National Weather Service San Juan PR
453 AM AST Thu Jul 5 2018
.SYNOPSIS...
Saharan dust is still established across the area, but on Friday
showers should help to lower the concentrations. The Saharan dust
is expected to once again increase on Saturday. Sunday a surge of
moisture will move in from the east ahead of invest 95L so
showers are expected to increase across the U.S. Virgin Islands
during the morning, then across Puerto Rico during the afternoon.
Monday invest 95L will transverse the area with scattered to
numerous showers with isolated thunderstorms, then the wave
clears the region on Tuesday with fair weather returning to the
region through Friday.
&&
.Short Term...Today through Saturday...
Saharan dust along with low relative humidity in the mid to upper
levels of the atmosphere will continue to dominate the local
weather today. Locally induced showers can be expected over the
western and western interior PR in the afternoon but due to the
lack of moisture along the mid levels and little instability,
showers are expected to be short lived. On Friday, Saharan dust
concentration is expected to decrease and a patch of low level
moisture along with the proximity of an upper level low will then
create a better platform for shower development over the local
islands. On Saturday, drier air will move into the area resulting
in mostly fair weather conditions once again.
Temperatures will be in the upper 80s to lower 90s in lower
elevations, and the upper lower to middle 80s in higher elevations.
Winds will prevail out of the east at 10 to 15 mph with higher
gusts. Also, because drier conditions continue and very little
rainfall has occured, fire danger will moderate today.
&&
.LONG TERM...Sunday through Friday...
There`s a lot of uncertainty in the long-term period due to
invest 95L in the eastern Atlantic, but what is certain is the
increasing rain chances for Puerto Rico and the U.S. Virgin
Islands on Sunday and Monday. Sunday moisture ahead of 95L will
reach the forecast area, as a result, rain will move into the U.S.
Virgin Islands during the morning and continue to spread east
across Puerto Rico during the afternoon.
The current GFS and ECMWF models both have invest 95L approaching
the local area as a tropical wave on Monday, this could cause an
increase in showers and thunderstorms over the region if this
comes to fruition. We will continue to monitor the situation as
invest 95L continues to move across the eastern Atlantic.
Remember the National Hurricane center is the official source for
all information concerning invest 95L. The moisture from the
tropical wave is forecasted to move out of the area on Tuesday,
then dry air and saharan dust works in from the east. A fair
weather pattern is expected to prevail starting Wednesday and last
through Friday.
&&
.AVIATION...VFR conds are expected to prevail. Hazy skies will
continue, but, visibilities will remain VFR cat. SHRA can be
expected in and around of TJMZ/TJBQ from 04/17-04/22Z. Winds will
continue from the east at around 10 kts increasing 15 to 20 kts with
higher gusts after 05/13Z.
&&
.MARINE...
Seas up to 6 feet and winds up to 15 kts with possible gusts up to
20 through Saturday. Small craft operators are urged to exercise
caution. Moderate risk of rip currents across most of the beaches
in PR, Vieques, Culebra, and Saint Croix.
&&
.PRELIMINARY POINT TEMPS/POPS...
SJU 89 79 89 79 / 10 10 20 30
STT 89 78 89 78 / 20 10 10 20