textproduct: San Juan

KEY MESSAGES

Issued at 103 PM AST Mon Mar 9 2026

* Update: Rip Current Statement Extended. Fresh to strong winds will continue to result in choppy to rough seas and a high risk of rip currents across the region. Small Craft Advisories and Rip Current Statements continue in effect.

* Breezy to locally windy conditions will continue across Puerto Rico and the U.S. Virgin Islands through at least Wednesday. Unsecured and outdoor objects may blow around.

* At least through Thursday, the flooding potential will increase across eastern and western Puerto Rico. Drier conditions are expected on Friday and Saturday.

* Across the USVI, quick passing trade wind showers will move at times, with a drying trend expected by the end of the week.

Short Term(This evening through Wednesday)

Issued at 103 PM AST Mon Mar 9 2026

Sunny to partly sunny skies were observed across Puerto Rico and the U.S. Virgin Islands during the morning hours. Passing showers were noted mainly across portions of southern, eastern and northern PR since midnight. The Doppler radar estimated between 1-1.50 inches from El Yunque to Guayama. For the rest of this afternoon, locally induced showers are expected to develop over portions of the interior and western PR. However, flooding is not anticipated. Across eastern PR and the USVI, streamers will continue to redevelop, and produce quick downpours at times. As of 1 PM, maximum temperatures were in the mid-80s across the lower elevations of the islands to the upper 70s and low 80s across the higher elevations. Winds were from the east up to 20 mph with higher gusts at times.

Persistent breezy trade winds (east winds) and highly variable moisture levels are expected to prevail through the rest of the short-term period. The 925 mb wind speeds (low-level winds) will remain consistently elevated, generally fluctuating between 18 and 23 knots, indicating breezy conditions will continue through midweek.

In terms of moisture content and shower potential, model guidance, and previous trend, suggest that the region will see a distinct dip (dry) and recovery (wet) period through Wednesday. Precipitable water values started relatively high at 1.70 inches based on this morning's sounding, but are forecast to drop to around 1.40 inches by tomorrow. This brief drying trend is reflected in the 850-700mb and 700-500mb relative humidity layers, both of which show a sharp decrease of around 20-30%, likely leading to mostly sunny skies and limited shower activity. However, this dry spell will be short-lived, as by early Wednesday another patch of higher moisture content is expected to move in, bringing the lower-level relative humidity back up to near 80%. While the 500 mb temperatures are notably cold (around -9C to -10C), the latest upper-air sounding shows an inversion layer from 700 to 500 mb, with enough dry air. This inversion will likely prevent thunderstorm development today, and, as similar conditions are expected on Wednesday, the increase in PWAT to around 1.70 inches will mostly translate into a noticeable uptick in fast- moving, shallow trade-wind showers rather than heavy, widespread rain.

Long Term(Thursday through next Sunday)

Issued at 304 AM AST Mon Mar 9 2026

A trough in the mid and upper level will allow for temperatures to cool down at the mid levels by Thursday. This, along with moderate moisture content at the lower levels, will result in increasing showers along eastern Puerto Rico and the Virgin Islands during the day. However, the heaviest activity is expected for the interior and west in the afternoon hours. Urban and small stream flooding will be likely, and there is a medium chance of experiencing thunderstorms as well. From Friday and into the weekend, strong surface high pressure centered over the northeastern Atlantic Ocean will steer the winds from the east-southeast. Speeds will be moderate, around 15 knots for this time period. In the lower levels, patches of moisture will be dragged in at times. Conditions aloft will not be as favorable as on Thursday, but in general, the pattern will favor passing showers across eastern Puerto Rico and the Virgin Islands, followed by stronger showers in the interior and west each afternoon. While urban and small stream flooding could occur in some areas, the most likely scenario is that the showers will lead to ponding of water in roadways, as well as water surges in creeks and small rivers. Also, with southeast winds, temperatures will warm up a little, with highs mostly in the mid and upper 80s for coastal areas.

AVIATION

(18Z TAFS) Issued at 103 PM AST Mon Mar 9 2026

Mainly VFR conditions are expected to prevail across all terminals during the next 24 hours. However, quick passing trade wind showers may cause brief -RA/VCSH periods across the area terminals, particularly at TIST/TISX/TJSJ. The 09/12z TJSJ sounding indicated east winds up to 33 kt blo FL050.

MARINE

Issued at 103 PM AST Mon Mar 9 2026

A broad surface high pressure extending across the Central Atlantic will continue to support moderate to fresh trade winds across the region, resulting in choppy to rough seas over the local Atlantic and Caribbean waters. Additionally, recent coastal buoy observations are reporting seas between 4 and 5 feet, with winds between 15 and 18 kt, gusts up to 20 to 25 kt. Given the current marine conditions, the Small Craft Advisory remains in effect for most of the local waters until noon on Wednesday. Conditions are expected to gradually improve across the nearshore waters early in the week; however, choppy conditions will likely persist across the offshore waters. Small craft operators are urged to exercise caution and check the latest marine forecasts before venturing into the local waters.

Passing showers will continue across the regional waters and passages this afternoon, with a low to medium chance of isolated thunderstorms over the offshore Caribbean waters.

BEACH FORECAST

Issued at 103 PM AST Mon Mar 9 2026

Some changes were introduced to the beach forecast. Breezy to windy conditions continue across the CWA, with winds between 15 and 25 mph and wind gusts up to 35 to 40 mph based on official and non-official stations. Additionally, local nearshore buoys are reporting seas between 4 and 5 feet, with winds between 15 and 18 kt, gusts up to 20 to 25 kt. Based on the latest model guidance, these conditions may persist tomorrow, resulting in breaking waves equal to or higher than 6 feet, hazardous for beachgoers. Therefore, the Rip Current Statement was extended for northern and eastern beaches of Puerto Rico, including Vieques and Culebra, and the U.S. Virgin Islands through 6 AM AST tomorrow, Tuesday. Residents and visitors are urged to continue to monitor conditions closely and strictly adhere to the advice of beach patrols, flag systems, and posted signs. While a moderate risk continues elsewhere for the next several days, all beachgoers should exercise caution, as life-threatening rip currents remain possible along the surf zone. Beach conditions are expected to gradually improve by tomorrow into Wednesday.

FIRE WEATHER

Issued at 103 PM AST Mon Mar 9 2026

Elevated fire weather conditions were noted in Cabo Rojo today. The relative humidity dropped to 48% earlier this morning, while the Keetch-Byram Drought Index (KBDI) at Cabo Rojo was at 667, indicating critically dry fuels highly receptive to ignition and rapid fire spread. Observed sustained winds were from 15 to 19 mph with gusts up to 27 mph during the past 3 hours. Therefore, a Fire Danger Statement (RFDSJU) was issued for the southern coastal plains.

The drying trend, breezy conditions and dry fuels could support rapid fire spread, if a fire starts, and outdoor burning is strongly discouraged.

SJU WATCHES/WARNINGS/ADVISORIES

PR...High Rip Current Risk through late tonight for PRZ001-002-005- 008-012-013.

VI...High Rip Current Risk through late tonight for VIZ001-002.

AM...Small Craft Advisory until noon AST Wednesday for AMZ711.

Small Craft Advisory until midnight AST tonight for AMZ712-716- 726.

Small Craft Advisory until noon AST Tuesday for AMZ723-733-741.