Scientific Forecaster Discussion
Area forecast discussion
National Weather Service San Juan PR
246 PM AST Wednesday Mar 4 2015
Synopsis...the local islands will continue under convergence aloft
with a ridge to the west and a trough to the east through at least
the end of the week. Middle level ridge continues to hold across the
area over the next several days. Surface high northeast of the area
will continue to promote a fresh to locally strong trade wind flow.
Discussion...mostly sunny to partly cloudy skies prevailed across
the local islands today...with showers observed across windward
areas. Afternoon showers were also noted across SW Puerto Rico...
but rainfall accumulations were minimal so far. Winds were from
the northeast at 15 to 25 miles per hour with coastal temperatures in the low
to middle 80s.
A generally fair and mainly stable weather pattern is expected to
prevail across the local islands during the next few days under
convergence aloft and below to normal precipitable water. However...
trade wind showers will remain possible across windward areas from
time to time as surface high northeast of the local area continues
to promote fresh to locally strong trade winds. Afternoon convection
will be limited...if any...each day due to a strong cap at 700-800mb.
A better chance of shower activity is expected next workweek as
the aforementioned cap collapses with a sharp increase in low level
Aviation....VFR conds will prevail through the forecast period.
Brief MVFR ceilings possible tonight and overnight in passing rain showers
over the USVI and leeward terminals. NE winds of 20-30 knots expected
Marine...breezy to windy conditions will keep the choppy to rough
conds across the local waters over the next several days.
Mariners should expected seas of 6-8 feet and winds of 15-23 knots
with occasional wind gusts of 25-30 knots.
Preliminary point temps/pops...
sju 74 86 74 86 / 20 20 10 10
stt 74 86 74 85 / 20 20 20 20
Coastal waters...Small Craft Advisory until 6 PM AST Saturday for Anegada Passage
southward to 17n-Atlantic waters of Puerto Rico and USVI from
10nm to 19.5n-Caribbean waters of Puerto Rico from 10 nm to
17n-coastal waters of northern USVI and Culebra out 10 nm-
coastal waters of southern USVI Vieques and eastern Puerto
Rico out 10 nm-Mona Passage southward to 17n.
Small Craft Advisory until 6 PM AST Thursday for coastal waters
of southern Puerto Rico out 10 nm.
Small Craft Advisory until midnight AST Friday night for coastal
waters of northern Puerto Rico out 10 nm.