Area Forecast Discussion
Issued by NWS San Juan, PR
Issued by NWS San Juan, PR
449 FXCA62 TJSJ 302103 AFDSJU Area Forecast Discussion National Weather Service San Juan PR 503 PM AST Sun Jun 30 2024 .SYNOPSIS... A dry air mass and subsidence ahead of Major Hurricane Beryl will limit rain activity through Monday afternoon. The most outer bands of Beryl could bring squally weather across the U.S. Virgin Islands and Puerto Rico from late Monday night into Tuesday. Marine and coastal conditions will gradually deteriorate across the Caribbean and local passages as Major Hurricane Beryl moves far to the south across the Caribbean Sea. Stay tuned for updates on this storm and the Invest 96L, which the National Hurricane Center monitors. && .SHORT TERM...Tonight through Tuesday... A breezy trade wind pattern will continue as a robust surface high across the Atlantic Basin and Hurricane Beryl stream trade winds across the region. Due to this passing showers remain possible across eastern Puerto Rico and the USVI during the night. By tomorrow a dry air mass that is preceding the moisture field of Beryl and strong subsidence ahead of the strong will be present across the area, limiting rainfall to brief passing showers and causing hot, muggy conditions. However by the evening hours into the night, conditions are expected to deteriorate as the hurricane moves into the eastern Caribbean basin. An increase of wind speeds and passing showers will focus heavy rainfall at times across the southern to eastern half of Puerto Rico including the USVI as Beryl moves well south of the region, currently projected to be over 200 miles south of islands by Tuesday morning. Squally weather is possible and could bring impressive thunderstorm activity that could cause flooding and wind impacts. This pattern will last through Tuesday evening as the system moves westward further away from the area. Following this, drier air fills in behind the storm by Tuesday night causing a dry pattern to prevail before the next system later in the week. The greatest impacts to our islands from Beryl will be across the southern and eastern coastal waters that will experience chaotic seas due to a strong swell on Tuesday. This will cause very hazardous coastal conditions with strong breaking waves in excess of 10 feet at times. Strong winds will also be present throughout this time and as mentioned, thunderstorms and heavy rain will likely be present as well. Stay vigilant as we approach Tuesday and stay informed with the latest forecast. .LONG TERM....Wednesday through Sunday... After the passage of Hurricane Beryl south of the local area, a drier airmass will quickly move over the islands. This drier airmass will promote stable conditions on Wednesday with limited shower activity. However, by Thursday onwards tropical activity is expected once again. The National Hurricane Center (NHC) is currently monitoring an area of low pressure located over the eastern Atlantic with a medium to high formation chance over the next 7 days. Latest model guidance suggest that this system will develop as a tropical cyclone before reaching the Lesser Antilles. Nonetheless, this system should remain south of the islands and over the Caribbean waters. At this moment some of the potential indirect impacts associated to this low are: localized flooding, gusty winds, squally weather, and deteriorated marine and coastal conditions. It is too early at this moment to determine the amount of expected rain. Therefore, residents and visitors of Puerto Rico and the U.S. Virgin Islands may continue to monitor the progress of this system as it moves towards the Caribbean. A vast moisture field of this low will persist across the region once it departs on Saturday, promoting afternoon convective activity across the western portions of Puerto Rico. Following the system, more drier air and Saharan Dust particles will take over, enhancing stable and dry conditions for few days. Despite of the expected weather, high temperatures will remain between the upper 80s to low 90s across the islands with heat indices surpassing the mid 100s. && .AVIATION... (18Z TAFS) VFR conds will prevail across terminals during the next 24 hrs. Convection will develop tomorrow, btw 01/15z-22z, due to local effects. The most outer bands of Beryl may reach the local flying area after 01/23z. Expect E-winds at 15-17 kt with stronger gusts and sea breeze variations, becoming calm to light and VRB aft 30/23z. Winds after 01/13z are expected to be similar to today. && .MARINE... The strong surface high pressure across the Central Atlantic will continue to promote moderate to locally fresh easterly winds over the islands. The latest National Hurricane Forecast trajectory moves Major Hurricane Beryl far to the south of the regional waters late Monday night into Tuesday, deteriorating marine and coastal conditions considerably, especially for the Caribbean Waters and Passages. The outer bands of Beryl may produce squally weather during that time. && .BEACH FORECAST... Swells from Beryl will create life-threatening rip currents along the south-facing beaches of Puerto Rico and the U.S. Virgin Islands from Monday afternoon onward. && .SJU WATCHES/WARNINGS/ADVISORIES... PR...Heat Advisory until 5 PM AST this afternoon for PRZ001-002-005- 008-010-012-013. VI...Heat Advisory until 5 PM AST this afternoon for VIZ002. AM...Small Craft Advisory from 6 PM Monday to 6 PM AST Tuesday for AMZ711-735. Small Craft Advisory from 6 AM Monday to 6 PM AST Tuesday for AMZ723-733-741. && $$ SHORT TERM...CAM LONG TERM....MMC AVIATION...WS