SAN JUAN — 
A prominent Saharan Air Layer will reach the islands later today prompting hazy skies and decreased air quality with pulses continuing to arrive through Sunday.
Excessive Heat Warnings and Heat Advisories will be in effect from 11:00 a.m. to 5:00 p.m. AST.
Showers will continue moving across windward sectors during the morning with afternoon shower and thunderstorm development forecast mainly over the interior to northwestern Puerto Rico, as well as possibly downwind of El Yunque. Troughs will continue to influence the local weather but will gradually weaken and move away.
A tropical wave will bring additional moisture and instability Friday through Saturday.
Breezy east to southeast winds will be present and continue into the weekend, promoting more choppy seas.
No tropical cyclone formation is expected over the next seven days.