mon May 20 2024

A weak front will continue to progress slowly southward across
central FL today. Mid level trough axis aloft will remain extended
across the region and will combine with some lingering moisture
(PW values of 1.3-1.4") to allow for some isolated to scattered
shower and storm development even behind the front, mainly into
the afternoon hours. PoPs range from around 20-40 percent. This
activity will largely form along a slight surge in northerly winds
behind the front and with the east coast sea breeze forming from
the Cape southward and moving inland.

Greatest potential for storms, however, will be across southern
portions of Okeechobee County and the Treasure Coast later this
afternoon into the early evening, near the frontal boundary where
greater moisture/instability will exist. A few stronger storms
will be possible, and SPC maintains a Marginal Risk (level 1 of 5)
for severe weather for today across this region. Strong to
locally damaging wind gusts of 40-60 mph and coin-sized hail will
be the main threats.

N/NE winds will become breezy up to 15 to 20 mph toward mid to
late afternoon, with gusts up to 25 to 30 mph possible. It will
remain seasonably warm behind the front, with highs ranging from
the low 80s along the Volusia County coast to the low 90s over the
interior, south of Orlando.

&&

.MARINE...
Issued at 1025 AM EDT Mon May 20 2024

Today-Tonight...Updated the forecast to increase wind speeds with
the surge of northerly winds later this afternoon into this
evening behind the front. Winds look to increase closer to around
15-20 knots north of Sebastian Inlet from late day into the
evening hours, with seas building up to 6 feet offshore. Have
added exercise caution headlines for the Volusia waters and
nearshore Brevard waters for late this afternoon, and these
headlines will need to be continued into the evening, including
the offshore Brevard waters. South of Sebastian Inlet, winds veer
to the N/NE and increase to 10-15 knots.

Isolated to scattered showers and storms still possible over the
waters, especially south of Sebastian Inlet, where a few stronger
storms will continue to be possible late this afternoon and
evening.


&&

.PREVIOUS DISCUSSION...
Issued at 419 AM EDT Mon May 20 2024

Today-Tonight...Early morning surface analysis has shown a weak cold
front sinking into the Florida peninsula, reaching the I-4 corridor.
Widely isolated showers developed overland this morning ahead of the
boundary with most convective activity limited to the far offshore
Atlantic waters. The front will continue to gradually track
southward through the morning, moving south of Lake Okeechobee into
the afternoon. Northerly winds behind the front are forecast to
increase to around 10 mph, remaining light enough for an east coast
sea breeze to develop. Only modest drying is forecast behind the
weak front today with model guidance holding on to PWATs around 1.1-
1.4". This lingering moisture could be enough to spark convective
activity as the sea breeze moves inland. The current forecast
includes a 30 percent chance of showers and storms north of a line
from Melbourne to Lake Marian. The greatest coverage of showers and
storms lies south of this line (40-50%) where the sea breeze is
forecast to interact with the Lake Okeechobee breeze. Surface
instability in place could allow for a stronger storm. However, an
inversion present above 700mb, warming 500mb temperatures (-8 C),
and dry air aloft could all aid in limiting strong updraft growth.
While strong storm development could be limited with some
uncertainties, there remains a Marginal Risk for an isolated severe
storm across Martin, southern Okeechobee and southern St. Lucie
counties where surface instability will be maximized.

Little relief from the heat behind the frontal boundary with
afternoon temperatures ranging the mid to upper 80s along and north
of the I-4 corridor, climbing into the low 90s southward. A few
degrees cooler along the coast. Lingering moisture will promote Heat
Index values in the mid to upper 90s across Okeechobee and the
Treasure Coast.

Tuesday...Mid level troughing settles across the western Atlantic,
extending southwestward across the Florida peninsula. Weak surface
troughing sits off the eastern coast of Florida while surface high
pressure extends along the eastern seaboard into the Florida
panhandle. Locally, light north-northeast flow will support
development of an afternoon sea breeze. Once again, modest moisture
remains in place to support scattered showers and lightning storms
along developing mesoscale boundaries. Temperatures cool two to
three degrees compared to Monday, with highs widely ranging the mid
to upper 80s. Areas near Lake Okeechobee will be the warmest with
highs forecast near 90 degrees.

Wednesday-Sunday...Ridging over the western Gulf of Mexico slides
eastward, extending into Florida. A short wave trough moving into
the eastern CONUS will then work to flatten ridging in place by late
week. The area of anomalous ridging aloft will support drying
conditions and warming temperatures at the start of the extended
period. Onshore flow continues to promote an east coast sea breeze
regime Wednesday and Thursday with only an isolated mention of
convection each afternoon. Surface flow begins to veer southerly
Thursday night, returning moisture and a mention of scattered precip
chances by the weekend. High temperatures in the upper 80s (coast)
to lower 90s (inland) on Wednesday follow a warming trend each day
into late week. High temperatures mostly in the mid 90s by Sunday.

&&

.AVIATION...
(12Z TAFs)
Issued at 735 AM EDT Mon May 20 2024

Continued mainly VFR across ECFL. Some stratus pushing southward
from north FL may lead to some IFR/LIFR conds early this morning,
primarily north of MCO, and patchy ground fog is producing some
MVFR visibilities at VRB/FPR. WRLY morning winds gradually
transitioning to NW/N around 10 kts into early afternoon ahead of
a N/NNE wind surge that will increase speeds to 15-20 kts with
frequent higher gusts. We continue to carry VCSH wording early
afternoon for many terminals, except VCTS for Treasure Coast
terminals (mid-late aftn), where confidence is higher for
convection - closer proximity to a frontal boundary and deeper
moisture here.

&&

.MARINE...
Issued at 419 AM EDT Mon May 20 2024

Today-Tonight...A weak frontal boundary slides southward across the
local waters today. North winds increasing to 10-15 kts behind the
front will build seas up to 4-5 ft in the Gulf Steam. Winds veer
east along the coast with the development of an east coast sea
breeze this afternoon. Isolated to scattered showers and lightning
storms are forecast.

Tuesday-Friday...North winds into Tuesday gradually veer onshore
into mid week, remaining 7-12 kts. Light winds then veer southward
into Friday. Seas up to 5 ft in the Gulf Stream on Tuesday
gradually subside, and seas become widely 2-3 ft by Wednesday
evening. Scattered to numerous showers and scattered lightning
storms are forecast on Tuesday with coverage following a downward
trend each following day.

&&

.PRELIMINARY POINT TEMPS/POPS...
DAB  83  70  83  70 /  30  10  40   0
MCO  89  70  87  70 /  30  20  50   0
MLB  87  73  85  72 /  20  10  50  10
VRB  89  71  87  71 /  30  20  50  10
LEE  87  69  87  70 /  30  20  40   0
SFB  87  69  87  70 /  30  10  50   0
ORL  88  71  87  71 /  30  20  50   0
FPR  90  69  87  70 /  30  20  50  20

&&

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

$$

UPDATE...Weitlich
AVIATION...Sedlock