969
FXUS62 KMLB 030655
AFDMLB

Area Forecast Discussion
National Weather Service Melbourne FL
255 AM EDT Wed Jul 3 2024

...New DISCUSSION, MARINE...

.DISCUSSION...
Issued at 255 AM EDT Wed Jul 3 2024

KEY MESSAGES:

- An extended period of above-normal temperatures continues
  through Independence Day and this 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.

- As Hurricane Beryl churns toward Jamaica and the Western
  Caribbean, high pressure will prevent any impacts for Florida.

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

Upper heights are building across the Southeast this morning as an
H5 anticyclone has nudged eastward, now centered over Alabama. This
is in response to a broad trough that has entered the northern High
Plains. Relatively flat upper ridging, characterized by H5 heights
exceeding 590 dam, extends from California to the subtropical
Atlantic. As the 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. 02/12Z ensemble cluster analysis
continued to indicate that large-scale agreement in the mass fields
remains excellent over Florida over the next several days.

Surface high pressure and relatively light background winds persist
throughout the next week. Its 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-----

Today - Independence Day:

Whether you`re heading to the beach, an area attraction, attending a
holiday celebration, or just spending time in the backyard - be sure
to stay hydrated and find a way to dip out of the hot sun from time
to time! Keep an eye to the sky, and head indoors when thunder roars!

Statistical guidance remains biased way too high on rainfall
potential. Therefore, we relied heavily on 03/00Z HREF probabilistic
guidance for storm chances for the next couple of days while
considering persistence. Only isolated showers are forecast near the
coast in the morning hours, then expect 30-40% coverage of a few
storms on the advancing sea breeze near and west of I-95 in the
afternoon. Our highest storm chances, at 50-60%, lie roughly
northwest of I-4 late afternoon/early evening. This is where
slightly deeper moisture is forecast to reside atop the sea breeze
collision. Proximity soundings indicate 1200-1500 J/kg MLCAPE and
dCAPE approaches 1000 J/kg, so there`s at least a low potential for
gusty winds to 40-45 mph from any stronger storm that develops.
Quick-hitting locally heavy rain of 1-3" leading to minor flooding
and frequent lightning are also potential hazards.

H85 T`s hold steady around +19C and 0-1 KM mixing ratios remain near
16 g/kg, so we fully expect the type of heat and humidity
experienced yesterday to persist. Highs will reach the mid 90s over
the interior and low 90s along the coast. Heat index values will
peak between 102-107F. Low temperatures will continue to run above
normal, in the mid/upper 70s - potentially threatening record warm
minima.

Friday - Weekend:

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:

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 255 AM EDT Wed Jul 3 2024

Today-Sunday... 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...
(06Z TAFs)
Issued at 140 AM EDT Wed Jul 3 2024

VFR expected thru much of the TAF. Isolated SHRA cannot be ruled
out along the coast, mainly from MLB south thru 12z. Light
southerly flow or otherwise variable wind will resume around 10 kt
or less after 15z, backing ESE behind the ECSB. Again, iso/sct
SHRA/TSRA will form along the inland-moving breeze, with the
highest coverage across inland sites after 19z-21z. Activity is
expected to wane after 02z Thu. Brief MVFR/IFR conds may accompany
the most organized convection.

&&

.PRELIMINARY POINT TEMPS/POPS...
DAB  91  77  92  76 /  40  10  50  10
MCO  94  77  95  76 /  50  30  50  10
MLB  91  77  92  77 /  30  10  40  10
VRB  92  76  92  76 /  30  10  30  10
LEE  94  78  95  78 /  60  50  60  20
SFB  94  77  94  77 /  50  30  50  10
ORL  94  77  95  78 /  50  30  50  10
FPR  92  76  92  76 /  30  10  30  10

&&

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

$$

DISCUSSION...Heil
AVIATION...Schaper