Thunderstorm or Supercell Thunderstorm, whats the difference?

My meteorology 111 final is coming up on Tuesday, so the next few articles will help me in studying for the test. Today we tackle thunderstorms.

I think it's safe to say that we've all experienced a thunderstorm in our lifetime, and most of us have probably heard of a supercell thunderstorm.  The big difference is at the core of the storm.  A regular old, garden variety thunderstorm is formed as warm air rises into the atmosphere, gets above the freezing level, condenses to form a nice tall cloud and then the air rushes back down toward the ground as a downdraft.  Regular mid-summer afternoon storms have a life cycle of about 45 minutes to an hour before the rain that is falling, cools the air below the storm enough that it no longer rises, robbing the storm of the lift it needs to continue on, and it rains itself out.  Regular thunderstorms don't usually need a strong trigger(i.e., frontal lifting or convergence lifting) to get going, they can pop anywhere that the atmosphere will support the lifting air.

A supercell storm is a little different kind of storm. The ingredients are all the same for a supercell, they are just much stronger.  A storm will be classified as a supercell if the core of the storm is rotating, also known as a "rotating updraft".  Supercells usually require some kind of "trigger" in the atmosphere to get the strong lifting they need. Triggers like a strong cold front, or moist tropical winds converging tend to do the trick.  The air that is drawn into the storm and forced upward will begin to spin, thanks mainly to wind shear in the atmosphere. Once it gets spinning, if the core of the storm is tall enough, it may be able to tap into the jet stream winds aloft and pull them into the storm, they usually get forced down to the surface by the existing downdraft, making it that much stronger.  Supercells have a much longer life cycle as the lifting mechanism that caused the storm also helps to continually provide the warm air needed to feed the updraft. The downdraft from a supercell can spread out for miles after it hits the ground, sometimes strong enough to case damage. Imagine pouring a bucket of water out on the floor.  The descending air from the downdraft does the same thing when it hits the ground. The rotating updraft of a supercell thunderstorm is also the main cause for tornadoes, which we will get to later on.  Don't get me wrong, both types of thunderstorms can cause tornadoes, for example, the November 17th storms that hit northeast Baltimore with an EF1 tornado were not supercells. The odds are much greater for a supercell to put down a tornado.

The thing to remember here is rotation. "Regular updraft"= regular thunderstorm. "Rotating Updraft" = Supercell.

The Return...

Sorry for the long delay.  Most of you know that I post mostly while at work, and my schedule has not been allowing me to post.  We had a guy leave and another take vacation.  Hopefully things will get better this week.  So here's the short story.  Those of you that know me or follow me on Twitter know that I crushed that Meteorology test, to the tune of a 97%.  The score made me feel so good.  I'm still carrying an A in my algebra class(although I'm playing hookie tonight to go to the Caps game).  So school is going well.   My car on the otherhand, was not doing so well.  I had to replace the clutch, the pump, the fly wheel and put two new oxygen sensors into it, in addition to replacing the tires(which I planned on.)  So, $2500 later I'm back on the road.  I guess that's part of the chance you take when you buy a used car with a manual transmission.  Lucky for me, I REALLY like the car, because it looks like we are going to be together for a long time.   Carey and I celebrated out 6th wedding anniversary over the weekend.  We went to the Melting Pot to cook our own food. It was great fun.   Lets see, what else....Carey is close to being done her Masters, we got a sectional couch for the "man cave"(that was before my clutch blew up, go figure.) That's all that comes to mind at the moment.  Oh yeah, one last thing.  Thanks to the "Pig Hat Girls" for the free tickets to the Caps pre-season game two Sunday's ago.  I'll have to tell you that story later.   Later!


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Cloud Types

I have my first Meteorology test tomorrow and I'm struggling to remember my cloud types, so I'm going to put them in writing and share them with you.   Lets start with the high clouds.  Cirrus, Cirrostratus, and Cirrocumulus. All are at the very top of the Thermosphere and are made up of ice crystals.  Its too cold for water not to be frozen up there.  They are usually very "whispy" looking and precede or follow a weather system. Next are the mid level clouds.  Altocumulus and Altostratus. These are liquid water vapor clouds and are generally non threatening looking. You can usually see blue sky between these clouds. We continue to descend as we start to see the stratus cloud type.  Also including cumulostratus and nimbostratus.  Stratus clouds and their ilk tend to be rain clouds. Nimbostratus cover the whole sky in grey and don't appear to have a defining shape. People often mistake a low hanging bank of stratus cloud for "lifting fog" as they are very similar in makeup.  Lastly we cover the clouds that grow from the ground to the top of the Troposphere, the cumulus family.  Regular cumulus clouds are generally small and broken up in nature, they tend to be what people call "fair weather clouds", but as they grow, conditions tend to deteriorate.  Cumulus clouds can grow in to towering cumulus(thunderheads), or even cumulonimbus which are widely known as thunderstorm clouds.   So there you have it, a "vertical tour" of cloud types from top to bottom..Cirrus at the top, cumulus at the bottom. Enjoy!

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College Update

I took my 1st unit exam in my algebra class last night.  I was actually nervous, considering I haven't taken a math test that counts since 1993.  I got 13 out of 15 correct, 87%.  Honestly I was hoping for better. The reality of it is, 87% because its on a heavily weighted test, brought my gaudy 97% class avg down to 90%, which was disappointing to me. One of the TA's was talking to me, and her point was "Hey, its still an A", but it really sucked to see my average dip so severely thanks to only two wrong answers.  I think I underestimated how hard it's going to be to carry an "A" in my classes....but I'm on a mission.  I'll have some more meteorology posts coming in the next few days.  My load at work hasn't allowed me to get any published in a while.  Until next time!


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Hydrostatic Balance

I don't have much news to report this week, it's been a slow one for me, which isn't always a bad thing.  I do have one thing to be proud of though.  I'm carrying a 92% avg in my Algebra class.  That's an "A".  I'm a solid two weeks ahead of the class, and I'm having fun.  Don't get me wrong, were only talking about Algebra I here, not rocket science, but I've never had an "A" in any math class ever.  I will keep you up to date.

I also learned this week another interesting fact about the atmosphere. There are two forces at work that keep our atmosphere in place. The first and most obvious is gravity. Gravity holds our thin little blanket of atmosphere close to the Earth's surface.  The second force is called the Gradient Pressure Force(GPF).  The GPF is essentially the atmosphere's desire to expand and fly away into space.  These two pressures form a perfect balance, known as "Hydrostatic Balance" that keep the atmosphere in place in a perfect position for us to be able to live under it.  Pretty cool huh.
Next week....wind. 

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Meteorology Fact of the Day:

Albedo:  The Earth or the Earth's atmosphere reflects 30% of the sunlight that hits it. Therefore the Earth's Albedo is 30%. 

Last night I had 3 more hours of Meteorology 111, or Meteorology without math or science as I call it.   We had an interesting discussing about measuring temperature using Fahrenheit, Celsius, or Kelvin. When it came time to do some actual conversions, the instructor said "we can either do the math, or press the 'I believe' button. I think I was the only one in class who voted for 'do the math'. Needless to say, I lost.  I still learned stuff, and that's the most important part.