Changing weather causes thunder, lightning in Philadelphia area. Here's the weather forecast
After an unseasonably warm day Saturday with high temperatures in the upper 60s with plenty of sunshine, conditions started to change Sunday before a significant drop in temperatures arrives for next week.
Thunder and lightning are happening in some places Sunday night because of atmospheric tension. NEXT Weather meteorologist Andrew Kozak explained what's happening on our Instagram page.
Even though these storms aren't severe, the sharp drop from nearly 70-degree air to the 20s and 30s creates a lot of atmospheric tension. When that cold, dense air rushes in and lifts the warm, moist air ahead of it, that sets off strong vertical motion. The temperature drops quickly with height, which makes the air unstable and helps build charge inside the clouds, which is what leads to all the lightning and thunder.
In this kind of setup, the storms are often "elevated," meaning they form just above the surface rather than right at ground level. They don't have the ingredients for damaging winds or hail, but the rapid mixing of warm and cold layers, along with ice and graupel particles colliding in the clouds, is perfect for generating electrical activity. The result is a vivid light show (and loud thunder!) without necessarily being a dangerous storm.
Temperatures Sunday night will remain relatively mild with lows in the upper 40s. Skies will also remain mostly cloudy Monday as cooler air starts to push in from the northwest. While temperatures start near 50 degrees Monday morning, they will only warm three to five degrees with highs in the middle 50s.
As the cooler air rushes into the region the winds will begin to increase going into Monday night. Temperatures will drop into the low 30s and upper 20s Tuesday morning, but because of the wind it'll feel more like the low-middle 20s to start Tuesday morning.
The cold northwesterly winds will produce some lake-effect snow, which could carry a few snowflakes into the Poconos and northern Lehigh Valley through midday Tuesday. Otherwise, conditions will remain blustery into Tuesday afternoon with high temperatures only in the mid-40s.
Temperatures will rebound back into the low 50s through the second half of the week, which while warmer than Tuesday, will remain cooler than normal through next weekend. The normal high temperature for the middle of November is 59 degrees.
Here's your 7-day forecast:
Sunday: A few showers. 64 degrees
Monday: Turning colder. High 53, Low 48
Tuesday: Chill arrives. High 44, Low 31
Wednesday: Much milder. High 54, Low 35
Thursday: Mostly sunny. High 54, Low 42
Friday: Partly cloudy. High 53, Low 38
Saturday: Mostly sunny. High 52, Low 35