777
FXUS62 KMLB 102006
AFDMLB

Area Forecast Discussion
National Weather Service Melbourne FL
406 PM EDT Wed Jul 10 2024

...New DISCUSSION, MARINE...

.DISCUSSION...
Issued at 405 PM EDT Wed Jul 10 2024

Key Messages:

- Isolated to scattered rain and lightning storms through mid
evening, capable of gusty winds and heavy rainfall

- Greater coverage of rain and storms Thursday and Friday, a strong
storm or two cannot be ruled out

- Hot temperatures this weekend into next week with heat indices
  100-107+

Now-Tonight...Shower and storm activity is increasing over portions
of Lake and Volusia counties this afternoon, as anvil cirrus
overspreads the area from east to west. Storms well offshore, in
association with a trough of low pressure, have been sending these
cirrus clouds in our direction since late morning. As a result,
temperatures have climbed into the low 90s but are struggling to
reach the mid 90s. This is keeping heat indices in the low to mid
100s, though a location or two have briefly hit 107-108 degrees.
While a Heat Advisory remains in effect through 6 PM, confidence is
increasing that many locations will approach or stay just below
advisory criteria through the remainder of the afternoon.

Short range model guidance has a decent handle on the overall lower
coverage of storms so far today. Attention now turns to any outflow
that can propagate south of the Lake/Volusia County storms, which
may help to produce additional showers and storms across the
remainder of the area this afternoon and evening. The latest RAP
analysis indicates a persistent dry layer around 700mb which is
working against convective initiation farther south. However, most
guidance suggests that atmospheric PW increases just enough from the
Orlando metro toward the Atlantic coast to support at least a 40-50
PoP through early evening. The aforementioned dry layer, interacting
with any convection, may briefly support higher wind gusts of 40-50
mph. Occasional to frequent lightning strikes and heavy downpours
will also accompany the most organized activity. After sunset,
lingering showers and isolated storms are forecast to decrease from
north to south. In their wake, temperatures will fall into the upper
70s and low 80s, except where heavier rain has already cooled
temperatures into the mid/upper 70s.

Thursday-Friday...A trough off of the southeast U.S. coast is
expected to drift west, and a mid level low attempts to organize
over the FL Peninsula Thursday afternoon. Increased mid level
support (20-25 kt 850mb winds), especially along the coast, will set
the stage for greater coverage of showers and lightning storms
Thursday afternoon. Surface flow remains rather light (10 mph or
less) from the WSW on Thursday, which keeps the east coast sea
breeze at bay. 60-70 PoP was included for much of the area, with
perhaps the highest rain chances focused across the southern two-
thirds of the forecast area as convection is generally steered
toward the south. Locally heavy rainfall, lightning strikes, and
instances of gusty wind are possible in the afternoon and early
evening. Temperatures are forecast to back down into the upper 80s
to low 90s, due to the widespread cloud cover and rain chances. By
Friday, temperatures warm a degree or two, reaching the low 90s
in most locations. Some models and ensemble guidance suggest a
push of comparatively "drier" air mixing in north of the Orlando
area, which could affect PoPs there in future forecasts.
Additionally, flow begins to back to the SSE, especially along the
coast. For now, expected isolated to scattered coverage once
again of showers and a few storms Friday afternoon, dissipating
later in the evening.

Saturday-Tuesday (modified previous)...Onshore flow is expected
to develop over the weekend as high pressure builds over the
western Atlantic and the state of Florida. NAEFS/ECMWF ensembles
show upper level heights reaching an all-time maximum this
weekend. Another heat wave is expected over the weekend and into
next week as 500mb heights reach 594-597dm. The potential exists
for heat indices 105-110 degrees from Sunday into early next week.
Isolated to scattered showers and lightning storms are forecast
each afternoon with the greatest chance expected over the far
western interior with boundary collisions expected mainly to the
west of east central Florida through the weekend. Shower and storm
chances increase slightly Monday and Tuesday with the pattern
expected to become more favorable for boundary collisions between
sea breezes and outflow over west-central Florida. Afternoon highs
in the low to mid 90s with heat index values between 105-110 are
forecast. Lows in the mid 70s to near 80 degrees are expected each
night.

&&

.MARINE...
Issued at 405 PM EDT Wed Jul 10 2024

Tonight...The overall pattern of westerly flow continues, with
winds increasing up to 10-15 kt offshore. Seas remain 2-3 ft,
except where locally higher in the vicinity of heavy showers and
lightning storms. The greatest chance for rain and storms will
retreat to the offshore waters overnight, gradually expanding
westward by daybreak Thursday.

Thursday-Sunday (modified previous)...Scattered to numerous
showers and lightning storms are expected Thursday afternoon and
evening, as west- southwest flow 10-15 kt continues. A few storms
could produce wind gusts in excess of 34 kt and locally higher
seas. Outside of storms, seas remain 2-3 ft.

Boating conditions will be favorable outside of lightning storms.
Offshore flow is forecast with winds backing southeast into the
afternoon around 10-12 kt Friday. Onshore winds develop into the
weekend, along with the daily afternoon sea breeze. Scattered
showers and lighting storms capable of gusty winds and occasional
to frequent lighting strikes are forecast. Seas are expected to
build up to 2-4 ft well offshore by Sunday afternoon. Otherwise,
expect seas of 2-3 ft.

&&

.AVIATION...
(18Z TAFs)
Issued at 150 PM EDT Wed Jul 10 2024

VFR conditions prevailing outside of convection. Scattered showers
and storms have developed from around DAB/LEE northward. Expect
activity to increase southward, with TEMPOs added in for all
sites through around 20-23Z. Gusty winds have already been
observed with these showers and storms at DAB, with a gust to
36kts. Activity is forecast to diminish this evening. However,
models suggest showers beginning to push onshore towards daybreak
Thursday morning. SHRA is then expected to increase late morning
into the afternoon, with embedded thunderstorms. The highest
chances look to be from Orlando southward. Surface winds westerly
around 10kts or less through the period.

&&

.PRELIMINARY POINT TEMPS/POPS...
DAB  77  91  75  93 /  30  50  20  50
MCO  78  89  76  92 /  20  60  30  70
MLB  76  90  74  91 /  30  70  40  60
VRB  76  90  74  91 /  30  70  40  50
LEE  79  90  77  94 /  30  50  20  60
SFB  78  90  76  94 /  30  60  20  60
ORL  79  90  76  93 /  20  60  30  70
FPR  76  89  74  91 /  40  70  40  60

&&

.MLB WATCHES/WARNINGS/ADVISORIES...
FL...Heat Advisory until 6 PM EDT this evening for FLZ041-044>046-053-
     058-141-144-154-159-164-247-254-259-264-347-447-547-647-747.

AM...None.
&&

$$

DISCUSSION...Schaper
AVIATION...Leahy