AFDSJU Area Forecast Discussion National Weather Service San Juan PR 525 AM AST Sun Feb 1 2026 ...New SHORT TERM, LONG TERM, AVIATION, MARINE, BEACH FORECAST, HYDROLOGY... .KEY MESSAGES... Issued at 448 AM AST Sun Feb 1 2026 * An elevated flood threat will persist through midweek. Urban and small stream flooding, localized flash flooding, and minor landslides in areas of steep terrain are possible, particularly from late today through Tuesday. Residents and visitors are urged to avoid small streams, creeks, and other recreational areas near rivers. * Life-threatening rip currents are expected once again today across the northern beaches from Rincon to Fajardo, Culebra and the northern USVI. A large, long-period northerly swell and increasing winds will bring hazardous seas and life-threatening rip currents across most waters and coastal areas of the islands from Monday onward. Rough surf and life-threatening rip currents are expected. Beach erosion and minor coastal flooding are likely in the most vulnerable coastal areas. * Isolated thunderstorms are possible through at least midweek, bringing localized lightning and brief gusty winds. * The USVI, will remain on the dry side of the frontal system today, but showers are still expected to increase late this afternoon into the evening hours. Shower activity will increase significantly between Monday and Tuesday. && .Short Term(Today through Tuesday)... Issued at 448 AM AST Sun Feb 1 2026 Overnight, mostly cloudy skies prevailed across Puerto Rico and the U.S. Virgin Islands. Scattered showers persisted throughout the night over Caribbean waters, reaching portions of southern Puerto Rico, particularly from Guanica to Salinas. Doppler radar estimated rainfall accumulations of up to 0.50 inches over the coastal areas of Guayanilla, Penuelas, and Ponce. Minimum temperatures were in the mid-70s across the lower elevations of Puerto Rico, while the higher mountains observed temperatures in the upper 60s to low 70s. Across the U.S. Virgin Islands, lows were slightly warmer, ranging from the upper 70s to low 80s. A wet and unsettled weather pattern is anticipated across the region for the next few days. This is influenced by an approaching frontal boundary to the northwest, associated with an upper-level polar trough and a mid-to-upper-level ridge to the east of the islands. This setup is promoting a southerly low-level flow and enhanced moisture lifting from the Caribbean. Under this deep-layer instability, periods of moderate to heavy rainfall and isolated thunderstorms are expected to persist through midweek. Today, bands of showers from the Caribbean will continue to affect portions of southern Puerto Rico during the morning, shifting toward central and northern Puerto Rico by the afternoon. Rain chances will increase late tonight as the front moves closer, particularly impacting western and northwestern Puerto Rico. Consequently, there is an elevated risk of flooding for these areas today and tonight. Across the U.S. Virgin Islands, showers will primarily affect the area during the morning hours. From Monday into Tuesday, winds are expected to shift to the north as the front crosses the islands. Under this pattern, shower and isolated thunderstorm activity will shift toward southern, southeastern, and eastern Puerto Rico, with some activity reaching the San Juan metropolitan area. The latest precipitable water analysis (PWAT) continues to show values well above the climatological normal, reaching approximately 2.25 inches daily. The flooding risk will remain elevated across most of the region over the next few days. If the current forecast materializes, there is potential for significant flooding, particularly in southern and eastern Puerto Rico. Expected impacts include rapid river rises, urban and small-stream flooding, potentially life-threatening flash floods, landslides, and gusty winds. Residents and visitors are urged to closely monitor weather updates as the week progresses. && .Long Term(Wednesday through Sunday)... Issued at 448 AM AST Sun Feb 1 2026 The frontal boundary is expected to linger near the local area through midweek, as a weak area of high pressure rolls from the western Atlantic and passes just north of the area into the central Atlantic by the end of the workweek. This will slow and turn winds more easterly, and keep an overall higher moisture content over the area, particularly on Wednesday. Also, a short-wave trough will promote colder than normal 500 mb temperatures around minus 7/8C, which destabilizes the atmosphere and increase once again the likelihood of thunderstorms. Therefore, another unsettled weather day is expected across the islands, and due to the expected saturated soils, any additional period of excessive rainfall will lead to quick flooding. Lingering moisture and small variations on the 500 mb temperatures will promote shower and isolated thunderstorm development once again on Thursday. However, a drying trend is now expected on Friday and early Saturday, before the arrival of the next deep polar trough and associated frontal boundary during the weekend. && .AVIATION... (06Z TAFS) Issued at 448 AM AST Sun Feb 1 2026 Mainly VFR conds are expected across all terminals thru the fcst pd. Today, SCT -SHRA/+SHRA will continue to affect PR and the USVI, that may result in brief MVFR/IFR CIGs/VIS at times, in particular at TJBQ/TJPS aft 01/13Z. Isolated TSRA could increase across TJBQ aft 01/17Z. S-SE winds at 10-14 kt with higher gusts and sea breeze variations aft 01/13Z. && .MARINE... Issued at 448 AM AST Sun Feb 1 2026 Moderate southerly winds will prevail today, before a frontal boundary moves from the Atlantic waters from late tonight through midweek. In response, winds will turn more northerly and are expected to increase significantly, from 20 to 25 knots with higher gusts through at least Tuesday. This front will bring heavy showers and isolated thunderstorms across the local waters. In addition, a large, long-period northerly swell will build hazardous seas between 8 and 12 feet across the regional waters during the first part of the workweek. Small Craft Advisory conditions are expected across most, if not all offshore and coastal waters. && .BEACH FORECAST... Issued at 448 AM AST Sun Feb 1 2026 The lingering northerly swell will continue to promote a high risk of rip currents through 6 PM this afternoon across all northern-facing beaches, including areas from Rincon to Fajardo, Culebra, and the northern U.S. Virgin Islands. Beginning Monday, a stronger, long-period northerly to north- northwesterly swell is forecast to arrive and persist through the workweek. This swell is expected to bring rough surf and life- threatening rip currents, while also increasing the potential for high surf and minor coastal flooding, particularly during the peak of the event from Monday into Tuesday across exposed Atlantic and northwestern coastlines. Beachgoers are urged to continue monitoring future forecasts as conditions evolve. && .HYDROLOGY... Issued at 448 AM AST Sun Feb 1 2026 An unusually moist and wet period is expected for early February. Although streamflows have been running around normal to below normal levels, taking out yesterday`s rainfall across the eastern half of PR, the expected rainfall on Monday and Tuesday could lead to flooding across main rivers and trigger small land slides in areas of steep terrain. Please be aware of your surroundings if you live in flood prone areas. && .SJU WATCHES/WARNINGS/ADVISORIES... PR...High Rip Current Risk through this afternoon for PRZ001-002-005- 008-010-012. VI...High Rip Current Risk through this afternoon for VIZ001. AM...Small Craft Advisory from 6 AM Monday to 2 AM AST Thursday for AMZ711-712-741-742-745. && $$