<p>I think the simple answer to your question is that sunlight widens the potential area for storms by producing a better convective environment, whereas nocturnal storms are highly localized based on climatological factors.</p>
<p>While a minority of storms do occur overnight due to local mesoscale features such as nocturnal low-level jets, the majority of storms will occur because of convective forcing. To have a convective environment, you have to have a parcel of air that is warmer than that of the environment it is traveling through, and that is what gives you lift. The easiest way for that to happen is to have parcels rise up from the ground at the peak heating of the day while the ground is much warmer than the air above it.</p>
<p>In an older (and still infinitely useful) thought process of meteorology, there is a temperature known as the &quot;convective temperature&quot; that can be gotten from a Skew-T diagram. It takes into account the dewpoint and vertical temperature profile of the atmosphere and produces a temperature at which the surface level has to get to in order to set off thunderstorms. The best way to get to and beyond that temperature is through the heating of the sun. Additionally, when the air is warmed through heating from the sun it makes the environment ripe for convective initiation through triggers such as fronts.</p>

CC BY-SA 4.0
2020-10-28T12:30:24.603Z
2020-10-28T12:30:24.603Z
Wxboyajm
<p>Your graph VALIDATES your perception of lightning happening at all times of the day. The graph ALSO shows that average frequency of lightning (well, thunder) is simply HIGHER during the mid-to-late afternoon. If you think that your local observations are contrary to this data, you would first need to diligently and accurately keep observing records. First, track thunder, not lighting. Lightning is perceived more easily at night. That is one key part.</p>
<p>Now, since thunder is produced by lightning, the graph is effectively showing that lightning goes on day and night. Your question implies the graph somehow disagrees with the idea that lightning is occurring throughout the day and night. It does not, it only highlights the frequency changes.</p>
<p>Second, you might have a biased memory. If you want to challenge this data, take accurate observations on your own. You might be surprised that what you thought you were observing was not actually what was happening. :-) Your local storms might not produce as much thunder (and thus lightning) as you think. Consider that massive tropical thunderstorms can produce more lightning than you can imagine, and this can happen day after day in the tropics. In the US, you can also get mesoscale systems that are blasting frequent lighting, but those don't occur as often as you may think. Sure, you might see thunderstorms every night for two weeks at some point in the summer if you live in the Deep South, but you won't see the same frequency of lightning day-after-day that you will see in some tropical storms. Consider that a complex that generates 800 lightning bolts is equivalent to TEN daily storms with 80 strikes. Then recall, the strikes you see at night don't count. You're counting thunder, so you can eliminate the bias of lightning being more visible at night.</p>
<p>In the end, the sunlight is clearly a dominant factor in timing, as confirmed by the data.  Of course, the thunder is generally more frequent when the sun is providing the most energy for thundercloud development. Some days that energy is not utilized well (it is reflected by cloud cover, there is a massive inversion, the air is too dry, etc.). On average, though, that is when the greatest amount of lightning-generating cloud development will occur.</p>

CC BY-SA 4.0
2020-11-03T03:42:18.063Z
2020-11-20T22:10:19.507Z
2020-11-20T22:10:19.507Z
Bruzote
<p>Atmospheric potential gradient changes during the day, as different areas of lightning activity come under Sun.</p>
<p><a href="https://i.sstatic.net/m1HcL.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/m1HcL.png" alt="enter image description here" /></a></p>
<p>This illustration from &quot;The Carnegie Curve&quot; by R. Giles Harrison shows contribution of different regions.</p>
<p><a href="https://i.sstatic.net/5BCnG.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/5BCnG.jpg" alt="enter image description here" /></a></p>
<p>Why region curves are so narrow and high - about 6 hours wide if lightning storms go day and night? As I understand most of cloud energy is stored in latent steam heat, so why sunlight makes such big contribution?</p>

CC BY-SA 4.0
2020-10-27T07:27:30.663Z
Well, where does the latent steam heat come from?
Erik
CC BY-SA 4.0
2020-10-27T22:29:53.987Z
@Erik I guess the biggest trouble for me is my experience - I usually see lightning storms at night. But I never lived in high lightning activity region, so I guess my experience would be different if I did.
Vashu
CC BY-SA 4.0
2020-10-28T09:26:10.790Z
Okay, let me rephrase: You say "**most** of cloud energy is stored in latent steam heat". The biggest energy source producing said heat is the sun. So naturally lightning storms tend to happen when there's the most energy influx.
Erik
CC BY-SA 4.0
2020-11-23T01:00:14.080Z
@Erik the way you say it sounds a bit misleading.  Because I'd say the amount of latent heat stored up doesn't increase too greatly during the day really.  But the sunlight is what gets the lift going to release the latent heat.
JeopardyTempest
<meteorology><lightning>
Lightning activity day curve - why it has high and narrow peak?
Vashu
# Lightning activity day curve - why it has high and narrow peak?

(Asked by: username_0 on 2020-10-27)

Atmospheric potential gradient changes during the day, as different areas of lightning activity come under Sun.

[![enter image description here](https://i.sstatic.net/m1HcL.png)](https://i.sstatic.net/m1HcL.png)

This illustration from "The Carnegie Curve" by R. Giles Harrison shows contribution of different regions.

[![enter image description here](https://i.sstatic.net/5BCnG.jpg)](https://i.sstatic.net/5BCnG.jpg)

Why region curves are so narrow and high - about 6 hours wide if lightning storms go day and night? As I understand most of cloud energy is stored in latent steam heat, so why sunlight makes such big contribution?

**Tags:** meteorology, lightning

> **Comments:**
> **username_1**: Well, where does the latent steam heat come from?  
> **username_0**: @username_1 I guess the biggest trouble for me is my experience - I usually see lightning storms at night. But I never lived in high lightning activity region, so I guess my experience would be different if I did.  
> **username_1**: Okay, let me rephrase: You say "**most** of cloud energy is stored in latent steam heat". The biggest energy source producing said heat is the sun. So naturally lightning storms tend to happen when there's the most energy influx.  
> **username_2**: @username_1 the way you say it sounds a bit misleading.  Because I'd say the amount of latent heat stored up doesn't increase too greatly during the day really.  But the sunlight is what gets the lift going to release the latent heat.  

---

## 2 answers

### Answer by username_3 on 2020-10-28. Score: 3

I think the simple answer to your question is that sunlight widens the potential area for storms by producing a better convective environment, whereas nocturnal storms are highly localized based on climatological factors.

While a minority of storms do occur overnight due to local mesoscale features such as nocturnal low-level jets, the majority of storms will occur because of convective forcing. To have a convective environment, you have to have a parcel of air that is warmer than that of the environment it is traveling through, and that is what gives you lift. The easiest way for that to happen is to have parcels rise up from the ground at the peak heating of the day while the ground is much warmer than the air above it.

In an older (and still infinitely useful) thought process of meteorology, there is a temperature known as the "convective temperature" that can be gotten from a Skew-T diagram. It takes into account the dewpoint and vertical temperature profile of the atmosphere and produces a temperature at which the surface level has to get to in order to set off thunderstorms. The best way to get to and beyond that temperature is through the heating of the sun. Additionally, when the air is warmed through heating from the sun it makes the environment ripe for convective initiation through triggers such as fronts.


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### Answer by username_4 on 2020-11-03. Score: 0

Your graph VALIDATES your perception of lightning happening at all times of the day. The graph ALSO shows that average frequency of lightning (well, thunder) is simply HIGHER during the mid-to-late afternoon. If you think that your local observations are contrary to this data, you would first need to diligently and accurately keep observing records. First, track thunder, not lighting. Lightning is perceived more easily at night. That is one key part.

Now, since thunder is produced by lightning, the graph is effectively showing that lightning goes on day and night. Your question implies the graph somehow disagrees with the idea that lightning is occurring throughout the day and night. It does not, it only highlights the frequency changes.

Second, you might have a biased memory. If you want to challenge this data, take accurate observations on your own. You might be surprised that what you thought you were observing was not actually what was happening. :-) Your local storms might not produce as much thunder (and thus lightning) as you think. Consider that massive tropical thunderstorms can produce more lightning than you can imagine, and this can happen day after day in the tropics. In the US, you can also get mesoscale systems that are blasting frequent lighting, but those don't occur as often as you may think. Sure, you might see thunderstorms every night for two weeks at some point in the summer if you live in the Deep South, but you won't see the same frequency of lightning day-after-day that you will see in some tropical storms. Consider that a complex that generates 800 lightning bolts is equivalent to TEN daily storms with 80 strikes. Then recall, the strikes you see at night don't count. You're counting thunder, so you can eliminate the bias of lightning being more visible at night.

In the end, the sunlight is clearly a dominant factor in timing, as confirmed by the data. Of course, the thunder is generally more frequent when the sun is providing the most energy for thundercloud development. Some days that energy is not utilized well (it is reflected by cloud cover, there is a massive inversion, the air is too dry, etc.). On average, though, that is when the greatest amount of lightning-generating cloud development will occur.


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