Area Forecast Discussion
Issued by NWS Miami, FL
FXUS62 KMFL 282341
Area Forecast Discussion
National Weather Service Miami FL
741 PM EDT THU JUL 28 2016
Shower and thunderstorm activity has begun to diminish across the
region, now limited to the far western portions of Glades,
Hendry, and Collier Counties. Short term models are still
consistent with pushing isolated showers and thunderstorms into
the east coast metro from the Atlantic later this evening into
tonight. Adjusted pops to reflect current radar trends,
otherwise, the forecast appears on par.
.PREV DISCUSSION... /issued 413 PM EDT THU JUL 28 2016/
A strong cell of high pressure north of the Bahamas will bring
easterly flow to the region through this weekend. This will continue
the general pattern of night/morning showers and storms over the
Atlantic waters and east coast metro, with the activity
transitioning to the interior and west coast during the afternoons.
Heat indices after the next couple days remain slightly above
normal, 100-105 F over the east coast and 105-107 F over the western
interior. A TUTT (weak upper level tropical disturbance) moving in
from the southeast may bring an in increase to the precipitation
chances on Sunday. Another bump in moisture on Tuesday and Wednesday
will bring additional high shower/thunderstorm chances to the
A deep layer high pressure cell, centered around 500
miles north of the Bahamas will be the main influencing factor of
the next couple of days. Anti-cyclonic flow around the high produced
easterly flow at all levels of the atmosphere on the morning 12Z
sounding. As with the past couple of days, this pattern aided the
shower and thunderstorm activity this morning over the east coast
metro region. By later this afternoon, highest chances of
precipitation will again shift to the interior and the west coast.
Through Saturday...precipitable water values are forecast to remain
between 1.5 and 1.75, slightly below the 1.78 average for this time
of year. This relatively drier air, in combination with a lack of
upper level features will lead to just isolated/scattered t-storm
activity during the afternoon and Atlantic/east coast activity
during the nights/mornings. Severe threats should be held at bay
with wind gusts to 50 mph, brief heavy rain, and cloud to ground
lightning being the main threats. Slightly warmer than normal
weather is also expected during this time frame with high temps near
90 along the coast with mid 90s inland. Heat index values will range
from 100-105 over the east coast metro and southern tip of Florida
and 105-107 inland over Collier County.
On Sunday, an upper level disturbance moving in from
the east (TUTT) will come into play. Models indicate 500 mb
temperatures to drop to between -8 and -9 Sunday afternoon. This, in
combination with a subtle rise of PW, will lead to increased chances
of showers and thunderstorms over all areas. On Monday, behind this
disturbance, anti-cyclonic vorticity advection and dry Saharan air
may cap convection and decrease POPs. Long range models show a
tropical wave propagating west over the area south of Cuba.
Southeasterly flow at 850 mb will usher in deeper tropical moisture
to South Florida and PW values are forecast to shoot over 2 inches.
This surge may make for active pattern during the Monday night
through Wednesday time frame.
Remnant showers will end at Naples by 2z, then generally dry/VFR
conditions should prevail into Friday. Friday afternoon shower and
thunderstorm chances are around 30 percent, so didn`t feel confident
enough to but VCTS, and instead went with VCSH. Light east wind
overnight will increase to around 10 KT on Friday.
High pressure centered north and east of the waters will continue
to dominate South Florida waters through the weekend. East and
southeast winds of 5 to 10 knots to prevail with seas of 3 feet or
less. Isolated to scattered thunderstorms, especially over Lake
Okeechobee and nearshore Gulf waters during the late afternoons
and evenings, will create locally strong and erratic wind gusts.
.PRELIMINARY POINT TEMPS/POPS...
West Palm Beach 80 93 77 92 / 10 20 20 10
Fort Lauderdale 80 91 80 91 / 20 30 30 10
Miami 81 92 79 91 / 20 30 30 10
Naples 77 92 77 92 / 20 40 40 40