048
FXUS62 KMLB 162021
AFDMLB

Area Forecast Discussion
National Weather Service Melbourne FL
421 PM EDT Thu May 16 2024

...Isolated Strong Storms this Evening Across the Far South...
...Warming Temperatures into this Weekend with Heat Index Values
as High as the Low 100s....

.DISCUSSION...
Issued at 414 PM EDT Thu May 16 2024

Thru Tonight...East coast sea breeze has formed this aftn and is
pinned near the coast due to the westerly flow. There is also a
Lake Okeechobee breeze boundary extending eastward across southern
St Lucie county. GOES-16 total precip water product shows pwats
around 1.8" across this area with much drier air across our
northern FA. So it is not surprising that the CAMs continue to
show an increase in showers and storms along the Treasure coast
next few hours given the moisture, strong heating and boundary
interactions. Any storms that form in St Lucie or Martin counties
will be capable of hail, strong wind gusts and very heavy rain. A
brief tornado/waterspout also cannot be ruled out given the
locally enhanced low level helicity provided by the sea breeze
boundary. Convective threat will end by 10 pm and a quiet
overnight is forecast. Added patchy fog across some portions of
the area to account for the stalled frontal boundary.

Fri...Some hi-res guidance shows a small MCS tracking E/SE across
the NE Gulf early in the day, weakening as it reaches our northern
sections during the late morning. Meanwhile, the frontal boundary
will begin to lift back northward along with its assocd band of
moisture. So have drawn a small 20 PoP across the area for
isolated showers and storms mainly in the afternoon. Max temps
will be hot with widespread mid 90s, even lower 90s at the coast
due to a delayed sea breeze onset. With the increasing
dewpoints/humidity, it will feel more oppressive with peak heat
indices 100-105.

Saturday-Monday... A mid/upper level ridge will build over the
Carribean and the state of Florida through Saturday with 500mb
heights expected to reach 592dm over south-central Florida Saturday.
Deep south-southwest flow in place with temperatures in the low to
upper 90s and dew points in the low to mid 70s will result in some
of the highest heat index values this season with values forecast at
or just below heat index criteria Saturday afternoon (108 degrees or
higher). A mix of sun and clouds is forecast with a moderate to high
Heat Risk and High to Extreme Wet Bulb Globe Temperatures (WBGT).
This level of heat for this time of year affects anyone without
adequate cooling and/or hydration, especially those working
outside and/or those in direct sunlight for extended periods of
time. Remember to take breaks from the heat and to hydrate
frequently if spending extended time outdoors this weekend. The
sea breeze is expected to push inland and be confined to eastern
Volusia, eastern Seminole, eastern Orange, eastern Osceola, and
near the Treasure Coast. Isolated to scattered showers and
lighting storms are expected to develop along the sea breeze as it
collides with the west coat sea breeze into the afternoon hours.
Drier air in the mid to upper levels will be a limiting factor for
any potential strong storms to develop with gusty winds and cloud
to ground lightning strikes the main concerns.

The previously mentioned ridge is forecast to breakdown Sunday as a
shortwave trough deepens over the Southeastern US. South to
southwest winds will increase Sunday with a 25-35kt low level jet
forecast to develop ahead of a cold front which is forecast to move
east-southeast across central Florida Sunday night into Monday.
South to southwest winds at 10-15mph with gusts to 25mph are
forecast. Isolated showers and lightning storms are forecast to
develop well ahead of a cold front situated over north Florida
Sunday morning, mainly along and to the north of I-4 before
scattered showers and lighting storms (PoPs ~40-50%) develop to
the south into the afternoon and evening Sunday. Forecast
soundings show that dry air (especially in the upper levels) may
again be a limiting factor. However, isolated strong storms cannot
be ruled out with high instability and moderate bulk shear in
place.

The main hazards associated with any strong storms that develop
will be wind gusts to 40-50mph, small hail, and cloud to ground
lightning strikes. Scattered showers and lighting storms are
forecast into Monday as the front slowly sags southeast across
east central Florida. Afternoon highs are forecast to reach the
upper 80s to low 90s north of I-4 and the low to mid 90s to the
south with heat index values in the mid 90s to low 100s. Low
temperatures are forecast to reach the low to upper 70s Saturday
and Sunday, then the upper 60s to mid 70s Monday.

Tuesday-Thursday... Low pressure will be slow to depart over the
western Atlantic with some of the guidance showing the low
strengthening offshore of the Southeastern US into Tuesday.
Northeast flow Tuesday is expected to veer east Wednesday and
southeast Thursday as high pressure builds over the eastern Gulf
of Mexico and the state of Florida through Thursday. Isolated to
scattered showers and lightning storms are forecast Tuesday before
daily sea breeze driven isolated showers and lightning storms
Wednesday and Thursday afternoons. Afternoon highs are forecast to
trend warmer each afternoon with the low to upper 80s along the
coast and the upper 80s to low 90s inland west of I-95 Tuesday.
Temperatures are then expected to rise into the mid 80s to low 90s
Wednesday and the low to upper 90s Thursday under mostly sunny
skies. Low temperatures are forecast to drop into the mid 60s to
low 70 under mostly clear skies.

&&

.AVIATION...
(18Z TAFs)
Issued at 147 PM EDT Thu May 16 2024

E to SE wind shift will occur at coastal terminals behind the sea
breeze through 22Z. Isold TSRA are possible FPR-SUA and have
inserted VCTS there btwn 20Z-24Z. Late tonight, have indicated
MVFR VSBYs at fog prone terminals VRB and FPR INVOF stalled
frontal boundary. On Fri, the front begins to return northward. A
west to southwest flow 5-10 knots will turn onshore (SE) at
coastal terminals aft 17Z.

&&

.MARINE...
Issued at 147 PM EDT Thu May 16 2024

Tonight/Fri...Frontal boundary draped across the southern waters
will remain nearly stationary tonight then begin to lift northward
Friday. Onshore flow near the coast into this evening behind a sea
breeze then flow becomes S/SW overnight less than 10 knots.
Isolated lightning storms are possible along the Treasure coast
through 8pm. On Fri, winds become S/SE 10-12 knots nearshore
behind the seabreeze and 7-10 knots offshore. Seas 1-2 FT.

Saturday-Monday... High pressure will build over the state of
Florida through Saturday before a cold front moves across the local
waters Monday. South to southwest winds at 10 to 15kts are forecast
to back southeast into Saturday afternoon and veer southwest
Sunday at 12-18kts. Winds are forecast to veer west-northwest
Monday at 8-12kts. Seas are forecast to build to 1-3ft Saturday,
2-4ft Sunday, and 3-5ft Monday. Scattered showers and lightning
storms are forecast mid morning and into the afternoon Saturday. A
higher chance for scattered to numerous showers and lightning
storms exists Sunday into Monday ahead of a cold front. Isolated
to scattered storms will be capable of gusty winds, small hail,
and cloud to water lightning strikes.

&&

.FIRE WEATHER...
Issued at 147 PM EDT Thu May 16 2024

Fri...No wind or low RH concerns. Above normal temps in the mid
90s, low 90s coast with min RH values around 40 percent.

&&

.PRELIMINARY POINT TEMPS/POPS...
DAB  68  91  73  92 /   0  20  10  30
MCO  69  94  74  96 /   0  20  10  40
MLB  71  90  74  92 /  10  20  20  40
VRB  70  92  73  94 /  10  20  10  40
LEE  69  92  75  93 /   0  20  10  20
SFB  69  94  73  95 /   0  20  10  40
ORL  71  94  75  95 /   0  20  10  40
FPR  69  92  72  94 /  20  20  10  40

&&

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

&&

$$

SHORT TERM...Kelly
LONG TERM...Fehling