064
FXUS62 KMFL 212323
AFDMFL

Area Forecast Discussion
National Weather Service Miami FL
723 PM EDT Fri Jun 21 2024

...New AVIATION...

.SHORT TERM...
(Rest of today through Saturday)
Issued at 1231 PM EDT Fri Jun 21 2024

As a tropical disturbance (Invest AL92) continues to move
northwestward this afternoon towards the Florida/Georgia coastline,
some drier air continues to wrap around the southern side of the low
towards the Lake Okeechobee region as well as South Florida. This
will help to limit the coverage of convection across the region for
the rest of this afternoon and into this evening. However, there
does remain enough lower level moisture to support some shower and
thunderstorm development with the main focus of initiation being sea
breeze boundaries. With the drier air pocket pushing into the mid
levels, this will also act as a cap which will help to keep strong
thunderstorm development rather limited this afternoon. As east to
southeasterly wind flow remains in place, the highest chances of
showers and thunderstorms will remain over the interior and west
coast heading into the afternoon and evening hours. While most of
the convection over land will diminsh as the evening progresses, the
hi res models are showing increasing shower and thunderstorm
development over the Atlantic waters overnight as the drier air
pocket erodes and moisture increases. Low temperatures tonight will
generally range from the lower to mid 70s across the Lake Okeechobee
region to around 80 across the east coast metro areas.

On Saturday, the tropical disturbance will have pushed inland across
Northern Florida and Southeastern Georgia, however, the weakness in
the mid level ridging will still remain in place across the region.
This will allow for a light steering flow through the day as the
surface flow remains east southeasterly. As moisture advection
continues throughout the day and PWAT values range between 2.1 and
2.3 inches, the coverage of showers and thunderstorms will be higher
compared to this afternoon. The main focus of convection will still
be sea breeze driven, however, with the lighter steering flow in
place, convection may linger closer to the east coast metro areas
upon development before slowly pushing towards the interior and
west. Some stronger thunderstorms cannot be ruled out mainly across
the interior sections on Saturday afternoon and they could contain
gusty winds and heavy downpours. High temperatures on Saturday will
generally range from the upper 80s along the east coast to the lower
90s across Southwest Florida.

&&

.LONG TERM...
(Saturday night through next Thursday)
Issued at 322 PM EDT Fri Jun 21 2024

A mid-level trough is forecasted to dip southward across the Great
Lakes on Sunday, triggering the breakdown of the dominant mid-level
ridging over the region. Consequently, the expansive surface ridging
over the western Atlantic will weaken and retreat, gradually
weakening the easterly surface flow. Despite this change, there will
still be sufficient easterly flow to drive convection across the
western half of South Florida. Combining large-scale ascent and low-
level forcing from sea breeze boundaries will enhance rain chances
late this weekend.

On Monday, a notable shift in the weather pattern is expected as the
surface flow is forecasted to change to a more southerly direction.
This is due to the waning influence of the high-pressure ridge. The
shift in the surface flow will concentrate convection primarily in
inland areas, particularly around the lake and other inland
locations, where boundary collisions will be more frequent. During
this period, deeper tropical moisture (PWATs exceeding 2 inches)
from the ongoing Central American Gyre (C.A.G.) will continue to
move into South Florida, sustaining elevated rain chances each
afternoon. It is important to note that the NBMs PoPs are too high,
so a reduction has been implemented.

As we progress into Tuesday, mid-level troughing will become
established over the eastern United States, accompanied by a surface
frontal boundary extending into the southeastern United States. In
response, surface winds will veer southwesterly, altering the
weather pattern. This southwesterly flow will promote the inland
progression of the Gulf sea breeze while confining the Atlantic sea
breeze to the East Coast. As a result, the highest concentration of
convection is expected along the East Coast metro areas from Tuesday
through Wednesday. With PWATs ranging between 1.8 and 2.2 inches
throughout the week and light 500mb flow in place, localized
flooding remains a concern, particularly in urban areas that
experienced significant rainfall last week.

Some uncertainty marks the extended forecast period. Numerical
guidance suggests that drier air, possibly a burst of Saharan dust,
could approach the region. Alternatively, other models indicate that
tropical moisture from the Caribbean could move into the CWA, driven
by mid-level troughing. Seasonal temperatures are expected to
prevail throughout the forecast period with heat indices exceeding
100.

&&

.AVIATION...
(00Z TAFS)
Issued at 720 PM EDT Fri Jun 21 2024

Increasing SHRA activity across the east coast terminals during
the early morning hours with widespread SHRA/TSRA developing across
South Florida tomorrow. Handled with VCSH/VCTS for now given low
confidence on timing/spatial extent. However, TEMPOs and
amendments may be needed tomorrow if SHRA/TSRA activity trends
increase and if terminals are directly impacted.

&&

.MARINE...
Issued at 1231 PM EDT Fri Jun 21 2024

A gentle to moderate east to southeasterly wind flow will remain in
place across most of the local waters into the upcoming weekend.
These winds will gradually veer and become more southerly as the
early portion of next week progresses. Seas across the Atlantic
waters will remain at 2 to 4 feet through the first part of the
weekend before subsiding and will remain at 2 feet or less through
the second half of the weekend and into early next week. Seas across
the Gulf waters will remain at 2 feet or less through the weekend
and into early next week. Scattered to numerous showers and
thunderstorms will be possible each day. Winds and waves could be
locally higher in and around showers and storms.

&&

.BEACHES...
Issued at 1231 PM EDT Fri Jun 21 2024

A high risk of rip currents will continue for the Atlantic Coast
Beaches through Saturday evening. The rip current risk could remain
elevated through the rest of the weekend and into early next week as
onshore flow remains in place.

&&

.PRELIMINARY POINT TEMPS/POPS...
Miami            80  90  79  89 /  30  60  30  70
West Kendall     78  91  77  90 /  30  60  30  70
Opa-Locka        80  91  78  91 /  30  60  30  70
Homestead        80  89  78  88 /  30  60  40  60
Fort Lauderdale  81  88  80  88 /  30  60  30  70
N Ft Lauderdale  81  89  80  88 /  30  60  30  70
Pembroke Pines   82  91  80  91 /  30  60  30  60
West Palm Beach  80  90  78  89 /  30  60  30  60
Boca Raton       80  90  79  89 /  30  60  30  60
Naples           77  92  77  90 /  40  70  40  70

&&

.MFL WATCHES/WARNINGS/ADVISORIES...
FL...High Rip Current Risk through Saturday evening for FLZ168-172-
     173.

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

$$

SHORT TERM...CWC
LONG TERM....Pine
AVIATION...Hadi