874
FXUS62 KMFL 181723
AFDMFL

Area Forecast Discussion
National Weather Service Miami FL
123 PM EDT Sat May 18 2024

...New SHORT TERM, AVIATION, MARINE...

.SHORT TERM...
(Rest of today through Sunday)
Issued at 114 PM EDT Sat May 18 2024

A hot and humid day is on tap across much of South Florida as a mid-
level ridge continues to slide across the area, being pushed along
by a shortwave moving along the northern Gulf states. The ridge will
continue to keep conditions mostly dry, however, scattered shower
and thunderstorm activity will be possible for coastal locations,
primarily on the Atlantic side as the sea breeze boundary pushes
inland in the afternoon and early evening hours. Steep low-level
lapse rates and enhanced shear along the sea breeze could support
stronger storms capable of producing damaging wind gusts and small
hail, although is viewed as unlikely.

With south-southwest flow and warming air mass from the overhead
ridge, high temperatures today will peak in the mid to upper 90s
across much of South Florida, with heat index values up to 110
possible. Heat Advisories have been issued for all counties due to
the hazardous conditions. Anyone sensitive to heat should plan to
avoid extended time outside, and if you are required to be outside,
take cooling breaks and stay hydrated.

On Sunday, the aforementioned shortwave and associated frontal
boundary will slowly spread over the Florida Peninsula, kicking the
ridge offshore into the Atlantic. This will lead to greater
instability and better chances for showers and thunderstorms across
the area, especially during the afternoon and evening hours when the
sea breeze develops. The extra instability assisted by the
shortwave along with the trough ushering in cooler temps aloft (-8
to -10 deg C) could enhance severe thunderstorm potential. Strong
to damaging wind gusts due to storm strength or downbursts plus
small to large hail will all be possible. Conditions will be
monitored tonight for adequate assessment of the hazards with any
convective storms tomorrow. Overall, the highest chances for
showers and storms will be in northern portions of South Florida
as low level flow will be southerly. PoPs around 60-70% are
forecasted for Hendry, Glades, Palm Beach and Broward counties
with mostly 40-50% PoPs elsewhere further south. Additionally,
even with the increased cloud cover and a slightly cooler air mass
compared to Saturday, heat will yet again be a concern as south-
southwest flow persists over South Florida for much of the day
ahead of the frontal boundary. High temperatures will be in the
low to mid-90s, with heat index values ranging from 103-108. Heat
advisories may be needed yet again for certain areas.

&&

.LONG TERM...
(Sunday night through Friday)
Issued at 227 AM EDT Sat May 18 2024

Increased rain chances and a bit of relief from the heat to start the long-term
period as a mid-level shortwave trough settles over Florida and
the Southeast US, and a surface front finally pushes across South
Florida. Scattered showers and thunderstorms are expected on
Monday and Tuesday, especially during the afternoon and early
evening hours, with locally heavy rain possibly leading to a few
instances of minor urban flooding across the East Coast metro. A
few storms may also be on the strong to severe side, with damaging
wind gusts from localized downbursts being the main threat.

From mid to late week, a mid-level ridge will slowly build in from over
the Gulf, while the mid-level trough lingers just east of the
Florida Peninsula. While chances for showers and thunderstorms
will gradually decrease, there will still be daily chances during
the afternoon and early evening hours, primarily driven by diurnal
sea-breeze convection.

Temperatures will gradually trend cooler each day from early to midweek,
and rebound towards the end of the week as the ridging builds
back in. Monday`s highs will be in the upper 80s to low 90s, with
mid to upper 80s on Wednesday, and back into the low 90s again by
Friday. Overnight lows will remain warm, in the mid to upper 70s
each day. While these temperatures are above normal, they will not
lead to the heat concerns that we have seen for much of the past
week.

&&

.AVIATION...
(18Z TAFS)
Issued at 114 PM EDT Sat May 18 2024

Generally VFR conditions will prevail through the period.
Restrictions due to scattered thunderstorms will be possible this
afternoon over the east coast terminals between 18 to 00Z. SE
winds are expected on the east coast for the afternoon sustained
10-15kts with gusts to 20kts while winds will become SW at KAPF.
Winds become variable overnight for a while but then increase out
of the SW late in the night as a disturbance approaches the
general vicinity. In addition, the disturbance could spark some
local shower development in the late night and early morning
tomorrow, thus VCSH has been introduced in the morning after 08Z.


&&

.MARINE...
Issued at 114 PM EDT Sat May 18 2024

Mainly benign conditions over the weekend with light to moderate
southwesterly to southerly flow. There will be scattered showers and
thunderstorms this weekend, mainly over the Atlantic waters, which
could create locally chaotic seas at times and gusty winds.
&&

.PRELIMINARY POINT TEMPS/POPS...
Miami            81  93  77  91 /  20  70  40  70
West Kendall     78  95  74  93 /  10  60  40  60
Opa-Locka        80  95  76  92 /  20  70  40  70
Homestead        80  94  77  91 /  20  50  50  60
Fort Lauderdale  80  91  76  89 /  20  70  50  70
N Ft Lauderdale  79  93  75  90 /  20  70  50  70
Pembroke Pines   80  95  77  93 /  20  70  40  70
West Palm Beach  76  92  73  89 /  20  70  50  70
Boca Raton       78  93  74  90 /  30  70  50  70
Naples           79  91  77  89 /  20  50  40  50

&&

.MFL WATCHES/WARNINGS/ADVISORIES...
FL...Heat Advisory until 8 PM EDT this evening for FLZ063-066>075-168-
     172>174.

AM...None.
GM...None.
&&

$$

SHORT TERM...Redman
LONG TERM....Culver
AVIATION...Redman