Official National Weather Service forecasts for Las Vegas and southern Nevada — Clark, Nye, Lincoln and Esmeralda counties, from the Strip and the Las Vegas Valley out over the Spring Mountains to Pahrump and the Amargosa, down the Colorado to Laughlin and the Hoover Dam bypass, northeast on I-15 through the Moapa and Virgin valleys to Mesquite, and north up US-93 and US-95 to Caliente, Tonopah and Goldfield.