531
FXUS62 KMFL 131442
AFDMFL

Area Forecast Discussion
National Weather Service Miami FL
1042 AM EDT Thu Jun 13 2024

...New UPDATE...

.UPDATE...
Issued at 1028 AM EDT Thu Jun 13 2024

South FL continues to enjoy a lull in rainfall this morning, but
conditions are set to deteriorate this afternoon as a frontal
boundary continues to sag southward towards our area. This
boundary will move into an area of significantly enhanced
moisture (PWATs of 2.19 in the 12Z MFL sounding) where heavy
rainfall could once again result in dangerous flash flooding
across portions of the region.

As of this update, a line of showers and storms is already set up
across portions of central and southwest FL where 1-2 inches of
rain have already fallen over the last 2 hours. This line will
gradually drift over our area later today, with potential rainfall
totals of 4-8 inches with locally higher amounts up to or even
exceeding 10 inches. This will pose a great danger to areas that
have already seen several inches of rain over the past few days
and which could experience flash flooding with even lower total
amounts. To this effect, WPC has placed the whole I-75 corridor,
including Fort Lauderdale and as far south as Tamiami Trail, under
a HIGH RISK for excessive rainfall this afternoon. This means that
there is at least a 70% chance that areas 25 miles away from any
given spot could see flash flooding concerns.

There is a very marginal concern for funnel clouds or even weak
tornadoes as this line enters our CWA; the limiting factor to this
development will be a cap that was shown to be in place in the 12Z
sounding. This risk decreases as the line moves southward.

All this said, few changes were made to the forecast for today as
conditions remain on track.

&&

.SHORT TERM...
(Today through Friday)
Issued at 243 AM EDT Thu Jun 13 2024

The very wet and unsettled weather pattern will continue across the
region today as a mid level shortwave slowly pushes into the
northeastern Gulf of Mexico. At the surface, a broad area of low
pressure along the stalled out frontal boundary to the north will
gradually begin to lift northeastward off of the Northern Florida
coastline and into the western Atlantic. This area of low pressure
will slowly try to intensify as it moves northeastward. The moisture
tail associated with this low will extend southwestward over the
region for today. This will result in another day of multiple rounds
of showers and thunderstorms across the area. Similar to yesterday,
with plenty of deep layer moisture remaining in place as PWAT values
remain at 2.5 inches or higher, multiple rounds of heavy and
intense rainfall will be possible. With these repeated rounds of
heavy rainfall potentially setting up over areas that saw
considerable flooding yesterday, this will continue to create
additional flood problems that are currently ongoing across the
region. As the low starts to gain traction heading northeastward, hi-
res guidance shows that another lull in activity may develop late
Thursday night into Friday morning with loss of diurnal heating. Any
break in the activity will be welcome as this will give any ongoing
flooding a chance to start to recede.

Heading into Friday, the mid level shortwave trough pushes further
south into the Gulf of Mexico as well as South Florida. At the
surface, the developing area of low pressure will push further to
the northeast off of the Carolina coastline. Deep tropical moisture
will continue to be funneled into South Florida along the south to
southwesterly wind flow. The moisture tail associated with this area
of low pressure will remain in place across South Florida allowing
for the potential of another day of multiple rounds of showers and
thunderstorms. Multiple rounds of heavy rainfall will continue
especially during the afternoon hours which could once again create
additional flooding across the already saturated area. In general,
additional rainfall amount of 4 to 8 inches are possible across most
areas through Friday evening. Some areas where the very heavy and
intense rainfall rates set up could see locally higher amount of 10
inches or more during this time frame. Because of this, the Flood
watch will remain in place across all of South Florida through
Friday Evening. High temperatures will continue to be held down in
the mid 80s across most areas on Thursday and Friday due to the
increased cloud cover and rainfall across the region.&&

.LONG TERM...
(Friday night through Wednesday)
Issued at 243 AM EDT Thu Jun 13 2024

This weekend: The surface low will remain off the Southeast CONUS on
Saturday and will be pushing towards the northeast. Upper level
troughing will still be the dominant synoptic feature over the area.
As the aforementioned surface low continues to push to the
northeast, surface flow across South Florida will remain southerly
to start the weekend, but easterly flow will return by Sunday
afternoon which will be the start of a return to normalcy. Modeled
PWATs will still remain at or above 2 inches Saturday and Sunday,
which is at or above the 90th percentile for this time of year. It
is possible we remain in the `moisture tail` of the surface low
through the weekend, with the most enhanced moisture draped across
far southern portions of the area. Showers and storms are likely
each day through the weekend before drier air finally begins to
filter across the area on Monday. As the low continues to push
further and further away from South Florida, the coverage of showers
and storms is not expected to be as widespread or numerous as what
we experienced earlier this week. Still, given the extremely wet
conditions this week, the Flood Watch may need to be extended into
the weekend.

Early next week: Surface high pressure will build across the region
again late Sunday into Monday which should return us to a more
typical summertime easterly regime. This will allow the eastern
sea breeze to progress relatively far inland, and should keep the
east coast metro areas cooler each afternoon. This will also keep
the best chances for showers and storms across interior South
Florida and Southwest Florida each afternoon.

Highs through the period will be in the upper 80s with heat indices
in the upper 90s to lower 100s. With the return of the easterly
regime, Southwest Florida will experience slightly warmer
temperatures and heat indices each day.&&

.AVIATION...
(12Z TAFS)
Issued at 733 AM EDT Thu Jun 13 2024

Generally VFR at all sites during the next few hours, but MVFR/IFR
conditions could be possible for all terminals later this
afternoon as a large band of SHRA/TSRA pushes through. Best timing
for most terminals will be between 16-22Z, with TEMPOs currently
in place for the 18-22 Z window. Generally southerly to
southwesterly winds will prevail outside of any storms and storm
outflows.

&&

.LONG TERM...
(Friday night through Wednesday)
Issued at 243 AM EDT Thu Jun 13 2024

This weekend: The surface low will remain off the Southeast CONUS on
Saturday and will be pushing towards the northeast. Upper level
troughing will still be the dominant synoptic feature over the area.
As the aforementioned surface low continues to push to the
northeast, surface flow across South Florida will remain southerly
to start the weekend, but easterly flow will return by Sunday
afternoon which will be the start of a return to normalcy. Modeled
PWATs will still remain at or above 2 inches Saturday and Sunday,
which is at or above the 90th percentile for this time of year. It
is possible we remain in the `moisture tail` of the surface low
through the weekend, with the most enhanced moisture draped across
far southern portions of the area. Showers and storms are likely
each day through the weekend before drier air finally begins to
filter across the area on Monday. As the low continues to push
further and further away from South Florida, the coverage of showers
and storms is not expected to be as widespread or numerous as what
we experienced earlier this week. Still, given the extremely wet
conditions this week, the Flood Watch may need to be extended into
the weekend.

Early next week: Surface high pressure will build across the region
again late Sunday into Monday which should return us to a more
typical summertime easterly regime. This will allow the eastern
sea breeze to progress relatively far inland, and should keep the
east coast metro areas cooler each afternoon. This will also keep
the best chances for showers and storms across interior South
Florida and Southwest Florida each afternoon.

Highs through the period will be in the upper 80s with heat indices
in the upper 90s to lower 100s. With the return of the easterly
regime, Southwest Florida will experience slightly warmer
temperatures and heat indices each day.&&

.AVIATION...
(12Z TAFS)
Issued at 733 AM EDT Thu Jun 13 2024

Generally VFR at all sites during the next few hours, but MVFR/IFR
conditions could be possible for all terminals later this
afternoon as a large band of SHRA/TSRA pushes through. Best timing
for most terminals will be between 16-22Z, with TEMPOs currently
in place for the 18-22 Z window. Generally southerly to
southwesterly winds will prevail outside of any storms and storm
outflows.

&&

.MARINE...
Issued at 243 AM EDT Thu Jun 13 2024

A moderate to fresh south to southwesterly wind flow will remain in
place across the local waters through the end of the week. Seas
across the Atlantic and Gulf waters will remain at 2 feet or less
through Friday. Winds and seas could be locally higher in and around
any shower or thunderstorm activity. &&

.PRELIMINARY POINT TEMPS/POPS...
Miami            86  76  86  76 /  90  80 100  70
West Kendall     87  74  85  74 /  90  90 100  70
Opa-Locka        86  75  86  76 /  90  80 100  70
Homestead        88  75  86  76 /  90  90 100  70
Fort Lauderdale  86  75  85  76 / 100  90 100  70
N Ft Lauderdale  86  75  85  76 / 100  90 100  70
Pembroke Pines   86  75  85  76 / 100  90 100  70
West Palm Beach  86  74  86  74 / 100  70 100  70
Boca Raton       86  75  85  75 / 100  90 100  70
Naples           88  77  85  76 / 100  90 100  70

&&

.PRELIMINARY POINT TEMPS/POPS...
Miami            87  76  86  77 / 100  80  70  70
West Kendall     88  74  87  74 /  90  80  70  70
Opa-Locka        88  75  88  76 / 100  70  70  70
Homestead        88  75  87  76 /  90  80  70  70
Fort Lauderdale  86  76  85  77 / 100  70  70  70
N Ft Lauderdale  86  76  87  76 / 100  70  70  70
Pembroke Pines   88  76  89  77 / 100  70  70  70
West Palm Beach  86  74  86  74 /  90  70  70  60
Boca Raton       87  75  87  76 / 100  70  70  70
Naples           87  76  87  77 /  90  70  80  80

&&

.MFL WATCHES/WARNINGS/ADVISORIES...
FL...Flood Watch through Friday evening for FLZ063-066>075-168-
     172>174.

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

$$

SHORT TERM...CWC
LONG TERM....Rizzuto
AVIATION...ATV