National Weather Service San Juan PR
352 AM AST Sat Jul 15 2017
.SYNOPSIS...Tropical wave south of PR will exit the area today. A
tutt low north of Hispaniola will continue to provide ventilation
aloft. Saharan dust is expected behind the wave. An upper ridge
will continue to build from the east through early next week.
Broad surface high pressure will remain anchored across the
Central Atlantic for the next several days. Another surge in
moisture is expected quickly on Tuesday, followed by another SAL
intrusion through mid week next week.
&&
.SHORT TERM...Today through Monday...Morning surface analysis
depicted a tropical wave extending from the northeast Caribbean to
the northern coast of Venezuela. The wave is expected to continue
moving westward today with the bulk of its moisture passing
mostly south of the local islands across the Caribbean waters. For
the rest of the morning the moisture associated with the northern
part of the wave will promote the development of showers and
possible thunderstorms mostly across the local Caribbean waters
and across the U.S. Virgin Islands, Vieques, Culebra and eastern
sections of Puerto Rico. For this afternoon this moisture in
combination with daytime heating and local effects are expected to
induce a new round of showers and thunderstorms across central
interior, western and northwest Puerto Rico. Due to previous days
rainfall over these same areas, urban and small stream flooding is
possible this afternoon. The limiting factors to this afternoon
convection is the abundant cloudiness expected from the morning
shower activity and an upper level ridge expected to remain over
the region. The wave is forecast to exit the area tonight.
Lingering moisture behind the wave will continue to produce some
cloudiness and showers across the region on Sunday. A relatively
drier air mass is expected to move across the region late Sunday and
Monday, limiting the development of shower and thunderstorm
activity. However, the typical afternoon convection will result in
showers and thunderstorms over western and interior PR each
afternoon with isolated showers elsewhere.
.LONG TERM...Tuesday through Sunday...A wind surge with an
increase moisture is expected briefly on Tuesday due to an
easterly perturbation. This will be followed by Saharan dust and
drier conditions through Thursday morning. Normal to above normal
temperatures will continue across coastal areas of the islands
through at least mid week. Another increase in moisture is
expected late in the week into the weekend as another tropical
wave moves across the local area.
&&
.AVIATION...Tropical wave moving across the forecast area will
continue to result in SHRA/TSRA through the forecast period. TEMPO
MVFR and brief VFR possible at times across the Leeward/USVI/Eastern
PR terminals through 16z. Afternoon SHRA/TSRA expected mainly to
affect the NW quadrant of PR impacting the flying area of TJMZ/TJBQ
and possible TJSJ after 16Z. Winds below FL150 from the ESE at 10-20
kt.
&&
.MARINE...Shower and thunderstorm activity will continue across
the local waters as the tropical wave exits the region today. Seas
expected between 3-5 feet and winds will prevail from the east to
southeast at 10-15 knots. Winds and seas are expected to increase
early next week. A moderate risk of rip currents will continue
through the weekend...for the east, north and southern beaches of
Puerto Rico, Culebra, Vieques and St. Croix.
&&
.PRELIMINARY POINT TEMPS/POPS...
SJU 89 79 90 79 / 40 20 20 20
STT 90 80 89 79 / 40 30 30 30