textproduct: San Juan

KEY MESSAGES

Issued at 423 AM AST Fri Nov 21 2025 * Pleasant temperatures will prevail across the USVI and PR from today through early next week.

* One or two thunderstorms will form this afternoon, especially near the southwest quadrant of PR.

* The north- and east-facing beaches of PR and the USVI will have a moderate risk of rip currents through Saturday evening, then drop to low from Sunday through Tuesday.

Short Term(Today through Sunday)

Issued at 423 AM AST Fri Nov 21 2025

A passing trough aloft, lingering moisture, and cooler northeast winds helped showers develop overnight and drift southwest across the local waters. Radar showed scattered showers mainly over the Atlantic, with some of this activity moving into northern and eastern Puerto Rico, Culebra, and the northern United States Virgin Islands. Since last evening, around one half inch of rain fell in an isolated spot in northeastern Puerto Rico. Overnight temperatures dropped into the mid 70s across lower elevations and the low 60s in the mountains, with a few upper 50s near Jayuya. These colder readings provided an early hint of the anticipated episode of Friiito Navideno. Winds over land were light and variable through the night.

A persistent moderate northeast breeze will continue to bring passing trade wind showers throughout the day, although they will be more frequent early this morning. A shortwave trough moving across the area will keep slightly cooler air aloft through early afternoon, supporting a few afternoon showers and isolated thunderstorms, mainly over southwestern Puerto Rico. Drier air will begin filtering in later this afternoon and will quickly shut down most activity. Highs will be slightly cooler than recent days, reaching the low to mid 80s across coastal and urban areas, further signaling the Friito Navideno expected to persist through at least Saturday. Today is the only period with any meaningful weather risk, with isolated lightning and minor flooding possible in afternoon storms.

Much drier and more stable air will move in as high pressure builds from the west, sharply reducing shower and thunderstorm activity tonight through Sunday. Saturday will be mostly dry with little to no rainfall expected. On Sunday, slightly patchier moisture may bring a few additional showers to windward areas, drifting inland at times and allowing for scattered showers to develop in the afternoon, but rainfall amounts will remain low. Temperatures will continue a cooling trend, with highs likely in the low 80s and some higher terrain barely warming to around 70 degrees. Lows may dip into the mid 50s in the highest elevations during clearer nights. Weather related risks will remain minimal through the weekend.

Long Term(Monday through Friday)

Issued at 423 AM AST Fri Nov 21 2025

Model guidance is trending toward greater consensus, suggesting a potential climatological pattern across the Northeast Caribbean, including Puerto Rico and the US Virgin Islands. However, a short- wave trough aloft will swing by the region from the west, increasing the potential for afternoon convection (30-50 percent chance of precipitation), especially around Monday afternoon into the evening along the Cordillera Central and crossing the USVI.

From Tuesday into Thursday, there is a better agreement that high pressure at mid levels will promote subsidence and a trade wind inversion over the region, trapping all the moisture at low levels. Thus, we expect a mixture of sunshine and clouds, with occasional patches of moisture embedded in the trades bringing showery weather over the windward locations of PR and the USVI. However, this activity does not represent a flooding threat for the region.

Temperatures across the islands are expected to continue cooling. Model forecasts suggest that temperatures at 925 mb will be slightly below normal, roughly at the 25th percentile compared to typical November conditions. However, there may be instances, particularly during peak heating in the afternoon, when temperatures can reach near-normal levels (around the 50th percentile).

AVIATION

(06Z TAFS) Issued at 423 AM AST Fri Nov 21 2025

Mostly VFR thru the prd with very ltd SHRA/TSRA. VCSH at TJSJ/USVI tmnls thru 21/14Z and again aft 21/23Z. Brief VCTS psbl nr TJPS 21/1720Z. Isold brief MVFR psbl due to MTN OBSC/REDUCED VIS, but confidence remains low. SFC winds LGT/CALM/VRB early, bcmg NE 1014 kt aft 21/14Z, with local S/B influences at TJBQ/TJPS causing VRB or onshore flow at times, then rtnng LGT/VRB aft sunset. Gen steering flow NE.

MARINE

Issued at 423 AM AST Fri Nov 21 2025

A surface high pressure will build over the western Atlantic during the next few days, promoting moderate to fresh trade winds from late tonight into the weekend. A surface low over the eastern Atlantic will generate pulses of long period northeasterly swells, arriving around Tuesday or Wednesday of next week. Afternoon thunderstorms will form across southwestern Puerto Rico today.

BEACH FORECAST

Issued at 423 AM AST Fri Nov 21 2025

A moderate risk of rip currents will prevail for the north and east-facing beaches in PR and the USVI through at least late Saturday night. The risk is forecast to be low from Sunday to Tuesday evening. Then, another long-period northeasterly swell will increase the risk to moderate or high from late Tuesday night into the middle of next week.

Additionally, beachgoers should be aware of other potential hazards, such as lightning and gusty winds, due to showers and thunderstorm activity expected this afternoon, especially near the southwest coast of PR. Remember: If thunder roars, go indoors!

SJU WATCHES/WARNINGS/ADVISORIES

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