Heat Advisory – Dangerous heat index Wed, Thu: Thunderstorms possible late Thu

A Heat Advisory is effective Wed 11am to Thu 8pm in RI, MA, and CT for dangerous heat index (combination of heat and humidity) up to 103. The body loses the ability to regulate its temperature by evaporating sweat, possibly causing severe illness such as heat stroke, which is life-threatening.

The heat index is an estimate of the “apparent temperature” based on the combined temperature in the shade as measured by an ordinary dry bulb thermometer and the relative humidity. Conditions in direct sunlight will usually be substantially hotter.

At Providence, Wed temperatures are expected to exceed 90F from 11am to 7pm with a high of 94F during the middle to late afternoon, although the relative humidity is expected to remain below 50%.

Thu temperatures are expected to be slightly lower, exceeding 85F from 10am to 6pm with a high of 89F in the afternoon, but relative humidity above 60% throughout the day.

NWS advises “Drink plenty of fluids, stay in an air-conditioned room, stay out of the sun, and check up on relatives and neighbors. Young children and pets should never be left unattended in vehicles under any circumstances. Take extra precautions if you work or spend time outside. When possible reschedule strenuous activities to early morning or evening. Know the signs and symptoms of heat exhaustion and heat stroke. Wear lightweight and loose fitting clothing when possible. To reduce risk during outdoor work, the Occupational Safety and Health Administration recommends scheduling frequent rest breaks in shaded or air conditioned environments. Anyone overcome by heat should be moved to a cool and shaded location. Heat stroke is an emergency! Call 911.”

Locally severe thunderstorms could develop Thu 3pm–10pm, with peak likelihood immediately before and after sunset (8–9pm) due to thermal instability as the air cools, although the chance of rain will remain below 20%.