NEXT Weather Alert: Timing out a severe weather threat in Philadelphia

[00:00:00]between 3 and around 9:00 and that will be the time frame where we could see some tree damage, some power outages, and again that threat for some flash flooding. Live look at the radar here as we track a few stray storms up to the north and west of the city, mainly through the Lehigh Valley, moving out of Burks up into Lehi, Northampton County.

[00:00:17]relatively isolated right now, but we do expect more of those organized showers and storms to develop as we head through around 4 or 5:00 and then roll through the Philadelphia area with those embedded gusty winds, that potential for a tornado, and the heavy rainfall moving across South Jersey down to our shore points through the second half of the day. We'll continue with hourly updates as we go through the rest of the afternoon with live coverage continuing on our stream of CBS Philadelphia. I'm CBS Philadelphia meteorologist Grant Gilmore. Have a safe afternoon.

[00:00:49]And those of you watching on the stream, let's get into the meat of this system as we watch it develop over the next couple of hours. We'll talk about what the potential is and and really what some of the limiting factors may be in the storms that develop. Now, what we're going to see overnight is a lot of those showers and storms gradually dissipating or at least pushing to the south and east. I think we start tomorrow morning with mostly sunny skies, though there still will be a chance for a few storms to develop in areas south through tomorrow afternoon. But today, we have the next weather alert with that building threat for potentially severe storms. And one thing that we're really watching is the cloud cover or maybe the lack of cloud cover because if we start to see more sunshine, which we are beginning to see in some places, the temperatures rise with more heat that then produces more instability. Right now here at 2:00 we're at 85° in Philadelphia. Most of South Jersey right through the I95 corridor into southeastern Pennsylvania temperatures are in the mid 80s with due points in the 70s. So it is warm. It is humid.

[00:01:54]Temperatures feel like the lower 90s, but it does feel very uncomfortable with all of this heat and humidity. One thing that we're watching, one of our products here is what we call convective available potential energy. a lot of words that basically just saying this is available energy for the thunderstorms to tap into to strengthen. And where we're finding some of the most unstable air is across South Jersey down into Atlantic County, Kate May County, there into Salem, Cumberland County, and most of Delaware. See this little pocket of relatively stable air over Montgomery, Bucks County, up into Lehigh, Northampton, and Burks County. That's because a little bit of rain that has fallen across the area has sort of stabilize the atmosphere. But as we go through the next couple of hours, we'll start to see the energy begin to fill back in with those peaks of sunshine in between some of those clouds. Now, that humidity that you feel, that's moisture in the atmosphere. There's a lot of moisture. And with the storms that develop, we will have the likelihood of these storms producing some locally heavy rainfall. We're talking about rainfall rates anywhere between 1 to 2 in an hour, maybe even more than that.

[00:03:04]So, when you have that much rain falling in a short period of time onto ground that is mostly covered in concrete, buildings, pavement, you have a lot of these urban centers or urban areas and that's why we have a flooding concern.

[00:03:19]So, there's a flood watch in effect for most of the I95 corridor and the adjacent counties. So, Montgomery, Bucks County, Philadelphia, Delaware County, Chester County, up into Mercer County in New Jersey, and then down through northern Burlington County, Camden, and then Gloucester County, also Newcastle County and Delaware in this flood watch that will remain in effect until 2:00.

[00:03:43]Now, remember, a watch, be it a flood watch, a severe thunderstorm watch, or any watch, basically just says, "Hey, look, the conditions are in place for this particular hazard to develop." So, this flood watch just says, look, no flooding happening now, but we do have the potential for some flooding to develop later on today into tonight.

[00:04:03]Again, that watch goes until 2:00 tomorrow morning. Now, we talk about these severe risk categories. This is what we call a convective outlook, and this is issued by the Storm Prediction Center. But they're out in Norman, Oklahoma, and they keep an eye on the entire country, and they've highlighted our region as having a level three out of five risk for severe storm. It's a relatively high threat for severe weather. This is an enhanced threat.

[00:04:29]Now, because it's three out of five, you could have a moderate or a higher risk.

[00:04:33]So, it's not the highest risk, but still an elevated risk, if you will. Now, if you break that down even more, you've got an a greater potential for seeing damaging wind. So, this is the severe wind risk breakdown. And with that, we have about a 45% chance of seeing damaging winds today. That's a pretty good chance of severe weather. So, as we watch more of these storms develop through the second half of the afternoon into the evening, we're primarily going to have to watch out for damaging winds.

[00:05:06]Now, I will say this. There's still a chance for a tornado as well. It's not the greatest threat that you'll ever see, but it's about a 5% chance, which is still pretty good, of some tornadoes developing. Now, whether it's a tornado or damaging winds, if that tree comes down and it causes damage to your home or knocks out power, you don't care what it was, right? It's damage nonetheless.

[00:05:26]And either way, we'll have to watch out for those threats, winds, tornadoes, or or maybe the that flooding threat as well, especially in some lowerlying areas and some some urban areas where you might typically expect to get some flooding. Radar loop over the last hour.

[00:05:41]Here's what we're tracking. A few isolated downpours out there because even though these showers are small, again, it taps into all that moisture that's in the atmosphere. So, it's producing locally heavy rainfall, but they are small, so they're not going to last very long. and then they're going to move out towards the east. But there is more showers on the way. We've just seen a couple of isolated showers pop up over the last 30 minutes or so moving through Camden County right now. Mount Laurel right along the Jersey Turnpike finding a couple of showers pushing through Tabernacle up towards Peton up towards Burlington and up to Bordontown area. Trenton probably going to see this very small shower develop. Otherwise, a little more scattered showers. A couple of lightning bolts just popping up there along uh 78. So, we're starting to see some of that convection develop into some thunderstorms now. A little bit of lightning to go along with it. The National Weather Service does not issue warnings based upon the lightning embedded within a storm. Um but it is certainly something that that we have to keep an eye on. Now, it looks like we're just getting information about a tornado watch coming in. And it looks like it is just for Lancaster, Pennsylvania out towards Lebanon, Lebanon, Skookul. So this tornado watch that was just issued looks like it is just west of our area.

[00:07:01]Still though, you can see that's where all these storms are coming from. There is actually a couple of tornado warnings already in effect north of us. So this is northern New Jersey up into New York.

[00:07:13]So that is the area where we're finding the active severe weather right now ongoing. In fact, three tornado warnings in effect to the north of us. Again, that's that's well north and that will stay north. So that's going to track east and north of our area. It will be this region right here, the storms that are just east of Pittsburgh and just south of Pittsburgh right now that will continue to march east through the rest of this afternoon and then into the evening hours. So we're going to continue to track this. We'll have hourly updates as we go through the rest of the afternoon. We have CBS Philadelphia at 4:00. But in the in the meantime, I do want to show you the latest run of our forecast model. And you see what is a relatively isolated to developing line of showers and storms moving across southeastern Pennsylvania, but developing as they do. So, we'll have to watch the development as this storm system moves to the east. I think it starts to ramp up especially across upper Montgomery, Bucks County, Chester County, and then into the Philadelphia area beginning around 6 to 7:00 and then it will roll across the I95 corridor, the Jersey Turnpike, 295, and then move across South Jersey as we head through 8, 9, 10:00. By 10:00, I think most of that severe threat should be ending. We may see a few trailing showers, but again, it it could be a situation where maybe the severe threat has ended, but we may still have some ongoing uh flash flood concerns. In fact, I I'm looking up here. I do want to step off screen just real quick because it looks like we are getting a tornado watch was just issued for the Philadelphia area.

[00:08:51]So, I want to make sure that we have that latest information for you here before we step away for another 45 minutes or so. Let me pull up the latest watches that we have and we'll we'll get the latest information to you. So, this is again what you're looking at is a future radar product. But what I'm pulling up right now is the watch that was just issued for our area. So, this tornado watch will be in effect until 9:00 this evening. So, that includes the entire Philadelphia area. does not include Dover, but it does include Newcastle County, does not include Kent County, includes the Wilmington area, all of Jersey and then it includes Eastern Pennsylvania, including Philadelphia. So, this just coming down from the National Weather Service moments ago. So, that's something that we're watching. A watch again like we just talked about is meaning that the conditions are favorable for the development. Meanwhile, we do have those tornado warnings to the north of us. So, that's where that tornado threat is ongoing. Meanwhile, this is the area that we're going to keep an eye on for that developing storm and that severe threat later on today. So again, just to recap, watching this line of potentially severe storms and maybe even tornadoes.

[00:10:02]So that's why we have the watch in place. We may have some tornado warnings. That threat goes until around 8 or 9:00. That moves across the region and then it starts to clear the coast as we head into the overnight. Quick look at the 7-day forecast here. 83 degrees by Thursday with sunshine. It's beautiful for the second half of the week. Tomorrow though, maybe a couple of storms in areas south, but not expecting a huge severe threat tomorrow. The rest of the week looks really nice. Low 80s on Saturday, 85 degrees on Sunday, and then mid 80s out there on Monday.

[00:10:31]Tornado watch in effect for the entire area until 9:00 this evening. We will keep you posted on everything that you need to know, whether it's here or on our website on cbsiladelphia.com.

[00:10:43]I'm CBS Philadelphia meteorologist Grant Gilmore. Stay safe this afternoon.

[00:10:47]15-year-old boy, meantime missing since Sunday, was hit and killed by a freight train last night. It happened at 11:30 on the overhead tracks near where Welsh Road and Grant Avenue split in Bustleton. Police say the teenager was walking southbound on the railroad tracks when the conductor spotted him and initiated emergency braking, but was unable to stop from striking.