Since 2001 providing the latest information on tropical cyclone activity in the Atlantic Basin and the weather conditions in Puerto Rico.

Local Weather Conditions

 

National Weather Service Today's Weather Impact Levels

National Weather Service Forecast for: San Juan, Puerto Rico  

Updated: 10:22 am AST Feb 26, 2024

Hazardous Weather Outlook
This
Afternoon
This Afternoon: Scattered showers and thunderstorms.  Partly sunny, with a high near 84. East northeast wind around 13 mph.  Chance of precipitation is 40%.
Scattered
Showers

Hi 84 °F
Tonight

Tonight: Scattered showers and thunderstorms before 10pm, then showers likely and possibly a thunderstorm between 10pm and 4am, then showers likely after 4am.  Mostly cloudy, with a low around 74. East northeast wind 7 to 9 mph.  Chance of precipitation is 70%. New rainfall amounts between a half and three quarters of an inch possible.
Showers
Likely

Lo 74 °F
Tuesday

Tuesday: Showers likely before 7am, then showers likely and possibly a thunderstorm between 7am and 1pm, then scattered showers and thunderstorms after 1pm.  Cloudy, then gradually becoming mostly sunny, with a high near 84. East northeast wind 7 to 11 mph.  Chance of precipitation is 60%.
Showers
Likely

Hi 84 °F
Tuesday
Night
Tuesday Night: Scattered showers, then showers likely and possibly a thunderstorm after 1am.  Partly cloudy, with a low around 73. East wind 7 to 10 mph.  Chance of precipitation is 60%.
Scattered
Showers then
Showers
Likely
Lo 73 °F
Wednesday

Wednesday: Showers likely and possibly a thunderstorm before 7am, then scattered showers and thunderstorms after 7am.  Mostly sunny, with a high near 85. East northeast wind 8 to 14 mph.  Chance of precipitation is 60%.
Showers
Likely

Hi 85 °F
Wednesday
Night
Wednesday Night: Scattered showers.  Partly cloudy, with a low around 74. East northeast wind 8 to 10 mph.  Chance of precipitation is 30%.
Scattered
Showers

Lo 74 °F
Thursday

Thursday: Scattered showers, mainly before 1pm.  Mostly sunny, with a high near 84. East northeast wind 9 to 15 mph.  Chance of precipitation is 40%.
Scattered
Showers

Hi 84 °F
Thursday
Night
Thursday Night: Scattered showers, mainly after 7pm.  Partly cloudy, with a low around 75. East northeast wind around 10 mph.  Chance of precipitation is 50%.
Scattered
Showers

Lo 75 °F
Friday

Friday: Mostly sunny, with a high near 85. East northeast wind 13 to 17 mph, with gusts as high as 22 mph.
Mostly Sunny

Hi 85 °F

National Weather Service Forecast Details

 

GRLevel3 Radar

  [10/10
GRLevel3 radar from NWS station TJUA

Day 1 rainfall

Day 2 rainfall

Day 3 rainfall



000
FXCA62 TJSJ 260931
AFDSJU

Area Forecast Discussion
National Weather Service San Juan PR
531 AM AST Mon Feb 26 2024

.SYNOPSIS...
Issued at 436 AM AST Mon Feb 26 2024

Merging cold fronts over the area will provide ample moisture and
some convergence in northeasterly flow to hold clouds and showers
over the area until Wednesday. Then, some clearing and drying
will occur despite persistent quick passing showers. Moisture
returns on Monday and Tuesday. A long wave trough with colder air
aloft will generate some instability and the possibility of
thunderstorms on Tuesday and Wednesday.

&&

.SHORT TERM...Today through Wednesday...

Overnight, mostly cloudy skies prevailed across Puerto Rico and the
U.S. Virgin Islands. Showers began to develop over the Atlantic
waters and proceeded to move inland along the northeastern and
northern coast of Puerto Rico at night, leaving around 0.50 inches
of rain. Temperature-wise, they stayed in the low to mid-70s along
the coastal areas, while over the mountains, they stayed in the 60s.
The dominating wind flow was mostly light from the north-northeast.

The latest model guidance continues to suggest unstable weather
conditions throughout the first half of the workweek as the moisture
from the old frontal boundary merges with another cold frontal
boundary lingering across the forecast area. At this time,
Precipitable Water (PW) models show values above the 75th
percentile or above normal climatological levels for this time of
the year today. Therefore, the forecast for today leans into a wet
pattern across the islands. Despite the fact that persistent
widespread heavy rains are not expected, some areas could receive
sufficient rain during short periods, possibly raising stream
levels and causing ponding of water on roadways. Today, winds will
become east-northeasterly as high pressure continues to build
over the western Atlantic. This wind flow will allow the better
chance for rain to take place across northern, interior, and
southwest sections of Puerto Rico. From Tuesday into Wednesday,
the mid-level temperatures will become cooler at around -8 to -10
Celsius. Therefore, the potential for isolated thunderstorm
development increases, and for that reason, we added them to the
short-term forecast. A gradual improvement in weather conditions
is anticipated on Wednesday as a strong high-pressure ridge
starts building aloft, diminishing cloud cover and shower
activity. A surface high-pressure ridge will also develop and move
into the southwest Atlantic and build across the region,
resulting in northeasterly winds and the return of stable weather
conditions.

&&

.LONG TERM...Thursday through Sunday...

High pressure at the surface in the western Atlantic will be
refreshed later in the week with another high out of the eastern
United States. A persistent inverted trough that wanders between
55 and 45 degrees west longitude in the sub-tropical Atlantic will
also help to maintain northeasterly flow across Puerto Rico and
the U.S. Virgin Islands through the long term period. This will
bring cool and fairly moist air out of the central Atlantic in the
lower levels. Although mid levels will be dry, the persistent
winds of 10 to 20 knots and the abundance of low level moisture
will produce bands of showers that will bring night and early
morning showers to the U.S. Virgin Islands and the north and
northeast coastal sections of Puerto Rico and afternoon showers to
the southwestern and interior portions of Puerto Rico. Amounts
are not expected to be particularly heavy, but will help to
alleviate the drier periods of the previous week. Because of the
uniformity of the air flow during the period out of the cooler
central Atlantic temperatures will be in a slight cooling trend
overall, but will be warmest on the south coast.

At upper levels on Thursday and Friday, the atmosphere will
recover from the cold it caught during the passage of a long wave
trough Tuesday and Wednesday. We will begin to feel the effects
of a weaker short wave trough Saturday and Sunday.

&&

.AVIATION...
(06Z TAFS)
Issued at 436 AM AST Mon Feb 26 2024

VFR conditions across all terminals. However, TJSJ and TJBQ
terminals could experience brief MVFR conditions with SHRA after
26/14Z. Sfc winds will remain NE. After 26/14Z, winds will
increase to 12kt with sea breeze variations. Then, after 22Z,
expect winds to become light, 3-5 kts. Max winds W 60-70 kts btwn
FL395-455.

&&

.MARINE...
Issued at 436 AM AST Mon Feb 26 2024

Seas will be generally gentle with moderate short period wave
action due to persistent northeast flow. A pulse of swell from a
low moving northeast out of the western Atlantic will reach the
area today and tonight, but more significant wave action will be
generated by local winds Friday through Sunday when small craft
advisories will likely be necessary in the local outer Atlantic
waters.

&&

.SJU WATCHES/WARNINGS/ADVISORIES...
PR...None.
VI...None.
AM...None.
&&

$$

SHORT TERM/AVIATION...MMC
LONG TERM/MARINE....WS

NWS SJU Office Area Forecast Discussion

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Wind Shear Tendency

Sea Surface Temperatures

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