Current conditions: The East Coast heat wave is exposing more than 80 million Americans to temperatures near or above 90 degrees Fahrenheit through at least the end of today, putting grid operators who run PJM Interconnection and the New York electrical systems on high alert • Thunderstorms are drenching the United States’ southernmost capital city, Pago Pago, American Samoa, and driving temperatures up near 90 degrees • Some 3,600 miles north i…