Scientific Forecaster Discussion
fxus62 kmfl 230059
Area forecast discussion
National Weather Service Miami Florida
859 PM EDT Mon Jul 22 2019
mainly VFR expected tonight with some vcsh periods still possible
through 04z. Light and variable winds prevail until around 14-15z,
then becoming south-southwest around 10kt in the late morning and afternoon
hours. Some adjustments to the forecast may be required depending
on the final solution of tropical depression 3, which is moving
across the Bahamas.
Previous discussion... /issued 302 PM EDT Mon Jul 22 2019/
Today through Tuesday...
Our attention is focused on an area of low pressure now over the
western Bahamas. Showers and thunderstorms have increased in
association with this feature, and the National Hurricane Center has
indicated a 60 percent chance for tropical development over the next
48 hours. While environmental conditions are only marginally
conducive for development, only a slight increase in organization is
needed for this feature to become a tropical depression. The core of
this low pressure system is forecast to remain offshore and to our
east, bringing increased shower and thunderstorm coverage from
tonight into tomorrow, particularly across our eastern areas.
Regardless of tropical development, our main messaging for South
Florida remains as follows:
1. Our main concern is for locally heavy rainfall and minor street
flooding. This hazard is greatest along the East Coast, including
the metropolitan Miami, ft. Lauderdale, and Palm Beach areas.
2. Gusty winds are possible in squalls. This will create
potentially hazardous marine conditions in the Atlantic and
Biscayne Bay waters, especially for small craft.
The main window for these impacts is from tonight into Tuesday
Wednesday and beyond...
Enhanced rain chances may continue into Wednesday, particularly
across northern portions of our area as deep moisture associated
with the low pressure system pulls away. Rain chances should then
be driven more by sea breeze circulation patterns later in the
Deteriorating marine conditions are expected for the Atlantic
waters tonight as showers and thunderstorms become numerous. Wind
speeds should increase into the 15 to 20 knot range, with higher
gusts possible in squalls. Small craft should exercise caution
into at least Tuesday evening due to the potential for squally
weather, gusty winds, and higher seas. Boating conditions should
begin to improve later on Wednesday.
Afternoon convection will be mainly over the interior and West
Coast this afternoon. Have removed thunderstorms in the vicinity from East Coast sites but
will still monitor activity moving west over the Atlantic from the
Bahamas. Easterly winds this afternoon except for apf, with some
occasional gust. Will continue to monitor convection from the
Bahamas overnight for impact along the East Coast. Included vcsh
for now but confidence is low. L/v winds will becoming south-southwest
Poor conditions are expected at areas beaches for tonight and
Tuesday. Onshore winds are expected for the Atlantic beaches,
with wind speeds increasing later tonight into Tuesday. This could
result in an enhanced rip current risk. Squally conditions are
possible later tonight into Tuesday, bringing lightning and
periods of heavy rainfall.
Preliminary point temps/pops...
West Palm Beach 78 86 77 91 / 70 70 50 60
Fort Lauderdale 79 86 78 91 / 60 70 60 60
Miami 79 88 78 92 / 60 70 40 40
Naples 76 87 77 88 / 30 50 30 40
Am...Small Craft Advisory until 8 am EDT Tuesday for amz670.