826 
FXCA62 TJSJ 070856
AFDSJU

Area Forecast Discussion
National Weather Service San Juan PR
456 AM AST Fri Oct 7 2022


.SYNOPSIS...An induced trough will increase moisture content 
gradually each day. Unstable conditions will persist across the 
region and favor better convective development across the islands 
each day. Marine conditions will improve this weekend and seas
at 5 feet or less will be observed across most of the local
waters.

&&

.SHORT TERM...Today through Sunday...

An upper-level low northeast of the Leeward Islands is expected to 
move over the Anegada Passage and the northeastern Caribbean Sea 
during the short term period. At the surface, an induced trough by 
the low will increase moisture content gradually each day. This 
scenario will promote unstable conditions across the region and 
favor better convective development across the islands each day. 
However, due to increasing trades, minor to moderate rainfall 
accumulations are expected across the USVI and eastern sections of 
PR, where streamers are expected to develop in the diurnal cycle and 
trade wind showers will move at times during the overnight/early 
morning hours. Meanwhile, across the interior and western PR, better 
organized convection is expected and thunderstorm activity could 
lead to urban and small stream flooding each afternoon. Seasonal 
temperatures are expected across the islands through the weekend.

&&

.LONG TERM...Monday through Saturday...

A surface high pressure located in the central Atlantic is expected 
to dominate for the first half of the long-term period. Nonetheless, 
in our local area, a seasonal weather scenario is forecasted for all 
the islands. By Monday, a tropical wave located east of the Leeward 
Islands is expected to bring showers and isolated thunderstorms. 
Winds are expected to shift from a more southeasterly flow, local 
afternoon convection is likely to be centered over the northwestern 
and western portions of Puerto Rico. The US Virgin Islands can 
expect morning showers across the area and scattered showers during 
the afternoons. This tropical wave will bring additional moisture 
content from the Caribbean that is forecasted to persist until 
Wednesday. From Thursday through Saturday, winds will persist 
with a east-southeast flow and shower activity will be observed 
across the northwestern, western and northern portions of Puerto 
Rico. Although, a slightly drier air mass will filter in to the 
region limiting the activity to the mentioned portions. A frontal 
boundary will move out of the eastern coast of the United States 
and associated moisture could reach the local area by the 
beginning of the following week. Heat index values will remain 
above 100 degrees each day, mostly over urban and coastal areas 
across north-central Puerto Rico. 

&&

.AVIATION...Mainly VFR conditions are expected to prevail across all 
terminals through the forecast period. However, +SHRA/TSRA is 
expected to develop over western PR, which may cause tempo MVFR 
conds at TJPS. VCSH expected across the rest of the area terminals. 
East winds increasing at 12-16 kt, with higher gusts and sea breeze 
variations aft 07/14z.


&&

.MARINE...Moderate to locally fresh trades are expected to prevail during the 
next several days. Tropical Depression Thirteen will continue to 
move across the Caribbean Sea during the next couple of days. Seas
have subside overnight and seas up to 6 feet or less will prevail 
across the Caribbean waters and the Mona Passage until today.
Mariners should exercise caution across the regional waters.

&&

.SJU WATCHES/WARNINGS/ADVISORIES...
PR...None.
VI...None.
&&

$$

DSR/GRS