National Weather Service San Juan PR
521 AM AST Tue Jan 31 2023
.SYNOPSIS...Moderate to fresh northeast trades due to a surface
high over the western Atlantic will continue to promote breezy
conditions and choppy to hazardous wind-driven seas for the next
few days. Life-threatening rip currents will persists across the
north and east facing beaches of the islands through midweek.
Passing trade wind showers will prevail through the end of the
week, with minor rainfall accumulations in general.
.SHORT TERM...Today through Thursday...
Variable weather conditions are expected today across the islands,
mainly across the northern and eastern portions of Puerto Rico, and
the USVI in the morning hours. The main hazards across the islands
continue to be choppy to hazardous seas across the Atlantic waters
and Passages until the end of the period. In addition, life-
threatening rip currents will continue along the north and east
facing beaches of the islands until the end of the workweek. For
today, the shower activity should be less than the previous days due
to dry air present across the local area. This weather pattern will
persist for the next few days. A broad mid level high pressure will
be the dominant weather feature and is expected to continue
promoting drier air across the region. For the rest of the period,
fragments of moisture will be carried by the trades, resulting in
passing showers overnight and during early morning hours across the
windward portions of the islands. During the afternoon hours,
convection still possible to occur across the western to
southwestern portions of Puerto Rico leaving minor rainfall
accumulations. Temperatures across the islands are expected to be
normal to below due to the northeast winds.
.LONG TERM...Friday through Tuesday...
A weak surface high pressure over the central Atlantic will be
replaced by a stronger high pressure on Sunday. In response,
winds will shift from the east to east-southeast and become
moderate to fresh once again later in the weekend. At upper
levels, a ridge west of the region is expected to shift east of
the Leewards by Sunday, as a long wave trough moves slowly
eastwards from the west through the rest of the long term period.
The 500 mb temperature is forecast to drop to around -10 degrees
Celsius during this period, increasing instability aloft.
From Sunday through Tuesday, weak trade wind perturbations will
stream across the islands during the morning hours, increasing
shower activity in early morning convection between the USVI and
eastern PR, followed by afternoon showers over western PR.
Rainfall amounts are expected to remain under an inch, but will
continue to monitor and adjust the forecast as needed during the
next couple of days.
.AVIATION...Mainly VFR conditions are expected to prevail across all
terminals during the next 24 hrs. Fast moving trade wind showers may
cause brief MVFR cigs at TJSJ/TIST/TISX btw 10z-22z. Winds will
continue from the NE at 10-18 kts with higher gusts after 31/14Z.
.MARINE...Choppy to hazardous seas between 5 and 8 feet will
continue through midweek due to a fading northeasterly swell and
wind-driven seas. NE winds at 15-20 kt with higher gusts will
prevail for the next couple of days, and SCAs are in effect for
most of the local waters.
Across the northwest to northeastern beaches of the islands there
is an elevated risk of rip currents, and a High Rip Current Risk
remains in effect for northern PR, Culebra, and St. Croix. Please
refer to the latest Coastal Hazard Message (CFWSJU) and Surf Zone
Forecast (SRFSJU) for detailed information.
PR...High Rip Current Risk through late Thursday night for PRZ001-002-
High Rip Current Risk through Wednesday afternoon for PRZ012.
VI...High Rip Current Risk through Wednesday afternoon for VIZ002.
AM...Small Craft Advisory until 8 PM AST Wednesday for AMZ710-712.
Small Craft Advisory until 2 PM AST Wednesday for AMZ715-741.
Small Craft Advisory until 2 PM AST this afternoon for AMZ722-
Small Craft Advisory until 2 AM AST Wednesday for AMZ742.