Rules of Thumb for Tropical Storms

[azskyman]

OK....I've been studying weather for a long long time.

Noah called ME to get a forecast. He got a second opinion, and then called Home Depot for a lot of lumber...waterproof of course.

But my understanding of the primary elements for cyclogenesis of a tropical storm needs some help....in laymen's terms.

If one or two of you might be able to lay down some simple rules of physics, in terms a Midwesterner might comprehend, of what are the most critical elements in tropical storm development, and which among those are encouraging signs for strengthening of these storms, I'd really appreciate it.

I love the lingo...and I enjoy watching you cyclogenes interact and get excited about what you are seeing, but please, if you can take a moment to help me, and I'm sure others as well, give us a pointer or two.

Think of it as TS 101.

Thanks.

[Anonymous]

#1 Sea surface temperatures at are above 79 degrees.

#2 low pressure

#3 Strong enough coriolis force (needs to be at least 5 degrees away from the equator).

#4 I would say vertical shear at or less than 20 knots

#5 Adequate supply of moisture.

[Derecho]

Actually more like 3 degrees away from the equator as a requirement, and of course the famous Typhoon Vamei formed 1.5 degrees away from the equator.

[Anonymous]

Well typically they must form at 5 or higher...but there are always exceptions. I believe another system formed almost as close to the equator as Vamei did either early this year or late last year.

[azskyman]

Ok....so the first rule of thumb is latitude must be sya 3 degrees from the equator so that there is interaction between trade winds and westerlies, right?

And where can one find information about the sea temperatures and wind shear. Is that info mostly provided by buoys?

[vbhoutex]

Ok....so the first rule of thumb is latitude must be sya 3 degrees from the equator so that there is interaction between trade winds and westerlies, right?

And where can one find information about the sea temperatures and wind shear. Is that info mostly provided by buoys?

Gosh you are up early this morning, at least in my current book.

A lot of the information is provided by satellites and some information information comes in from ships in different areas.

Even though there are numerous buoys closer to landmasses, there are none in the ICTZ or MidAtlantic that I know of due to maintenance and anchoring issues.

[mf_dolphin]

Steve, we have tried to provide as much information about the Atlantic basin (and other regions) through the Weather Central. The Atlantic basin information pages start here http://www.storm2k.org/Weather-Central/Tropics/Weather-Tropics-Atlantic.htm Hope this helps!

[Anonymous]

Ok....so the first rule of thumb is latitude must be sya 3 degrees from the equator so that there is interaction between trade winds and westerlies, right?

Well, in the Atlantic, the most southerly forming storm was around 7N. Actually, in any location across the globe, it's unusual to see anything form within 5 degrees of the equator. So saying within 3 degrees is pretty inaccurate, IMO.

[isobar]

Marshall, you guys have put together a nice collection of maps and data here at S2K. One stop shopping.

I have a question about the models. Which ones do you guys find to be most accurate?

[JetMaxx]

Marshall, you guys have put together a nice collection of maps and data here at S2K. One stop shopping.

I have a question about the models. Which ones do you guys find to be most accurate?

Donna, once a storm becomes a hurricane and becomes a U.S threat, I keep close tabs on the ECMWF (European forecast model model). I was sold on it's accuracy in 2002 by meteorologist David Tolleris (WxRisk.com). It handled both hurricanes Isadore and Lili extremely well.

God Bless,
Perry

[JetMaxx]

Ok....so the first rule of thumb is latitude must be sya 3 degrees from the equator so that there is interaction between trade winds and westerlies, right?

And where can one find information about the sea temperatures and wind shear. Is that info mostly provided by buoys?

Steve, here is one of my favorite SST maps of the Atlantic Basin....it's from the U.S. Navy and is updated daily. The 26°C contour map...everything in white is below 79° F (26°C)...too cool to form or maintain a tropical storm or hurricane.

http://128.160.23.54/products/MCSST/HPCg26.gif

Perry

[isobar]

Thanks a lot Perry. Nice SST map too.

[azskyman]

That's exactly the kind of help us tropical novices need, Perry. So now I know I need to watch the location with respect to the equator and also the sea surface temperatures. Then, check the European Forecast model since that seems to be the most accurate at this time.

How about wind shear. Where is the best source of information on wind shear? 500mb maps? Any suggestions?

Thanks for helping me (us) out.

[JetMaxx]

Steve, here's a wonderful source for shear maps, SST data, satellite & radar and more...

Atlantic Tropical Weather Center
http://www.atwc.org

(There are several nice shear sites..just click on Shear Maps on the legend at left)

God Bless,
Perry

[JetMaxx]

Thanks a lot Perry. Nice SST map too.

Thanks Donna...I'm just glad I was able to be of assistance

God Bless,
Perry