Markell arrived at a Delaware State Police troop in Rehoboth Beach early Friday to get an update on conditions after the storm prompted road and school closings throughout the southern Delmarva peninsula.
Markell also plans to visit the bridge over Indian River inlet, which was closed by high water. State Route 1 between Dewey Beach and Bethany Beach remain closed after water broke through the dunes.
Officials say a morning high tide could leave further flooding, but conditions are expected to improve later in the day.
Delmarva Power crews are working to restore power to about 1,000 customers, almost all of them in Sussex County.
RELATED SLIDESHOW: Pictures of the storm's impact
The Sussex County Emergency Management Office says 69 people voluntarily left their homes in the Long Neck and Oak Orchard areas on Thursdaynight.
Eleven of them are still sheltered at the Community Church on Oak Orchard Road across from the Indian River Fire Dept.
Route 1 remains closed from Dewey Beach to Bethany Beach.
For a complete list of current road closures, visit the DelDOT Web site at www.deldot.gov
Widespread moderate flooding is expected to continue today in low-lying, flood-prone areas, particularly in and around communities surrounding the Inland Bays, along the Delaware River, and near the Nanticoke River.
National Weather Service forecasters, however, now believe severe tidal flooding that had been predicted will be limited to smaller pockets in the county as the coastal storm and a blocking high pressure system to the north slowly slip eastward.
The Associated Press contributed to this report