The heat is on.

The National Weather Service (NWS) forecast calls for a high temperature of 97 degrees on Thursday in the Greeneville area, and an even more oppressive high of 100 degrees on Friday.

There's no relief over the weekend, with highs of 100 degrees forecast for Saturday and 100 again on Sunday.

"We're expecting near-record temperatures through Sunday," said Kate Guillet, at the NWS Morristown office. We have high pressure moving in and its pretty much going to stay over the area the whole weekend."

There's strong potential for long-established heat records to be broken in the Greeneville area. Tri-Cities temperature records are 96 for Thursday, set in 1952; 95 for Friday, set in 1952; 95 for Saturday, set in 1959; and 98 for Sunday, set in 1959.

Average high temperatures for Northeast Tennessee this time of year range from the mid-to-upper 80s, Guillet said.

"This would be abnormally high for this time of year," she said of the impending heat wave.

"The days that look like we will get the closest [to the record temperature] are Friday and Saturday," Guillet said.

The spell of hot weather is expected to generate dry heat, with low humidity, she said.

"The more moisture in the air, the higher the heat index will be," Guillet said. "There will be relative humidities around 50 percent during the afternoon."

The best chances for rain are on Saturday and Sunday, but the NWS calls for only a 20 percent likelihood of precipitation.

Some Greene County residents were preparing for the hot weather on Tuesday.

At Ace Hardware on West Main Street in Greeneville, there was already a run on garden hoses and sprinklers.

Stock was temporarily exhausted, but merchandise should be restocked today, store manager David Dean said.

The sale of fans is also on the upswing, Dean said.

"Most of it is last-minute buys," he said. "Most of the things we are seeing are fans and lawn and garden [equipment] and sprinklers and hoses."

Other retailers like Lowe's have seen an increase in the sale of air conditioners, a store employee said.

The forecast of hot, dry weather is a continuation of a pattern from last week, according to the U.S. Department of Agriculture's (USDA) National Agricultural Statistics Service.

Soil moisture reports indicate that moisture levels in East Tennessee are "70 percent short to very short," according to the USDA Tennessee Crop Weather report issued Monday.

"The effect of the extended dry spell on crops have begun to show, but most crops continue to be rated in fair-to-good condition," the report said.

There has been 1.64 inches of precipitation in the Greeneville area this month through June 24, well below the long-term average of 4.22 inches for the corresponding period, according to figures compiled by the University of Tennessee Research & Education Center on East Allens Bridge Road.

The NWS suggests taking some precautions to help safely weather the heat wave.

Limit outdoor activity to early morning and around sunset, and "drink plenty of water," Guillet said.

"If you must go out in the afternoon stay out of the sun as much as possible," she said.

For more heat wave safety precautions, go to http://www.srh.noaa.gov/ssd/html/heatsafe.htm