491 
FXUS62 KMLB 130253
AFDMLB

Area Forecast Discussion
National Weather Service Melbourne FL
1053 PM EDT Sun Sep 12 2021

.UPDATE...

Current radar imagery shows later precipitation development than
usual this evening. Scattered showers with isolated embedded
lighting strikes have developed near Cape Canaveral with an
increase in coverage building towards Osceola and central Brevard
counties. A few showers are also located just off the Treasure 
Coast. Upper-air analysis charts show the subtropical jet 
stretching from eastern TX, southern AR, and into southern GA. 
Moisture can be seen on water vapor imagery advecting into the 
region as moisture rotates anticyclonically along the peripheral 
of the subtropical jet stream. A surface high situated north of 
Florida has continued to produce onshore flow to east- central 
Florida through this evening. Additionally, analysis charts at the
500mb level show a minor shortwave over the western Atlantic. 
Observed skew-t soundings this evening indicated that there's 
plenty of moisture still present with values greater than 2," weak
bulk shear, and high instability with CAPE values greater than 
3,500 J/kg. Also of note, the greatest surface converge is 
currently located along and south of Cape Canaveral. 

With the increase in moisture, weak minor shortwave, surface 
convergence, and unstable atmosphere in place, precipitation is 
expected to linger a bit longer into the night than usual. With 
that said, POPs have been increased to account for the later 
precipitation development. The best chance for rain through the 
late evening and early morning hours will continue to be where the
greatest surface convergence and moisture is located which would 
be across northern Brevard, southern Volusia, Orange, and Osceola 
counties. Precipitation will dwindle over the aforementioned areas
by the early morning hours. Further development is then expected 
across the southern Atlantic waters before moving onshore near the
Treasure Coast during the early morning hours to kick off the 
workweek. Temperatures overnight are on track to reach the mid 70s
to low 80s with the warmest temperatures forecast near the coast.

&&

.AVIATION...

Predominantly VFR conditions tonight and into Monday morning, with 
winds out of the east at 8-12 knots easing to 4-6 knots. Isolated 
coastal showers, with one or two over performing thunderstorms, that 
may drop CIGS to MVFR are streaming onshore in the vicinity of the 
Space and Treasure Coast terminals. Coverage is light so going with 
VCSH and no TEMPOs. Only light showers with no categorical impacts 
are reaching inland terminals. Monday, easterly winds freshen to 8-
12 knots again. Expecting an early start to, but relatively low 
coverage of, convection through the early afternoon and into the 
evening, with only isolated to scattered showers and
thunderstorms.

&&

.PREV DISCUSSION... /issued 310 PM EDT Sun Sep 12 2021/ 

Current-Tonight...Scattered showers and lightning storms ongoing,
mainly from Melbourne northward. Cell movement is generally to 
the west around 5-10 mph, however some storms have erratic motion 
due to outflow boundaries. Widespread mid to high level clouds are
streaming across the local area, emanating from Tropical Storm 
Nicholas, which is centered well to the SW over the Bay of 
Campeche. Any lingering showers and lightning storms should be 
west of the local area by sunset, with a small (around 20 percent)
chance for coastal showers tonight. Mild temperatures expected 
tonight, with overnight lows in the low to mid 70s inland, and 
upper 70s along the coast. There remains a high risk for dangerous
rip currents at area beaches today. Entering the surf is not 
advised. 

Monday-Wednesday... (Modified Previous Discussion) High pressure 
along and offshore of the eastern US to begin the week, with mid-
level high pressure over the eastern GOMEX. Meanwhile, the ridge 
axis will remain well north of the local area. Thus, onshore flow 
will persist, with winds around 10mph each afternoon. PWATs 
remaining around 2" or less through mid-week, as the overall flow 
keeps much of the afternoon convection on the western half of the 
peninsula. Nonetheless, with ample moisture to tap from, have 
maintained near normal PoPs at around 40-50% Monday, before a slight 
increase to around 50-60% on Tuesday and Wednesday. While convection 
will largely end for east central Florida by sunset, onshore flow 
will keep the possibility of at least a slight chance of showers and 
even a storm or two along the immediate coast overnight, should any 
offshore activity drift inland. Highs continuing in the upper 80s to 
low 90s, with morning lows in the mid-70s, though upper 70s will be 
possible along the coast.

Thursday-Saturday...(Previous Discussion) As high pressure moves off 
of the east coast of the US, it will weaken the high pressure 
influence over the local area after mid-week. Meanwhile, models 
continue to suggest a tropical wave moving northward towards the end 
of the work week. Luckily, while they disagree in timing and 
strength, they continue to agree that this feature will remain well 
east of the Bahamas. Nonetheless, as the wave moves northward, it 
looks to drag an inverted trough through the local area. This will 
allow winds to veer more southeasterly, ushering in deep moisture to 
the Florida peninsula. PWATs could approach 2.2-2.3", which is well 
above normal when compared to XMR sounding climatology. So, higher 
than normal shower and storm chances will be possible to end the 
work week and start the weekend. However, with confidence being 
lower since this would be the day 5-7 time frame, have capped PoPs 
at around 50-60%. Afternoon highs remaining in the upper 80s to low 
90s, with morning lows in the mid to upper 70s

&&

.MARINE...

Current-Tonight... Scattered showers and lightning storms ongoing 
across the Atlantic waters this afternoon. Cell movement is 
generally towards the west around 5-10 KT. Widespread mid to high 
level clouds continue to stream across the local waters this 
afternoon. Current buoy 41009 observations show seas are 3 ft with 
winds out of the ENE around 10 KT. Seas will continue to diminish 
through the overnight hours, with seas 3-4 ft this afternoon, and 2-
3 ft after midnight. The long period swell will likewise, continue 
to diminish through the overnight hours. Easterly flow will persist 
through the time period with wind speeds around 10 KT. Rain chances 
will diminish after sunset, however isolated showers will be 
possible along the coast overnight. 

Monday-Thursday...(Previous Discussion) Persistent onshore flow 
through mid-week, as a high pressure ridge axis over the eastern 
US/western Atlantic remains well north of the area. By Thursday, a 
possible tropical wave well east of the Bahamas could veer wind 
southeasterly across the local Atlantic waters. Afternoon showers 
and storms will largely be pushed to the western half of the 
peninsula. However, chances will increase from the beginning of the 
work week to the end. Winds around 10-12kts or less through the 
period, with seas 2-3ft.

&&

.PRELIMINARY POINT TEMPS/POPS...
DAB  76  88  75  88 /  10  30  10  50 
MCO  77  92  76  91 /  40  50  10  50 
MLB  78  88  76  88 /  40  40  20  50 
VRB  77  90  76  90 /  30  40  30  60 
LEE  76  92  76  91 /  10  40  10  50 
SFB  75  90  75  90 /  20  40  10  50 
ORL  76  91  76  90 /  40  50  10  50 
FPR  76  88  74  88 /  40  40  30  60 

&&

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

$$

Fehling/Negron/Haley