Scientific Forecaster Discussion
Area forecast discussion
National Weather Service San Juan PR
524 am AST Monday Jul 14 2014
Synopsis...an upper level low just northeast of the region...will
remains as the main weather feature through midweek. A weak tropical
wave will pass mostly south of the local islands on Wednesday.
Middle-upper level ridge expected to build from the east Thursday and
Discussion...clear to partly cloudy skies prevailed across the local
islands overnight and early this morning with isolated to scattered
passing showers affecting the U.S. Virgin Islands and eastern
sections of Puerto Rico from time to time. However...most of the
area remains under a generally dry and hazy weather pattern. Latest
satellite images this morning depicted an increase in moisture with
trailing showers from the east. This moisture will continue to move
westward today...inducing passing showers across eastern sections of
Puerto Rico during the rest of the morning...followed by afternoon
convection across western Puerto Rico this afternoon.
TUTT lows northwest and northeast of the region will weaken during
the next few days...but will remain as the main weather feature
across the local islands until middle week. A weak tropical wave over
the Windward Islands is expected to move across the eastern
Caribbean today and Tuesday. This feature and associated limited
moisture is expected to pass mainly south of the local islands late
Tuesday and Wednesday. Middle-upper level ridge will build over the
area by middle week. In general...expect the continuation of early
morning trade wind showers across eastern sections of Puerto Rico
followed by some afternoon convection across western and interior
Puerto Rico each afternoon.
Aviation...VFR conds at all taf sites xcpt isolated passing -shra/rain showers
mainly offshore of local islands overnite/early morning west/mostly scattered
low level cloud layers by the way fl020-fl080...few towering cumulus mainly north of PR and northern USVI
during early am...and scattered-broken hi level cloud by the way fl200-fl250 en Route by the way
local islands. Scattered rain showers/isolated thunderstorms and rain xptd over west-northwest PR during afternoon by the way
14/18/14/22z. Wind below fl150 east 5-15 knots...becoming from west and increase west/heat above
Marine...winds will continue to diminish today and now winds of
16 knots or less are expected with seas up to 4 feet.
Preliminary point temps/pops...
sju 87 77 87 78 / 20 10 20 20
stt 89 78 89 79 / 20 20 20 20