Area Forecast Discussion
Issued by NWS San Juan, PR
FXCA62 TJSJ 260206
Area Forecast Discussion
National Weather Service San Juan PR
1006 PM AST Tue Oct 25 2016
Most of the showers dissipated, however the doppler radar
continues to indicate showers across the northeast section of
Puerto Rico, and approaching St Thomas, as well as near the
coastal areas of northwest Puerto Rico. Today`s heavy rains
saturated the soils and increase the level of the rivers along the
northern slope of Puerto Rico. Also the River sensors at
Hormigueros continues to indicate the levels are running above
normal levels. Therefore, flood warnings continues in effect for
the Rio Grande de Arecibo, and the Rio Grande de Manati as well as
their tributaries. Any additional rain could produce hazardous
conditions along the northern rivers of Puerto Rico.
An induce surface trough and moisture will linger across the
region through most of the work week. Expect periods of early
morning showers focused mainly across the north and east sections
of Puerto Rico and adjacent islands. This will be followed by
afternoon convection mainly over parts of the central mountain
range and west to southwest sections of Puerto Rico each day.
Therefore, the combination of an unstable atmosphere, moisture,
saturated soils and any persistent moderate to heavy rain could
lead to flash flooding as well as mudslides during the next few
VFR conds expected for all terminals durg the forecast
period. However, ocnl trade wind showers on ENE wind flow will reach
portions of the Nrn leewards/USVI and E and NE coastal areas of PR
thru 26/14z. This will lead to brief MVFR in SHRA...cld lyrs SCT
ocnl BKN FL020...FL050...with Mtn top obscr ovr eastern PR due to
low clds/-RA. FM 26/16z-26/22z, SHRA/TSRA fcst to develop ovr and
downwind of the Central Mtn ranges of PR. Brief MVFR expected at
TJMZ/TJPS and vcty TJBQ. SFC winds fm ENE at 5-15 kt. Sea breeze
variations aft 26/14z.
Tranquil marine conditions are expected to continue through the
next few days with seas up to 5 feet and winds around 15 knots.
Moderate risk of rip currents expected across most of the northern
beaches of Puerto Rico.
.PREV DISCUSSION... /issued 150 PM AST Tue Oct 25 2016/
SYNOPSIS...Upper level trough across the region will move
northeastward and away from the local islands tonight. A frontal
trough will remain close to the region for the next few days
maintaining abundant low level moisture across the local islands.
Upper level ridge will build again over the northeast Caribbean by
DISCUSSION...A pre-frontal trough just north of the region will
maintain a moist an unstable weather pattern across the local
islands until at least Thursday. Doppler weather radar detected
scattered to numerous showers and isolated thunderstorms across
central interior, western and northwest sections of Puerto Rico
early in the afternoon. This activity is expected to continue for
the rest of the afternoon and until the early evening hours.
Soils are well saturated due to the previous days rainfall and
therefore Urban and Small Stream flooding and river flooding are
possible late this afternoon and evening across central interior,
Western and northwest of Puerto Rico.
Model guidance suggests that the frontal boundary remnants will
remain north but close to the region for the next few days. This
moisture will maintain a moist and unstable weather environment,
favorable for the development of shower and thunderstorm activity
across the local islands until at least Thursday and possible
beyond. Showers and thunderstorms are therefore expected and
Thursday across portions of the local islands. A weak tropical
wave, near 60 West this afternoon will continue to move westward,
passing mostly south of the local islands Wednesday and Thursday.
This feature will aid to maintain the wet weather pattern across
AVIATION...Brief MVFR with mountain obscurations expected at
TJMZ/TJPS until at least 25/23Z. After 25/23Z mostly VFR
conditions will prevail across the local flying area with vicinity
SHRA across the Leewards, USVI and TJSJ taf sites. After 26/16Z
SHRA/TSRA will develop again around Cordillera Central and
downstream from El Yunque. Winds remain from E-NE at 5-15 kt with
sea breeze variations after 26/14Z.
MARINE....MARINE...Tranquil marine conditions are expected to continue
through mid this week with seas up to 5 feet and winds around 15
knots. Moderate risk of rip currents expected across most of the
northern beaches of Puerto Rico.
.PRELIMINARY POINT TEMPS/POPS...
SJU 78 88 79 88 / 50 50 40 40
STT 78 89 78 88 / 50 50 40 40