00:00 - From the Ban Family Studios in the Department

00:03 - of Meteorology and Atmospheric Science at Penn State.

00:07 - This is Weather World.

00:21 - Hello everyone, and welcome to Weather World.

00:23 - Today is July 1st, 2026.

00:25 - I'm Rob Ledoux, joined by Grant live shot with the forecast this evening.

00:29 - Grant we just flipped the calendar over to July.

00:31 - It is hot and humid outside.

00:33 - July is just straight up nasty out there.

00:36 - Even if you're out there at 8 or 9 a.m., it's still like a

00:38 - oh, did I make the right decision even stepping outside today?

00:41 - Yeah, it's one of those things where it's actually reaching dangerous levels.

00:44 - So we want to make sure we're aware of that in the forecast.

00:47 - And you've got more heat on the way. Yep.

00:49 - Yeah. And it's not getting any better anytime soon.

00:51 - Okay. Details coming up in just a moment.

00:53 - Also on Tonight.

00:54 - Show, I've got the extended forecast that will take us

00:56 - through the Independence Day weekend.

00:58 - And Giannis has weather-wise talking about the weather of Independence Day.

01:01 - But first here's grand.

01:03 - Thank you. Rob.

01:03 - We're going to start off our forecast here today

01:05 - by looking at a time lapse from Harrisburg.

01:07 - You see this morning we start off with plentiful sunshine

01:10 - which really allowed us to start baking relatively earlier.

01:12 - We could see the development of some of those boundary layer

01:15 - cumulus clouds that remain relatively on the shallow side

01:18 - as we get off into our early afternoon afternoon and evening hours here.

01:22 - And that's really been the picture across much of the Commonwealth here.

01:24 - As we've extended off into the middle of our workweek.

01:27 - Here we can see the small little speckles representing some of those similar clouds

01:30 - that we saw in the time lapse.

01:31 - We actually had the development

01:33 - of a quick thunderstorm that popped up very shortly over Scranton.

01:35 - But really, other than that,

01:37 - we've remained on the dry side and remained on the hot side,

01:39 - across a lot of the region.

01:41 - We can see that when we're looking at the temperatures

01:43 - here, seeing in the 90s across most locations, some still hang

01:47 - lingering up in the upper 80s.

01:48 - But really a really warm one out there.

01:50 - And especially as we look across the Delaware River

01:52 - valley, parts of southeast Pennsylvania, we're getting very close to 100 degrees,

01:56 - in some locations.

01:58 - Now, when you combine that with looking at the dew point temperature,

02:01 - a measure of our humidity, how moist it is out there, we can see that

02:05 - we are on the tropical side in many locations at that

02:08 - dew point above the 70 degree mark, in many spots.

02:11 - Now, this is where typically where it starts

02:12 - to feel like when you step outside, you're like, oh, it is super moist out here.

02:16 - When you combine that,

02:17 - with the temperatures that we're seeing, we're seeing very large heat index values

02:20 - across the Commonwealth in excess of 100 degrees across many locations.

02:24 - And of course, our locations here,

02:26 - with some of those higher temperatures, are getting heat index values

02:29 - that are starting to approach, the 110 degree mark.

02:32 - So really, not surprisingly so we do have extreme heat

02:35 - warnings out that have been issued

02:36 - by the National Weather Service for much of the Commonwealth.

02:39 - There are some areas here that have heat advisories, that are out

02:42 - and through through the beginning part of our weekend.

02:45 - But when we look at this heat risk product that's produced

02:47 - by the National Weather Service, we can see a bunch of purples on our map

02:50 - here for our Thursday, which indicate the most high end,

02:53 - version of this product, indicating very large heat impacts are possible.

02:58 - And by the time we get off into our Friday,

03:00 - the beginning of our Independence Day weekend,

03:02 - we can see that that purple really covers almost the entirety of Pennsylvania,

03:05 - but as well as the surrounding region, which is really strong signal

03:09 - for the development of heat related impacts entering our July 4th weekend.

03:13 - And we can see that we have our excessive heat

03:15 - not only across Pennsylvania, but this also stretches across parts

03:18 - of the entirety of Ohio, Indiana and Illinois, and parts out to our west.

03:22 - And we can see when looking at the satellite

03:24 - imagery here, very similar picture.

03:26 - We actually can kind of see this clockwise or anti cyclonic rotation

03:29 - sitting overhead.

03:30 - Really little cloud cover, little storm activity.

03:33 - All that's kind of being diverted off to our north.

03:35 - And that's really allowing some of those temperatures

03:36 - to really blossom here as we get off into the middle of our week.

03:39 - Many spots in the 90s across the eastern,

03:42 - essentially two thirds of the United States

03:43 - and our cool areas kind of limited to the northwest corner, where we kind of

03:46 - had the remnants from a cyclone that passed through earlier this week.

03:50 - Looking at the surface analysis here, we can kind of see this blue age

03:52 - doesn't really go anywhere as we get it

03:54 - kind of extend off into the later half of our week here.

03:57 - This high pressure system is still lingering.

04:00 - By the time we get off into our Thursday and our Friday,

04:02 - and we really don't have the developed or the passage of any, impactful

04:05 - weather, which is really allowing that heat to be persistent.

04:08 - And we're going to see that has the impact of of allowing our temperatures

04:11 - overnight to not really get much cooler for tonight.

04:15 - We have little relief.

04:16 - We're going to be dry, but we're going to

04:17 - still have those muggy conditions that are just going to feel really gross.

04:20 - And this is dangerous because these temperatures

04:22 - are 10 to 15 degrees above average.

04:24 - We're not really seeing those temperatures get down in the 60s.

04:26 - So still warm overnight.

04:28 - And when you couple that with those warm temperatures that we see

04:30 - during the daytime, it really allows for not a large period of relief,

04:34 - from these really high temperatures that we've been seeing over

04:37 - the last few weeks, conditions will mean very humid.

04:39 - And this is very dangerous heat.

04:40 - So if you have to work outside, it's best to stay hydrated as easily as you can.

04:45 - We're going to see this heat position to our Friday with storm chances increasing.

04:48 - And up next we have the extended.

05:18 - Today's edition

05:19 - of the extended forecast features the Independence Day holiday weekend.

05:23 - It also takes us into the first half of next week.

05:26 - I see a continuation of some of the heat as we begin the weekend.

05:29 - Certainly hazy, hot and humid going into the second half of the weekend,

05:32 - but eventually some relief from the big heat.

05:35 - I think we'll also see several chances for rain and storms on the way.

05:38 - More on that in just a moment.

05:39 - First, we'll begin with a look at the water vapor satellite imagery.

05:42 - You can really see that ring of fire pattern

05:44 - that is set up across the eastern seaboard, producing that big time heat.

05:48 - And I think by the time we get to the beginning of this period on Saturday,

05:52 - you can still see where that area of high pressure is in charge over the Carolinas.

05:56 - So he's still with us on Saturday, maybe not to the same magnitude as what

06:00 - we'll see these next couple of days, but I think we still could see some triple

06:03 - digits, especially in southeast Pennsylvania on Independence Day.

06:07 - By the time

06:07 - we get to the second half of the weekend, high pressure starts to went off.

06:11 - Went out off to our north and east, and eventually some cooler air,

06:14 - or at least more seasonable air moves in across New England

06:17 - and into Pennsylvania come Tuesday and Wednesday of next week.

06:20 - Maybe another ripple moving in here, producing some shower chances.

06:24 - But that's one thing we'll see just about every day during this period.

06:27 - The chance for some scattered showers and storms with the heating of the day,

06:30 - series of leftover boundaries or some instability showers

06:33 - over some of the mountains,

06:35 - and when it does rain, it could pour produce some locally heavy rainfall

06:38 - at that humidity tracker reveals very muggy conditions on Saturday.

06:43 - Dew points once again in the 70s in a big way across the Commonwealth.

06:46 - I think we'll still see widespread 70s for dew points on Sunday

06:50 - and maybe even into Monday as well.

06:52 - So important to stay hydrated.

06:54 - Keep in mind by Saturday, heat index values that feels like

06:56 - value could be once again over 100 degrees by Tuesday and Wednesday,

07:01 - some slightly less humid air should make its way,

07:03 - I think, into Pennsylvania and across New England.

07:05 - Still might be a bit muggy in some places, but overall less humid compared

07:09 - to what's going on out there now.

07:11 - And this weekend.

07:13 - So a breakdown of the extended forecast shows a hazy, hot and humid Independence.

07:17 - Day temperatures in the 90s, and even some lower triple digits

07:20 - for some folks in southeast Pennsylvania, rounds of scattered

07:23 - thunderstorms possible many dry moments, but when it does rain,

07:27 - we could see some locally heavy

07:28 - rainfall and localized flooding as well, especially in any training thunderstorms.

07:32 - But scattered cloud cover on Sunday, temperatures once again, mainly

07:35 - in the 90s.

07:36 - Monday we start to see a decrease in the temperatures,

07:39 - many of us in the 80s to lower 90s and then more seasonable.

07:42 - Come Tuesday and Wednesday, a few isolated thunder showers will be possible.

07:46 - Clouds increase on Tuesday.

07:48 - We'll still be mostly

07:49 - cloudy on Wednesday, but less humid through the middle of next week.

07:52 - That's your extended forecast.

07:53 - Stay with us. Weather wise is next.

08:15 - I remember

08:16 - back in high school watching the movie 1776, based on the musical that chronicled

08:21 - the events leading to the adoption of the Declaration of Independence

08:25 - by the Second Continental Congress in Philadelphia.

08:28 - Now, in the movie, the delegates often talk about the heat.

08:31 - Not surprising, given the time and place, but is that just the stuff of legend?

08:36 - Well, we can reconstruct the weather leading up to that first Independence Day.

08:40 - And though there was no organized weather observing network at that time,

08:44 - we do have observations from a few individuals.

08:47 - The most complete come from Mr.

08:49 - Phineas Pemberton, a member of a prominent Philadelphia family.

08:53 - He observed temperature, wind and weather each day

08:55 - at seven in the morning and three in the afternoon.

08:58 - Now, given that many of the delegates were in Philadelphia

09:01 - a month early, let's start in June 1776.

09:05 - Based on Pemberton's observations.

09:07 - The averages for that month were 66 at 7 a.m.

09:11 - and 74 at 3 p.m..

09:13 - The lowest 7 a.m.

09:14 - temperature that month was 54.

09:16 - The highest, at 3 p.m., was 82.

09:19 - The modern average is at 7 a.m.

09:21 - and 3 p.m.

09:21 - in June are 68 and 81, respectively.

09:25 - So at least the afternoons in Philadelphia in 1776, on average,

09:31 - were significantly colder than today.

09:34 - This just completed June in Philadelphia, was a few degrees

09:38 - above the modern averages, at both 707 a.m.

09:41 - and 3 p.m., and well above the averages from June

09:45 - 1776, in both the morning and the afternoon.

09:48 - Much warmer if you compare the highest temperature

09:51 - in June 1776 with 96

09:55 - in June of 2026.

09:58 - Bottom line June 1776

10:01 - doesn't seem all that hot to me, at least not by modern standards.

10:05 - But of course, clothing styles have changed and we have air conditioning

10:08 - now, starting on July 1st, 1776, we also have Philadelphia temperature

10:14 - observations from Thomas Jefferson, usually 3 or 4 per day.

10:20 - Now, if we combine Pemberton's and Jefferson's data,

10:23 - we can get a pretty good idea of the weather.

10:25 - Those first two days of July 1776, July 1st started foggy,

10:31 - but the sun came out and southerly breezes sent temperatures into the 80s.

10:36 - Pemberton reported a thundershower at 5 p.m..

10:39 - To me, this looks like a typical humid

10:42 - summer day in Southeast Pennsylvania.

10:45 - Temperatures stayed in the 70s on July

10:48 - 2nd as Pemberton observed much rain.

10:51 - This forenoon, wind shifted to northwest in the afternoon with clearing skies.

10:56 - That's a classic sequence of events with a summer cold front going through.

11:01 - Wind stayed northwesterly on July 3rd,

11:04 - a partly sunny and breezy day with temperatures in the mid 70s.

11:08 - That sounds like a typical refreshing summer day behind a cold front.

11:13 - The temperature fell to 64 by 7 a.m.

11:16 - on the morning of July 4th.

11:17 - And by that historic afternoon, winds had shifted to the southwest

11:22 - and Jefferson recorded 76 degrees at 1 p.m.

11:25 - as skies clouded up.

11:27 - The kind of weather associated with warm air

11:30 - trying to return, at least based on the available data.

11:34 - That first Independence Day seems fairly uneventful weather wise to me.

11:39 - Have a great 4th of July weekend.

11:41 - Stay tuned. We'll be back in a moment with more.

11:55 - Wrapping up our forecast for this evening.

11:58 - For tonight,

11:58 - we are going to see a little relief because the temperatures

12:00 - are going to be in the 70s across all locations in the Commonwealth.

12:03 - This evening.

12:04 - Those muggy conditions are going to remain.

12:06 - And this is important because this is about 10 to 15 degrees above average.

12:09 - So a couple of these lower

12:11 - these higher low temperatures with these really high high temperatures.

12:14 - We're seeing a really dangerous period of really dangerous heat

12:17 - across the Commonwealth kind of entering our Independence Day week.

12:20 - An extreme heat warning is out for most folks,

12:23 - especially for these areas where we're seeing these heat

12:25 - index values that will be exceeding the 105 degree mark.

12:28 - Getting off to our Friday.

12:29 - We are going to see a slight downtick

12:31 - in those high temperatures, but that heat is going to persist

12:33 - across most locations,

12:34 - and there will be a chance for afternoon thunderstorms across the Commonwealth.

12:38 - And really our first chance at seeing, I think wet skies here or wet

12:41 - wet conditions.

12:42 - As we enter our Independence Day period this weekend

12:46 - celebrating the 250th birthday of America.

12:48 - Yeah, good plan to find a pool or somewhere to kind of cool off.

12:52 - Find some air conditioning and and everything.

12:54 - I wanted to take some time tonight.

12:56 - This is actually your last show with us for Weather World.

12:59 - Grant made his debut on the show almost three years to the day, by the way,

13:03 - then helping us behind the scenes with giving some forecast.

13:06 - You folks here at home, And while pursuing your PhD,

13:10 - we should mention and congratulations to you on successfully defending that.

13:13 - Thank you. One day.

13:14 - What's next for you, Graham?

13:15 - I'm going to be heading to the United States.

13:16 - Naval Academy at the end of this month, and I will be teaching for a while.

13:20 - I'll be a professors there teaching students this coming far future.

13:23 - Officers in the Marine Corps. In the Navy?

13:26 - Yeah.

13:26 - Joining Scott Leffler, another weather old person who, joined us with forecast

13:30 - just a couple of years ago.

13:31 - Really excited for this new chapter and come back and visit anytime.

13:34 - Of course, I have to.

13:35 - Absolutely.

13:36 - Well, great to have you with us and thank you for tuning in tonight.

13:38 - We'll see you back here tomorrow for some throwback features.