Area Forecast Discussion
Issued by NWS San Juan, PR
FXCA62 TJSJ 242304
Area Forecast Discussion
National Weather Service San Juan PR
704 PM AST WED AUG 24 2016
.UPDATE...The risk for widespread flooding will continue to
decrease this evening and tonight...as the bulk of moisture
associated with invest 99l continues to move away from the
forecast area. Although periods of showers and isolated
thunderstorms will remain possible over the regional waters...
the USVI as well as the eastern third of Puerto Rico tonight
and early Thursday morning...environmental and atmospheric
conditions do not support widespread flooding tonight. As a
result...the Flash Flood Watch has been cancelled.
.PREV DISCUSSION... /issued 444 PM AST WED AUG 24 2016/
SYNOPSIS...A tropical wave located over the forecast area will
continue to produce showers and thunderstorms through tonight.
Residual moisture associated with the trailing edge of the
tropical wave will likely bring another round of showers and
thunderstorms on Thursday. Moisture will gradually diminish on
Friday, with drier than normal conditions expected during the
DISCUSSION...Showers and a few thunderstorms associated with the
tropical wave have been affecting the local islands since this
morning. The heaviest rainfall was observed across portions of the
Central Interior and Northwest Puerto Rico this afternoon. Rainfall
accumulations of 1.5 to 2.5 inches were estimated by the doppler
radar in portions of Aguada, Lares, Utuado and St. Croix.
At this time...visible satellite imagery showed dry air mass filtering
from the Caribbean waters. As a result...the shower and thunderstorm
activity has been diminished significantly over Puerto Rico and
the U.S. Virgin Islands. If this trend continues the Flash Flood
Watch could be cancelled this evening.
As the tropical wave moves away from the local region...moisture
will gradually diminish through Friday. Then...fair weather conditions
expected during the weekend.
AVIATION...MVFR or IFR conds still possible in and around the
Leeward...USVI and JSJ terminals as a tropical wave moves across the
area. Wx conds expected to slowly improve across the Leeward
terminals late tonight. However, periods of SHRA/TSRA will remain
possible at USVI and JSJ tonight through at least early Thursday as
this feature moves away. Southerly winds 10-20 knots but higher and
variably in TSRA.
MARINE...A strong tropical wave will bring hazardous winds and
seas to the east and northeast portions of the local waters this
afternoon and tonight. Winds and seas will diminish later tonight
and Thursday morning.
.PRELIMINARY POINT TEMPS/POPS...
SJU 77 87 76 88 / 50 60 40 50
STT 78 84 79 86 / 60 60 40 40
AM...Small Craft Advisory until 8 PM AST this evening for Anegada
Passage Southward to 17N-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.
Small Craft Advisory until 8 AM AST Thursday for Atlantic Waters
of Puerto Rico and USVI from 10 NM to 19.5N.