Ask The Weather Expert!

[phw115wvwx]

Hi, twcfan68!  We're in the active phase of a well-documented natural cycle that fluctuates tropical activity roughly every 20 years, which is one reason why we're seeing a lot of tropical activity lately.  However, current research seems to indicate that global warming could result in stronger but fewer tropical storms and hurricanes.  Warmer water certainly provides more energy, but there are so many other factors involved.  For example, we're finding that El Nino conditions in the Pacific weaken tropical activity in the Atlantic, but periods of normal to La Nina conditions in the Pacific strengthen tropical activity in the Atlantic.  El Nino and La Nina conditions drastically change the winds throughout the atmosphere worldwide, and we already know that the winds matter as too much wind shear (the change of wind speed and direction with height) tears the storms apart.  Scientists feel there will be more El Nino periods in the future due to global warming as that's been the trend lately, which would reduce the number of active Atlantic seasons.  Another point I should mention is that stronger storms would take up more warm water to where it would take longer for the ocean temperature to recover and be able to support the next storm.

With so many of these competing factors present, that's why I agree with the current research perspective of stronger but fewer tropical storms and hurricanes on average.  This topic is still under heavy research as predicting the strength and activity of a tropical season is extremely difficult, and we don't know how much global warming will offset the effects we'll experience when we enter the inactive phase of that natural cycle I described beforehand in the next ten years.  You gave a really hard question, but I hope that I answered you well enough so that you can appreciate the complexity of this issue!

[twcfan68]

Wow, thank you so much for the detailed information. I'm sorry, I didn't know it was that complicated, but thank you so much for your insight.

[phw115wvwx]

Wow, thank you so much for the detailed information. I'm sorry, I didn't know it was that complicated, but thank you so much for your insight.

It's okay!  If there's anything I can tell all of you on TWCT about the weather, it's that the weather is far more complicated than what we all realize.  What I have in my signature now sounds crazy but is very true.  There are still many unsolved mysteries in this field despite the great leaps in progress we've made over the last 50 years.  Thus, we'll be continuing to explore the weather more to figure out these unsolved mysteries, and we'll be calling upon all of you as part of the future generations of meteorologists to help us!

[jtmal0723]

Here's one I thought about emailing TWC about answering, but maybe Patrick can explain it better. What exactly is a "front" and what are the differences between a cold front and a warm front? I could never properly differentiate the two.

[phw115wvwx]

Hi, Jesse!  A front is simply the boundary between two different air masses.  For example, a cold and dry air mass coming from Canada could clash into a warm and moist air mass coming from the Gulf of Mexico, which happens very often over the Central Plains.  Where the two air masses literally clash at each other is the front.

Now, the difference between a cold front and a warm front is determined by which air mass is winning the battle at the front.  A cold front means that the cold air is literally forcing the warm air upwards like a plow.  The cold air would be advancing forward in this case, and it would look like this picture:


In a warm front, the warm air is advancing forward as it's forcing the cold air backward, and it would look like this picture:


Another key difference between the two fronts pertains to the steepness and strength.  Cold fronts are steeper going up in the vertical and stronger than warm fronts.  It's far more effective for the heavier cold air to plow up the lighter warm air rather than the other way around where the warm air is trying to push the cold air back.  In both cold and warm fronts, the lighter warm air with its moisture is forced upward to create clouds and precipitation.  The steeper slope of a cold front allows for greater rising motion and heavier precipitation than a warm front.

There's your quick lesson on fronts.  There is more to this topic than what you see here as there can be more than two air masses involved, and there are also special situations that allow for two other kinds of fronts.  Hope this helps, Jesse!

Note:  The two images above come from a nice e-book by PhysicalGeography.net

[jtmal0723]

Awesome explanation! Thanks! 

So basically in a stationery front, neither mass is winning, correct?

[phw115wvwx]

Awesome explanation! Thanks! 

So basically in a stationery front, neither mass is winning, correct?

Right, the winds would be blowing parallel along the front, so nothing forces the boundary to move.  It's literally a stalemate, which is a dangerous situation for flooding.  By the way, I hope all of you saw the note to indicate where you can find the e-book and browse through more of these figures.

[beanboy89]

Patrick, you're probably gonna slap me for this, but here goes...

My original intention in college was to be a meteorologist. After going a year and taking some introductory courses, like chemistry, earth sciences, and precalculus, I soon realized that I was in way over my head. I was never strong at math (in high school, I got up to algebra 2 and geometry), and I just barely got by with my precalculus class. I can tell anyone first-hand that you need to be strong with math to be a meteorologist. I can not imagine myself ever being able to get through things like calculus 2 and 3, which are required for the meteorology degree.

I don't want to discourage anyone from choosing meteorology here, but I just wanted to share a personal experience.

Although, now I've found a place in geography. I hope to become an environmental geographer. I'm currently taking a physical geography class, and we've covered basic atmospheric phenomenon like pressures, clouds, and fronts. In fact, that image above looks like something that came right from my physical geography class. I really enjoy geography, and best of all, it's very light in math.

[phw115wvwx]

Billy, I won't slap you too hard.   I realize that mathematics is a difficult subject, and I continually remind myself that I'm very fortunate here.  When I went to Penn State to pursue my bachelor's degree in Meteorology, several of my classmates couldn't keep up with the math and eventually switched to Geography.  The bottom line is that you can pursue any major within the earth sciences if you still want to work with the weather and not have the heavy math requirements.  Naturally, you won't be able to understand why the weather works without the deep mathematics, so be aware of your interests and your abilities.  My best advice for everyone here who really wants to learn about the weather is to at least try out the Meteorology major and give it a chance.  If you later find that the math is too much to handle, then switch out to an alternative earth science major.  Most colleges don't force you into deciding about your major permanently until the end of your sophomore year.

By the way, Billy, those above images about cold and warm fronts came from an e-book from PhysicalGeography.net, so it shouldn't shock you that they look familiar if you've had a physical geography class!

[ruhgster]

I'd like to add to the discussion about classes to take.  If you are interested in meteorology, I would highly recommend considering taking some computer programming in college if it is not required.  If it is available, I'd highly recommend taking a class in FORTRAN, and/or learning it and IDL on your own, as well as some basic shell scripting.  FORTRAN was requiered for my Meteorology degree, and they now require IDL knowledge along with it, and honestly with my job now I am using my programming skills much more than my meteorology knowledge.  Having this knowledge can open your doors to many more oppurtunities in the meteorology field.

[phw115wvwx]

Many colleges now do require one computer programming class in the Meteorology major.  I actually had to learn some forms of FORTRAN and shell scripting when doing the research for my Master's thesis, so take Ruhgster's point seriously!

[ruhgster]

Even though FORTRAN is an old language that not many people use any more, it is still widely used in the meteorological community because it is very efficient at running calculations of large amounts of data.  I work with a few meteorological models, and they are all mostly FORTRAN based, with some scripting to tie it all together.  IDL is good for visualizing stuff (making graphs, maps, etc).  I have found it much easier to work with than Excel if you know what you are doing with it.

[phw115wvwx]

I'm bringing this thread back from the dead to remind you all that I'll still take weather questions here as I've seen a demand for it recently.

[Charismatic Applesauce]

When is a storm considered a tropical depression? Tropical storm?

P.S. This should be made a sticky.

[phw115wvwx]

A tropical depression has winds of 38 mph or less, and it's not named but only assigned a number.  A tropical storm has winds ranging from 39 to 73 mph, and it's strong enough to earn a name.  Both systems have to be tropical cyclones with well-defined centers and closed circulations at the surface.  They just can't be tropical waves that are only troughs of low pressure, which are not closed in circulation.  Hope that helps!