115
FXUS62 KMLB 032010
AFDMLB

Area Forecast Discussion
National Weather Service Melbourne FL
410 PM EDT Wed Jul 3 2024

.DISCUSSION...
Issued at 400 PM EDT Wed Jul 3 2024

KEY MESSAGES:

- An extended period of above-normal temperatures continues
  through this holiday weekend. Residents and visitors will need
  to take extra precautions to prevent heat-related illness.

- Daily chances for showers and storms hold near 30% to 60% from
  today through the weekend. Overall, storm coverage will be near
  to below normal, lowest Friday and Saturday.

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

Relatively flat upper ridging, characterized by H5 heights
exceeding 590 dam, extends from California to the subtropical
Atlantic. As a mid-latitude trough works through the Great Lakes
by this weekend, the H5 high will sink toward North Florida and
remain nearby through at least Monday. Hurricane Beryl continues
to be steered beneath this ridge on a track WNW through the
Caribbean Sea, well south of Florida.

In the low levels, high pressure and relatively light background
winds persist throughout the next week. The ridge axis will also
sink slowly southward, reaching Central Florida late Saturday and
then slipping toward the FL Straits by late Sunday or Monday. The
daily sea breeze circulation will be unimpeded within this
pattern. Near-normal tropospheric moisture will remain in place,
except late Friday through early Sunday when somewhat drier air
briefly filters in aloft.

This overall pattern will continue to support scattered afternoon/
early evening storms and above-normal temperatures which will
pose a Moderate to Major HeatRisk across Central Florida.

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

Thru tonight...East coast sea breeze is pushing steadily inland
this aftn propelled by outflow from convection along the
boundary. Late morning Cape sounding continues to show deep
moisture with precip water values of 2.1" and this is largely all
below 700 mb. So very moist low levels will support intense rain
cores. Boundary collisions between the sea breeze, lake breezes
and storm outflows will produce the stronger storms through early
evening over the interior. Some drier air in the mid levels will
support gustier downburst winds than we have seen in recent days.
Coastal communities will remain mostly dry.

Thu...A weak backdoor front is forecast to settle south across
central FL with weak low pressure offshore over the Atlc. A very
weak pressure gradient will be in place though so the sea breeze
will develop on schedule by late morning and push inland.
Northerly steering flow should bring aftn storms south from north
FL during the aftn and focus over the interior, or at least inland
from the coast. Significant heat and humidity will persist with
max temps in the low 90s coast and mid 90s inland. High dewpoints
will produce peak heat indices 103-107. Residents and especially
visitors not acclimated to such heat should take precautions if
spending long durations outdoors. Stay well hydrated and take
frequent breaks out of direct sun, such as shade or an air
conditioned space.

Friday - Weekend: (previous)
Not a whole lot of change as we move forward in time. It`s going to
stay hot (maybe even a degree or two hotter) and there remains a
daily chance for a few storms.

The upper high will reside very close to us this weekend. Its large-
scale subsidence and warm mid-level temperatures (-3C to -4C at H5,
above the maximum climatological moving average) will suppress
sustained deep convection. PWAT values also briefly sneak below 2"
from Friday through Saturday. The near-surface ridge axis will move
southward through the weekend, veering the synoptic PBL flow more
southerly by Sunday. This translates to roughly 30-50% storm chances
Fri/Sat (lowest near the coast and highest far interior), increasing
to 50-60% on Sunday as moisture values start creeping upward again.

H85 T`s climb slightly this weekend to around +20C, so we would not
be surprised if surface temperatures are also a degree or two
hotter. Statistical guidance suggests at least a 40% chance of
reaching 95 degrees near and northwest of I-4 each day. Combined
with seasonably high humidity, peak heat indices should reach 102-
108F. Confidence in how hot our heat indices will get is somewhat
challenged by an increase in interquartile dew point spread
within the model suite. Two takeaways, 1) there is still a
potential for portions of the area to reach Heat Advisory
criteria, and 2) either way, the Moderate to Major HeatRisk will
persist, indicating an unusually high potential for heat stress.

Early Next Week: (previous)
Deep-layer ridging is forecast to extend from the Bermuda High to
the Gulf of Mexico. Meanwhile, a weakness in upper heights is
indicated from the Midwest to Texas. Boundary-layer winds are
forecast to hold southerly or even veer slightly SSW, and a slug
of higher moisture extending north from a tropical wave over the N
Caribbean may pass overhead. Thus, storm chances look a little
higher on Monday. At least scattered storm chances (40-60%) will
persist into the middle of next week, but confidence does drop off
next Tue/Wed as the upper high holds close by and a SAL (Saharan
air layer) may advance toward the state.

Temperatures should continue to run near to above normal, with
low/mid 90s by day and mid 70s at night. Heat indices will keep
lurking at or just below the 108F advisory threshold.

&&

.MARINE...
Issued at 235 PM EDT Wed Jul 3 2024

A high pressure axis will hold north of Florida through Friday,
leading to light daytime SE breezes up to 10 KT (locally enhanced
at the coast during the afternoon). Winds become light SW late in
the overnight hours. The high pressure axis will settle southward
through the local Atlantic this weekend, with light (5-12 KT) S/SE
winds by day turning offshore at night. Seas 2-3 FT through the
period, with a light to moderate chop over the Intracoastal. A few
showers or isolated storms are forecast during the overnight and
early morning hours offshore, shifting closer to the coast in the
late morning and early afternoon hours.

&&

.AVIATION...
(18Z TAFs)
Issued at 143 PM EDT Wed Jul 3 2024

VCSH/VCTS along and ahead of the east coast sea breeze this
afternoon, gradually clearing at the coastal terminals. TEMPOs
included at MCO/ISM (21/23Z) and LEE (22/24Z) where there is the
greatest confidence in TSRA impacts. Coverage of showers and
storms across the interior are forecast to diminish after 02/03Z.
South to southeast winds become east with the passage of the sea
breeze, generally remaining around 10 kts or less. Light and
variable winds tonight.

&&

.PRELIMINARY POINT TEMPS/POPS...
DAB  77  92  76  91 /  20  50  10  30
MCO  77  94  76  94 /  30  70  10  40
MLB  78  92  77  91 /  10  40  10  40
VRB  76  92  76  91 /  10  30  10  40
LEE  78  94  78  94 /  40  70  20  50
SFB  77  94  77  94 /  30  70  10  40
ORL  78  94  78  94 /  30  70  10  40
FPR  76  92  76  91 /  10  30  10  40

&&

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

&&

$$

DISCUSSION...Kelly
AVIATION...Law