Area Forecast Discussion
Issued by NWS San Juan, PR
FXCA62 TJSJ 300845
Area Forecast Discussion
National Weather Service San Juan PR
445 AM AST Sun Apr 30 2017
.SYNOPSIS...TUTT and plenty of moisture across the forecast area
will continue to result in periods of showers and thunderstorms
through at least midweek. As a result, there is a chance of urban
and small stream flooding each day with localized river flooding
also possible. A generally fair weather pattern is expected across
the forecast area by the end of the work week.
.SHORT TERM...Tonight through Wednesday...
Mostly cloudy skies prevailed across Puerto Rico and the U.S.
Virgin Islands overnight. An area of showers and thunderstorms
affected the eastern section of Puerto Rico. Rainfall accumulation
from one to two inches were estimated by the Doppler weather
radar in some localized areas mainly in El Yunque rainforest. For
today, a very moist and unstable environment,will aid in the
development of showers and thunderstorms across the Cordillera
Central of Puerto Rico early in the afternoon, with the activity
expected to spread across the western interior and northwest
sections of Puerto Rico. Heavy rainfall will lead to urban and
small stream flooding. Flash flooding cant be ruled out.
An upper level trough is expected to linger across the local region
enhancing the development of showers and thunderstorms across the
local area through at least Wednesday. Low level moisture is
expected to remain high through this period. As a result, periods
of showers with thunderstorms can be expected mainly each afternoon
across the Cordillera Central of Puerto Rico. Soils across Puerto
Rico are saturated from previous rainfall. Therefore, local and
visitors in Puerto Rico are urged to stay tuned during the next
few days as the risk for flooding continues high.
.LONG TERM...Wednesday Afternoon through Sunday...
As the TUTT weakens, a mid to upper level ridge is expected to
build across the forecast area from the west. This feature is
expected to hold Thu through at least the upcoming weekend. At
lower levels, as a broad high pressure across the central Atlantic
weakens and a boundary moves across the western Atlantic, winds
are expected to become more east southeast by the end of the week.
Therefore,still expect periods of showers and isolated thunderstorms
on Wednesday. As the ridge builds and moisture erodes, a fair
weather pattern is then expected to prevail late in the week with
warmer temps under the aforementioned east southeast wind flow.
.AVIATION...VCSH are expected across most TAF sites through at
least 30/16Z. Tempo MVFR and even IFR conditions with mountain
obscurations can be expected after 30/16Z in and around TJSJ,
TJMZ and TJBQ in SHRA/TSRA. Low level winds will be mainly east
at 10 to 15 kts.
.MARINE...A surface high pressure to the north of the local
islands will continue to persist through midweek to result in
moderate to locally fresh easterly winds. As the surface high
shifts eastward, east to southeast winds will prevail by the
end of the week. Hazardous wind driven seas and isolated
thunderstorms with areas of heavy rainfall will be likely
across the local waters during the rest of the weekend. Seas
up to 6 feet and winds 15 to 20 knots with a moderate risk of
rip currents across most of the local beaches.
.PRELIMINARY POINT TEMPS/POPS...
SJU 84 75 84 75 / 60 50 50 20
STT 84 74 84 74 / 50 50 50 30
SHORT TERM & AVIATION...FC
LONG TERM & MARINE......OM