089
FXUS62 KMLB 301420
AFDMLB

Area Forecast Discussion
National Weather Service Melbourne FL
1020 AM EDT Sun Jun 30 2024

.UPDATE...
Issued at 1020 AM EDT Sun Jun 30 2024

Mid level disturbance near Grand Bahama Island early this morning
will continue to move toward the SW today across S FL then the
Straits of FL tonight. This feature brought scattered showers and
lightning storms to portions of the Treasure coast and adjacent
Atlc waters this morning. Morning Cape sounding shows a deep N to
NE flow through the column along with deep moisture with precip
water of 2.29". The east coast sea breeze will develop by early
afternoon and push inland, sparking scattered to numerous showers
and lightning storms. The focus for storms will shift from just
inland from the coast to the interior. So have lowered PoPs along
the Volusia coast. Localized flooding resulting from a quick 1 to
3 inches of rain will be possible esp in urban locations and where
recent heavy rains have fallen. Frequent lightning strikes will
also be a threat. A reminder that lightning can occur well away
from a parent storm where it is not yet raining or has stopped
raining. If thunder is heard, seek shelter in an enclosed
building or hard-topped automobile. Picnic shelters, dugouts and
screen porches offer no protection from the dangers of lightning.

The debris clouds from previous convection across the south will
gradually thin allowing max temps to warm into the upper 80s/near
90 while widespread lower 90s will occur across northern interior
sections. Peak heat indices near 105.

&&

.PREVIOUS DISCUSSION...
Issued at 222 AM EDT Sun Jun 30 2024

KEY MESSAGES:

- 50% to 80% coverage of lightning storms today, highest near and
  west of Orlando to the Lake Okeechobee region. Threats include
  localized minor flooding, brief gusty winds, and frequent
  lightning.

- Turning hotter through the week, with a Moderate to Major
  HeatRisk each afternoon. Increasing risk of heat-related health
  impacts from Independence Day into next weekend as high
  pressure settles over the state.

- A 40% to 60% chance for showers and storms through midweek;
  storm coverage may lessen somewhat toward Independence Day and
  Friday.

---------Synoptic Overview----------

On this last day of June, anomalous mid-level ridging extends across
the subtropics from the Desert Southwest to the SW Atlantic. Florida
resides immediately south of its axis, and a weak disturbance will
push across the state today within the easterly flow. Deep tropical
moisture will remain in place over the next 72 hours, with PW values
exceeding 2" at times. As a trough digs into the Northern Rockies
early this week, heights will build across the Southeast U.S. and
over Florida. This is forecast to steer Hurricane Beryl, currently
east of Barbados, through the Caribbean Sea and to the south of
Florida. More information on Beryl can be found at hurricanes.gov.

Near the surface, the axis of high pressure will generally hold near
or north of Central Florida through late this week before settling
southward next weekend. Within this regime, there will be daily
chances for showers and lightning storms. However, coverage may
lessen later this week as the influence of the ridge is felt over
Florida. This would also allow temperatures to turn hotter from the
Independence holiday and into next weekend.

-----Sensible Weather & Impacts-----

Through Daybreak...

The nearby disturbance is interacting with deep moisture to spark a
few showers, mainly along the Treasure Coast, near Lake Okeechobee,
and offshore. Farther north, clear skies, light winds, and near-
saturation may lead to patchy fog over portions of Lake and Volusia
Counties.

Today & Tonight...

With modest vorticity and deep moisture transiting the state, expect
another round of scattered to numerous storms today. Coverage should
range from 40-60% along the coast to over 70% near and west of
Orlando to Indiantown, including Okeechobee. An earlier start to the
showers and storms is on the table today, particularly for the
Treasure Coast and Lake O region. Approx. 20 KT of deep-layer shear
and abundant tropical moisture could result in somewhat more
organized storms. Gusty winds to 40-50 MPH, frequent lightning, and
a Marginal Risk (5%) of excessive rainfall leading to flooding of
urban and poorly drained areas are the main threats. HREF members
indicate a 10-15% chance of isolated 3"+ rain tallies around Greater
Orlando today. Seasonably hot temperatures are forecast, with highs
in the upper 80s to lower 90s. Peak heat indices will range from the
upper 90s to around 105, hottest near and north of I-4.

Monday - Wednesday...

Southeasterly flow will tend to prevail with an embedded daily sea
breeze. Near-to-above-normal available moisture will support a rinse-
and-repeat pattern of daily scattered storms, with 40-50% coverage
near the coast and 60-70% coverage over the interior, including
Greater Orlando. Beach-goers will likely find quite a bit of dry
time. Ridging looks to build across the state, so mid-level
temperatures will increase through the period, leading to poorer
lapse rates and somewhat less impressive storm cores. Fairly
widespread low to mid 90s are forecast, with peak heat indices 102-
107F. Overnight lows will range in the mid 70s, except upper 70s
over portions of Greater Orlando and the coast.

Independence Day - Next Weekend...

The global ensemble suite strongly suggests that deep-layer ridging
will extend across the Sun Belt, with its axis potentially
retreating southward toward Florida by next weekend. This should
steer Hurricane Beryl on a WNW track through the Caribbean, well
south of Florida. In this scenario, the primary concern appears to
be a period of above-normal temperatures while many folks are
outdoors. As H85 temperatures approach +20C, statistical
guidance is indicating low/mid 90s Thu-Fri and more widespread mid
90s next weekend. As surface high pressure drifts southward,
light southerly flow will begin to take shape, pumping in more
muggy air (dew points in the mid 70s F). Heat indices may drift
closer to our Heat Advisory criteria (108F), particularly next
weekend. Our HeatRisk guidance is already reaching into the Major
category along and north of Interstate 4.

Storm chances during this period drop into the widely scattered
range (35-55%), focusing over the interior most afternoons. A
handful of ensemble members indicate some mid-level dry air may get
kicked southward over the state, which may further limit storm
chances on one or more days during this period. Subsidence and warm
temperatures aloft will also tend to hinder sustained, deep
convection through at least Saturday.

&&

.AVIATION...
(12Z TAFs)
Issued at 743 AM EDT Sun Jun 30 2024

Shower and isolated storm development will occur this morning
along the Treasure Coast, especially with outflow boundary from
storms over the coastal waters pushing westward toward KVRB and
KFPR. So have added TEMPOs TSRA to start at these terminals.
Otherwise, greatest potential for showers and storms producing
tempo IFR/MVFR conditions will be during the afternoon and early
evening hours, mainly across the interior. No significant changes
this TAF package, with tempo TSRA groups advertised at inland
terminals around 19-23Z where rain chances are greatest. VCTS
continues at coastal terminals this afternoon where convection may
be a little more limited as east coast sea breeze initially
develops and moves inland.

Showers and storms will diminish into the evening hours, with some
drier air then moving into the area overnight. Winds will be light
and variable through early morning, with winds picking up slightly
out of the NE by late morning and then out of the E/SE through the
afternoon around 7-10 mph as sea breeze moves inland.

&&

.MARINE...
Issued at 222 AM EDT Sun Jun 30 2024

Today-Thursday... A ridge of high pressure will remain just north of
the local Atlantic waters, with predominant southeast breezes from 5-
12 KT each day. Winds will turn offshore around 5 KT near the coast
in the overnight hours. Seas generally 2 FT or less through Tuesday,
then 2-3 FT on Wednesday & Thursday. Scattered showers and isolated
lightning storms are possible each day, though there will be a lot
of dry time. Offshore-moving storms appear unlikely. Intracoastal
and inshore boaters will find a light to moderate chop each
afternoon.

&&

.PRELIMINARY POINT TEMPS/POPS...
DAB  91  74  92  77 /  50  30  50  20
MCO  91  74  93  76 /  70  40  60  20
MLB  89  75  91  77 /  40  20  50  20
VRB  89  74  91  76 /  50  20  50  20
LEE  92  76  93  77 /  70  50  60  30
SFB  92  75  93  77 /  60  30  60  20
ORL  92  76  93  77 /  70  40  60  20
FPR  89  74  91  76 /  50  30  50  20

&&

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

&&

$$

UPDATE...Kelly
AVIATION...Weitlich