National Weather Service San Juan PR
559 AM AST Tue Feb 7 2017
.SYNOPSIS...Broad surface high pressure will continue across the
Central Atlantic promoting a moderate to fresh trade wind flow
across the islands. A polar trof and associated front will enter
the Western Atlantic on Wednesday and move north of the area by
late in the work week. In the short term, weak short wave trofs
will continue to promote moisture advection across the islands.
Mid level ridge will build from the east and a surface
perturbation will also move from the east on Thursday enhancing
the available low level moisture and weakening the cap inversion.
&&
.DISCUSSION...Trade wind showers continued across the local waters
with a some moving at times across the USVI and eastern portions
of Puerto Rico. The Doppler radar estimated less than a quarter of
an inch of rain with the heaviest showers over eastern PR. For the
rest of the day, trade wind shower pattern will continue and
diurnally induced scattered to numerous showers can be expected in
the afternoon across portions of western/northwestern PR. Similar
conditions are expected on Wednesday, but showers should be
isolated to scattered during the afternoon. Trade winds will
increase today as surface high north of the area moves and builds
across the Central Atlantic.
Later on Thursday, a surface perturbation will increase once again
the chances of showers across the islands through the late evening
hours. A polar trof and associated frontal boundary are forecast
at the moment to remain north of the area by Friday and linger
through the weekend. Meanwhile a strong surface high pressure
will build behind the front bring patches of the remnants of the
front and moisture advection on a northeasterly wind flow by early
next week.
&&
.AVIATION...Mostly VFR conds will prevail across the area thru the
fcst pd. However, -SHRA in trade wind SHRA could affect the
Leeward/USVI and TJSJ terminals through 07/16z. Brief MVFR cigs and
mtn obscurations are likely near TJBQ/TJMZ btwn 07/18-21Z due to
afternoon SHRA over the mtn ranges and downstream from central and
wrn PR. Llvl winds from the E-ESE will increase to 15-20 kts aft
07/13Z with higher gusts and sea breeze variations expected aft
07/14z. Maximum winds 285/55 kt at FL410.
&&
.MARINE...Seas up to 8 feet and east winds up to 21 knots are
expected today. Small craft advisories are in effect for all the
near shore waters the islands, except the southern and western
coastal waters of Puerto Rico. There is a high risk of rip
currents along the Atlantic beaches of the islands.
&&
.PRELIMINARY POINT TEMPS/POPS...
SJU 85 74 86 75 / 40 20 20 10
STT 84 75 83 74 / 30 10 20 10