ChristofferB
EF2
- Joined
- Aug 27, 2009
- Messages
- 197
I am doing some intense studying at the moment and new (newbie) questions popup all the time that I can't google easily. So, instead of polluting the entire forum I thought I'd start a thread where I, and other newbies, could post general questions about forecasting and storm chasing hoping that some of you more experienced will be kind enough to explain.
Most of these first questions are things I thought about after taking the SpotterNetwork training.
Wind directions
1. Which winds are determining the direction of the storm? Is that typically the midlevel (500 mb?) winds? Before I thought you could determine the direction of a storm by looking at the anvil but after watching radar images it seems like the best storms have an anvil going in another angle than the direction of the storm.
2. A continuation of the previous question. It IS preferable to have the anvil in another direction than the storm direction, right?
3. What do the surface inflow wind directions determine? As far as I understand they are just a part of creating the recipe for shear, right? Is it typically the surface winds that bring in the moisture?
Chasing from home
4. I was doing some "home chasing" during the last two nights of TX and FL storms in order to try to understand radar images better. I don't have any better program than the RadarPro iPad app at the moment but I was following this in Northern FL yesterday:
![bild.jpg bild.jpg](https://stormtrack.org/data/attachments/6/6029-a340524e9eed0e2e91f609fe66e8f6a6.jpg)
is this a:
a. Squall line? (my guess)
b. Multicluster thunderstorm?
c. Weather front with some thunderstorms and clouds in it?
d. Derecho? I know for a fact it isn't, but how could one tell, they have the same shape right?
I'm thinking a multicluster would be less "even" in its shape, right?
5. Is it possible to see what was observed from a storm afterwards. Like, if I want to check the "results" of a storm the day after. I'm thinking those kind of things that can be seen on GR LevelX (tornadoes reported, rotating wall clouds, hail size of x etc)?
Mesoscale
6. I'm trying to figure out what a mesocyclone really is. As far as I understand it is the upward, rotating column of air inside a supercell. You cannot see a mesocyclone but you can see the rotation of it on radar (?). A tornado is basically the bottom end of a huge rotating cyclone inside the supercell. Is that correct?
I was looking at a couple of the Moore May31-tornado videos and in one (I think in Skip Talbot's) he discuss that many didn't see that a much larger area was under a mesocyclone and that's a reason why the tornado could grow so rapidly. I could confuse that with Mike Hollingshead Storm Analysis 101-video as well, from a large SD-storm.
Well, basically...my question is. Is my understanding of a mesocyclone correct? Then, I assume that a tornado can spin out under a mesocyclone pretty much anywhere?
7. Regarding single cell and superell thunderstorms. Is it possible to see on one single cloud, during its maturing state if it will be a single cell or supercell? They all start as single cells but may continue to be a supercell. Is that correct?
I'm thinking about a note that most FL tornadoes are not created by supercells but merely single cell thunderstorms (and are weak). I assume it has to do with an abundande of moisture but weak shear?
8. I'm trying to figure out the horseshoe-shape of supercells and map that against the models, such as this one (from SpotterNetwork.org):
![SUPERCELL.jpg SUPERCELL.jpg](https://stormtrack.org/data/attachments/6/6030-616d57a7abb4333239e51a20f62a3636.jpg)
Are we looking into that horseshoe here (created by the purple and green inflow winds)?
9. I am trying to compare that horseshoe with this photo, that I took in KS on last year's chase (non-tornadic, high based supercell):
![horseshoe.jpg horseshoe.jpg](https://stormtrack.org/data/attachments/6/6031-c1b6fcd79eafbb7995af7eca898c529d.jpg)
If there would have been a tornado in this storm, would it have been in the inner part of the U in that horseshoe?
10. Is it correct that the RFD notch is a band of colder, clear air (i.e. no clouds) that "cuts out" the mesocyclone? For example, do the red dots mark the RFD notch in the photo below?
![rfd_notch.jpg rfd_notch.jpg](https://stormtrack.org/data/attachments/6/6032-141030dc6b103fb7d2996e03c3c3ac5e.jpg)
11. Regarding downbursts. As far as I understand downbursts are not a conitnuous part of a storm but rather something that happens when a part of the storm collapse and bring a huge chunk of air to the ground? As opposed to a gust front, of a storm, which is always present?
Synoptic scale
12. Is it possible to see whether a weather system is HP or LP on a satellite photo? I image googled both:
https://www.google.com/search?q=low+pressure+satellite+photo
https://www.google.com/search?q=high+pressure+satellite+photo
...and they seem to look the same to me.
13. LP's have winds moving into the system, bringing them aloft (and HP) quite the opposite. This must mean that LP's have winds going out from the system aloft, right? I mean, the wind has to go somewhere? So, the winds moving into the system are surface or low level winds, is that correct?
....
I am very grateful for any answer to any of these questions!
Most of these first questions are things I thought about after taking the SpotterNetwork training.
Wind directions
1. Which winds are determining the direction of the storm? Is that typically the midlevel (500 mb?) winds? Before I thought you could determine the direction of a storm by looking at the anvil but after watching radar images it seems like the best storms have an anvil going in another angle than the direction of the storm.
2. A continuation of the previous question. It IS preferable to have the anvil in another direction than the storm direction, right?
3. What do the surface inflow wind directions determine? As far as I understand they are just a part of creating the recipe for shear, right? Is it typically the surface winds that bring in the moisture?
Chasing from home
4. I was doing some "home chasing" during the last two nights of TX and FL storms in order to try to understand radar images better. I don't have any better program than the RadarPro iPad app at the moment but I was following this in Northern FL yesterday:
![bild.jpg bild.jpg](https://stormtrack.org/data/attachments/6/6029-a340524e9eed0e2e91f609fe66e8f6a6.jpg)
is this a:
a. Squall line? (my guess)
b. Multicluster thunderstorm?
c. Weather front with some thunderstorms and clouds in it?
d. Derecho? I know for a fact it isn't, but how could one tell, they have the same shape right?
I'm thinking a multicluster would be less "even" in its shape, right?
5. Is it possible to see what was observed from a storm afterwards. Like, if I want to check the "results" of a storm the day after. I'm thinking those kind of things that can be seen on GR LevelX (tornadoes reported, rotating wall clouds, hail size of x etc)?
Mesoscale
6. I'm trying to figure out what a mesocyclone really is. As far as I understand it is the upward, rotating column of air inside a supercell. You cannot see a mesocyclone but you can see the rotation of it on radar (?). A tornado is basically the bottom end of a huge rotating cyclone inside the supercell. Is that correct?
I was looking at a couple of the Moore May31-tornado videos and in one (I think in Skip Talbot's) he discuss that many didn't see that a much larger area was under a mesocyclone and that's a reason why the tornado could grow so rapidly. I could confuse that with Mike Hollingshead Storm Analysis 101-video as well, from a large SD-storm.
Well, basically...my question is. Is my understanding of a mesocyclone correct? Then, I assume that a tornado can spin out under a mesocyclone pretty much anywhere?
7. Regarding single cell and superell thunderstorms. Is it possible to see on one single cloud, during its maturing state if it will be a single cell or supercell? They all start as single cells but may continue to be a supercell. Is that correct?
I'm thinking about a note that most FL tornadoes are not created by supercells but merely single cell thunderstorms (and are weak). I assume it has to do with an abundande of moisture but weak shear?
8. I'm trying to figure out the horseshoe-shape of supercells and map that against the models, such as this one (from SpotterNetwork.org):
![SUPERCELL.jpg SUPERCELL.jpg](https://stormtrack.org/data/attachments/6/6030-616d57a7abb4333239e51a20f62a3636.jpg)
Are we looking into that horseshoe here (created by the purple and green inflow winds)?
9. I am trying to compare that horseshoe with this photo, that I took in KS on last year's chase (non-tornadic, high based supercell):
![horseshoe.jpg horseshoe.jpg](https://stormtrack.org/data/attachments/6/6031-c1b6fcd79eafbb7995af7eca898c529d.jpg)
If there would have been a tornado in this storm, would it have been in the inner part of the U in that horseshoe?
10. Is it correct that the RFD notch is a band of colder, clear air (i.e. no clouds) that "cuts out" the mesocyclone? For example, do the red dots mark the RFD notch in the photo below?
![rfd_notch.jpg rfd_notch.jpg](https://stormtrack.org/data/attachments/6/6032-141030dc6b103fb7d2996e03c3c3ac5e.jpg)
11. Regarding downbursts. As far as I understand downbursts are not a conitnuous part of a storm but rather something that happens when a part of the storm collapse and bring a huge chunk of air to the ground? As opposed to a gust front, of a storm, which is always present?
Synoptic scale
12. Is it possible to see whether a weather system is HP or LP on a satellite photo? I image googled both:
https://www.google.com/search?q=low+pressure+satellite+photo
https://www.google.com/search?q=high+pressure+satellite+photo
...and they seem to look the same to me.
13. LP's have winds moving into the system, bringing them aloft (and HP) quite the opposite. This must mean that LP's have winds going out from the system aloft, right? I mean, the wind has to go somewhere? So, the winds moving into the system are surface or low level winds, is that correct?
....
I am very grateful for any answer to any of these questions!