037
FXUS62 KMLB 161830
AFDMLB

Area Forecast Discussion
National Weather Service Melbourne FL
230 PM EDT Sat Aug 16 2025

...New KEY MESSAGES, DISCUSSION, MARINE...

.KEY MESSAGES...
Issued at 230 PM EDT Sat Aug 16 2025

- Unusually Hot: A Heat Advisory is effect through 7pm this
  evening for Volusia, Lake, Orange, Seminole, Osceola, and
  Brevard counties. Peak heat index values are forecast between
  105-109 degrees.

- Beach & Boating Hazards Next Week: Swells from Major Hurricane
  Erin to bring a HIGH risk of life-threatening rip currents
  starting Monday. This threat - along with higher surf, the
  potential for minor beach and dune erosion, and hazardous seas -
  will likely continue through much of the upcoming work-week.

- More Unsettled: Showers and lightning storms will become more
  widespread late this weekend, especially near, north, and west
  of the I-4 corridor. Slow storm motions will contribute to a low
  risk of localized flooding.

&&

.DISCUSSION...
Issued at 230 PM EDT Sat Aug 16 2025

Today-Tonight...Emphasis remains on heat impacts this afternoon.
High temperatures will realize a few degrees above normal with M90s
across the interior and L90s along the coast. Deep moisture, esp
north/west of the Treasure Coast and Okeechobee County, will
contribute to peak heat index values between 105 to 109 degrees. A
Heat Advisory remains in effect from Osceola and Brevard northward.
A Major to Extreme HeatRisk exists for the Orlando metro and areas
of Lake County. This level of heat affects anyone without adequate
cooling and hydration. Temperatures will be "slow" to cool through
the evening with values lingering in the 80s beyond 10 PM. Warm low
temperatures only fall into the M-U70s overnight with conditions
muggy.

A weak area of low pressure will push off of the southeast U.S. with
deep moisture pooling along and just south of it to include much of
ECFL. Aloft, mid-level high pressure loses its grip across the
region as witnessed by height falls. Highest shower and lightning
storm chances (50-70%) will favor near/north of I-4 this afternoon
and evening. Drier conditions favored southward toward Lake Okee and
the Treasure Coast. With DCape values in excess of 1000 J/Kg, a few
stronger storms may be capable of producing wind gusts of 45-50 mph
locally. Continued weak steering flow will allow for rainfall
accumulations of 1-3 inches in slow-moving storms, with minor and
nuisance flooding a concern.

Previous Extended Forecast Discussion Modified...

Sun-Wed...Major Hurricane Erin will track west-northwest, remaining
just north of the outer waters of Puerto Rico, early Sunday. Storm
movement will gradually slow as it begins an anticipated northward
turn into Mon. Ensembles remain well-clustered, keeping distant Erin
well east of Florida. In addition, Erin is forecast to grow
significantly in size as it tracks northward across the Atlantic and
interacts with more shear, undergoing a series of eyewall
replacement cycles. While direct impacts are not forecast locally,
significant coastal and marine hazards are expected. Increasing long
period swell (~10-14 seconds) is forecast to arrive by early Monday,
with several days of numerous, strong, life-threatening rip currents
and rough surf will also be present at area beaches. Offshore seas
building to 8-12 ft will become dangerous to mariners by mid-week.
Will continue to monitor the potential for coastal erosion during
times of high tide as large breaking waves arrive along the ECFL
coastline.

Moisture sagging into central Florida should increase rain chances
areawide Sun/Mon with PoPs near to just above normal (50-70%). As
Erin passes well offshore, north-northeast flow will advect a drier
airmass across east central Florida Tue/Wed. The drier air will keep
highest rain chances stymied near 40-50% Tue and 50-60% for Wed.

Temperatures decrease only slightly compared to prior days, mostly
ranging the L90s along the coast and L-M90s inland. Peak heat index
values will continue near to just below Heat Advisory criteria Sun.
A more, if only slight, noticeable reduction in heat indices will be
observed Tue and Wed due to slightly drier air. Low temperatures in
the M-U70s, with some normally cooler rural locations realizing L70s.

Thu-Fri...Rain chances continue to trend near normal (50-60%) as
moisture remains fairly high and WRLY flow takes afternoon/evening
storms back to the coast with plentiful boundary interactions across
the eastern FL peninsula. Mid-level ridging extends westward from
the WRN Atlc across the central FL peninsula, with only a few subtle
impulses and 500 mb temps -5C to -6C. Long period swells will be
slow to recede as Erin lifts northeastward away from the ERN
Seaboard. A lingering "strong" rip current threat is forecast to
continue at all local beaches. High temperatures hold in the L90s
along the coast with M90s across the interior.

&&

.MARINE...
Issued at 230 PM EDT Sat Aug 16 2025

Thru Thu...Generally favorable boating conditions continue this
weekend. Light and variable winds become onshore near the coast as
the sea breeze develops each afternoon. Seas 1-3 ft. Isolated to
scattered showers and lightning storms will increase in coverage
on Sun.

Boating conditions begin to deteriorate Mon as Major Hurricane Erin
passes well east of the local Atlantic waters. Northeast winds
increase to around 10-15 kts on Mon. Long period swell associated
with distant Erin will build seas 6-8 ft offshore Mon night becoming
increasingly hazardous Tue and Wed. Seas peak around 6-9 ft near
shore and 8-12 ft offshore by Wed morning. Winds diminish Thu with
seas slow to subside into late week. Isolated to scattered showers
and storms are forecast near shore, with higher coverage expected
offshore.

In addition, hazardous conditions will exist at inlets during the
outgoing tide cycle due to the developing long period swell produced
by Erin.

&&

.AVIATION...
(18Z TAFs)
Issued at 141 PM EDT Sat Aug 16 2025

Already starting to see some convective development near to NW of
I-4 early this afternoon. Greatest shower/storm chances (up to
40-60%) will exist across these inland areas today. Have VCSH to
start for inland TAF sites (KMCO/KSFB/KLEE/KISM) transitioning to
VCTS at 20Z, with tempo groups for 3SM TSRA ranging from 21-24Z.
Along the coast kept mention of VCTS to start for KDAB/KTIX as sea
breeze is moving inland and this is where greater moisture and
better potential exists for developing showers and storms near to
just west of these terminals from 18-23Z. From KMLB south, drier
airmass will keep rain chances too low for any mention of even
VCSH/VCTS at these sites for today.

Winds at the coast will be out of the E/SE up to 10 kts behind the
sea breeze, with winds variable around 5 knots inland ahead of
this boundary. However, gusty and variable winds will be possible
from any storms or outflow boundaries pushing through these sites.
Winds and convection will diminish into this evening.

&&

.PRELIMINARY POINT TEMPS/POPS...
DAB  76  90  77  89 /  30  70  30  50
MCO  77  94  76  94 /  40  70  20  70
MLB  78  92  77  92 /  10  50  20  50
VRB  76  93  75  92 /  10  40  20  50
LEE  77  92  77  92 /  50  70  30  60
SFB  77  93  77  92 /  40  70  30  60
ORL  78  93  77  93 /  40  70  20  60
FPR  74  93  74  92 /  10  40  20  50

&&

.MLB WATCHES/WARNINGS/ADVISORIES...
FL...Heat Advisory until 7 PM EDT this evening for FLZ041-044>046-053-
     141-144-247-347-447-547-647-747.

AM...None.
&&

$$

DISCUSSION...Sedlock
AVIATION...Weitlich