Area Forecast Discussion
Issued by NWS San Juan, PR
FXCA62 TJSJ 271743
Area Forecast Discussion
National Weather Service San Juan PR
143 PM AST Thu Oct 27 2016
.SYNOPSIS...A seasonable weather pattern will prevail Friday and
into the upcoming weekend with locally induced showers and Tstorms
under a mid to upper level ridge pattern. Rainy conditions possible
next week as the aforementioned ridge pattern weakens and a trough
develops north of the area. Meanwhile, tropical wave will continue
to move away from the local islands tonight.
.DISCUSSION...As a tropical wave moves away from the forecast
area this evening and tonight, the chance of showers and isolated
Tstorms will decrease. However, continue to expect shower and
thunder development over and west of the Cordillera Central through
the afternoon hours followed by a few passing showers across
windward areas overnight.
Friday through the upcoming weekend, a seasonable weather pattern
is expected to prevail with locally induced afternoon showers and
thunderstorms each day. Showers and Tstorms will be focused across
central and northwest PR as well as portions of the San Juan Metro
Area under a gentle southeast wind flow. Although widespread
convection is not expected at this time, urban and small stream
flooding still possible Friday and the upcoming weekend due to
already saturated soils and slow moving showers/Tstorms.
The ridge aloft will then erode next week as a broad upper level
trough develops across the tropical Atlantic and into the Caribbean
basin. This will result in deep tropical moisture pooling across
the forecast area Tuesday-Saturday with a rainy weather pattern
.AVIATION...Afternoon SHRA/TSRA are possible till 27/22z across
the interior and West Half of PR. This activity could produce
brief MVFR conds at TJPS/TJMZ/TJBQ. Elsewhere frequent VCSH are
possible. Easterly winds at 10kt during the afternoon and evening,
becoming light and variable overnight.
.MARINE...A moderate swell NNE of 4-6 ft at 10 sec will continue
to move across the local Atlantic Waters and Caribbean Passage
over the next few days. Seas will subside somewhat during the
weekend and early next week. Seas are expected to remain below
advisory levels through the forecast period. However...Small
craft operators should exercise caution through Friday due to
seas up to 6 feet across the offshore Atlantic Waters.
.PRELIMINARY POINT TEMPS/POPS...
SJU 79 89 78 89 / 20 20 40 40
STT 80 87 79 87 / 30 30 40 40