Area Forecast Discussion
Issued by NWS San Juan, PR
FXCA62 TJSJ 051737
Area Forecast Discussion
National Weather Service San Juan PR
137 PM AST Mon Dec 5 2016
.SYNOPSIS...Mid to upper ridge will continue to build from the
west through the rest of the work week. Surface high north of the
area will continue to build into the central Atlantic by the end
of the week. Remnants of a frontal boundary will linger across
the local area for the next few days. An easterly wave and short
wave trof will increase the chances of showers and thunderstorms
across the Caribbean waters and enhance afternoon convection over
mainland PR on Friday.
.DISCUSSION...Some cloudiness and isolated to scattered shower
activity associated to a frontal boundary was observed across much
of PR and the northern USVI`s during the day. As of 1 PM, around
half an inch of rain was reported with this shower activity
across portions of northern and eastern PR. For the rest of the
afternoon hours, showers currently developing over the interior
and southwestern sections of PR will continue through at least
sunset. Trade wind shower activity will follow overnight into
Tuesday morning across the USVI and PR.
As ridge builds aloft moisture will erode quickly through at least
Friday. Weather conditions should continue to improve, with
limited trade wind shower activity across the area and shallow
afternoon convection over the interior/western portions of PR. On
Friday as easterly wave moves across the Caribbean waters and
trofiness pattern press against the ridge, moisture and
instability will increase across the forecast area. Ridge pattern
is forecast to follow through the weekend.
.AVIATION...VFR conditions are expected across all terminals
through 06/18z. VCSH possible at TJSJ...TIST...TJBQ and TJMZ through
05/22Z as SHRA develop across interior, Western and SW-PR. Winds
will be East around 10 kt expected with sea breeze variations in the
.MARINE...Seas should continue between 3-5 feet through the rest
of the day, increasing overnight with the arrival of a northerly
swell. This swell will result in a high rip current risk across
the Atlantic coastline of PR, Culebra and St. Thomas. Moderate
risk expected elsewhere across the rest of the north and east
facing beaches of the islands.
.PRELIMINARY POINT TEMPS/POPS...
SJU 77 86 76 85 / 40 40 30 30
STT 76 86 76 85 / 20 20 30 30
PR...High Rip Current Risk from late tonight through late Tuesday
night for Culebra-North Central-Northeast-Northwest-San
Juan and Vicinity-Southeast-Western Interior.
VI...High Rip Current Risk from late tonight through late Tuesday
night for St.Thomas...St. John.. and Adjacent Islands.