Scientific Forecaster Discussion
fxus62 kmfl 140601 aaa
Area forecast discussion...updated
National Weather Service Miami Florida
103 am EST Thursday Nov 14 2019
some gusty periods around 25kt are still possible through the mid
morning hours over pbi and fxe with showers moving ashore, then
subsiding for the rest of today. MVFR cigs will occur intermittently
with the heaviest showers, but expect bkn mid level clouds to
prevail today as a frontal boundary backtracks across the area.
Prev discussion... /issued 307 PM EST Wed Nov 13 2019/
The main weather for the next day will be associated to a cold
front that is about through the area already. Models are
indicating the front should stall just to the south of the cwa,
over the Keys or Florida Straits. The shower activity currently
over the water is probably associate with some weak upper level
dynamics. Looking at 500mb, the models are showing continued trend
towards height falls this afternoon over the area. However, The
Heights falls are minor, with a little over 10 dm through the day
today. The GFS was also showing some moderate 500mb positive
vorticity advection over the near shore Atlantic waters, which
likely helped produce the showers. The models are showing this
should move out of the area, to the south, through this
afternoon. Pwats also show a very slight drying trend through the
day, but still remaining over 1.5 to 1.6 inches.
Models, so far, have been way overdoing precipitation over the
Mainland through the day, with almost all rain over the Atlantic
water, just skimming by the coastal areas. This should continue to
be the case through the overnight hours.
Late tonight and into tomorrow, a low pressure system should
develop along the frontal boundary, causing the front to push back
to the north tomorrow, causing the County Warning Area to be in the warm sector
tomorrow, which is reflected in the high temperatures forecast to
be several degrees higher than today. Models are also indicating
the wind flow to be more easterly, at least in the morning, then
turning more southeast to southerly by tomorrow afternoon. This
would allow for showers tomorrow, especially in the afternoon in
the western interior and along the Gulf Coast. By late afternoon,
shower activity should increase in the lake region, especially due
to the change to a southerly flow.
Thursday night through Sunday...
A compact shortwave trough will traverse the northern Gulf of Mexico
before phasing with an amplifying wave over the eastern Continental U.S..
surface low pressure will develop from northern Florida towards the
offshore Carolinas, with the attendant cold front sweeping through
Mainland Florida by Friday evening. Southerly winds will provide
deep and focused moisture advection into our area, with
precipitable water values reaching 2 inches on Friday. Rain
chances will increase before the frontal passage, with enough
instability present for a few thunderstorms to be possible as
well. Temperatures should remain seasonally cool on Friday given
the increased cloud coverage and shower chances.
The upper trough axis will depart to our east through the weekend as
the deepening surface cyclone locates just offshore from the
Carolinas. Post frontal conditions are expected, with northwesterly
flow aloft, low-level cold advection, and plentiful low-level
moisture. This should keep scattered to broken cloud cover through
the weekend, with showers possible. The weekend should be seasonally
cool, with highs mostly in the upper 70s, and lows ranging from the
mid/upper 50s around the lake to near 70 along the Atlantic coast.
Monday through Wednesday...
A meridional flow pattern will prevail aloft with sharpening
troughing crossing the eastern states by mid week. An attendant
frontal zone should pass through during this time. Shower chances
should increase towards mid week with the front in the vicinity.
Thereafter ridging aloft should support surface high pressure as
it builds across the southeast Continental U.S.. therefore quieter conditions are
expected across South Florida to close out the week.
The northerly component of the wind through the day and into the
night will help to cause seas to build in the Atlantic waters,
possibly to around 10 feet, especially in the Gulf Stream. There
is a Small Craft Advisory in affect through Friday morning. As
the wind becomes more easterly then southerly tomorrow, seas
should slowly subside tomorrow and tomorrow night.
As another cold front moves through this weekend, the northerly
wind will return, causing seas to build once again for the latter
half of the weekend, possibly bringing back hazardous marine
conditions for the Atlantic waters by Sunday afternoon.
A northeasterly wind behind a cold front and a weak swell this
afternoon are combining to bring a high risk of rip currents to
the Palm Beach area, and a moderate risk to the remaining beaches
along the East Coast. As the wind becomes more easterly tomorrow,
the enhanced risk of rip currents will continue.
Also, the Spring tides continue to bring chances of minor flooding
along the Atlantic Coats this evening, and possibly another cycle
of the high tide in the morning hours.
Preliminary point temps/pops...
West Palm Beach 71 81 71 81 / 20 20 40 70
Fort Lauderdale 74 82 74 82 / 30 20 40 70
Miami 73 83 73 83 / 30 20 40 70
Naples 68 84 70 80 / 10 40 40 60
Florida...high rip current risk through Thursday evening for flz168.
Am...Small Craft Advisory until 5 am EST Friday for amz650-651-670-