Severe Thunderstorm Warning In Effect Until 8:30 p.m. Thursday: "Tornadoes Cannot Be Ruled Out."

Update as of 5:12 p.m.

The National Weather Service has issued a severe thunderstorm warning until 8:30 p.m. Thursday.

"A line of severe thunderstorms is currently moving through central New York and central Pennsylvania, and is on track to enter the [Madison] area this evening. This line will first enter the lower Hudson Valley, northeast New Jersey, and New York City between 5 p.m. and 6 p.m. and will move east into Connecticut and Long Island between 7 p.m. and 8 p.m. Additional thunderstorms will linger over the area through midnight."

The National Weather Service said the storms are capable of damaging winds over 58 miles per hour and hail over 1 inch in diameter.

"Frequent and dangerous lightning strikes are expected with these storms. Torrential rain with rates between 1 and 2 inches per hour is likely, possibly producing flash flooding over the area. Isolated tornadoes cannot be rule out. Please stay advised for warnings that will be issued."

The weather as of 5:16 p.m. on Madison was sunny and humid. The downtown sidewalk sales were packed, kids were out playing on the side streets, and people were out enjoying the beach and their pools. And everyone was talking about the weather.

Earlier story:

The National Weather Service says there is a moderate risk for severe thunderstorms Thursday afternoon and evening.

"Damaging winds and heavy rainfall are the main threats. Large hail is possible as well. An isolated tornado cannot be ruled out," the NWS said in a hazardous weather statement issued Thursday morning.

WXEdge, part of the WTNH.com website, says there is a five percent chance of a tornado over 75 percent of the state:

I wanted to add a quick note regarding the potential for tornadic activity across the state. ...  approximately 75% of the state falls under a 5% risk of being affected by a tornado. Now it is very hard to confirm and even pinpoint whether we will actually be hit, but with intense wind veering through the upper levels and wind speeds greater that 65 knots (referencing the 300mb and 200 mb charts) and increasing CAPE values (currently less than 1000J/kg) the potential is alarming.

The Red Cross in Connecticut says it is ready for a possible severe weather event and offered the following safety tips, which are also posted as a PDF with this article. The Red Cross says it has volunteers placed on alert.

Here is the prepared statement from the Red Cross:

The American Red Cross is preparing to respond today if severe weather forecast for the afternoon creates a need, said Connecticut and Rhode Island Region CEO Mario Bruno.

“We have reached out to our volunteers asking them to keep an eye on the weather and to let us know their availability in the event we need their help later today,” Bruno said. “We ask them first to be prepared for their own safety so that they can be ready to help others.”

Bruno said the Red Cross would be monitoring the situation throughout the day and would, if needed, coordinate any activity with state emergency planners and be ready to help local communities. “If there is a need for us to help with possible sheltering or distribution of supplies, we will have our team ready.”

Today’s forecast includes the potential for strong winds, heavy rain, damaging hail and flooding. Bruno said Connecticut residents should prepare ahead of the weather to avoid problems later.

“Take in outdoor furniture that could be damaged or could cause damaged in high winds,” Bruno said. “Be sure you know where your flashlight and portable radio are, and have fresh batteries. And make sure your cell phone is fully charged in the event you need to communicate in a power outage.”

If storms do materialize, Bruno urged people to seek shelter and keep tuned to local media for information. “If you can hear thunder, you are close enough to the storm to be struck by lightning. At the first sound of thunder, seek shelter indoors. Open-sided shelters are not adequate protection. Stay away from windows during severe storms. And don’t bathe, shower or use plumbing during electrical storms.”

If the storms bring flooding or power outages, Bruno had additional advice. “Don’t drive through standing water. It can hide hazards such as washed-out roads or dangerous debris. If you seen downed power lines anywhere, STAY CLEAR! Assume those lines are live and dangerous.”

More information about severe weather safety and other preparedness tips are available at www.ctredcross.org. The Red Cross also offers a free First Aid and preparedness information app for iPhone or Android smartphones. It is available for download by visiting www.redcross.org/firstaidapp or by texting GETFIRST to 90999.

The unsettled weather looks like it will last through much of the rest of the week, the National Weather Service says:

• Thursday: A slight chance of showers and thunderstorms. Some of the storms could be severe. Mostly cloudy, with a high near 86. Light south wind increasing to 8 to 13 mph in the morning. Chance of precipitation is 20%.
• Thursday night: Showers and thunderstorms likely, mainly before 2am. Some storms could be severe, with large hail, damaging winds, and heavy rain. Cloudy, with a low around 73. South wind 5 to 7 mph. Chance of precipitation is 70%. New rainfall amounts between a half and three quarters of an inch possible.
• Friday: A chance of showers and thunderstorms, mainly after 8am. Mostly cloudy, with a high near 88. Southwest wind 5 to 7 mph. Chance of precipitation is 40%.
• Friday Night: A slight chance of showers and thunderstorms. Mostly cloudy, with a low around 71. Light and variable wind becoming northeast around 6 mph after midnight. Chance of precipitation is 20%.
• Saturday: A chance of showers and thunderstorms, mainly after 1pm. Mostly cloudy, with a high near 82. Northeast wind around 7 mph becoming northwest in the afternoon. Chance of precipitation is 40%.
• Saturday Night: A chance of showers and thunderstorms, mainly before 11pm. Mostly cloudy, with a low around 67. Chance of precipitation is 40%.
• Sunday: Mostly sunny, with a high near 82.