933
FXUS62 KMLB 132010
AFDMLB

Area Forecast Discussion
National Weather Service Melbourne FL
410 PM EDT Mon May 13 2024

.DISCUSSION...
Issued at 354 PM EDT Mon May 13 2024

Key Messages:

-Marginal Risk for a few strong to severe storms this afternoon and
 evening.

-Potential for strong to isolated severe storms will continue
 through mid-week.

-Unseasonably hot conditions Tuesday into late week, with highs in
 the 90s most days and peak heat index values rising to 100-105.

Thru Tonight...Scattered showers and storms developing over the
interior will increase in coverage as sea breeze collision occurs
with motion toward the east coast. Have drawn likely (60%) PoPs
for the interior through 8 pm and scattered (30-50%) along the
coast. The late morning (15Z) Cape sounding shows temps aloft have
indeed warmed to -8.1C (from -9.7C). A couple strong to marginally
severe storms remain possible given bulk shear of 40 kt. The
primary threat will be damaging wind gusts and hail. Of course,
with boundary collisions producing localized enhancement to the
low level shear/helicity, an isolated tornado cannot be ruled
out. Hot on the heels of this diurnal convection is an MCS
tracking E/SE across the NE Gulf. CAM guidance shows this feature
reaching northern sections of FA late this evening (aft 10PM),
weakening as it does so. Have maintained scattered PoPs north of
Orlando through 2 am, after which the remnant MCS will push
offshore.

Tue...EC FL will be in the warm sector with the warm front just
north of the area. There is some uncertainty on timing of
convection which will have an effect on max temps. Have greater
confidence that areas south of Orlando will be quite hot reaching
the mid 90s with heat indices 100-105 due to offshore flow and a
delayed or prevented sea breeze. More persistent clouds should
keep northern sections slightly lower but still hot in the low to
mid 90s. A minority of CAM solutions shows an early round of
showers/storms across the north in the morning which would have a
more significant effect on temps (not as hot). Have drawn only a
20 PoP through mid morning increasing 30-50 percent areawide
during the aftn. It is possible that some areas will see more than
one round of rain/storms over the course of the day/evening.

Wednesday... An area of surface low pressure will continue to
gradually move eastward across the Ohio Valley on Wednesday, with
its associated mid-level troughing moving across the eastern US. The
attendant cold front will shift southeastward across the SE US as
the low moves eastward, leading to increasing rain and storm chances
on Wednesday locally. Southerly flow out ahead of the frontal
boundary will lead to increasing moisture across the peninsula, with
forecasted PWATs in the 1.7 to 2.0" range. As a result, rain chances
will increase to 50 to 65 percent across east central Florida.

In addition to the rain, storms will also be possible as the front
moves across the area. The Storm Prediction Center has highlighted a
majority of east central Florida in a Marginal Risk (1/5) on their
Day 3 outlook because current modeled guidance indicates that the
environment could be favorable for some strong to marginally severe
storms. In general, instability will be present across the
peninsula, with dewpoints well into the 60s and even low 70s in some
areas, which will help promote the development of storms.
Additionally, strong westerly flow ranging from 30 to 50 knots
between 925 mb to 700 mb along with 500 mb temperatures in the -11
to -10C range indicate the potential threat for strong wind gusts
and small to coin-sized hail in association with any well-organized,
strong storms that develop out ahead of the front. Activity will
gradually diminish into Wednesday night, though isolated to
scattered showers and isolated storms will continue to be possible
as the frontal boundary settles across the Florida peninsula and
begins to slowly weaken.

Conditions across east central Florida are forecast to be warm on
Wednesday ahead of the front, especially across the Treasure Coast
and Okeechobee County. Increased cloud coverage across the northern
portions of the area will help keep temperatures in the upper 80s to
low 90s. However, warm, muggy conditions across the Treasure Coast
and Okeechobee County are forecast, with afternoon temperatures
climbing into the mid 90s. For reference, temperatures across all of
east central Florida are forecast to be approximately 5 degrees
above normal on Wednesday, with areas across the Treasure Coast and
Okeechobee up to 10 degrees above normal. Heat indices may reach
100 to 105 Wednesday afternoon in some areas, especially south of
the Orlando metro. Overnight lows will remain in the low 70s, with a
few isolated areas dropping into the upper 60s across northern
Volusia and Lake counties.

Thursday... The frontal boundary will remain draped across the
Florida peninsula on Thursday, continuing to weaken throughout the
day. There continues to be some slight discrepancies between the
Euro and the GFS related to just how much moisture will remain
present along the boundary, with the GFS remaining the drier
solution of the two. Have kept PoPs primarily focused south of the
Orlando metro on Thursday afternoon, generally between 30 to 50
percent. Isolated storms also cannot be ruled out, especially in
areas where the east coast sea breeze is able to develop and move
inland. Any activity that does develop is forecast to diminish into
the overnight hours, with rain and storms continuing to be possible
across the local Atlantic waters south of the Cape.

The above normal temperatures will continue across east central
Florida into Thursday, with afternoon highs climbing into the low to
mid 90s. Overnight lows will be slightly cooler, falling into the
mid 60s to low 70s.

Friday-Monday... The weakening frontal boundary will lift northward
on Friday as a warm front, with the Florida peninsula forecast to
remain under a warm, moist airmass into the weekend and early next
week. This will result in the potential for isolated to scattered
showers and storms each afternoon. There continues to be
discrepancies in the long-term global models with respect to just
how much moisture will remain over the peninsula, with the GFS
continuing to indicate drier conditions than the Euro (PWATs of 1.3
to 1.7" in the GFS versus 1.6 to 2.0" in the Euro). As a result,
have stuck with the NBM as a good middle ground between the two,
with PoPs generally remaining under 40 percent each afternoon for
now. Will make adjustments as time moves on and confidence increases
in shower and storm development. Westerly winds will push showers
and storms offshore, with continuing development possible across the
local Atlantic waters each evening. Warm temperatures will persist,
with afternoon highs generally in the low to mid 90s and overnight
lows in the upper 60s to low 70s.

&&

.AVIATION...
(18Z TAFs)
Issued at 354 PM EDT Mon May 13 2024

Gusty E to SE winds 10-15 knots with gusts around 25 knots will
persist thru 00Z. Scattered sea breeze storms are forecast to
develop btwn 20Z-24Z over the interior assocd with a collision.
This activity will propagate toward the East Coast terminals after
21Z through around 14/02Z. Will also be watching an approaching
MCS from the W/NW which should weaken as it reaches LEE/DAB and
possibly SFB/MCO btwn 03Z-06Z. Have added VCTS for DAB/LEE and a
TEMPO may be needed. MVFR CIGs possible late tonight/early Tue
across the northern terminals incl. MCO. On Tue, breezy S/SW flow
10-15 knots, gusting to 25 knots should turn onshore aft 18Z at
VRB-SUA. SCT aftn SHRA/TSRA forecast though an early round of
convection may affect north of MCO.


&&

.MARINE...
Issued at 354 PM EDT Mon May 13 2024

Tonight/Tue...Fresh SE winds this evening will veer southerly Tue
as warm front lifts north of the local waters. Pressure gradient
will support 15-20 knots and possibly periods of around 20 knots
over the offshore waters. So will maintain Caution headline
nearshore and an Advisory will go into effect at 8 pm for the
offshore waters. Scattered storms over inland areas late this aftn
will push east toward the intracoastal and nearshore Atlc waters.
Another round of storms may push offshore from the Cape northward
overnight. Additional scattered showers and storms will push
offshore Tue. Choppy seas 3-4 FT building to 5 FT offshore.

Wednesday-Saturday... Boating conditions will continue to slowly
improve across the local Atlantic waters on Wednesday, with
southwesterly winds diminishing to 10 to 15 knots across most of the
waters and seas subsiding to 2 to 4 feet. Winds across portions of
the far offshore waters may linger around 15 to 20 knots into
Wednesday night, diminishing towards early Thursday. By Thursday,
winds will veer to out of the northeast to southeast at 5 to 10
knots, picking back up out of the south-southeast Friday and
Saturday at 10 to 15 knots. Seas are forecast to remain between 2 to
4 feet, with the potential for 1 to 2 foot seas across the nearshore
waters.

An approaching cold front on Wednesday will lead to increasing rain
and storms chances across the local waters, with some storms
potentially become strong to marginally severe on Wednesday. The
front will stall across the waters and gradually weaken on Thursday,
with the best chances for any showers and storms remaining primarily
across the waters south of the Cape. Friday, the boundary will lift
northward as a warm front, with a return of isolated to scattered
showers and storms across all legs of the local Atlantic waters
through the remainder of the period.

&&

.FIRE WEATHER...
Issued at 354 PM EDT Mon May 13 2024

Increasing moisture out ahead of a frontal boundary will keep
minimum RH values above critical thresholds through Wed, though
breezy SW to W southwest winds around 15G25 mph could lead to
spread of any new or ongoing fires. Through the remainder of the
week and into the weekend, warm temperatures across the area may
lead to minimum RH values dropping back into the 35 to 45 percent
range. Winds will remain out of the west- southwest around 10 to
15 mph through Saturday.

Isolated to scattered showers and storms will also be possible each
afternoon, with the potential for some strong to marginally severe
storms Tue-Wed in association with the aforementioned frontal
boundary.

&&

.PRELIMINARY POINT TEMPS/POPS...
DAB  72  92  73  90 /  60  60  40  60
MCO  73  95  75  91 /  40  50  30  60
MLB  75  92  75  92 /  40  50  30  60
VRB  74  95  74  95 /  30  50  20  60
LEE  74  92  75  88 /  50  50  40  70
SFB  73  95  75  90 /  50  50  30  60
ORL  73  94  76  91 /  40  50  30  60
FPR  74  95  73  96 /  30  40  20  60

&&

.MLB WATCHES/WARNINGS/ADVISORIES...
FL...None.
AM...Small Craft Advisory from 8 PM this evening to 4 AM EDT
     Wednesday for AMZ570-572-575.

&&

$$

SHORT TERM...Kelly
LONG TERM...Tollefsen