Area Forecast Discussion
Issued by NWS San Juan, PR
FXCA62 TJSJ 211745
Area Forecast Discussion
National Weather Service San Juan PR
145 PM AST Tue Feb 21 2017
.SYNOPSIS...A seasonable weather pattern is expected to prevail
during the next several days as a mid to upper level trough moves
away and a ridge pattern builds across the forecast area. Above
normal temperatures are likely by the end of the week and into
the upcoming weekend.
.DISCUSSION....Partly cloudy skies and brief passing showers
along the northern half of Puerto Rico and the USVI prevailed
during the morning hours as well as early in the afternoon.
Temperatures were generally in the low to mid 80s under a
northerly wind flow at 15 to 20 mph.
A mid to upper level trough with its associated surface low
across the northeast Caribbean will continue to move southeast
and away from the forecast area tonight while weakening. As
this feature moves away; a ridge pattern will build across the
forecast area tomorrow and hold through early next week.
At lower levels, northerly winds will continue to prevail tonight
and tomorrow becoming southeast Thursday and into the upcoming
weekend as a surface low develops across the southwest Atlantic.
Therefore under the aforementioned pattern and guidance
suggesting precipitable water near or slightly below the normal
values, continue to expect a seasonable weather pattern with trade
wind showers in the morning and evening hours followed by limited
afternoon convection. The southerly wind flow which is expected
Thursday and into the upcoming weekend likely to result in above
normal temperatures along the northern slopes of Puerto Rico.
.AVIATION...VFR conditions are expected to prevail across all TAF
sites through the forecast period. Some light passing showers can
be expected in the vicinity of TNCM, TKPK, TIST, TISX and TJSJ
tonight. Low level winds will be mainly North at 10 kts.
.MARINE...Small pulses of northerly swell are forecast to reach
the regional waters during the next few days with swell action
expected to peak Friday morning. There is a moderate to high risk
of rip currents along the Atlantic shoreline with seas between 5
and 6 feet this afternoon. Seas and winds subsiding overnight
with seas around 5 feet.
.PRELIMINARY POINT TEMPS/POPS...
SJU 72 83 71 86 / 20 30 30 30
STT 74 82 72 83 / 20 30 30 30
PR...High Rip Current Risk until 6 PM AST this evening for Mayaguez
and Vicinity-North Central-Northeast-Northwest-San Juan and