Area Forecast Discussion
Issued by NWS San Juan, PR
FXCA62 TJSJ 251758
Area Forecast Discussion
National Weather Service San Juan PR
158 PM AST WED MAY 25 2016
.SYNOPSIS...Mid to upper level ridge will continue to dominate
the local weather conditions through the end of the work week. At
low levels...surface high pressure over the Central Atlantic will
weakens...diminishing the trade winds across the local region. Then...
a deep layer trough will amplify over Cuba and Bahamas during the
next few days...favoring the moisture transport across the Central
and East Caribbean during the weekend. As a result...weather pattern
will become moist and unstable across the local area by the end
of the week.
.DISCUSSION...Sunny skies have prevailed across most of Puerto
Rico today...resulting in strong daytime heating across the local
islands. Although...max temp remains in the upper 80s across most
of the islands...the heat index reached the mid to upper 90s. Sea
breeze formed over western PR early this afternoon. This have
resulted in shower development over the west and southwest Puerto
Rico so far this afternoon. The activity is forecast to taper off
Ridge aloft combined with somewhat dry air at mid level will
likely result in a generally fair weather pattern across the
islands through Friday. Typical showers over western PR will
develop each afternoon due to the sea breeze convergence and the
orographic effects. Mid to upper clouds will stream across the
islands from late Thursday into the weekend.
Operational models suggest a wetter pattern by the end of next
week as a mid-upper level trough amplifies over Cuba/Bahamas. This
will bring deep tropical moisture into the local area. As a result...
High moisture content combined with somewhat favorable upper dynamics
will increase the potential for organized convection across the
forecast area...especially Sunday and Monday.
.AVIATION...VFR conds expected thru the forecast period. Afternoon
showers across SW-PR may affect the vicinity of TJMZ until 25/22z
but the rest of the terminals should remain with fair weather...
only light and brief SHRA in the vicinity during the night. Winds
from the East at around 10kt with sea breeze variations until
25/23Z...then winds decreasing overnight...becoming light and
variable...increasing once again and from the East after 26/12Z.
.MARINE...Winds and seas will subside sightly as surface high
pressure over the Central Atlantic weakens. Therefore...expect
moderate winds and seas of 3-5 ft over the next 5-7 days. No Small
Craft Advisories are anticipated during the forecast period.
.PRELIMINARY POINT TEMPS/POPS...
SJU 77 88 77 90 / 20 20 40 40
STT 78 87 77 87 / 20 20 40 40