Heat Advisory in Effect for Suffolk, Heat Index Could Hit 100 Degrees

The National Weather Service has issued a heat advisory for Suffolk County, in effect until 10 p.m. Sunday.

High temperatures on Friday, Saturday and Sunday will be around the 90-degree mark, but the heat index (how hot it really feels when the humidity is factored in) will be near 100 degrees, the National Weather Service says.

The combination of the heat and humidity will increase the risk for heat-related health issues, especially for the elderly, those with chronic health problems such as lung and heart disease, those working outdoors and other heat sensitive groups of people, the NWS says.

Find some heat safety tips here.

There's a 30-40 percent chance of showers and thunderstorms through the weekend. Any thunderstorms that develop will be capable of producing torrential rainfall and localized flash flooding, the NWS says.

Here's Friday's hour-by-hour forecast:

• 11 a.m.- 87 degrees, heat index- 96 degrees
• Noon- 88 degrees, heat index- 98 degrees
• 1 p.m.- 88 degrees, heat index- 98 degrees
• 2 p.m.- 88 degrees, heat index- 98 degrees
• 3 p.m.- 88 degrees, heat index- 98 degrees
• 4 p.m.- 86 degrees, heat index- 95 degrees
• 5 p.m.- 85 degrees, heat index- 93 degrees
• 6 p.m.- 83 degrees, heat index- 90 degrees
• 7 p.m.- 82 degrees, heat index- 89 degrees
• 8 p.m.- 80 degrees, heat index- 85 degrees
• 9 p.m.- 81 degrees, heat index- 87 degrees
• 10 p.m.- 80 degrees, heat index- 85 degrees
• 11 p.m.- 80 degrees, heat index- 85 degrees