textproduct: San Juan

KEY MESSAGES

Issued at 238 AM AST Wed Oct 28 2026

* Exceptionally high tides will continue today, with localized flooding across vulnerable areas anticipated, mostly across northern Puerto Rico.

* High Rip Current Risk will continue today for northern Puerto Rico and Culebra, while a moderate risk continue for Vieques and for the Virgin Islands.

* Hot and humid conditions will persist, mostly affecting urban and low-elevated areas across Puerto Rico and the Virgin Islands.

* Showers will taper off later in the morning along southwestern Puerto Rico. Additional showers are expected in the afternoon along the interior and the northwest.

Short Term(Today through Friday)

Issued at 238 AM AST Wed Oct 28 2026

The night was cloudy, with showers affecting the southwestern municipalities of Puerto Rico. Showers and thunderstorms were widespread across the Mona Channel. The rest of the area was mostly clear, but a few showers did move across the vicinity of the Virgin Islands. Temperatures dropped to the 70s in Puerto Rico and hovered around 80 degrees in the Virgin Islands. Showers are expected to gradually taper off across western Puerto Rico around mid-morning, allowing for skies to continue to clear out.

High pressure northeast of the Caribbean maintain the steering flow from the southeast at nearly 10 knots. Just west of Puerto Rico, moisture is being pulled from the south. This has been creating unsettled weather conditions across the Mona Channel. While there drier air to the east of the forecast area, leftover moisture and diurnal heating should be enough for convection. As a result, showers are expected to redevelop along the interior and west. The risk of flooding is low, but localized urban flooding cannot be ruled out. Lightning is expected as well with the afternoon storms. By the end of the week, upper level trough moves from the west. While this should usually result in unsettled conditions, mid-level dry air entrainment may limit shower potential.

In terms of heat, 925 mb temperatures are expected to remain nearly two standard deviation above normal, which would normally translate into a moderate heat risk. However, due to the current cloud desk moving into the region, heating could delay a little. While the Heat Advisory was held for now, the users are advised to stay tuned for updates during the mid-morning hours.

Long Term(Saturday through Wednesday)

Issued at 238 AM AST Wed Oct 28 2026

Moist and unstable conditions are forecast to start the long term period. Moisture will continue moving over the local area, maintaining PWAT values above 2 inches for most of the period. A surface high over the Atlantic will result in an easterly flow to start the period, before becoming more southeasterly to start the next week and continue throughout the period. Mid-level drier air is forecast to persist Saturday, before becoming less pronounced Sunday onwards. An upper trough will be mainly west of the region to start the period, however some uncertainty persists with model guidance now suggesting that the upper trough will move away from the region early next week. However, guidance shows low- to mid-level moisture increasing as the period continues. The trough will support through at least the weekend, cool mid-level temperatures (-6 to -7 C), steep lapse rates, and upper-level divergence, factors that promote cloud development and support deeper convection over the region. 500 mb temperatures will warm up somewhat to around -6C during the workweek. Nocturnal and morning showers and t-storms are expected mainly over the weekend, especially across the U.S. Virgin Islands and eastern to southeastern Puerto Rico. With above normal moisture persisting, afternoon convection will focus primarily over interior, western, and northwestern Puerto Rico, with streamers also developing from El Yunque and the local islands. Heavy rainfall totals may trigger urban and small stream flooding. Additionally, t- storms may produce frequent lightning and gusty winds.

AVIATION

(06Z TAFS) Issued at 238 AM AST Wed Oct 28 2026

Passing SHRA expected across the Caribbean and Mona Passage through 12-13Z, then rain should dissipate. TSRA expected to develop after 17Z across the Cordillera Central and NW PR, causing mountain obscuration and periods of reduced VIS and low ceiling for TJBQ. SHRA will form in the vicinity of TJSJ, from 17-21Z. Winds will be from the SE AT 8-13 kts.

MARINE

Issued at 238 AM AST Wed Oct 28 2026

The latest nearshore buoys continue to report subsiding seas, as the long-period northerly swell continues to diminish today. However, seas between 4 to 6 feet can be expected across Atlantic offshore and coastal waters, including the Monday Passage; small craft must continue to exercise caution. A surface high pressure over the central Atlantic will continue to promote moderate to locally fresh east-to-southeasterly winds across the region for the next several days. Showers and thunderstorms will continue to move the Caribbean waters and local passages today, bringing gusty winds and lightning, leading to locally hazardous conditions for small craft.

BEACH FORECAST

Issued at 238 AM AST Wed Oct 28 2026

Beach conditions should gradually improve today, as the long-period northerly swell diminishes. Nevertheless, breaking waves between 5 and 7 feet across northern-exposed beaches of the islands could lead to life-threatening rip currents. Therefore, the high rip current risk continues for the beaches along western to northeast Puerto Rico through this afternoon. Residents and visitors are encouraged to heed the advice of lifeguards, beach patrol flags and signs. Although the risk will become moderate over the next few days, beachgoers must still exercise caution as life-threatening rip currents are possible along the surf zone. Besides rip currents, extreme high tides will continue today, peaking up to 2 feet during the morning. This combined with the fading swell could lead to localized minor coastal flooding across vulnerable coastal 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 until 6 AM AST early this morning for VIZ001.

AM...None.