Southwest Florida under severe thunderstorm watch until 5 p.m.

FORT MYERS, Fla. – All Southwest Florida counties are under a severe thunderstorm watch until 5 p.m. Friday, the National Weather Service said.

Isolated wind gusts of up to 70 mph are possible, along with the potential for tornados, the National Weather Service said.

Power lines are down on Estero Boulevard on Fort Myers Beach, backing traffic up in both directions, the Lee County Sheriff’s Office said. Authorities warn visitors to avoid the area for the next several hours.

Power lines are down at Estero Boulevard on Fort Myers Beach. That, along with rain, has traffic at a near… https://t.co/46THN9aw5H

— Lee County Sheriff (@leesheriff) January 22, 2016

Sarasota and Charlotte counties were under a severe thunderstorm warning until 8:45 a.m. Power outages were reported across Charlotte County.

Power outages happening throughout Charlotte County. Most are temporary. Be safe at dark or flashing traffic signals. — CharlotteCountyATMS (@CharlotteATMS) January 22, 2016

Strong thunderstorms are expected to reach Lee County during lunchtime and move into Collier County by the afternoon.

The storms are connected to a larger weather system that is expected to blanket the Northeast with snow and blizzard conditions.

Flights out of Southwest Florida International Airport to Washington, D.C., Charlotte, N.C. and other northern cities are either delayed or canceled.

Southwest Florida could experience over an inch of rainfall on Friday, along with strong onshore winds and higher tides through Saturday.

The region will be cooler over the weekend as temperatures will drop into the 60s.

The U.S. Coast Guard urged mariners to use caution while out on the water on Friday and through the weekend.

“Mariners should take proper precautions to ensure their vessels and loose items are properly secured,” the Coast Guard said. “Before getting underway, boaters should check local marine forecasts for areas they will be transiting through prior to leaving the dock.”

The Coast Guard offered the following tips:

• Have working communication equipment aboard your vessel. A VHF-FM radio is the best method of communication while on the water. Although cell phones are a good backup, they can be unreliable due to gaps in coverage area and battery life.
• Make sure a friend or relative knows your float plan. A float plan states where you are going and how many people are aboard your vessel. It also gives a vessel description, details your destination and what time you expect to arrive there. If you are delayed for some reason, make sure you let someone know.
• Wear your life jacket! In 2014, 84 percent of boaters who drown were not wearing their life jackets. In an emergency there might not be enough time to put one on, so wearing one at all times may save your life.
• The Coast Guard recommends you have an Emergency Position Indicating Radio Beacon, EPIRB, aboard your vessel. In the event of an emergency on your boat, such as capsizing or sinking, the EPIRB will help tell rescuers your approximate location and expedite a rescue. EPIRBS take the search out of search and rescue.
• Download the Coast Guard Mobile app. The app helps boaters request a vessel safety check, call the Coast Guard or 911 in an emergency situation, as well as shows required safety equipment mariners will need aboard their vessel.
• Obtain a free, no-fault vessel safety check, from your local Coast Guard Auxiliary, before heading out on the water. The safety checks are courtesy examinations of your vessel, verifying the presence and condition of certain safety equipment required by state and federal regulations.