Advisory FFA Flood Watch — Sat Oct 28, 2023 11:13 AM

FFASJU) issued by WFO San Juan PR.

.LONG TERM...Tuesday through Saturday...

The period will start with a mid- to upper- level ridge overhead of
the islands. Model guidance suggests a mid- to upper- level trough
building to our east slowly eroding the ridge throughout the long
term period and gradually increasing instability aloft. GFS model
suggests precipitable water (PWAT) values up to around 2.4 inches
across the region Tuesday, decreasing to around 2.0 inches on
Wednesday with drier air filtering in on late Thursday and Friday,
and finally more moist air filtering in again and increasing PWAT to
around 2.0 inches on Saturday. Southerly windflow will persist over
the area through Thursday, helping lift tropical moisture into the
area from the ITCZ. Winds are forecast to become more easterly and
increase late Thursday and into Friday. Although the environment
will remain moist, the driving force for the afternoon convection
will be diurnally induced to start the period, as conditions will be
more stable aloft during that time, with additional instability from
perturbations reaching the region and a lingering surface trough.
Instability aloft due to the mid- to upper- trough and and increase
in moisture will in turn increase rain chances during to end the
period. Discrepancies continue between the GFS and the ECMWF model
but already saturated soils from events in the short term period
increase the potential for urban, small stream and flash flooding,
along with mudslides in areas of steep terrain. Please continue to
monitor future updates.

&&&

.AVIATION...Periods of MVFR conds will remain possible at all TAF
sites in SHRA/TSRA through the forecast cycle, particularly
JSJ/IST/ISX late tonight into the overnight hours. ESE winds
between 10 to 15 knots with higher gusts in showers and
thunderstorms.

&&


.MARINE...Hazardous marine and coastal conditions will persist
through early next week due to northerly swells. Small Craft
Advisories are in effect for the Atlantic Offshore Waters and
Caribbean Passages until at least late Sunday night due to seas
between 8 and 12 feet. At 5 AM AST the San Juan, Arecibo and
Rincon CariCOOS buoys reported 7-10 foot wave heights with
periods of 13-14s. Beachgoers, avoid the Atlantic Coastline in
Puerto Rico and the U.S. Virgin Islands due to hazardous coastal
conditions. Please see the CFWSJU and MWWSJU products for more
information.

&&

.SJU WATCHES/WARNINGS/ADVISORIES...
PR...Coastal Flood Advisory until 6 PM AST this evening for PRZ001-
     002-005-008.

     Flood Watch through Monday morning for PRZ001>013.

     High Rip Current Risk through Monday morning for PRZ001-002-005-
     008-010-012-013.

     High Surf Advisory until 6 PM AST Sunday for PRZ001-002-005-008-
     010-012-013.

VI...Flood Watch through Monday morning for VIZ001-002.

     High Rip Current Risk through Monday morning for VIZ001-002.

     High Surf Advisory until 6 PM AST Sunday for VIZ001.

AM...Small Craft Advisory until 6 AM AST Monday for AMZ711-712-716-
     723-726-741-742.

&&

$$