National Weather Service San Juan PR
542 AM AST THU SEP 29 2016
.SYNOPSIS...Tropical Storm Matthew is currently about 300 miles to
the SSE of the local islands. Matthew is forecast to continue
moving westward today with its center of circulation passing 250
miles or more to the south of the local islands. However, we
expect breezy conditions with showers and thunderstorms across the
local area today. Weather to improve late today and Friday.
&&
.DISCUSSION...Showers and isolated thunderstorms have been
observed over the local waters through the overnight hours. Some
showers have affected the land areas but the amounts have been
modest since the showers are moving rather fast. It has been
breezy and we expect breezy conditions to continue today with
winds at 15-30 mph and higher gusts. Shower and thunderstorm
activity is expected to gradually increase through the morning
hours and affecting most of the land areas by this afternoon. The
proximity of TS Matthew to the local islands means that the local
marine conditions will deteriorate significantly. We currently
have several advisories in effect such as Small Craft, High Risk
of Rip Currents and High Surf advisories.
Things are expected to improve weather wise this afternoon and
evening, and Friday is not expected to be as active as today. The
rest of the weekend and early next week is going to be highly
dependent on the track that TS Matthew takes. So there is
considerable uncertainty on the local weather for the upcoming
days. Having said that, there is some agreement in the forecast
models that we will be under a great deal of moisture early next
week under a southerly flow, which if it verifies, would cause a
great deal of shower and thunderstorm activity over the local
islands, so that is definitely something to monitor.
&&
.AVIATION...Brief MVFR or even IFR conds with mountain obscurations
will remain possible at all TAF sites as TS Matthew moves across the
Caribbean waters and south of the local islands. Wx conds will
slowly improve this afternoon across the Leeward terminals and
during the evening hours across the PR and USVI terminals. Sfc wnds
15 to 25 with ocnl gusts 30 to 40 kts with passing SHRA/TSRA.
&&
.MARINE...Very hazardous marine conditions are expected today as
TS Matthew passes to our south. Winds of up to 30 knots and seas
of 14 feet and occasionally higher are forecast across the local
waters, especially the offshore Caribbean waters, therefore there
is a Small Craft Advisory for all of our local waters. There is a
high risk of rip currents for just about all of the PR and USVI
coasts and there is also a High Surf Advisory for the beaches in
southern and eastern PR, Vieques, and Saint Croix.
&&
.PRELIMINARY POINT TEMPS/POPS...
SJU 88 78 89 77 / 60 50 40 20
STT 90 79 89 78 / 60 50 40 30