Area Forecast Discussion
Issued by NWS Miami, FL
FXUS62 KMFL 301130
Area Forecast Discussion
National Weather Service Miami FL
730 AM EDT Thu Mar 30 2017
VFR conditions to prevail through the forecast period. SE wind
140-150 degrees will increase to around 8-10 knots around 14z,
then 10-13 knots with gusts approaching 20 knots after 16z.
Gradual wind shift to 180-200 degrees at KAPF after 18z as weak
Gulf sea breeze moves a few miles inland. SCT to occasionally BKN
ceilings 040-050 mainly inland of the terminals, but could briefly
occur at the TAF sites between about 14z-19z. Wind decreasing to
less than 10 knots after 00z with VFR continuing.
.PREV DISCUSSION... /issued 402 AM EDT Thu Mar 30 2017/
Today-Tonight: One more relatively quiet day across South Florida
as the ridging at the surface and aloft begin to break down.
Increasing south-southeasterly flow will usher in a few more
afternoon clouds and keep temperatures warm in the mid-upper 80s,
with the potential for a few 90 degree readings across Glades,
Hendry, and interior Collier counties. While the Gulf coast breeze
is still expected to develop this afternoon, it will be much
weaker, later in the day, and not move as far inland as earlier
this week. Similar to the past few days, while a shower or two
can`t be ruled out with the evening sea breeze collision, chances
remain too low for a mention in the forecast.
Friday-Sunday: The track of the upper level and surface low
moving across the TN/OH valley and Mid-Atlantic late week has
shifted further north. With the surface front so far removed from
its parent low, it will be losing a lot of its momentum as it
moves into Florida on Friday. Deep moisture return also looks less
robust, especially given the dry airmass currently in place that
needs to be modified.
However, gusty southerly flow will lead to a modest increase in low
level moisture across the region, which along with a robust 90-100kt
jet crossing the peninsula, above normal daytime highs in the mid
80s, and surface convergence with the dying front, will help
generate a few afternoon showers and storms as the front moves into
South Florida Friday afternoon. Overall rain chances are lower
than previous forecast, focused towards the east coast, where a
weak seabreeze will help with convergence.
Front is expected to wash out across South Florida/FL Straits into
Saturday. This will leave some lingering moisture that may generate
isolated showers and a storm or two with daytime heating and the
seabreeze collision Saturday and Sunday afternoons.
Next Week: The southern stream jet remains active into next week
with the next upper level low swinging through the southern tier of
the US into Monday and another robust surface low expected to move
into the TN/OH valleys and Mid-Atlantic Monday-Tuesday. Timing
differences remain in the approach of the next front(s), but it
appears there will be at least low end threat for afternoon showers,
and potentially thunderstorms into mid next week.
MARINE...Southeasterly flow picks up today ahead of the next system
through the end of the week, becoming 10 to 15 kts today, and more
southerly at 15 to 20 kts on Friday. The front is expected to bring
some showers, and maybe even a few thunderstorms to South Florida
waters on Friday.
Winds become light and somewhat variable as the front washes out
over the region into Saturday with both the east coast and Gulf
seabreezes dominating the wind pattern. Winds are expected to
increase out of the southeast again Sunday and Monday ahead of
another approaching system.
AVIATION...Light and variable winds with VFR conditions will
prevail through the overnight hours across South Florida.
Southeast winds begin to increase to around 10 knots by mid day
with a few brief gusts up to 15 knots. Gulf Sea breeze will shift
winds southwest in the afternoon over APF but return to the
southeast by the evening hrs. As the next front moves closer into
the area tonight, expect winds to remain around 10 to 15 knots
along the coastal areas.
FIRE WEATHER...Dry conditions continue across the region today,
though a little stronger southeasterly flow will help modify
locations east of Lake Okeechobee this afternoon. Afternoon RH
values are expected to drop below 40% across Glades and Hendry
counties for 4-6 hours this afternoon. Inland Collier county may
also see a few hours around 40%. While winds speeds will be a
little stronger this afternoon, with dispersions in the good to
very good range, overall they are expected to remain less than 10
mph. Due to longer duration of RH, the Fire Weather Watch has been
upgraded to a Red Flag Warning for Glades and Hendry.
The approach of a frontal boundary along with a few showers and
storms will bring a modest increase in RH values on Friday and
Saturday. Drier conditions behind the front may allow interior
locations to see RH values back into the mid 30%-low 40% range
across Glades, Hendry, and interior Collier counties on Sunday.
.PRELIMINARY POINT TEMPS/POPS...
West Palm Beach 84 69 86 68 / 0 10 30 20
Fort Lauderdale 83 72 85 71 / 0 0 30 20
Miami 83 71 86 70 / 0 0 20 10
Naples 84 67 84 67 / 0 0 20 10
FL...Red Flag Warning from 1 PM this afternoon to 8 PM EDT this
evening for FLZ063-066.