(LOS ANGELES) — Storms will also begin to fire up during the early evening hours along the dry-line in south-central Texas. Not long after, storms will initiate in the Central Plains and continue to move eastward.An estimated 16 million Americans are bracing for the threat of severe thunderstorms today. The primary threats include damaging wind and large hail with any storms that develop in the shaded region.Heat alerts are already up across the Southwest in anticipation for dangerous heat threatening nearly 26 million people by mid-week. Potentially record breaking high temperatures will increase the potential for heat related illness, particularly for those without access to air conditioning or those participating in outdoor activities.With temperatures in the triple digits, record high temperatures will be challenged on Tuesday, Wednesday and Thursday before any relief is on the horizon.Memorial Day is looking fine on both coasts with the exception of Florida and northwest Washington. Washington, D.C. will be enjoying temperatures in the upper 70s. However, passing showers and thunderstorms threaten areas west of the Rockies to the Ohio River Valley. Rain could be particularly heavy and pose a flash flood risk across central Texas on Monday.Copyright © 2020, ABC Audio. All rights reserved.