Killarney, Florida Weather Forecast Discussion

670
FXUS62 KMLB 021934
AFDMLB
Area Forecast Discussion
National Weather Service Melbourne FL
334 PM EDT Thu Oct 2 2025
...New KEY MESSAGES, DISCUSSION, MARINE...
.KEY MESSAGES...
Issued at 324 PM EDT Thu Oct 2 2025
- Wet weather pattern next several days with increased
  winds/moisture off the Atlantic supporting locally heavy
  rainfall. Localized flooding will be a concern, especially along
  the coast where a Flood Watch has been issued through Saturday
  night.
- Prolonged, dangerous beach and marine conditions will continue
  into the weekend with life-threatening rip currents, high surf
  with breaking waves of 5 to 8 feet, and minor to moderate beach
  erosion especially near times of high tide&&
.DISCUSSION...
Issued at 324 PM EDT Thu Oct 2 2025
Rest of Today-Tonight...There is increasing potential for locally
heavy rainfall leading to flooding along the coast, the starting
on the Treasure Coast this afternoon, then gradually shifting
northward Friday and Saturday, and a Flood Watch has been issued
for all East Central Florida coastal counties through Saturday
night. For the rest of today and tonight, an axis of high moisture
lifting northward in freshening onshore flow from a tightening
pressure gradient on the south side of high pressure over the
eastern seaboard will support rounds of onshore moving showers,
especially along the Treasure Coast. 12Z HREF guidance calls for
mean rainfall amounts of 2-5", and 90th percentile values over 6",
which would lead to flooding of roads, urban low- lying, and poor
drainage area if realized. Individual HRRR runs have called for
some eye watering rainfall amounts over 10" which could result in
greater flooding impacts, but there is very low confidence in that
scenario. Chances for overnight heavy rainfall and flooding along
the coast corridor decrease northward, but could still seem some
1-3" rainfall amounts with locally higher values. The threat for
heavy rainfall and flooding drops off inland of the coastal
corridor where coastal convergence is maximized, but bands of
showers will be expected across the rest of the area through the
night, with a non-zero threat for heavy rainfall and minor
flooding.
Beach and marine conditions remain hazardous as onshore flow
increases again and we continue to see long period swell produced
by Imelda and Humberto reach the coast. High Surf Advisories, Rip
Current Statements, and Small Craft Advisories remain in effect.
Entering this life-threatening surf is not advised.
Friday-Saturday...There is potential for a disturbance to develop
over the Atlantic waters near Southeast Florida along the remnant
frontal boundary and axis of high moisture. The National
Hurricane Center currently has a low (10%) chance of tropical
development over the next 7 days, but any development of the
feature, closed low or even an open wave, would cause the pressure
gradient along the East Central Florida coast to further tighten
and increase onshore flow. Easterly winds 15-25 mph with higher
gusts would worsen already hazardous beach conditions, and in a
very high moisture and low instability environment supporting
efficient rain makers, further enhancing the potential for
locally heavy rainfall leading to flooding. This threat will be
highest along the coastal corridor where coastal convergence will
cause onshore moving showers and storms to pile up. Rounds of
these showers are forecast to produce widespread rainfall amounts
of 1.5-3" along the coast, and locations that see multiple rounds
of heavy rainfall and/or training of showers have a medium (40%)
chance of locally high amounts of 3-5", and there is a low (10%)
chance for one or two locations to receive 5-8" of rainfall
through Sunday morning. Areas where soils are reaching saturation
from previous heavy rainfall will have higher sensitivity to
additional rainfall, particularly coastal Volusia and portions of
the Treasure Coast. Confidence where these locally higher rainfall
amounts will occur is low, but there has been a fairly consistent
signal for the coast south of the Cape Friday, shifting northward
to include most of the coast Saturday, with this highest over all
chances Saturday. WPC has issued a Slight (level 2 of 4) for
excessive rainfall/flash flooding in these aforementioned areas
while the remaining parts of the coast are in a Marginal (level 1
of 4) risk. All that sad, widespread flooding is not expected, and
most locations are going to see the lower end of these forecast
values. Rainfall amounts will vary significantly across relatively
small areas, and we may see cases where only a couple
neighborhoods see significant rainfall that leads to flooding.
Showers are expected to push inland, but once they get west of
that coastal convergence zone the risk for excessive rain
decreases, though is non-zero. Most likely inland rainfall amounts
are 0.5-2.0", but some locally higher amounts are possible. On
the St Johns River, Astor is forecast to reach Moderate Flood
stage by the weekend, and heavy rainfall could cause rises on
other sections of the basin.
At the beaches, large breaking wave of 5-8 ft are will continue
to pound the coast, producing high/rough surf and numerous life-
threatening rip currents. While overall water levels are currently
forecast to remain below coastal flood criteria, wave run-up to
the dune will still cause minor to moderate erosion near the times
of high tide. Numerous coastal hazard products remain in effect,
including High Surf Advisories, Rip Current Statements, and Small
Craft Advisories.
Sunday-Wednesday...Forecast confidence in the long-term decreases
due to uncertainty how (of if) the disturbance evolves. Guidance
agrees it should depart the area by Monday, but how developed it
becomes, what direction it goes is less clear, and how much
moisture is dragged across the area in its wake is less clear. For
what it`s worth, 12Z guidance is in decent agreement for a quick
north-northwestward track across peninsula as an open wave or very
weak closed low, continuing moderate onshore/easterly flow with
the GFS opting for higher moisture and the ECM lower. As a result
there is a continued risk for excessive rainfall along the coast
corridor through at least Monday. Very high rain chances Sunday
gradually decrease through the week.
&&
.MARINE...
Issued at 324 PM EDT Thu Oct 2 2025
(Modified Previous Discussion) NE to E pressure gradient will
continue to tighten over the local Atlc waters the rest of today
around high pressure wedging down the eastern seaboard. There is
also potential for a weak disturbance to develop over or just
south of the waters this weekend. Thus, hazardous to dangerous
boating conditions are forecast to continue across the local
Atlantic waters over the next several days. Wind speeds 15-25
knots with combined seas (wind wave and swell) of 7-12 feet. Small
Craft Advisory (SCA) will continue through Sat for all the
waters. There should be some relaxation of the pressure gradient
Sun-Mon as winds turn E-SE but seas will be slow to subside. An
extension of the SCA appears likely to include Sunday, at least
for the offshore waters, but given some uncertainty over
development of the disturbance, have opted to not extend with this
forecast cycle.
Meanwhile, moisture increases locally which will promote a high
coverage of showers and isolated storms containing heavy rain and
cloud to water lightning. Brief waterspouts will also be possible
especially where cell mergers occur or spin-ups driven by coastal
convergence.
&&
.AVIATION...
(18Z TAFs)
Issued at 140 PM EDT Thu Oct 2 2025
Onshore moving showers persists this afternoon, with VCSH at all
terminals starting at 18Z. Showers will begin to decrease across
the north later this afternoon, with VCSH ending at DAB and LEE
at 19Z, which will continue through the overnight. VCSH will end
at 01Z for all the interior sites through the overnight hours,
with VCSH persisting along the coast tonight. Breezy northeast to
east winds this afternoon at 10-15 KT with gusts 20-30 KT. Winds
will begins to decrease to around 10KT across the interior into
the evening and overnight, with the coast staying around 10-15 KT
with gusts 20-25 KT. NE winds will increase once again by mid
morning Friday, with speeds 10-15 KT with gusts 20-25 KT. Have
VCSH starting at 15Z on Friday for all sites and persisting
through the TAF period. Mainly VFR conditions with brief MVFR
conditions in showers.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB  73  82  73  82 /  40  60  50  70
MCO  73  84  73  84 /  30  60  40  70
MLB  75  83  75  83 /  40  70  60  70
VRB  74  83  75  84 /  60  70  70  70
LEE  72  84  72  83 /  10  40  30  60
SFB  73  83  73  83 /  30  50  50  70
ORL  73  84  73  83 /  30  50  40  70
FPR  74  83  74  84 /  70  70  70  70
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...Flood Watch through Sunday morning for FLZ041-141-154-159-164-
     247-254-259-264-347-447-547-647-747.
High Surf Advisory until 4 AM EDT Sunday for FLZ141-154-159-164-
     347-447-647-747.
AM...Small Craft Advisory until 4 AM EDT Sunday for AMZ550-552-555-
     570-572-575.
&&
$$
DISCUSSION...Haley
AVIATION...Watson

NWS MLB Office Area Forecast Discussion