271
FXUS62 KMFL 171127
AFDMFL

Area Forecast Discussion
National Weather Service Miami FL
727 AM EDT Tue Sep 17 2024

...New AVIATION...

.SHORT TERM...
(Today through Wednesday)
Issued at 245 AM EDT Tue Sep 17 2024

The consolidation of a mid-level low across the southeastern
United States today, comprised of two previous lobes of 500mb
vorticity (ex-PTC 8 and ex-Francine) will usher in a period of
troughing across a large swath of the eastern United States by
late Monday. This will maintain cooler temperatures aloft (-6C to
-7C at 500mb) and facilitate the development of stronger
southwesterly 500mb flow across the region. The mid-level portion
of the atmospheric column does appear to moisten slightly today
with the CAMs (Convection Allowing Models) such as the HRRR, RAP,
etc depict less dry air in the mid-levels today on the overnight
model soundings. At the surface, light and variable surface winds
will continue to prevail at the surface which may facilitate the
development of fairly patchy inland fog this morning that should
quickly burn off after sunrise. Our area will remain situated to
the south of a persistent stationary front draped across Central
Florida which will keep us on the warm and unstable side of the
boundary. With the onset of sunrise and diurnal heating, humid and
warm conditions will be realized across the area as we quickly
heat up into the upper 80s and lower 90s. With the mid-level low
over the southeast United States and light surface flow, incipient
updrafts/cores during the early afternoon hours will create
outflow boundaries that will interact with the Gulf and Atlantic
sea-breezes. As these updrafts create cold pools and radially-
outward propagating outflow boundaries interact, scattered to
potentially numerous convection will overspread the region through
the remainder of the afternoon into the early evening hours.

Combining the mesoscale and synoptic factors listed above, there
is once again the potential for a few strong to marginally severe
storms across the area today. Heavy rainfall, gusty winds, and
frequent to excessive lightning will be possible with any storms
today. Strong to marginally severe wind gusts will be possible
once again with the most robust thunderstorms today. A threat of
localized flooding persists as well, especially where boundary
collisions come together and heavy rainfall is prolonged over
urban areas. HREF`s LPMM once again depicts the potential of a few
localized pockets of 1-2 inches which could result in some urban
flooding once again.

The mid-level low across the southeastern United States will
gradually lift northeastward through the mid-week period which
will veer 500mb flow across the region to a westerly then
northwesterly direction. The elongation of troughing over the
eastern United States will keep 500mb temperatures in the -6C to
-7C range during the mid-week period with forecasted daily
afternoon lapse rates in the 5.5 to 6.0 C/km range. At the
surface, we will remain situated to the south of the weak yet
quite persistent stationary boundary still draped across Central
Florida. Ample precipitable water (PWAT) values of 2.0+ inches and
a fairly moist saturated column will result in daily afternoon
rain chances near climatological norms. The prevailing weak
surface winds and the generally westerly flow aloft will keep a
rain pattern favoring SoFlos interior and eastern metro areas.
Deeper convection will again focus along sea breeze and outflow
boundaries mainly in the afternoon hours, with the continued
potential of a few isolated strong to marginally severe pulse
storms when ascent is briefly maximized along those aforementioned
mesoscale boundaries.

High temperatures each afternoon will remain just above seasonal
norms with heat indices remaining just below heat advisory
thresholds. The overspread of convective cold pools across the
region will help cool the region off during the mid to late
afternoon hours.

&&

.LONG TERM...
(Wednesday night through Monday)
Issued at 245 AM EDT Tue Sep 17 2024

With the continued propagation on the mid-level low across the
northeastern United States and western Atlantic waters, 500mb
flow over the region will remain out of a light northwesterly
direction on Thursday and Friday. Like a broken record, the pesky
stationary boundary over will remain to the north of the region
resulting in light winds at the surface. The mesoscale phenomenon
will once again dictate where convection develops and propagates
with the northwesterly flow favoring the Atlantic sea-breeze for
convective initiation each afternoon. 500mb temperatures will
remain in the -6C to -7C range as we remain on the periphery of
the influence of the departing mid-level low/troughing. By this
weekend, the influences of mid-level ridging across the central
United States will gradually nose into the region. Model guidance
hints at the potential of a surge of drier mid-level air into the
region which may act to limit spatial coverage of convection this
weekend. Temperatures will remain near seasonal norms for this
time of year with high temperatures in the upper 80s to near 90
currently forecast.

&&

.AVIATION...
(12Z TAFS)
Issued at 725 AM EDT Tue Sep 17 2024

Morning showers will give way to a VFR convective lull before
storms return for the afternoon. Light winds through much of the
period with sea breezes developing and moving inland late morning
into the afternoon. Short-fused AMDs for IFR/LIFR may be necessary
for storms later today. Activity should diminish late evening into
the overnight.

&&

.MARINE...
Issued at 245 AM EDT Tue Sep 17 2024

Generally light winds will prevail across the area through most
of this week as a weak surface boundary remains just to the north
of the area. Seas across the northern Atlantic waters will
gradually lessen as northerly swell declines through mid-week.
Scattered showers and thunderstorms will be possible each day
through the period and could lead to locally higher winds and
seas.

&&

.BEACHES...
Issued at 245 AM EDT Tue Sep 17 2024

Decreasing northerly swell will result in a high risk of rip
currents for the Palm Beaches coast once again today with a
moderate risk of rip currents elsewhere on the east coast of South
Florida.

There will also be the continued potential for minor to moderate
coastal flooding around periods of high tide due to astronomically
higher tides associated with this full moon through mid-week.

High Tide Times:

Naples: 12:56 PM Tue, 1:25 AM Wed, 1:46 PM Wed
Lake Worth: 7:46 AM Tue, 8:14 PM Tue, 8:38 AM Wed
Port Everglades: 8:06 AM Tue, 8:31 PM Tue, 8:58 AM Wed
Virginia Key: 8:53 AM Tue, 9:18 PM Tue, 9:45 AM Wed

&&

.PRELIMINARY POINT TEMPS/POPS...
Miami            91  77  91  77 /  70  50  70  50
West Kendall     91  75  90  74 /  70  50  70  50
Opa-Locka        91  77  91  77 /  70  50  70  50
Homestead        90  76  90  76 /  70  50  70  50
Fort Lauderdale  90  77  88  77 /  60  50  70  50
N Ft Lauderdale  91  77  89  77 /  60  50  70  50
Pembroke Pines   93  78  90  77 /  60  50  70  50
West Palm Beach  92  76  90  77 /  50  40  70  40
Boca Raton       93  77  91  77 /  60  40  70  50
Naples           90  78  91  77 /  50  30  60  30

&&

.MFL WATCHES/WARNINGS/ADVISORIES...
FL...High Rip Current Risk through Wednesday evening for FLZ168.

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

$$

SHORT TERM...Hadi
LONG TERM....Hadi
AVIATION...RAG