Marine Weather and Tide Forecast for Mayagüez, PR

SHORT TERM
Today through Friday...

Overnight weather remained calm, with mostly clear skies over Puerto Rico and the U.S. Virgin Islands. Winds were primarily from the east, maintaining a northeasterly component. Urban and coastal areas experienced temperatures hovering in the 70s, creating a comfortable environment for both locals and visitors. In contrast, mountainous and rural regions were cooler, with temperatures in the 60s.

The latest satellite imagery indicates a dominant drier air mass over the local region. Precipitable water models suggest values slowly transitioning from the 25th percentile (below normal) to the 50th percentile (near normal) for this time of year. As a result, little to no rain is expected across the islands today. Winds will gradually shift east-southeast due to the interaction between a surface high-pressure system and a frontal boundary moving westward into the North Atlantic. Maximum temperatures are forecasted to remain in the 80s to low 90s across lower elevations, while higher terrains will experience temperatures in the 70s. These conditions could contribute to a significant fire danger risk, particularly along the southern and western sections of Puerto Rico.
Consequently, a Red Flag Warning has been issued for these areas.
Therefore, we urge people to be aware of and stay updated on any changes in the forecast today.

However, from Thursday into early Friday, increasing moisture will allow precipitable water values to be around 1.6 inches, reaching the 75th percentile. This will result in a higher frequency and intensity of showers. Both ensemble models and local guidance indicate that Thursday will likely be the wettest day of the short- term period.

LONG TERM
Saturday through Wednesday...

A short wave trough will increase instability across the islands by the weekend, promoting diffluence around Monday into Tuesday over the Northeast Caribbean. A jet stream will also move closer to the region by early next week. These factors will result in some instability in the US Virgin Islands and Puerto Rico region, giving place to periods of moderate to locally heavy rains if enough moisture arrives, especially during the maximum diurnal heating.

As a frontal boundary lingers north of the islands, a prefrontal trough will promote moisture pooling over or near Puerto Rico and the US Virgin Islands during the weekend, increasing the probability of precipitation across the region. There is a good chance to observe flooding rains on Saturday.

Monday through Wednesday, winds will shift mainly from the east- southeast, resulting in warmer temperatures across the islands.
Under this wind flow, patches of moisture embedded in the winds will be the primary source of moisture. Low-level convergence will enhance the formation of showers across the windward locations each day. Additionally, sea breeze variations will promote the formation of afternoon showers across the western locations of PR.
Model guidance suggests moisture erosion around Wednesday as a mid-level high pressure tries to build over the islands.



AVIATION
(06z TAFs)

All TAF sites should experience VFR conds. Brief periods of VCSh could filter across eastern Puerto Rico, affecting JSJ. Some afternoon rainfall activity could impact JBQ after 19/22Z. ESE winds should prevail from 6-20 kt and occasional higher gusts.

MARINE

A fading northerly swell will continue to move across the Atlantic waters. The surface high pressure across the central Atlantic interacting with the frontal boundary over the western Atlantic will promote choppy seas due to moderate to locally fresh east to east- southeast winds across the region during the next few days. A prefrontal trough will increase shower activity by the weekend.

Fresh to locally strong winds will deteriorate marine conditions for small craft later this evening. As a result, a Small Craft Advisory is in effect.

BEACH FORECAST

Life-threatening rip currents will continue to form along the north-facing beaches in PR and the northern US Virgin Islands due to fading pulses of northerly swells, where a high risk of rip currents is in effect. Additionally, the risk of rip currents is moderate for the rest of the local beaches. Pulses of another northerly swell and increasing winds will increase the risk of rip currents again on Friday.



FIRE WEATHER

The drying trend continues across the islands, especially across the south-central and western areas of PR, where the rainfall deficits throughout the past 30 days are notable. The hazardous KBDI values at the stations along the southern, southwest, and western locations, combined with increasing east-southeast winds, sea breezes, and strong gusty winds, as well as relative humidity values around the low 40s or lower, will create a dangerous fire weather conditions. Therefore, a Red Flag Warning has been issued due to the high risk of wildfire spreading associated with these conditions.

SJU WATCHES/WARNINGS/ADVISORIES
PR...High Rip Current Risk through this afternoon for PRZ001-002-005- 008-012.

Red Flag Warning from 8 AM this morning to 5 PM AST this afternoon for PRZ014-015-018-027.

VI...High Rip Current Risk through this afternoon for VIZ001.

AM...Small Craft Advisory from 6 PM this evening to 6 PM AST Thursday for AMZ711.