Area Forecast Discussion
Issued by NWS Miami, FL

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FXUS62 KMFL 260813
AFDMFL

Area Forecast Discussion
National Weather Service Miami FL
413 AM EDT FRI AUG 26 2016

.SYNOPSIS...
A broad upper-level ridge will remain established across the
Southeast CONUS through the weekend along with high pressure at the
surface. A strong tropical wave will track near the region during
much of the weekend and into early next week.

&&

.DISCUSSION...

NEAR TERM /THROUGH 6 PM FRIDAY EVENING/...

...Moderate Risk of rip currents for Atlantic beaches today...

As of 410 AM EDT...Scattered showers and thunderstorms have been
ongoing for much of the night, mainly across the local Atlantic
waters into portions of the east coast metro and across the lake
region. This activity is in response to broad synoptic lift from a
strong tropical wave located between the southeastern Bahamas and
the northeastern coast of Cuba, as of the 2 AM National Hurricane
Center Tropical Weather Outlook.

Much of the day will feature unsettled weather, with scattered to
numerous showers and thunderstorms as a very moist tropical airmass
remains in place across South Florida with PWAT values well in
excess of 2.0 inches. Frequent lightning and locally heavy rainfall
will be the primary threats with thunderstorms. Periods of extensive
cloud cover may limit high temperatures somewhat, but highs are
still expected to reach into the lower 90s for most locations. The
tropical airmass will continue to make it feel quite muggy, with
heat indices generally ranging from 100-105 degrees.

Rip current risk will continue to remain Moderate for the Atlantic
beaches.

SHORT TERM /6 PM FRIDAY EVENING THROUGH SUNDAY NIGHT/...

...Continuing to track the westward progress of tropical
disturbance Invest 99L...

...Increased risk of rip currents for Atlantic beaches continuing
through the weekend...

The main weather story this weekend will continue to be the
monitoring of a strong tropical wave...Invest 99L. This system
continues to remain disorganized and lack a well-defined center of
circulation. It is expected to continue moving west/northwest during
the next several days, with the possibility that conditions could
become more favorable for development as it moves near the central
Bahamas this weekend.

The latest National Hurricane Center Tropical Weather Outlook valid
at 2 am, gives this tropical disturbance a medium chance for
development into a tropical cyclone within the next 5 days...at
60%. Development is generally not expected in the next 48 hours,
with upper-level winds not conducive. Beyond 48 hours,
environmental conditions may become slightly more favorable for
development.

Regardless of the final outcome of Invest 99L, forecast confidence
is fairly high that the weekend will feature wet and occasionally
breezy weather, with scattered to numerous showers and
thunderstorms and mostly cloudy skies expected across South
Florida. Heavy rainfall will be the primary threat, especially for
southern areas. The rainfall forecast is highly dependent on the
evolution of Invest 99L, with several inches of rainfall possible
through early next week which may lead to some flooding issues.

Rip current risk for the Atlantic beaches will remain at least
Moderate through the weekend, with a High risk possible by the end
of the weekend.

While the forecast continues to remain uncertain, the trend over the
past 24 hours is for a decreasing threat to South Florida with this
system, and a more southern track for any possible development.

However, this does not mean that South Florida is in the clear.
Residents and visitors to South Florida should continue to closely
monitor the products of the National Hurricane Center and National
Weather Service in Miami over the next few days to stay alert for
any potential impacts to South Florida with this system. The
forecast will continue to be adjusted with the latest model
guidance.

Temperatures will be near to slightly below normal during the short
term period, with highs in the upper 80s to lower 90s, and lows
generally in the 70s.

LONG TERM /MONDAY THROUGH THURSDAY/...

...Continuing to track the westward progress of Invest 99L into
early next week...

...Increased risk of rip currents continuing into early next
week...

Long range guidance is in fairly good agreement that Invest 99L will
exit the region by the middle of next week. Unsettled weather is
still expected to continue through much of the work week, with
scattered to numerous showers and thunderstorms, especially during
the afternoon and evening hours. Monday and Tuesday look to be the
wettest days across South Florida, with locally heavy rain
possible as the flow shifts more southerly.

Rip current risk will continue to remain at least Moderate into
early next week for Atlantic beaches. Depending on the eventual
track of Invest 99L, an increased risk of rip currents may also be
possible for Gulf Coast beaches as well.

&&

.MARINE...
Northeast to easterly flow will prevail over the local Atlantic
and Gulf waters through Friday, becoming more easterly over the
weekend. Winds will generally be 10-15 knots through Saturday,
increasing to 15-20 knots by Sunday. Seas will increase to 3-6
feet over the local Atlantic waters with an easterly swell of 1-2
feet, and 2-4 feet over the local Gulf waters for this weekend
with little to no swell. Scattered to numerous thunderstorms will
be possible through the weekend, with rough seas and locally
erratic winds will be possible.

There continues to remain considerable uncertainty for winds and
seas late this weekend and into early next week as a tropical
disturbance over the southern Bahamas moves closer to the region.
Please consult the products of the National Hurricane Center and
our latest forecasts for additional information.

&&

.AVIATION...
The winds will remain northeast today over all of South Florida
taf sites. The speeds will be around 5 knots this morning before
increasing to around 10 knots this afternoon. VCSH will continue
over the east coast taf sites through 15Z before going to VCTS.
For KAPF taf site, the weather will remain dry through 17Z then
VCTS for the afternoon hours. The ceiling and vis will remain in
the VFR conditions over all of the taf sites outside of any
showers or thunderstorms, but could fall into MVRF or even IFR
conditions with the passage of a shower or thunderstorm.

&&

.PRELIMINARY POINT TEMPS/POPS...
West Palm Beach  91  81  90  81 /  40  40  50  40
Fort Lauderdale  90  81  89  80 /  40  40  50  40
Miami            91  80  90  79 /  40  40  50  40
Naples           92  77  92  77 /  60  40  60  30

&&

.MFL Watches/Warnings/Advisories...
FL...None.
AM...None.
GM...None.
&&

$$

SYNOPSIS/DISCUSSION/MARINE...92/IRL
AVIATION...54/BNB


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