Area Forecast Discussion
Issued by NWS San Juan, PR
FXCA62 TJSJ 271804
Area Forecast Discussion
National Weather Service San Juan PR
204 PM AST WED JUL 27 2016
.SYNOPSIS...Saharan dust is creating hazy skies across the forecast
area. A TUTT to the northeast of the islands will move westward
and across the forecast area on Thursday. The next tropical wave
is expected to enter the eastern Caribbean on Sunday.
.DISCUSSION...Hazy skies prevailed across the islands Today. This
limited the shower development across much of the forecast area.
However, locally induced showers and two isolated thunderstorms
developed during the last few hours. One briefly developed across
the Toa Baja/Dorado area and the doppler radar estimated between
1-2 inches. The other one developed over western PR, with intense
cloud to ground lightning observed across Mayaguez and Anasco.
Urban and small stream flooding is likely with this activity
during the next hour or so. Fair weather conditions are expected
overnight into early Thursday morning. However, during the
afternoon hours, TUTT will enhance showers and thunderstorms
across the mountain ranges of PR. This will result in periods of
heavy rainfall, gusty winds and cloud to ground lightning. Flash
flooding can`t be ruled out due to saturated soils across western
During the weekend, a somewhat drier air mass is expected on
Saturday ahead of the next tropical wave. However, showers and
isolated thunderstorms can`t be ruled out during the afternoon
hours. Moisture increases with the passage of the topical wave on
Sunday through Monday. This unstable environment will once again
enhance the development of scattered to numerous showers across
the regional waters and portions of the islands.
.AVIATION...Mostly VFR conditions with a Saharan air mass,
which could reduce visibilities at the local islands are expected
during the next 24 hours. However, VCSH/ISOLD TSRA are likely at
TJBQ/TJMZ this afternoon thru 21z. Then aft 23z a few VCSH and
brief SHRA are possible over the Leewards, USVI and Eastern PR taf
sites. E-ESE winds will prevail at 10-15 KT. Winds are expected
to diminish at 10 knots or less overnight.
.MARINE...Seas between 3-5 feet are expected through at least
Friday. Increasing between 4-6 feet during the weekend as a
tropical wave. Winds will continue mainly from the east between
.PRELIMINARY POINT TEMPS/POPS...
SJU 81 90 80 89 / 40 40 30 30
STT 80 90 79 89 / 40 40 30 30