889
FXUS62 KMLB 151823
AFDMLB

Area Forecast Discussion
National Weather Service Melbourne FL
223 PM EDT Mon Jul 15 2024

...New DISCUSSION, AVIATION, MARINE...

.DISCUSSION...
Issued at 223 PM EDT Mon Jul 15 2024

KEY MESSAGES:

- Temperatures turn hotter through the work week. There is an
  increasing risk of heat-related illness for those without
  access to proper hydration and cooling later this week.

- The highest chances (40-70%) for storms through midweek will
  continue to focus over the Interstate 4 corridor. Gusty winds
  and locally heavy rain to accompany the strongest storms.

- Storm chances increase again for much of East Central Florida by
  the weekend.

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

A rather stagnant upper-air pattern is forecast over North America
and the W Atlantic over the next week, characterized by ridging over
the Western U.S., a trough developing over the nation`s mid-section,
and additional ridging from the East Coast well into the Atlantic
Basin. Near the surface, an axis of high pressure will move
little for the next few days as it holds very close to Central
Florida.

MIMIC-TPW satellite data shows a ribbon of higher atmospheric
moisture slowly lifting into N Florida as drier air attempts to nose
in from the Atlantic. Ensemble guidance continues to show this drier
air pushing westward over the state during the middle of the week.
By late this week and through the weekend, PW (total moisture)
values are modeled to return to near or just above normal.

H85 temperatures will continue to run near the max moving
climatological average for mid-July (~ +19C), leading to continued
above-normal temperatures through at least Saturday. The potential
is increasing for more widespread impacts from heat late this week
as the hot temperatures combine with additional humidity.

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

Through Tonight...

As suspected, we have quite a moisture gradient today as some drier
air tries to poke into the Treasure Coast from the Atlantic. Above-
normal atmospheric moisture still exists along the I-4 corridor,
however. Thus, we expect storm coverage to range from 50-70% near
Orlando to Titusville and points northward, lessening to 20% for the
Treasure Coast beaches. Storms firing up now on the sea breeze
east of Orlando will push/develop toward the interior/Orlando
area along propagating outflows, culminating with a collision
with the Gulf breeze by early evening. The primary hazards from
today`s storms: gusty winds (10-15% chance of 40-50 MPH), heavy
rain leading to localized urban flooding, and frequent lightning
strikes. Storms will diminish by mid/late evening with clearing
skies overnight. Lows will fall into the mid/upper 70s.

Tuesday - Thursday...

Guidance has struggled some with progression of the dry air on
our doorstep through midweek, now delaying its progression by
around a day. In essence, tomorrow`s forecast looks nearly
identical to today with 20-40% coverage south of Melbourne
increasing to 50-70% for the I-4 corridor. From Wednesday into
Thursday, the drier air is forecast to push over a larger portion
of the district. While it won`t completely stave off rain chances,
it should lower our coverage with 40-50% storm chances near
Orlando decreasing to 20-40% along the coast.

High temperatures will turn a degree or two warmer, with widespread
mid 90s over the interior and low 90s beachside. The hot
temperatures may get offset by ever-so-slightly lower dew points,
but in most cases, our heat indices will still top out from 100-107F
each day.

Friday - Next Monday...

Indicators suggest that peak heat impacts during the next week
will come on Friday and potentially even Saturday as dew points
increase but rain coverage remains just low enough that we keep
attaining widespread 93-96F high temps. Combined with lows in the
mid/upper 70s, which are also above normal, the HeatRisk algorithm
is locally Extreme for portions of Lake Co. and Greater Orlando,
and Major for a sizable chunk of the district. Extreme HeatRisk
typically only occurs during rarer episodes of long-duration
extreme heat with little to no overnight relief. Heat indices are
now forecast to reach 105-110F, which may necessitate advisories
in future forecasts if these trends hold.

The pocket of drier air aloft will be gradually replaced by
deeper moisture from the tropics as we move into the weekend.
Guidance continues to highlight a weak easterly wave moving toward
the state by Sunday or next Monday. Storm chances will ramp back
up in response, with 50-70% coverage presently in our forecast.
However, statistical guidance is already hinting at 80% chances
over the interior next Sun/Mon. It is typically high-biased with
rain chances, but the pattern does look increasingly unsettled.

As storm chances build Sun/Mon, high temperatures are forecast to
dip at least a couple degrees.


&&

.AVIATION...
(18Z TAFs)
Issued at 223 PM EDT Mon Jul 15 2024

VFR is forecast outside of storms. Scat`d storms are expected into
the early evening with chances diminishing shortly after sunset.
TAFs begin with VCTS (18Z-19Z) for TAF sites N of the Treasure Coast
with TEMPO TSRA groups this afternoon/evening for inland sites, as
well as KDAB and KTIX. E/SE winds at 5-10kts in the afternoon are
forecast to become light and variable overnight into the morning.

&&

.MARINE...
Issued at 223 PM EDT Mon Jul 15 2024

Boating conditions remain favorable over the next few days. As high
pressure holds sway, light southerly winds at night turn SE during
the day, increasing to 10-15 KT, especially near the coast with the
sea breeze. There is a 20-40% chance for showers and isolated
storms, primarily during the overnight and morning hours. Seas
generally 2-3 FT, occasionally up to 4 FT beyond 40 NM.


&&

.PRELIMINARY POINT TEMPS/POPS...
DAB  76  93  75  94 /  30  60  10  50
MCO  76  95  76  96 /  30  70  20  40
MLB  76  90  76  91 /  20  30  10  20
VRB  76  92  75  92 /  10  20   0  20
LEE  77  95  77  94 /  50  70  30  60
SFB  76  95  76  95 /  30  70  20  50
ORL  77  95  77  95 /  40  70  20  40
FPR  76  92  75  91 /  10  20   0  20

&&

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

$$

DISCUSSION...Heil
AVIATION...Fehling