First comes rain, then the heat turns on

The heat wave spreading across the Great Plains and portions of the Midwest is going to reach Long Island by the weekend. But a wave of showers beat the heat wave to the punch last night, dropping almost an inch of rain in a 90-minute burst.

Lauren Nash, a meteorologist with the National Weather Service in Upton, said weather patterns show most of the precipitation moving off Long Island by late this morning. But as that rain rides out on one high-pressure system, the heat will move in on another.

The incoming system has dropped broiling heat on places like Rapid City, S.D., and even Minneapolis, with 100-degree temperatures expected. But it won't be quite as sizzling by Thursday, when it reaches the East Coast, meteorologist John Murray said.

"Eastern New Jersey and New York City could get temperatures comparable to what is happening there," said Murray, noting temperatures in the high 90s across the Plains and Midwest. Most of Long Island will get temperatures in the low- to mid-90s, he said.

"Friday looks to be the warmest day," Murray said, noting the forecast for a high of 93 degrees on Long Island.

Saturday calls for a high of 92, Sunday 87. While that's a bit of a break, Murray said the advance forecast for the rest of July calls for slightly warmer temperatures than the normal average temperature for the month, about 75 degrees.

Early Monday, the National Weather Service called for rainfall amounts of between a quarter-inch and a half-inch, but after noon the forecast was updated for amounts of one-tenth to a quarter of an inch.

"Most of the rain that we expect to move through the area will likely be before midnight," said Nash, who added that 0.78 of an inch of rain fell onto Islip in the early evening Monday, and just over half an inch was measured at the weather service's Upton location by 8 p.m. "There is still the potential for some of these storms to be severe."

Heavy rain also was likely for portions of southern Connecticut, northeastern New Jersey and New York City, the service said.

Also Monday, Nassau and Suffolk counties, plus parts of the city and Westchester County, faced an air-quality alert -- meaning a higher than normal amount of airborne pollutants -- until 11 p.m.

Because of the airborne pollutants, those with respiratory issues should limit strenuous activity, the New York State Department of Health said.