Study ties hurricanes to Sahara

(Reference: www.physorg.com)

A U.S. government study suggests that the relatively tame 2006 hurricane season may have been tied to activity in Africa's Sahara desert.

The study, by the National Aeronautics and Space Administration, found that several major dust storms in June and July in the Sahara sent dust drifting over the Atlantic Ocean, where it prevented sunlight from reaching the water, The Washington Post reported Tuesday.

The lack of sunlight cooled the waters and the dust absorbed the heat, warming the atmosphere and contributing to increased surface winds that aid in evaporation and ocean churning, further cooling the waters.

"This research is the first to show that dust does have a major effect on seasonal hurricane activity," said William Lau, lead author and chief of the Laboratory for Atmospheres at NASA's Goddard Space Flight Center.

Only five hurricanes and four tropical storms were recorded in 2006, a marked decrease from the 15 hurricanes and 12 tropical storms recorded in 2005.

Copyright 2007 by United Press International

The initial study was laid out during the summer of 2006:

NASA Africa Mission Investigates Hurricane Origin, Development

For hurricanes to develop, specific environmental conditions must be present -- warm ocean waters, high humidity and favorable atmospheric and upward-spiraling wind patterns off the ocean surface.

Atlantic hurricanes usually start as weak tropical disturbances off the coast of West Africa and intensify into rotating storms with weak winds, called tropical depressions.

If depressions continue to intensify and reach wind speeds of at least 63 kilometers per hour, they are classified as tropical storms. Hurricanes have winds greater than 117 kilometers per hour.

...snip...

“Dust blown off the Sahara and Sahel can interfere with the birth process of hurricanes,” said Jason Dunion, director of the NOAA Hurricane Research Division 2006 Hurricane Field Program in Miami, Florida.

“Occasionally,” he added, “great elevated plumes of hot dusty air interact with African waves as they move across the Atlantic. When the extremely dry air within the dust layer is ingested by a wave disturbance, it evaporates the deep clouds and thus limits the potential of a wave to develop into a storm.”

So in brief, the dust from the Sahara does indeed suck the moisture from the clouds, lowering the humidity thereby interfering with the development of the tropical wave into a cyclone. Additionally, should a tropical cyclone develop, the cooler sea surface temperatures lessens the ability for it to be able to intensify significantly. The end result is fewer and less severe storms.

From a climate engineering standpoint, if we see another heavy season like 2005 develop again, maybe designing a method to pump dust and sand over the eastern Atlantic could lessen a severe hurricane season before too many strong storms develop.

Tropical Development in the Eastern Pacific

From the National Hurricane Center

000
ABPZ20 KNHC 211655
TWOEP
TROPICAL WEATHER OUTLOOK
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1000 AM PDT SAT JUL 21 2007

FOR THE EASTERN NORTH PACIFIC...EAST OF 140 DEGREES WEST LONGITUDE..

SHOWERS AND THUNDERSTORMS ASSOCIATED WITH AN AREA OF LOW PRESSURE
ARE CENTERED ABOUT 600 MILES SOUTHWEST OF THE GULF OF TEHUANTEPEC.
THE CIRCULATION ASSOCIATED WITH THIS SYSTEM IS BECOMING BETTER
DEFINED...AND THE LOW HAS THE POTENTIAL TO BECOME A TROPICAL
DEPRESSION DURING THE NEXT DAY OR TWO AS IT MOVES TOWARD THE
WEST-NORTHWEST AT 10 TO 15 MPH.

ELSEWHERE...TROPICAL CYCLONE DEVELOPMENT IS NOT EXPECTED DURING THE
NEXT 48 HOURS.

$$

FORECASTER RHOME

No La Nina this summer after all

Early this spring predictions ran hot and heavy that we would have a very active hurricane season. Much of these predictions were due to the indication that a La Nina was forming in the Pacific. The general cooling of equatorial Pacific waters generally results in an increase in tropical activity and intensity. Add this to an expectation of an already high activity and we could eb in for a very busy season. It certainly looked that way with the first storm forming before the season even started and the second storm forming on June 1st, the first day of the season.

Well it seems like we will not be experiencing a La Nina this summer after all. NOAA has predicted that La Nina will not form in the Pacific during the next two months, which are the most active months of the season.

Of course we should not let our guard down.

"There are so many other ingredients that contribute to the development of
tropical cyclones, it's not just the fact that we don't have a La Nina that
comes into play here," Feltgen said

This year, forecasters have predicted an above-average hurricane season,
which runs June 1 through November. They believe there will be 13 to 17 named
storms, with seven to 10 of them becoming hurricanes and three to five of those
reaching at least Category 3 strength.

Part of the reason behind this,
Feltgen said, is that we're in an active hurricane cycle - a phenomenon of
heightened activity that can last for decades. The last one spanned the 1940s
through 1960s. The current one started in 1995 and could last for another
decade, Feltgen said. "So all things being equal, we expect an above average
number of cyclones," he added. "Be prepared."

Of course the key thing is to be prepared. We must remember that when hurricane Andrew came ashore, it was the only storm in that year (1992, I think) but it was a doozy.

Tropical Storm Cosme

UPDATE: Cosme has been upgraded to Hurricane status. The storm has 60 kt (75 mph) winds making it a Category 1 hurricane. Based on current water temperatures in the area which are below 26C right now, it is likely that the storm has reached or is close to its peak intensity. The storm track still predicts that Cosme will pass just south of Hawaii Island. Tropical storm force winds will likely affect Honolulu and most of the islands. See the Pacific Storm updates in the sidebar for the most detailed information.


Tropical Storm Cosme has developed and is moving west northwest across the Pacific. Right now the forecasts show that the storm is expected to remain at tropical storm strength through Thursday or Friday. By Friday afternoon, the big island of Hawaii should start feeling the effects of the cyclone. If Cosme degrades to a depression as predicted, there should be no issues. If the storm intensifies then it could be a different situation.

We'll watch this and update as the situation develops.

TAG!....I'm It.

OK Angel was ever so kind as to tag me/ I think it was an excuse to get off my duff and post something. So as an aside to tropical weather, which has been fairly quiet so far this season and since the last time I got tagged (with an award no less) I just let it drop, here we go:

The rules:

1. Post the rules for the meme at the beginning of your post.
Ok, I blew that one already. ha

2. This meme consists of the blogger listing eight random facts/habits about themselves.
random?

3. People who are tagged in this post are to write their own post listing their own eight random items and list the rules.

4. At the end of the post/meme, list the folks you are tagging and leave them notice of such in their comments.

Eight Random Facts:

1. - My kids are the most important to me in my life. All seven.

2 - My religion is very important in my life, yet I question if I've instilled any of that value in the lives of my children.




3. - The best vacation I have ever had was the 3 days we spent on the big island of Hawaii hiking on Kilauea volcano. I'd love to go back there as soon as possible.

4. - The place I've enjoyed for a business trip the absolute most was the weekend stays between meetings in Heidelberg, Germany. I really want to go back there. Make sure to stop by the Kulturbrauerei for a fine ale or a good meal.




5. - I've tried twice to start my own business without success. This last time I had a decent chance but as usual cash flow, or the lack thereof, go in the way. I still intend to make it some day.

6. - I enjoy the work I do, but I hate the long hours and the expectations that surround them.

7. - I love sailing and wish I could be on the water way more than I am.

8. - My hurricane tracking enthusiasm is an enjoyable hobby and led to this site and all the friends I've found in cyberspace.



Now for my targets. Tags to

Dumb Ox
Butch
Gayle
Roxie
AB Freedom

If you choose not to participate, that's OK, just think of this as another endorsement of y'alls blog.

Potential Development in the E. Pacific