Latest Timing For 'Ring Of Fire' Storms As Extreme Heat Lingers In MD

Another day of brutal heat will blanket Maryland Wednesday before conditions turn stormy in the evening in what forecasters are calling a "ring of fire" thunderstorm system.

Extreme heat Wednesday, unsafe conditions remain

But before the weather turns unsettled, expect high temperatures in the area to reach the upper 90s. A high temperature of 98 is predicted for Baltimore/Washington International Thurgood Marshall Airport, with heat index values as warm as 109 degrees.

Tuesday saw thermometers swell to 105 degrees at Baltimore's Inner Harbor, breaking the previous June 24 temperature record of 101 degrees set in 2010.

"As a persistent dome of high pressure aloft weakens a bit, temperatures drop by a few degrees from previous days," the National Weather Service said in a Wednesday morning briefing. "However, conditions remain hot and humid with Heat Advisories in effect for a vast majority of the area."

A heat advisory is in effect for the Western shore of Maryland until 9 p.m. Wednesday. The Eastern Shore is under an extreme heat warning until 8 p.m.

'Ring of fire' storms move in

Severe weather could move in as early as Wednesday evening, causing temperatures to tick down before a noticeable change Friday, when the high temperature will linger around 80 degrees.

"A few severe thunderstorms are also possible today, with a better chance of more widespread thunderstorm activity on Thursday into Friday," the National Weather Service said Wednesday. "This is in response to a slow moving front that drops down from the southern Great Lakes."

AccuWeather reports that a large swath of thunderstorms surrounding the massive heat dome that has engulfed Texas to New England could bring a "ring of fire" to the mid-Atlantic region Wednesday evening.

The pattern is referred to in the weather community as a "ring of fire" because thunderstorms form along the edges of the heat dome, AccuWeather explained. Because the heat dome is warm through most layers of the atmosphere, clouds and storms have difficulty forming.

"However, on the edges of the heat, especially along the northern and western flanks thereof, the air is cooler well above the ground, which makes it easier for clouds to tower and produce thunderstorms," AccuWeather said. "Within this ring, there can be spotty, individual thunderstorms, large clusters of thunderstorms or a solid line of storms that can repeat or meander back and forth as hot and cool air change hands."

The severe weather threat will extend into the Northeast, where the threat of locally severe thunderstorms will extend eastward through Pennsylvania and the southern tier of New York to New Jersey.

Here is the National Weather Service's seven-day forecast at BWI Airport:

Wednesday: Isolated showers and thunderstorms after 2pm. Mostly sunny and hot, with a high near 98. Heat index values as high as 109. Calm wind becoming northwest around 5 mph in the afternoon. Chance of precipitation is 20%.

Wednesday Night: Scattered showers and thunderstorms before 2am, then isolated showers between 2am and 3am. Partly cloudy, with a low around 77. Calm wind. Chance of precipitation is 30%.

Thursday: A chance of showers, then showers likely and possibly a thunderstorm after 2pm. Mostly sunny, with a high near 93. Heat index values as high as 103. Calm wind becoming east around 6 mph in the afternoon. Chance of precipitation is 70%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.

Thursday Night: Showers likely and possibly a thunderstorm before 2am, then a chance of showers and thunderstorms after 2am. Mostly cloudy, with a low around 70. East wind 3 to 5 mph. Chance of precipitation is 60%. New rainfall amounts between a quarter and half of an inch possible.

Friday: A chance of showers and thunderstorms, mainly after 2pm. Mostly cloudy, with a high near 80. East wind around 7 mph. Chance of precipitation is 40%.

Friday Night: A chance of showers and thunderstorms, mainly before 2am. Mostly cloudy, with a low around 71. Chance of precipitation is 30%.

Saturday: A chance of showers and thunderstorms after 2pm. Partly sunny, with a high near 90. Chance of precipitation is 50%.

Saturday Night: A chance of showers and thunderstorms before 2am. Mostly cloudy, with a low around 73. Chance of precipitation is 30%.

Sunday: A chance of showers and thunderstorms after 2pm. Mostly sunny, with a high near 90. Chance of precipitation is 50%.

Sunday Night: A chance of showers and thunderstorms before 8pm. Mostly cloudy, with a low around 74. Chance of precipitation is 30%.

Monday: A chance of showers and thunderstorms. Mostly sunny, with a high near 90. Chance of precipitation is 50%.

Monday Night: A chance of showers and thunderstorms. Mostly cloudy, with a low around 75. Chance of precipitation is 30%.

Tuesday: Showers likely and possibly a thunderstorm. Partly sunny, with a high near 92. Chance of precipitation is 60%.