437
FXUS62 KMLB 121102
AFDMLB

Area Forecast Discussion
National Weather Service Melbourne FL
702 AM EDT Wed Aug 12 2026

...New AVIATION...

.KEY MESSAGES...
Issued at 255 AM EDT Wed Aug 12 2026

- Heat Advisory issued for all of east central Florida today from
  11am to 8pm for heat index values up to 108F-112F degrees;
  Remember to practice heat safety!

- A Major Heat Wave is expected with Hot and humid conditions for
  the next week. Maximum heat index values will reach near or at
  Heat Advisory criteria (108F+) each day through at least Friday;
  A Heat Advisory is likely for at least areas of east central
  Florida through the end of the week

- Mostly below normal rain chances this week. Drier air aloft due
  to a Saharan Dust Layer will support strong gusty winds in any
  lightning storms each day.

&&

.DISCUSSION...
Issued at 255 AM EDT Wed Aug 12 2026

Currently-Tonight... KMLB radar imagery shows dry weather over east
central Florida. GOES-19 satellite imagery and local observations
indicate clear to partly cloudy skies. Temperatures are currently in
the mid 70s to low 80s with dew points in the mid to upper 70s.
Analysis charts show a mid/upper level high over the Gulf with 500mb
heights at 594dm (90th percentile), as well as a mid/upper level
trough over the eastern US coast and the western Atlantic. At the
surface, high pressure (~1020mb) is centered over the eastern
Gulf. Meanwhile, the 00Z XMR sounding indicates drier air than
normal for this time of year, especially in the mid to upper
levels.

The airmass is not expected to change much today from the 00Z XMR
sounding from last night, therefore, the dry air in the mid to upper
levels is expected to keep rain chances (20-50%) below normal
today. Isolated to scattered showers and lightning storms are
forecast to develop in the afternoon and evening as collisions
occur between west-northwest surface winds, the east coast sea
breeze, and outflow from previous showers/lightning storms. Rain
chances diminish by around 8PM. West-northwest winds at 4-8mph are
expected to turn onshore in the afternoon and evening with the
east coast sea breeze mainly to the south of I-4. Hi-res guidance
indicates MLCAPE up to 2,000-3,800 J/kg, 0-6km shear up to
10-30kts, PWATs up to 1.80-2.20", and conditionally unstable mid
level lapse rates. The aforementioned parameters are sufficient
for an isolated strong storm or two to develop which are capable
of frequent lightning, wind gusts up to 30-50mph, and heavy
rainfall (up to 1-2") if they can overcome the dry air in the
mid/upper levels. A hot and very humid day is expected with
afternoon highs in the low to mid 90s. Additionally, a Heat
Advisory has been issued for all of east central Florida from 10AM
to 8PM for heat index values up to 108-112F degrees. Remember to
take frequent breaks from the heat, drink plenty of fluids, wear
light colored clothing, and shift outdoor work away from the
hottest parts of the day between the hours of 10am to 4pm. Near to
above normal lows in low 70s to near 80F degrees are forecast
overnight.

Thursday-Saturday... A similar and persistent forecast is expected
with a continuation of the heat wave through the week with little
change in the weather pattern. The 500mb ridge is forecast to expand
as it builds north and east over the Gulf, as well as the southern
US through Saturday. The mid/upper level trough over the western
Atlantic will fill as this occurs. 500mb heights over the southern
US and the state of Florida are forecast to reach the maximum
percentile (598dm) for this time of year by Friday evening into
Saturday. Below normal rain chances (30-40% Thursday, 20-50%
Friday, and 10-40% Saturday) will continue through Saturday with
mostly dry air in the mid to upper levels. Light west-northwest
winds at 4-8mph are forecast to back more southerly each day.
Winds will back onshore (mainly south of I-4) each afternoon and
evening with the east coast sea breeze. Isolated to scattered
showers and lightning storms are forecast to develop in the
afternoons and evenings as collisions occur between sea breezes
and outflow from previous showers/lightning storms. The potential
exists for isolated strong storms capable of frequent lightning,
wind gusts up to 30-50mph, and heavy rainfall (up to 1-3"). Hot
and humid conditions will continue with afternoon highs in the low
to mid 90s and heat index values near or at Heat Advisory
criteria (heat index 108F+ degrees). A Heat Advisory is likely to
be issued for at least areas of east central Florida through at
least Friday. A widespread Moderate to Major HeatRisk with
widespread Extreme HeatRisk mainly north of the Treasure Coast
exists each day. A Major and Extreme HeatRisk effects anyone
without adequate cooling and hydration.

Sunday-Tuesday... A very persistent forecast is expected with the
heat wave forecast to continue through the forecast period.
Ensembles, LREF-clusters, and deterministic models are in good
agreement that the 500mb ridge will build over the eastern CONUS
through Sunday before gradually shifting west-southwest on Monday
into Tuesday. 500mb heights at the maximum percentile (597dm) are
forecast through at least Sunday. The NBM has the probability of
temperatures of 95F degrees or greater at 25%-80% each day with the
greatest probabilities at inland locations west of I-95, as well as
Stuart and Titusville. Additionally, the probability of a Major
HeatRisk is likely to very likely for much of east central Florida
each day; the probability of an Extreme HeatRisk is 20-50% over
areas of Lake, Orange, Osceola, and Volusia counties each day. More
information on HeatRisk can be accessed at
wpc.ncep.noaa.gov/heatrisk. Below normal rain chances are expected
each day with chances at 40% or less.

&&

.MARINE...
Issued at 255 AM EDT Wed Aug 12 2026

Currently-Tonight... Favorable boating conditions are expected.
Isolated to scattered generally offshore moving showers and
lightning storms are forecast in the afternoon and evening. The
potential exists for a strong storm capable of wind gusts at 34kts
or greater. West winds at 5-15mph will turn south over the local
Atlantic waters into the afternoon and evening waters, as well as
onshore near the coast at 5-10mph. Seas up to 1 ft nearshore and
up to 1-2ft offshore (20-60n) are expected.

Thursday-Sunday... Favorable boating conditions are expected to
continue through the forecast period with high pressure over east
central Florida. Below normal rain chances are forecast to
continue with mostly dry conditions each day. However, isolated
offshore moving showers and lightning storms cannot be ruled out
on Thursday and Friday. West winds at 5-10mph are forecast to
turn south over the local Atlantic waters into the afternoon and
evening waters, as well as onshore near the coast at 5-10mph on
Thursday. South-southwest winds at 5-15mph are expected to back
south-southeast each afternoon and evening Friday to Sunday. Seas
up to 1 ft nearshore and up to 1-2ft offshore are forecast to
build to 1-2ft nearshore on Friday.

&&

.AVIATION...
(12Z TAFs)
Issued at 610 AM EDT Wed Aug 12 2026

VFR conditions outside of confection through the TAF period.
Light and variable winds will become west to northwest and
increase to 5-10 KT by mid-morning. The east coast sea breeze will
form in the afternoon, backing the winds onshore (E-SE) along the
coast. Isolated to scattered showers and storms are forecast to
form along the east coast sea breeze, with highest coverage of
storms expected to be along the coast this afternoon and evening.
Have maintained VCSH across the interior sites starting at 17Z and
along the coast starting 16/17Z from VRB southward, and starting
at 18/19Z from MLB northward. Have VCTS starting along the coast
19/20Z and have added at MCO and SFB starting at 20Z. Have
maintained TEMPOs for MVFR conditions in TSRA starting at 20/21Z
along the coast. Have added PROB30 for SFB starting at 00Z due to
lates CAMs. Any lingering activity will diminish after 03Z
Thursday. Winds will become light by 02Z across the interior, and
by 03Z along the coast.

&&

.PRELIMINARY POINT TEMPS/POPS...
DAB  94  77  94  77 /  30  20  40  20
MCO  96  77  97  77 /  20  20  40  20
MLB  94  77  93  77 /  20  20  30  20
VRB  94  75  94  76 /  30  20  30  10
LEE  96  77  96  78 /  20  20  40  20
SFB  96  77  96  78 /  20  20  40  20
ORL  96  77  96  78 /  20  20  40  20
FPR  94  75  94  76 /  40  20  30  10

&&

.MLB WATCHES/WARNINGS/ADVISORIES...
FL...Heat Advisory from 10 AM this morning to 8 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...Fehling
AVIATION...Watson