National Weather Service San Juan PR
151 PM AST Wed Oct 19 2016
.SYNOPSIS...A persistent band of moisture out of the south
associated with a low pressure north of the Windward Passage
tonight will slowly dissipate overnight with drier weather to
follow on Thursday. Patches of moisture will move through the area
into early next week on more easterly trade winds.
At upper levels...A NE-SW ridge of high pressure will migrate to
Hispaniola over the weekend and then yield to a passing shortwave
traveling east late Monday night into Tuesday. The ridge will
return to Puerto Rico by Thursday.
At mid levels...A ridge extending into the Caribbean out of a
high pressure northeast of the Leeward Islands will cross Puerto
Rico Friday. High pressure will then continue over the Caribbean
and the Greater Antilles chain through early next week.
At lower levels...High pressure ridging into the northeast
Caribbean Sea from a moderate high in the north central Atlantic
Ocean will pull north and join high pressure over the coast of
South Carolina Sunday night while weak N-S troughing moves east
toward the local area. During the rest of the week high pressure
builds east into the western Atlantic generating a steady easterly
trade wind flow.
&&
.DISCUSSION...A persistent band of showers and thunderstorms
associated with a trough that has extended out of a low over the
Bahama Islands north of the Windward passage moved out of the Mona
Channel this morning and over the western end of Puerto Rico
during the day. With moisture also migrating out of the Caribbean
Sea to the south, eventually the whole island, and parts of
Culebra and Vieques received at least some rain. Gusty winds were
reported in various parts of Puerto Rico, although no damage has
been reported so far. The Guanajibo river was slowly approaching
flood stage of 20 feet again and was within 6 inches as of 1:45 PM
AST. The rain that has fallen is expected to produce no more than
minor flooding on the Guanajibo.
The rain band is expected to dissipate and possibly reform over
Hispaniola on Thursday leaving considerably less wet weather for
Puerto Rico Thursday. As high pressure connects north of the area
winds will become more easterly and showers will return to a more
seasonal and limited pattern. Moisture reaches a minimum on
Sunday, but slowly recovers through Thursday of next week.
&&
.AVIATION...TSRA/SHRA across mainland PR will continue to impact
the flying area of all PR terminals through the early evening hours.
TEMPO mvfr at TJSJ and TJPS with gusty winds up to 30 kts possible
with TS. -RA and VCTS elsewhere in PR. Some of this activity could
spread later into the flying area of the USVI terminals. But mainly
VFR expected. Low level winds expected from the S-SE at 8-20 kts
with higher gusts near showers and thunderstorms.
&&
.MARINE...Marine conditions are slowly subsiding but buoy 41043 is
still over 7 feet and the buoy at Rincon is now close to 6 feet.
All areas should be below small craft advisory conditions by
Thursday afternoon. Small craft advisory conditions are not
expected to return before Tuesday.
&&
.PRELIMINARY POINT TEMPS/POPS...
SJU 79 90 78 92 / 20 30 20 20
STT 79 89 81 85 / 20 20 30 30