textproduct: San Juan

KEY MESSAGES

Issued at 251 AM AST Wed Oct 14 2026

- Afternoon showers and isolated thunderstorms may pose localized flooding, lightning, and gusty wind concerns, mainly across interior and western Puerto Rico. These threats will decrease Friday into the weekend.

- A limited heat risk will persist through the weekend into early next week, primarily affecting individuals highly sensitive to heat, especially those outdoors without adequate cooling or hydration.

- A moderate risk of rip currents will continue along north and east-facing beaches of Puerto Rico, including Culebra, potentially expanding to Vieques, western Puerto Rico, and portions of the U.S. Virgin Islands over the weekend.

- Across the U.S. Virgin Islands, brief passing showers are expected mainly overnight and during the morning hours, with limited rainfall accumulations and a low potential for flooding.

Short Term(Today through Friday)

Issued at 251 AM AST Wed Oct 14 2026

A mid-to upper-level ridge will promote progressively drier and more stable conditions across the region today. Pronounced drying near 700 mb will limit deep convection, although occasional moisture patches arriving from the northeast and localized afternoon moistening may briefly offset this trend. Moderate east to east-northeast winds will favor passing morning showers across windward sections of Puerto Rico and the U.S. Virgin Islands, aided by nocturnal cooling and low-level moisture advection. Daytime heating, sea-breeze convergence, and local effects will then support afternoon showers and isolated thunderstorms across interior and western to southwestern Puerto Rico, with the prevailing steering flow favoring west to southwestward movement. Convective activity should diminish this evening, followed by passing showers across windward areas overnight.

The ridge will strengthen Thursday into Friday, reinforcing subsidence warming and mid-level drying, with below-normal moisture expected to dominate by Friday. Although occasional moisture patches and localized convergence may briefly support convection, the increasingly stable environment will limit shower coverage and thunderstorm development. Passing overnight and morning showers will continue across windward areas, followed by increasingly isolated afternoon activity over western and southwestern Puerto Rico. Moderate east to east-northeast winds will prevail, with occasional fresh breezes mainly over the offshore Caribbean waters, particularly during the early morning hours. Mostly dry conditions are anticipated Friday night.

An elevated excessive rainfall risk today will decrease in coverage Thursday and transition to a limited risk Friday. Locally heavy downpours could produce urban and small-stream flooding, mainly across western Puerto Rico. A limited lightning risk will persist, primarily during afternoon thunderstorms over western Puerto Rico and the adjacent western coastal waters. Meanwhile, a limited heat risk is expected each day, with localized higher heat stress possible across warmer coastal and urban areas, especially where reduced cloud cover and rainfall allow greater daytime heating.

Long Term(Saturday through Wednesday)

Issued at 251 AM AST Wed Oct 14 2026

The long-term forecast remains mostly on track, with primarily stable weather conditions expected Saturday through Monday, followed by more active afternoons and slow-moving showers Tuesday and Wednesday.

A mid-to upper-level ridge will maintain dry and stable conditions aloft through Monday. Precipitable water (PWAT) will fluctuate between seasonal and below-seasonal levels, ranging from 1.4 to 1.7 inches. Predominantly easterly steering winds will persist as low-level surface high pressure and a frontal boundary remain north of the local area. Passing cloud patches and trade wind showers will reach eastern sections of the islands (including the U.S. Virgin Islands) from time to time, with no significant impacts. Afternoon showers and isolated thunderstorms remain possible across interior to western Puerto Rico, as well as downwind from El Yunque toward the southern half of the San Juan metropolitan area, and downwind from the USVI, Vieques, and Culebra. A limited flood threat will remain present each afternoon across interior to western Puerto Rico.

More unstable conditions will develop Tuesday and Wednesday as a mid- to upper-level trough approaches from the north, replacing the ridge. This will induce mid-level cooling, dropping 500-millibar temperatures to between -6 and -7 degrees Celsius and steepening mid-level lapse rates. The atmospheric column will moisten under the influence of the trough, yielding seasonal to slightly above- normal precipitable water values. Additionally, steering winds will collapse to around 5 knots and shift southeasterly to southerly as surface low pressure develops north of the region, relaxing the local pressure gradient. This will result in more active afternoons, with scattered to numerous showers and isolated thunderstorms focused mainly across the interior, northwestern, and northern sections of Puerto Rico. An elevated flood threat is expected each afternoon, particularly where persistent shower activity develops. Consequently, urban and small stream flooding is likely, with isolated flash flooding possible.

A limited heat threat remains favored throughout the long-term period. While widespread heat hazards are not anticipated, extremely sensitive individuals could be affected and should take appropriate precautions to protect themselves from heat-related stress.

AVIATION

(06Z TAFS) Issued at 251 AM AST Wed Oct 14 2026

Mainly VFR conds expected across all terminals thru the fcst period. Brief MVFR conds psbl in passing SHRA, mainly at TJSJ and USVI terminals thru the morning hrs. Increasingly dry and stable conds aloft will limit SHRA/TSRA coverage, although aftn convection may result in VCSH/VCTS and brief MVFR conds at PR terminals. Calm to VRB winds overnight, increasing to E-ENE at 10-14 kt aft 14/13Z, with higher gusts mainly near TSRA and local sea-breeze variations. Winds bcmg light aft 14/23Z.

MARINE

Issued at 251 AM AST Wed Oct 14 2026

Generally tranquil seas and light to moderate east to east-northeast winds will favor small craft operations across the local waters through the weekend. Occasional fresh breezes may produce locally choppy conditions, mainly across the offshore Caribbean waters. A lingering northeasterly swell will gradually subside across the Atlantic waters through late week, followed by a slight increase in seas over the weekend. Passing showers and isolated thunderstorms will remain possible through midweek, with the greatest lightning potential during the afternoon over the western coastal waters of Puerto Rico. Mariners should remain alert for sudden wind gusts, locally higher seas, and reduced visibility near thunderstorms.

BEACH FORECAST

Issued at 251 AM AST Wed Oct 14 2026

A moderate risk of rip currents will persist along north and east-facing beaches of Puerto Rico, including Culebra, through midweek, with a low risk elsewhere. The risk may expand to additional beaches, including portions of the U.S. Virgin Islands, over the weekend as northeasterly swell build seas. Afternoon thunderstorms will pose a lightning threat to beachgoers, particularly along western Puerto Rico, although this threat should gradually decrease through late week. Meanwhile, a limited extreme heat risk will persist each day, with locally higher heat stress possible during the late morning and afternoon hours.

SJU WATCHES/WARNINGS/ADVISORIES

PR...None. VI...None. AM...None.