Area Forecast Discussion
Issued by NWS San Juan, PR
FXCA62 TJSJ 281753
Area Forecast Discussion
National Weather Service San Juan PR
153 PM AST SAT MAY 28 2016
.SYNOPSIS...Upper level low located over the Bahamas and digging
into Cuba...will remain over that general area through at least
the middle of the upcoming week. There is also the current
Tropical Depression 2 to the north of the Bahamas...the proximity
of this Tropical Depression will help pull moisture from the south
and over the local area...the combination of these 2 features will
keep a moist and unstable environment across the Central and
Eastern Caribbean for the next few days. Surface high pressure
northeast of the local area will keep a southeasterly flow through
the end of next week.
.DISCUSSION...Scattered to locally numerous showers affected the
local islands in the morning and early afternoon hours...mostly
over the island of St. Croix as well as northern and eastern PR.
Some minor and urban flooding was observed over PR as well as
rapid river rises on those river stemming from El Yunque
Rainforest. As of this writing...showers are still affecting
portions of northern and eastern PR but they have diminished in
intensity. Latest guidance and current observations indicate that
some showers are still expected this afternoon across the north
and eastern portions of PR including the islands of Vieques and
Culebra...some light rain expected over St. Croix.
The upper trough is expected to move slightly to the west by
Sunday...which will cause slightly less instability in the upper
levels over the local area. This means that even though there is
still plenty of available moisture...the expected cloud cover and
the slightly less upper level dynamics should cause less shower
and thunderstorm activity on Sunday. Having said that...there is
still a chance of showers and thunderstorms over the local area.
For next week...the upper trough is still expected to be over Cuba
and perhaps a bit northwest of the Bahamas...this will give way to
an upper ridge establishing over the local islands next week. This
means that we expect to have plenty of moisture with a
southeasterly wind flow but a ridge in the mid and upper levels
which should limit thunderstorm development to only isolated
thunderstorms once the moisture combines with the local effects.
.AVIATION...VCSH across most of the local terminals. CIGS at
around FL060 through the afternoon. SE wind flow may cause SHRA to
move into TJSJ later in the afternoon and some SHRA may develop
near TJBQ. Winds will decrease to around 5-10kt after 28/23Z then
increase once again to around 10-15kt after 29/12z.
.MARINE...Small craft should exercise caution for winds up to 20
knots and seas increasing up to 6 feet across the offshore
Atlantic waters tonight...decreasing up to 5 feet on Sunday.
Showers and isolated thunderstorms expected over the waters
through the weekend.
.PRELIMINARY POINT TEMPS/POPS...
SJU 77 89 77 88 / 40 50 40 40
STT 79 86 79 86 / 40 40 40 40