Area Forecast Discussion
Issued by NWS San Juan, PR
FXCA62 TJSJ 270134
Area Forecast Discussion
National Weather Service San Juan PR
934 PM AST SUN JUN 26 2016
Scattered showers and thunderstorms affected the central
interior, western and interior sections of Puerto Rico. Some
sections received accumulations between one and three inches of
rain. Brief trade wind showers will move across the local waters
and across the windward over eastern Puerto Rico overnight and
early Monday morning. Once again, another round of locally
induced convection is expected across the interior and western
sections on Monday afternoon.
VFR conditions expected over most terminals through
27/17Z. SHRA and ISOLD TSRA expected to develop over west and
interior Puerto Rico between 27/17Z and 27/22Z so at least VCTS is
expected for TJBQ, TJMZ, and TJPS. However, these is also a chance
of SHRA and ISOLD TSRA in the vicinity of TJSJ, but not as
persistent. Sfc winds should prevail from the E at 10-15KT with
occasional gusts and sea breeze variations.
Tranquil marine conditions are expected through most of the work
week, with seas of 5 feet or less, and winds at 10 to 15 knots
increasing at 15 to 20 knots during the afternoon hours.
.PREV DISCUSSION... /issued 202 PM AST SUN JUN 26 2016/
SYNOPSIS...Broad surface high pressure will continue across the
north central Atlantic for the next several days. Weak mid level
ridge across will continue to move west across the forecast area.
TUTT will move to the northeast of the area as an upper level
short wave takes it place just north of the area. Moderate trade
winds will continue through the forecast period. The next
tropical wave passage is expected on Friday.
DISCUSSION...Showers and isolated thunderstorms developed late in
the morning hours across the northern U.S. Virgin Islands...then
by early in the afternoon hours across San Juan and vicinity and the
interior and southern sections of Puerto Rico. The doppler radar
estimated between 1-2 inches of rain across areas in Juana Diaz
and Ponce. Urban and small stream flooding is expected with the
heaviest showers through at least this afternoon.
TUTT will continue to shift to our northeast while weakening and
leaving the area on its convergent side during the next 12-24 hours.
Another TUTT will develop across the western Atlantic and extend a
short wave trof into the northern Caribbean islands with favorable
upper level dynamics expected across the area once again from
Tuesday thru Wednesday evening. Therefore, afternoon showers and
thunderstorms are expected across the interior and western Puerto
Rico on Monday. Increasing on intensity and coverage from Tuesday
and Wednesday as moisture increases and divergent pattern settles
aloft. Fair weather pattern is expected to prevail under limited
low level moisture by the end of the week. As wind direction and
local effects will favor afternoon convection across the interior
and western sections of PR. The next tropical wave passage is
expected by Friday.
AVIATION...SHRA and ISOLD TSRA expected to continue across west
and interior PR thru 22Z...so at least VCTS is expected for TJBQ,
TJMZ, and TJPS. However, there is also a chance of SHRA and ISOLD
TSRA in the vicinity of TJSJ, but not as persistent. Sfc winds
should prevail from the E at 10-15KT with occasional gusts and sea
MARINE...Tranquil marine conditions are expected during the next
few days, with seas 5 feet or less, and winds at 10 to 15 knots.
However...higher gusts due to thunderstorms and showers can be
expected each afternoon over the coastal waters of western PR.
.PRELIMINARY POINT TEMPS/POPS...
SJU 79 90 78 91 / 20 20 20 30
STT 80 91 79 91 / 30 30 30 30