Welcome to Weathered Questions, where we answer the questions on your radar.
Welcome everyone to another episode of Weathered Questions, the podcast that's all about your weather wanderings.
And we want to know what's on your radar.
Always remember, you can email us your questions to weatheredquestions at gmail.com to join on in on the conversation.
We are now getting deeper into October.
Halloween costume ideas are coming out.
Maybe it's already complete in your house.
ours is still up for debate.
We'll see what happens as we get a little bit closer.
But we're just going to get right into some of the topics because we've got some really good stuff to talk about on today's episode, Jan.
And we're just going to get into this.
Obviously, we looked at a lot of radar in September with how wet it was around the area.
Thankfully, it's been a little bit drier as of late.
Sometimes when I look at the radar, I see a thin band of rain ahead of the main area of rain.
And the question is,
Why does this happen?
This is a great one.
And I'm sure a lot of people have seen this before.
And most people probably just assume, no, it's just rain.
But rarely, when whatever that is gets to you, is there precipitation falling.
So what that actually is, a lot of people maybe have heard the term gust front before.
And essentially, what it is, is that is the kind of
Where the leading edge of the storm where the wind picks up and what you're seeing on the radar is actually what the wind is blowing around So it could be leaves.
It could be bugs.
It could be
pieces of corn stock, it could be a bunch of different things like that that are essentially getting blown in front of the storm as the winds are kind of diving down, hitting the ground, spreading out and pushing out in front.
And if you watch radar for a extended period of time,
generally that little kind of thin line starts very close to a stronger storm.
And over time, it gets a little further out and kind of, you know, starts spreading out further from where the storm actually is.
Again, because what's happening is the winds are coming down, hitting the ground and kind of spreading out.
And so they're spreading out further and further and further away.
So that's what it is.
It's bugs, it's leaves, it's, you know, just
biological debris from from the the world around that's getting blown around that's light enough for the winds to be able to pick it up and move it around and radar how it works is
It is hitting something you know the the pulse gets sent out from the radar beam it hits something and it comes back So radar doesn't know if it's hitting a leaf or if it's hitting a raindrop or something on General reflectivity, which is what most people think of as quote-unquote radar We do have other special dual pole products that we can use to help us see those different shapes and stuff but The in general if you're just looking at basic radar and you see something you think it's rain, but
radar itself, that pulse doesn't know what the shape of that thing is or what the makeup of that thing is.
And so it just comes across as that kind of green or blue or whatever your color table is of the lightest precipitation.
So yeah, it's kind of fun to see.
Yeah, and there's a way to actually experiment with this if you really want to.
I would recommend doing it outside, preferably in a garage, especially if you've taken
If you've taken liberty over the past week to 10 days of kind of cleaning things out for the fall, maybe sweeping the garage out, you ever take a shop vac and put it in reverse?
Oh, yeah.
Same thing.
Aim the hose at the ground and watch what the dust does.
It blows away from you.
If you were to actually record that process on a phone in super slow mo, what you'd see is the air actually hits the ground and it doesn't just stay on the concrete floor.
it actually kicks some of it up.
And with these storm down drafts that are going on, the storm down draft hits the ground and spreads out very much like that shop vac air plume hits the garage floor spreads out kicks the dust back up.
And you can actually see the dust go back up in the air again.
And so that's the exact same science behind this except you could recreate it in your own environment.
I wouldn't do it in your house.
I'd do it outside your house.
But that's the science.
That's the science behind exactly what Jan was saying.
Yeah.
Or if you haven't cleaned
the garage yet, you can go try that now and test it out.
Or just get the leaf blower out and blow leaves with it.
There you go.
And if you have a leaf blower, I don't particularly have one.
But it's the same science.
Put it straight down in a pile of leaves a couple feet off the ground and just watch what happens.
The leaves bounce right back up again.
And it's the exact same thing.
Exactly.
If you
don't have one of these fun power tools either, you can just get a little pile of dust or maybe like flour
or something.
Stop
on it.
And we'll just blow on it, right?
Yeah.
Very much so.
Basically, it's that quick burst of air that you can actually see what's going on.
Yeah, you shouldn't have to spend any money for this experiment.
Please don't.
No, please don't do that.
Don't send us the bill either.
No, that'll go in the non-expense column.
Not approved.
Yeah.
Not at all
approved.
All right, we're keeping on the theme of moving air here for this next question.
Why does high pressure mean sinking air and why does low pressure mean rising air?
We've talked about this a lot where we say, well, high pressure is rising, or high pressure is sinking, excuse me.
Low pressure is rising, but we haven't maybe dove into the science behind why that's the case.
Right, right.
And so a lot of it just comes down to some of the horizontal motion with the air initially.
It does have a drive into the vertical, though.
And so what I used to think growing up was wrong.
until I actually went to college and figured out what was correct.
When I saw, you know, I always figured that high pressure air was flowing away from high pressure systems, which is generally correct.
It's flowing out in a way.
But in low pressures, I thought, all right, the low might be, because I was taught this in school and it's dead wrong.
The low is like your bathroom tub drain.
It's the lowest areas while the moisture is going to flow there.
No, that's not true.
So I went, all right, so then if that's not true, then what is true?
So if you have a lower area of pressure and higher pressure air surrounding you, at least relatively, then the air can't go underground to fill that void.
It actually starts to converge in the horizontal plane.
And so it comes in from the east and west.
Let's just keep it simple.
And if it collides there, that's fine.
But it can't go underground.
It has to go upward.
And so your low pressure systems actually have upward motion associated with them just because of converging air.
Likewise, high pressure is diverging air.
The air is coming apart.
And so as it's doing so, it's going down and away from the high pressure system.
Denny Freire was a longtime chief meteorologist at KCRG.
And to this day,
Since the 1970s, there's only been two chief meteorologists at that TV station.
And Denny would always explain it on the air like this, from the mountain of the high to the valley of the low is how he would put it.
Like air running down a mountainside.
So that's not, you know, 100% accurate, but it's pretty close for people to understand.
At least that's where the wind direction is going to be coming.
But then you've got all these various different forces and things like that.
But if air is going to pool up somewhere, it's going to have a higher pressure to it.
And so as a result, you don't see the air parcels going up or down, being able to condense into cloud particulates and cloud droplets and eventually precipitation.
If it's a high pressure situation and the air is moving down in a way, then you're not getting that lift, that upward motion to create
precipitation to create clouds, you'll get the opposite with that.
So that's our general difference there.
In terms of like the wind flow and everything, that gets into some pressure gradient and Coriolis force type things.
But the big thing is, if you can just understand this term, the low pressure system is creating a void in the atmosphere and surrounding air is coming in to fill that void.
It's colliding in like
an offensive line and a defensive line.
Nobody's going to go underground.
We're back in football season.
The football
analogies are back.
We've got both lines going against each other.
And no player is going to go underground.
If anything, a player is going to go up and over the top of the line.
Upward motion.
So that's one way to think about it.
And I think if you realize what low pressure is, realize that high is the exact opposite.
So that's kind of how I think I would take that and explain that going forward.
Yeah, no, I like that explanation a lot.
I don't have much to add to it.
I think you think you covered it all
You know what I will tell you though temperature plays a role in pressure quite often and my wife is super sensitive to pressure shifts and Usually in the early evening.
She'll let me know the pressure is doing something and in reality You've looked out the window all day long.
This guy's been clear
If you have a home weather station, as the air warms up, it actually has less pressure by default.
And then as it cools down shortly after sunset, it's usually cooling.
So in the absence of the air moving around, any major weather changes, if it's the same air mass, it does change throughout the day.
It's not like it sits at the same pressure all day long.
As the air warms, it changes its pressure a bit.
And then as it quickly cools after dinner, which this time of year, you'll notice it a lot.
If you're outside at five o'clock and go back out at seven, there might be a 20 degree difference between when that happens.
And the air pressure will go up with that localized cooling because cooler air is more dense.
And it's essentially gonna weigh a little bit more.
So that's just a little piece of trivia there too.
It's a small change, but it does happen with the way that our days work.
Absolutely.
And speaking of that little...
a little bit of trivia you gave us, we'll get into our trivia question, which deals with a lot of the same concepts that you just noted here, Kai.
So something else you might start to notice a lot more here this time of year is that your little tire pressure light is turning on a lot more and you got to go stop at the gas station or get the air compressor out and fill them up.
Well, today's question is exactly about that.
Tires lose about one to two PSI
for what change in temperature?
So as the temperature's going down, we just noted with Guy, right?
That temperature drop is mean that we're going to have a pressure change also.
So for tires losing about one to two PSI, what do you think that temperature difference is?
We'll give you some multiple choice on this one.
Do you think it's one to two degrees Fahrenheit, about five degrees Fahrenheit, about 10 degrees Fahrenheit, or about 20 degrees Fahrenheit?
So we've got tires lose about one to two PSI for what change in temperature?
One to two degrees, five degrees, 10 degrees or 20 degrees.
We'll be back with the answer here in just a few.
All right, hopefully I had a chance to think about that.
And we know that
we're going to lose some pressure as the temperature falls.
But the specific part about this was what change in temperature.
And the answer on this is C, 10 degrees.
So tires will lose about one to two PSI for every 10 degree temperature change.
Now, that is not Voodoo.
That is from Jiffy Lube and the Firestone Total Auto Care Center websites.
So those are my citations for that.
But here's what it means for you.
If you have a tire that is currently running at 37 psi and you park your car outside and let's say you went out and did some errands and it was 65 degrees that afternoon when you were out driving around, I would think that the air inside your tire would at least take on that temperature, if not more, because of the friction of the road, you know, heat from the engine, things like that.
Well, then you park that in the driveway.
And let's say you go from 65 down to 35.
That next morning, it's a 30 degree change.
So by this math, that's about a three to six PSI drop.
So that 37 PSI might be more like 31 to 34 when you get up.
And then the way the cars are nowadays, if it's super sensitive and it just trips that little threshold, your tire light might come on and you do a once over around your car and you don't see any visual problems.
and you wind up driving it to work, coming back home, it's fine.
Maybe when you get in your, here's the crazy part, you really think you're losing your mind because at 3.30 in the afternoon when you get off work, now the tire light's gone and you get it back home again.
And then the next morning it turns back on again and you go like, what is going on?
This is what's happening.
Now, I learned to drive on my 88 Buick Skylark.
That was before any of this fancy stuff.
And then I got my 99 Ford Ranger, never had a tire light.
The O4 Venture Van, I drove that thing with a flat right front, never had a tire light.
So tire lights to me are annoying, but I understand why they exist.
I understand why we have them in modern day vehicles.
But I'm just telling you, as October and November move on and you park your vehicle outside, even if you don't, even if your garage takes on a little bit of that cool air.
You may notice your tire light coming on more.
And that's just, I think, a good physical, scientific reason as to why.
Good chance there's nothing wrong with your tire.
You just need to head up to quick star cases or whatever's close to you, eventually, and pop some more air in there.
And if you do it as part of routine maintenance, you know, the dealerships and mechanics will probably say, notice you're a little low on air, probably because of the weather.
We'll get you aired back up.
And all of a sudden, now you're good to go.
As you can see, in the summertime versus the wintertime, if you have 100 degree temperature swing, it's a huge difference.
For those that do sports, don't leave your basketball in the trunk all night.
Because by the time you get to the gym the next day, it's flat.
Nothing's wrong with the ball.
It's just that the air takes up.
a whole lot less space when it's cold and dense like that.
So then you'll be showing up to your basketball game with a flat basketball.
You didn't do anything wrong.
You just left it in the trunk outside when in reality you should have left it in the 65 degree house instead of the 10 degree below zero winter night.
Makes a difference.
If you don't believe me, try it.
I don't want you to have a flat basketball.
Yeah, you can do that with balloons.
Yeah, we had in when I would do school visits at our station, we had this like beach ball.
with like weather questions all
over it
and sometimes we would leave that in the in our weather car overnight if you know we're doing back-to-back school visits or something and yeah I had that happen multiple times or honestly because it was such thin material obviously a basketball a little thicker you know so it's gonna
and take a little bit more time to take on those temperature differences.
But this little plastic beach ball thing, like you could literally, I could have it under my arm as I was walking out of the station on a cold winter day.
And by the time I got to the car, you know, in the parking garage,
it was already, you
know, deflated and a little bit more malleable.
But then, you know, put it in the car that's
warming up and drive, you know, an hour to wherever you're going and it's perfectly fine again.
So yeah, you can see that in real time with those kinds of things.
Yeah, it's kind of cool.
If you're really impatient and you want to see this today, go, if you don't have a two liter bottle or a 20 ounce bottle, go to your neighbor's house and get one of theirs.
Because they probably have somebody's got a 20 ounce bottle.
Ask first.
Somebody's got a 20 ounce bottle laying around or a two liter laying around.
And just
Take it in the kitchen and just put the cap on it.
And just set it outside.
And then when you wake up in the morning, or even just after 15 minutes, you'll see that it is contracted, pulled in a little bit.
So it's good science.
It's a very solid science.
So another experiment where it shouldn't cost you anything.
Exactly.
Definitely shouldn't.
So I guess we're going to continue on with this changing theme here.
So this is a follow-up from an earlier episode.
Why does a weather balloon expand as it rises?
Why is
that?
We mentioned this, what was it, 6.2, where we talked about weather balloons a little bit and just kind of all things weather balloons.
So if you're curious about that, go back and listen to that.
But one of the things we said is, well, as they get higher up in the atmosphere, they pop.
So I think the question is basically, what's going on?
Why is that happening?
It is essentially, as has been the topic here all show, it's a pressure change.
So basically,
As you go up through the atmosphere, you have lower pressure.
So you have less air outside the balloon, pushing in on the balloon from the outside so that inside air pressure becomes higher than the surrounding air around the balloon.
So it continues to expand.
as with any material, there are limits of how far that latex material can stretch.
And so once it gets to the point in the atmosphere where the pressure outside is so low compared to the inside and it can't expand anymore, then it pops.
So yeah,
just pressure
changes.
Yeah, very basic stuff.
But we see it a lot.
We see it a lot.
And that's also
you know, to what you mentioned, a reason why it's going to get colder in the upper parts of the atmosphere as well.
Yeah.
Um, if we think about our physical laws here, we're cooling and we're going to just, and we have to expand that out to try and conserve what we've got inside that balloon.
And that's, that's everything is
connected.
It is.
It is.
Yeah.
No question about it.
So another one, if you don't have a balloon laying around the house, somebody in your block probably does.
Um,
And another fun experiment with air pressure on that one is just what I always would did growing up.
Blow them up and then just let them fly around.
Oh, yeah.
Don't tie the end off.
Just let it go.
And that's a great air pressure experiment because you've got greater air pressure inside the balloon versus out and it just goes until it's done.
I saw an experiment recently online because my algorithm is super fun and just full of science experiments because that's the thing that I sit and
watch for
hours on end.
But they had this special two-way valve and it had two balloons connected to it.
One was blown up pretty far, one was not blown up quite as much.
And, and he was just kind of doing, you know, out on the street asking like, which one do you, if I, if I open this valve so that the air between the two balloons can flow freely, what do you think is going to happen?
What do you think would happen, Kai?
I think it would equalize.
Yeah.
So that's
what I would have thought too.
Yeah.
But what happens basically is, is one of them gets filled up more than the other.
And I have to remember which way it goes, but it should be the, the bigger one gets bigger.
I believe, which is counterintuitive
because
of that, because of the pressure change and how basically the amount of balloon material that's pushing in on the air, think of it as like, if you were blowing up a balloon, is it easier to start blowing it up or is it easier after you've kind of gotten it started?
So the material of the balloon,
it gets a little bit easier.
We have gone completely off of weather balloons now.
We're just on
balloons, but the
same principle kind of follows, right?
Yeah, it's all good.
Just another fun little thing that I found recently.
Yeah.
All right.
Talking about how everything's connected, all of the things with weather, it's not just one symbol.
This is the reason.
There's so many different facets to all of it.
It's why it's so complicated.
It's why it's a science.
we're going to dive into a little bit of radar and changing daylight.
So you may have noticed here recently that if you go to bed and check the radar right before bed or something that there's a lot more stuff, a lot more clutter on the radar, then you would normally
expect to see.
So what is going on around that time, around sunset, that we're getting more stuff cluttering up the radar archive?
Well, what winds up happening is everything radiates.
So you, me, a glass of water, something that's been out in the sun, it radiates.
When we start to lose the daylight of the day, now the net radiation is outward.
So surfaces are cooling very quickly.
And you'll know this, but even an hour after sunset, go out and touch your car.
It's chilly.
Even if the air isn't that cool, your car is actually quite chilly.
Roof shingles get chilly as well.
Part of the reason why cars and roof shingles get frosty first.
Your lawn is probably starting to cool down.
Sidewalks are starting to cool down.
And so as a result, we're actually seeing what we call an atmospheric inversion setup, where the warm air leftover may be at a few thousand feet up.
It's still sitting there.
It hasn't gone anywhere, but the stuff down near the ground is cooling so quickly.
It's actually cooler down near the ground than it is about 1,000 feet up.
So when the radars beam goes around in circles,
If you did an animation of it all day long, let's say there was really not much precip anywhere, you would see a few speckles around what we call the radome, which is where it's circulating.
And that's the initial, you know, buildings and other vegetation and things that the beam might be hitting.
And then it clears out.
You don't see anything.
At night, when this inversion starts developing, it can actually work to bounce that radar beam downward and hit some of those targets on the ground.
And so you see this circular just expansion.
of what we call radar echoes.
And a lot of times people see that and they think that it's like the government at work or something.
Like, mind control is beginning.
And you can see all the Weather Service officers and cahoots, you know, trying to turn this on and make us all believe the same thing.
It's actually not true at all because you can watch it from the east coast to the central to the west.
And why?
It's because the sun is going down and the atmosphere is becoming stable.
Now, if there's precipitation in the area,
or the weather service is running their radar in a different mode, this doesn't apply.
This may be totally different because there's clear air mode and precipitation mode, and then there's various what they call volume coverage patterns behind that, which we won't get into today.
That's the chief reason is you're starting to see this happen.
And then in the mornings, you see the reverse happen.
You see the circles shrink back.
Sometimes you'll actually see birds taking off.
We call those roof strings.
They're really cool.
Brewstrings are very neat.
They look like little splashes on the radar screen, but I can assure you the radar is just there It's picking up on something and there's a good chance that beam is getting ducted down to the ground And then once you get to 10 or 11 in the morning sun is out and you'll see a really clear radar picture We see clutter with wind turbines a lot as well So you might see those light up at night, especially you're in the early morning So that's just a bit of an explanation as to why you see radar become really busy at night even though there's absolutely
no precip and sometimes not even a cloud in the sky.
Yeah, radar radar
can
see all kinds of things.
You know, we talked
about
that with with the with the bugs and stuff at the
start of
the show, right?
Like there are all kinds of things that the radar can see or sense, I guess, that that we maybe aren't intending it.
You know, we don't
we don't
want we want it to be good at rain.
But radar was first developed by the military to see
planes, right?
That's what it was for.
And rain kept getting in the way and cluttering up the picture.
And they're like, oh, this is really good for this.
So all that radar is doing is it is picking up on something.
It is sensing something.
It
is
not only able to sense weather.
We just have it angled upward so that it is where weather is happening, right?
Right.
And sometimes when it's rain, it's very obvious to everybody what the radar is detecting.
Other times,
Um, you actually, you need a meteorologist to look at it and you need somebody to translate it for you to everyday language.
And so hopefully what we just discussed was every day enough to, uh, have you learned something?
Because in the fall, this is very common.
This is very, very common that we see this happen.
Yep.
And during those, those transitional seasons,
absolutely.
Yep.
Yep.
All right.
Well, that brings us to the end of yet another episode of Weathered Questions.
We hope you learned something today.
We hope you can share something maybe in conversation with your friends and family.
That is really the best way to support the show.
The second best way is...
to send us your questions.
Let us know what's on your radar.
Let us know what you are wondering so we can continue to keep those questions coming in and are able to keep this show going.
Do that to our email at weatheredquestions.
W-E-A-T-H-E-R-E-D questions.
I almost, I almost misspelled it.
Yeah, you did.
Don't forget the
ED.
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the main part.
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main part of me spelling it out.
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We want to know what's on your radar.
And thank you as always for following along.
Until next time, stay safe.
