680
FXUS62 KMLB 120822
AFDMLB

Area Forecast Discussion
National Weather Service Melbourne FL
422 AM EDT Mon May 12 2025

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

.KEY MESSAGES...
Issued at 411 AM EDT Mon May 12 2025

- A very soggy start to the work week as rounds of scattered to
  numerous showers continue ahead of an approaching front.

- Strong to marginally severe thunderstorms and excessive rainfall
  risks continue today.

- Drier conditions expected by Tuesday, with no rain chances the
  second half of the week, but in exchange very warm conditions
  are expected by late week and the weekend.


&&

.DISCUSSION...
Issued at 411 AM EDT Mon May 12 2025

Currently...Widespread moderate to heavy rainfall has overspread
the Florida peninsula early this morning. Modest shear has allowed
for weak organization of convection, with KMLB and neighboring
radars showing broad rotation in the lines of heavier showers,
despite the lack of lightning. RAP analysis attributes this to SRH
values increasing to 200-300 m2/s2 early this morning, and
indicates values further increasing towards 400 m2/s2 by daybreak.

Today-Tonight...The mid-level low and associated frontal system
over the Deep South finally lift northeast in response to a sharp
trough swinging into the western US and ridging building over
Mexico and Texas. Large scale ascent over the Florida peninsula
combined with anomalously high moisture will continue to support
rounds of heavy showers and storms through the evening. Primary
hazards continue to be a Slight (level 2 of 4) risk for excessive
rainfall, and a Marginal (level 1 of 5) risk for strong to severe
thunderstorms.

For the flooding threat, main issue will be any flooding prone
locations that receive multiple rounds of heavy rainfall through
the event. Southwesterly steering flow 20-35 kts will keep heavy
convection moving along with few if any boundaries for convection
to get hung up on, minimizing the threat for training rainfall.
Widespread rainfall accumulations of 1-3" are expected, with
locally high amounts of 4-5" possible through this evening. With
antecedent drought conditions, most locations will be readily able
to handle these rainfall amounts, especially given the
periodicity. That said, while training isn`t generally expected,
some banding leading to locally high rainfall amounts over a few
hours has been observed. Minor flooding could eventually develop
in poor drainage or low-lying areas, and heavier downpours will
lead to ponding of water on roads.

For the convective threats, models continue to show a
conditionally favorable threat for strong to marginally severe
thunderstorms. As mentioned before, veered wind profiles
contributing to high SRH values early this morning have supported
some storm organization, and will need to keep an eye on the
current activity until it pushes offshore, probably by around 7 AM.
Later today, the environment evolves as the front approaches and
pushes through central Florida. Drier air moves into the mid-upper
levels while the lower levels remain fairly moist, and
temperatures aloft cool a bit, slightly increasing lapse rates and
instability. In addition, any daytime heating we manage to get
would also contribute to destabilization. However, while
instability increases, SRH will decrease as shear becomes
uniformly southwesterly. Models roughly agree on band of deeper
convection with embedded lightning storms developing along and
ahead of the front, tracking through central Florida sometime
sometime between 1 PM and 10 PM (wide range due to low confidence
in timing), with the highest chances for stronger storms after 4
PM. Looks this this band will essentially close out the rainfall
event, with rain and storm chances quickly decreasing behind it.
Primary storm threats continue to be gusty winds 40-50 mph, with a
5% chance for locally damaging winds to 60 mph, small hail, cloud
to ground lightning, and locally heavy rainfall. In addition,
there is a low (2%) chance for a tornado, mainly along the coastal
corridor.

In addition, a High Risk of life-threatening rip currents
continues at the beaches, and small craft should continue to
exercise caution for with 15-20 kts in the local Atlantic waters.

Tuesday-Wednesday...The mid-level low continues to slowly lift
through the eastern US, as ridging aloft builds over the Gulf. The
time line for the cold front`s departure has accelerated a bit
since last night`s package, with pretty good model agreement the
boundary will have made it through most of ECFL by Tuesday
morning, as much drier air wraps into the surface low behind the
front, and tenuous high pressure starts building at the surface.
As a result, rain chances for Tuesday have come down
considerably, now just 20-40% with most CAMs very pessimistic.
Wednesday`s rain chances are even more on the ropes. Ended up
departing from guidance a bit and keeping a 20% for most of the
area to avoid over correction, but wouldn`t be surprised to see
these chances pulled back or outright gone in the next couple
forecast packages. Otherwise, daytime temperatures warming to near
normal after all being below normal from the cloud cover and
rainfall.

Thursday-Sunday...Dry and hot as ridging builds over the Gulf and
Florida, developing weak high pressure at the surface. Some nuance
in how the surface high interacts with the Atlantic high, and
whether the former remains discrete or gets absorbed into the
ridge axis of the latter. Temperatures climb well above normal
into the mid to upper 90s by the weekend with heat risk impacts
felt either way, but whether we see record warm heat is less clear
now. No mentionable rain chances at this time.

&&

.MARINE...
Issued at 411 AM EDT Mon May 12 2025

Today-Tonight...Poor boating conditions as a front pushing
through Florida today and the local Atlantic waters later tonight
keeps southeasterly winds around 15-20 kts and continues to
produce scattered to numerous showers and lightning storms. Seas
4-5 ft.

Tuesday-Friday...Generally favorable, albeit increasingly hot
boating conditions as the front over portions of the local
Atlantic waters finally departs and high pressure builds over the
area. W-SW winds 5-10 kts shift SSE-SE and increase to 10-15 kts
in the afternoons and evenings with the sea breeze circulation.
Seas 3-4 ft Tuesday subside to 2-3 ft Wednesday onward. Rain and
lightning storm chances linger into Tuesday and possibly
Wednesday, then dry conditions expected Thursday onward.

&&

.AVIATION...
(06Z TAFs)
Issued at 135 AM EDT Mon May 12 2025

High coverage of showers continues to overspread the area as of
around 5Z. Intensity of showers will vary at times, though MVFR
conditions look to prevail into Monday afternoon. Occasional IFR
conditions cannot be ruled out in stronger showers or any TS that
develop, though confidence in timing is too low to include a
mention at this time. Showers are forecast to continue into Monday
morning, with occasional periods of drier conditions, especially
between 14-19Z. Thus, have increase VIS for this period, though
MVFR CIGs will likely persist.

A cold front will make its way through the area in the afternoon
hours, with VCTS and TEMPOs included from 19-22Z along and north
of I-4 (with the exception of LEE) and 20-01Z for the coastal
terminals south of Cape Canaveral. Behind the front, VCSH may
linger for a few hours before diminishing, with drier conditions
into the overnight hours. S/SSE winds 9-12kts, with gusts up to
20kts along the coast, will veer SSW in the evening and overnight
hours.

&&

.PRELIMINARY POINT TEMPS/POPS...
DAB  80  67  86  66 /  80  40  30  10
MCO  80  68  86  67 /  80  40  20   0
MLB  81  69  86  67 /  80  60  20  10
VRB  83  69  87  66 /  80  70  30  10
LEE  80  68  85  68 /  80  30  20   0
SFB  81  68  87  67 /  80  40  20   0
ORL  81  69  86  68 /  80  40  20   0
FPR  82  69  86  66 /  80  70  30  20

&&

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

$$

DISCUSSION...Haley
AVIATION...Leahy