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000
FXUS62 KMLB 220054
AFDMLB

Area Forecast Discussion
National Weather Service Melbourne FL
854 PM EDT Sun Apr 21 2024

.DISCUSSION...

Current-Overnight...First wave of ISOLD convection has pushed off of
the Treasure Coast, with ECSB pinned along the immediate Space and
Treasure coasts with dominant offshore flow. A cold front will
approach overnight with ISOLD-SCT showers and ISOLD lightning storms
possible. If any storms are able to develop, primary threats will be
occasional lightning, gusty winds, small hail, and locally heavy
downpours. Gusty SW/W afternoon winds will diminish this evening.
Wind direction will veer W/NW later tonight, post-frontal. We will
also see an increase in cloud-cover with ceilings lowering. By
sunrise, the front should be located across our southern counties,
just north of Lake Okeechobee. Overnight lows remain mild and in the
60s areawide.

Mon...Previous...Models are quicker bringing the front through our
southern sections in the morning and bringing drier air into the
northern sections. After collaborating with SPC, the MRGL risk for
severe storms was pared back slightly to only include Okeechobee and
the Treasure Coast counties. Model trends show decreasing CAPE
values across the south on Mon so would not be surprised if
additional adjustments are needed in the MRGL risk with a focus more
on south FL. But if deep convection (thunder) can develop, fairly
cold temps aloft (-10 to -11C) could produce gusty winds and hail.
Gusty north winds will develop along the Volusia coast mid day
behind the front as high pressure builds in, 20 mph gusting near
30 mph, and this will spread southward during the afternoon.

&&

.AVIATION...A cold front slides southward thru much of the area
overnight, accompanied by ISOLD-SCT SHRA`s and ISOLD TSRA`s. Primary
threats include occasional lightning strikes, downpours, small hail,
and gusty winds. Prevailing MVFR CIGs will march north to south
across ECFL overnight, with IFR CIGs possible toward sunrise Mon
morning in spots. Gusty SW/W winds diminish into this evening and
direction will veer W/NW overnight, post-frontal. Gusty NRLY winds
spread southward during the day on Mon, strongest (15-20G25-30 kts)
along the coast. ISOLD-SCT convection continuing on Mon, with
greatest threat Okeechobee County/Treasure Coast where moisture
remains deepest.

&&

.MARINE...Overnight/Mon...We continue Cautionary Statements this
evening across the offshore waters of Brevard County and the
Treasure Coast for S/SW winds 15-20 kts. With a weak cold front
approaching, we may see some scattered showers and isolated
lightning storms developing from north to south (offshore-moving)
across the local waters tonight. The cold front will promote a wind
shift to out of the northwest overnight (north to south). Initial
wind speeds around 15 kts will increase 18-23 kts with frequent
higher gusts out of the north on Mon. A Small Craft Advisory goes
into effect at 15Z/11AM Mon for all waters north of Sebastian Inlet.
At 20Z/4PM the Advisory gets extended south thru Jupiter Inlet.
Initial seas 2-4 ft in the period will build during the day on Mon
(esp afternoon) to 4-6 ft near shore and 6-8 ft offshore (north of
Sebastian Inlet). Northerly winds will diminish Mon night (north to
south) as the cold front pushes further into south FL. Seas 5-6 ft
Mon night near shore and 7-8 ft offshore. A few storms on Mon could
be on the strong side, mainly south of Sebastian Inlet, though drier
air pushing south during the day could take this threat even further
south.

&&

.FIRE WEATHER...Thru Mon...Rain chances are forecast to increase
overnight into Mon ahead of an approaching weak cold front. Isolated
lightning storms will also be possible. Any storms that can develop,
esp Mon afternoon may be capable of producing lightning strikes,
gusty winds, and small hail. West-southwest winds veering to out of
the north-northwest behind the front becoming gusty along the coast.
Min RH values will be greater than 55 percent along the coast and as
low as 45 percent interior Mon. Afternoon smoke dispersion will be
Generally Good to Very Good on Mon.

&&

.MLB WATCHES/WARNINGS/ADVISORIES...
FL...None.
AM...Small Craft Advisory from 11 AM Monday to 4 AM EDT Tuesday for
     AMZ550-552.

     Small Craft Advisory from 4 PM Monday to 11 PM EDT Tuesday for
     AMZ555-575.

     Small Craft Advisory from 11 AM Monday to 4 PM EDT Tuesday for
     AMZ570.

     Small Craft Advisory from 11 AM Monday to 11 PM EDT Tuesday for
     AMZ572.

&&

$$

Sedlock/Volkmer