00:00Well, we are dealing with a big combination, a nasty combination of heat and humidity,
00:04but also there's relief on the way. The relief is going to be disruptive, though,
00:09as we step into the holiday weekend here. The relief from the heat will come in the form of
00:14thunderstorms. Those thunderstorms will be in the way of some of our outdoor experience here
00:21into Saturday evening with the fireworks happening during some thunderstorm risk as well. So let's
00:27take a look at our headlines here for the next few days. And here we are. Three things to know
00:32for the holiday weekend. Record challenging heat holding in the mid-Atlantic. Most widespread still
00:38Saturday, becoming a little bit more trimmed down into the coastal mid-Atlantic on Sunday as more
00:45areas in the interior further to the north and west find some relief. Scattered strong thunderstorms
00:50every afternoon in the Midwest and the Northeast. So I think that you're going to feel better when
00:55those storms pop. There will be some damaging wind potential. There will be some lightning dangers,
00:59but it will also bring relief from the heat. And the heat, meanwhile, in the western U.S.,
01:04which has been largely absent this week, is going to gradually begin to return. All right,
01:10let's take a look at some models. And we're going to get into the details here. And then we'll take
01:15a
01:16look here at some other factors here, other things regarding potential for some thunderstorms.
01:22It will be especially fueled by high, high moisture and heat content in the atmosphere.
01:28All right, so here we are. This is the upper level flow in the atmosphere. And I'm going to plot
01:31the
01:31big upper level high pressure system. There we are. It's centered right over parts of the Carolinas
01:37and Virginia here. As we begin, as we close out this work week, might be an abbreviated work week for
01:42some of you, you'll notice that bubble kind of disappears into Saturday. That closed contour,
01:49the 594 height line. We're looking at how high up in the atmosphere you have to go to get to
01:54500
01:54millibars and pressure. Kind of complicated. Basically, mountain of air. The mountain of air
01:58is beginning to shrink a little bit. That's a sign the heat wave is beginning to step past its prime.
02:04So it's still present Friday, and it's not there on Saturday. In fact, here's a little bit of a bubble
02:11beginning to appear over New Mexico. And look at that in the next week. We begin to see an absence
02:16of that by, this is Tuesday night, Wednesday morning, an actual trough in the east. And here's
02:21the 594 thickness line now over the desert southwest. So there will be a big pattern change. But the
02:30contrast of this transition is going to happen with thunderstorms, unfortunately. And that's how
02:34virtually all summer heat waves end in the northeast with strong thunderstorms. And there are going to be
02:40these little ripples of energy. Here's one. Here's another one. Trying to highlight these. Those
02:45are troughs. And each of them will be the impetus for some more strong thunderstorms. And this one
02:52here, Sunday afternoon, this will have a bona fide cold front associated with it, which is really going
02:58to be the end of the heat wave here in the northeast once that fully kicks through. But even some
03:02thunderstorms and noise in advance of that will chip away at the heat this weekend. So let's take a look
03:07this here. This is the temperature index. It's the shift of tails, a statistical approach to looking
03:13at how hot it is compared to normal. And again, we've been dealing with some extreme heat out
03:18there. You can see as we move through the end of the work week, this is July 3rd. I know
03:24that this
03:24says valid 0Z, July 4th, 0Z. That's Greenwich Mean Time. So the clock's straight to midnight from the
03:303rd to the 4th in England. We're four hours behind that in the east. We're seven hours behind that in
03:34the western U.S. This is July 3rd. This is Friday. And the purple, that's just off the charts heat.
03:40Again, dabbling near record highs. But let's go to Saturday, July 4th. Still extremely strong signal,
03:47sweltering weather, but it begins to get trimmed down a little bit. Let's go to Sunday. Trim down
03:52even more. Progress. The heat wave is ending. And then into Monday, it's restrictive. Tuesday,
03:57down into just the Carolinas. And you begin to see even a hint, just a mere hint, maybe something a
04:02smidge cooler than the norm near the mid-Atlantic coast or near the New England coast. Basically
04:07near normal again. And we begin to see the heat begin to build into Arizona. So the heat wave will
04:11be ending. But look at this in the transition. Man, this is soupy, soupy air. There are two blues on
04:16the map here on the two ends of the spectrum. This deep blue, purple blue, is extraordinarily dry air.
04:22Very dry air. Those are dew points down near zero. This blue here, that's a 75 degree dew point. That
04:30is
04:30really, really, really much air you can wear. Some of this being fueled by the corn crop there in
04:35Iowa. Some of this just a straight up air mass coming out of the Gulf, slowly drifting. There's
04:40not much flow. This is a stagnant air mass. Man, that's humid air. Saturday, still very humid. Sunday,
04:47still very humid. But it's beginning to get chipped down. And you can see by Monday and Tuesday,
04:51look at this, lighter greens up into parts of Virginia. You can even see the wind direction there.
04:58That's a cooler wind direction. Dryer air as well, suppressing the high, high moisture content down
05:04south of Tennessee. So we have extremely high fuel for storms. Now, this is a look at CAPE,
05:13convective available potential energy. Basically, the fuel for updrafts. Warm, humid air near the ground,
05:19colder air upstairs. And you can see there's plenty of fuel for these storms. Saturday,
05:23it's optimized over the Midwest. But we do have some fuel for storms over the Northeast as well.
05:29It's very juicy air. But the greatest, strongest, tallest updrafts will be in the Midwest for the
05:34next couple of days. And then as the front moves in, we're going to see a lot of noise here
05:38in the
05:38Northeast. So even though the updrafts may not be tremendously tall in the Northeast compared to
05:43those in the Midwest, we're going to see storms out there. So let's go through it Saturday.
05:48The GFS has been hinting at a large cluster of thunderstorms around Baltimore, DC. It's kind
05:53of problematic on Saturday evening. Not a good time. And then up into the area around New York
05:57City. We're actually forecasting a moderate risk of severe weather on Saturday. It's two out of four
06:02on the AccuWeather Severe Threat Index in New York City because of damaging wind potential. Slow
06:07moving storms. Here's the European model. Nothing in the early afternoon. Storms activate across the
06:12Northeast. Many storms in the Midwest during that timeframe. So let's take a look at our fireworks
06:18forecast. We got a lot of red on the map there in the Midwest. We're very confident in numerous
06:23thunderstorms that will get in the way of the fireworks activity. And then for the Northeast,
06:28it's difficult to time. Let me get myself out of the way here. It's difficult to get real specific
06:33on the timing of the actual thunderstorms moving through one area or the next. But we are looking at,
06:37again, some concerns in the Northeast as well. So use caution. Keep an eye on the AccuWeather
06:42app. But the good news is next week, we're looking at a change in the wind here, turning drier and
06:48cooler.
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