Area Forecast Discussion
Issued by NWS Miami, FL
FXUS62 KMFL 250112 AAC
Area Forecast Discussion...UPDATED
National Weather Service Miami FL
912 PM EDT SUN JUL 24 2016
The mid to upper level low pressure will continue to move west
into the Gulf of mexico tonight, as some saharan Dust east of the
Bahama Islands moves west towards South Florida. This will help to
reduced the shower and thunderstorm activity over the Atlantic
waters down to isolated coverage, with rest of South Florida
remain mostly dry tonight. Therefore, the pops have been removed
from most of South Florida for rest of tonight except for a slight
chance over the east coast metro areas.
The Saharan Dust will continue to move west into South Florida on
Monday helping to reduced the coverage of the showers and
thunderstorms. However, the east and west coast sea breezes will
develop and push inland on Monday helping to generate isolated to
scattered showers and thunderstorms. The wind flow will be
southeast on Monday over South Florida focusing the best coverage
over the interior and west coast metro areas. Therefore, the pops
have been lowered a little bit over South Florida on Monday.
Rest of the forecast looks good at this time and no other changes
are planned at this time.
.PREV DISCUSSION... /issued 728 PM EDT SUN JUL 24 2016/
Scattered showers with embedded thunderstorms are still possible through
the rest of this evening, but overall radar representation shows only
a few showers developing over the southern Atlantic coastal waters
and along some outflow boundaries moving over interior areas.
Pops/Weather coverage have been trimmed to low end scattered, 30
percent at best, through midnight. Coastal locations, especially
over the Atlantic side, could experience some showers and
thunderstorms moving in from the coastal waters.
The rest of the forecast package remains on track and no other
adjustments will be made at this time. Overnight lows should
remain in the mid to upper 70s, warmest near the coast.
The showers and thunderstorms have dissipated this evening, but
there could still be a few showers over the east coast taf sites
this evening before going dry for the overnight hours. Therefore,
VCSH will remain in the forecast until 02Z then dry conditions for
rest of the night time hours. VCSH will be added from 14Z until
17/18Z on Monday, before going to VCTS for the afternoon hours at
all of South Florida taf sites.
The winds will be light and variable tonight at all of South
Florida taf sites, before becoming easterly 5 to 10 knots on
Monday. The only exception is at KAPF taf site where the winds
will become westerly after 18Z.
The ceiling and vis will remain in the VFR conditions tonight into
Monday, but could fall down into MVFR or evening IFR conditions
Monday afternoon with any shower or thunderstorm.
PREV DISCUSSION... /issued 424 PM EDT SUN JUL 24 2016/
Short term (Tonight-Tue)...an upper level low moving over Florida
is keeping cooler temperatures around 500 mb, between -7 to -8
degrees celsius, while abundant low level moisture lingers across
South Florida tonight. This will keep enough instability and
moisture in place for at least scattered showers and thunderstorms
to continue through this evening.
At 400 pm edt radar data was showing the most active thunderstorms
moving over the Gulf coast areas, and a couple of cells developing
northwest Miami-Dade county. Several outflow boundaries from these
cells are moving across the eastern half of South Florida, which
may trigger additional convection through the rest of the
afternoon and early evening hours.
Most of South Florida remains under a marginal risk for severe
storms through this evening. Most storms will be capable of
producing strong gusty winds in the 40 to 55 mph range, small hail
and localized flooding, but can not rule out the possibility of
experiencing an isolated severe storm or two before the evening is
over. Overall atmospheric setup tonight may be also supportive of
waterspout activity over the nearshore waters.
Model guidance shows the aforementioned upper low migrating
further west and away from the area by Mon, allowing for warmer
temps and drier air to start filtering aloft. However, there
should be enough low level moisture in place to combine with
daytime heating and sea breeze activity to bring another round of
scattered to numerous thunderstorms in the afternoon hours. Also,
winds will begin to increase and veer to a more southeasterly flow,
which will again keep best chances of showers and thunderstorms
over interior and Gulf coast areas. Coverage will be mainly
scattered on Tue as drier air and warmer temps establish aloft,
while some models insist in bringing some Saharan dust intrusion
into the regional air mass as early as Tue afternoon. This may
further decrease chances of showers and thunderstorms,
Afternoon highs remain in the upper 80s to lower 90s over most
coastal metro areas, and climbing into the mid 90s over interior
areas. Heat index readings could reach the lower 100s again by Tue
afternoon, especially if the Saharan dust intrusion materializes.
Long Term (Wed-Sat)...with models showing mid level ridging re-
establishing across the region, 500 mb temps returning to normal
values, and prevailing light to moderate southeasterly flow at the
sfc, expect mainly scattered coverage of showers each afternoon
with a more stable air mass in place. A caveat to this forecast
scenario could be the arrival of a tropical wave feature into the
Caribbean by mid week, but there is still time to adjust the long
term forecast as future guidance becomes available.
Afternoon max temps will rise into the lower to mid 90s, except
along the immediate Atlantic coast where highs will likely remain
in the upper 80s.
Generally light east/southeasterly flow will prevail across the
South Florida coastal waters, around 10 knots or less tonight and
Mon. Only exceptions will be around thunderstorms, which will
generate brief periods of strong gusty winds, rough seas and
frequent to excessive cloud to water lightning. Seas will remain
around 3 feet or less with little to no swell. The
east/southeasterly flow will begin to increase during the first
half of the work week, with minor increases in seas possible.
An upper level low continues to bring lots of instability to South
Florida this afternoon. While there is currently a lull in
activity along the east coast, the chances of activity increasing
again at any given time this afternoon are high enough that the
SHRA VCTS has been left in the forecast for the rest of the
afternoon, and possibly will be needed into the evening hours.
Otherwise, VFR conditions will prevail outside of heavy showers or
storms, which could bring temporary IFR conditions through the
.PRELIMINARY POINT TEMPS/POPS...
West Palm Beach 77 91 80 92 / 20 40 20 10
Fort Lauderdale 77 89 80 90 / 20 40 10 10
Miami 77 91 80 91 / 20 40 10 10
Naples 74 90 76 92 / 10 40 20 30