Howard Reynolds, 21, of Middle Island, reads a book at...

Howard Reynolds, 21, of Middle Island, reads a book at the Upper Lake in Yaphank as a man fishes in the background on Tuesday, May 18, 2021. Credit: James Carbone

Tuesday will be mostly sunny with a slim, 20% chance of afternoon and evening showers — the only rain likely through Sunday, according to the National Weather Service.

"Surface high pressure is building in from the west today with conditions expected to remain mostly dry through much of the morning and early afternoon," the weather service said.

A low pressure system now over Maine and southeast Canada may bring a weak cold front to Long Island, triggering isolated showers after noon on Tuesday.

"While it's not likely these will be strong enough to produce thunder, it's not out of the realm of possibility that there be a rumble of thunder with a stronger shower," the weather service advised.

The high for the day should reach 63 degrees.

And it could be breezy, with wind gusts reaching 25 mph or more.

In high pressure systems, air falls in a column, cooling and drying. In contrast, air rises in columns in low pressure systems, allowing vapor to condense into clouds and rain.

Daytime highs from Wednesday to Monday should run around the mid- to upper 60s. Night time lows will be in the upper 40s to 50, the weather service said.

The high pressure system should dominate the weather through Sunday, the weather service said, before possibly giving way to a warm front on Monday.

"Much of the time will be dry," the weather service said.

However, there is a "slight chance to chance probabilities for showers" Friday through Sunday, the weather service said.

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