National Weather Service San Juan PR
557 AM AST Sat Nov 19 2016
.SYNOPSIS...Broad upper ridge will continue for the next several
days meandering over the eastern Caribbean Sea as polar troughs
press against it through early next week. Meanwhile at lower
levels, a cold front and prefrontal trough will meander
between Hispanola and the local Atlantic waters for the next
couple of days providing abundant moisture across the area.
This will result in periods of showers and thunderstorms over
already saturated soils across mainland PR, keeping a high threat
of flooding along major rivers and tributaries and mudslides
across areas of steep terrain.
&&
.DISCUSSION...Scattered to locally numerous showers affected the
northeastern portions of PR during the overnight hours as a line
of showers developed just off the northern coastal waters of PR.
This activity left around 3 inches of rain across portions of
Rio Grande. For the rest of the morning hours, under an easterly
light steering wind flow additional showers with heavy rainfall
are possible across the north/eastern portions of PR. For the rest
of the day, cloud cover is not expected as yesterday and daytime
heating will aid to the development of showers and thunderstorms
across the interior/western portions of PR.
The prefrontal boundary is expected to meander across the Mona
Passage and western PR through early next week. Precipitablewater
will remain very high across the forecast area and as trough
pattern holds through the short term period...shower and
thunderstorm activity across the local waters and mainland PR
will likely continue for the next several days. Therefore, the
flash flood watch has been extended through this afternoon and
could likely continue through the rest of the weekend as the rain
threat remains high.
&&
.AVIATION...VFR conds with some VCSH will prevail across the TAF
sites during the morning hours. SHRA/ISOLD TSRA will affect the
coastal waters, the north and east of PR and the USVI thru 16Z.
Brief MVFR/IFR conditions possible with passing SHRA/TSRA at TJMZ
and TJPS between 17Z-22Z. Mtn top obscr expected across the
interior sections of PR. Sfc wnd fm E 10-15 kts.
&&
.MARINE...Seas will continue at 5 feet or less Today. A northerly
swell around 7 feet will enter the Atlantic waters and Passages
late Sunday and continue through at least Monday. This will
result in hazardous seas and dangerous rip currents along the
Atlantic coastline of Puerto Rico, Culebra and St. Thomas. Winds
will continue from the east at 10-15 kts increasing 15-20 kts from
the northeast across the Atlantic waters by Sunday.
&&
.PRELIMINARY POINT TEMPS/POPS...
SJU 86 76 84 76 / 60 40 60 50
STT 87 78 86 77 / 60 40 40 50