Archive for the ‘Tropical disturbance’ Tag

ANA, BILL, AND CLAUDETTE!

zAnaBillClaudett38-16-09

To have this current explosion of activity in the Gulf and Atlantic after so many quiet weeks is a real attention-getter.  Most recently, a tropical system off the Florida panhandle has developed into a tropical storm.  In the meantime Ana and Bill out in the Atlantic are both commanding attention.

Tropical systems are not all bad, particularly when the wind velocities are not too high and this is because they can provide much needed precipitation.  Let’s hope that these three systems prove to be more of an advantage than anything else.  So many people are reminded of Andrew in 1992, another year in which El Nino was a  factor.  Andrew was the only hurricane to make landfall in the U.S.A. that season but he was a whopper and there are many people yet today who will testify that it changed their lives – myself included.

I am likely to be inactive on this site for the next few days for two reasons.  My laptop is behaving badly and either needs some serious attention (like a new hard drive) or I need to bite the bullet and get another machine.  Also – I will be traveling.  For those of you who know me – don’t be alarmed.  The traveling has nothing to do with the current tropical weather activity.

In the meantime if you want to stay on top of things weatherwise I recommend the Weather Channel if you have cable and also the Masters’ Blog at http://www.wunderground.com/tropical/

The Masters’ Blog link is usually at the upper part of the page on the right hand side.

Peace be with you!

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TROPICAL DISTURBANCE – JULY 20, 2009

LEFT CLICK TO ENLARGE THIS IMAGE

LEFT CLICK TO ENLARGE THIS IMAGE

TIME SENSITIVE! – THIS WAS POSTED AROUND

11:30 PM EST

ON JULY 20, 2009.

A tropical disturbance (also known as a tropical wave) has moved over Barbados and is continuing on its general path toward a direction just a little north of west.  The image above is a color-enhanced infrared.  At the time of this posting, the National Hurricane Center is indicating that they do not expect development into a cyclonic system within the next 48 hours.  To be cyclonic there must be a closed rotation.  tropical depressions, tropical storms, and hurricanes rotate counterclockwise in the northern hemisphere (except in the higher levels of the storms).  For more information on cyclonic circulation in a hurricane go to this link:

https://cloudman23.wordpress.com/2008/09/09/hurricane-circulation-lesson-1/

My most trusted source, Dr. Jeff Masters, at this time expects the disturbance to be torn apart by upper level wind shear within the next few days.

To follow Dr. Masters’ reports, go to the following link:

http://www.wunderground.com/cgi-bin/findweather/getForecast?query=34442

Then, in the “Features” bar at the top, click on Tropical/Hurricane.

That will take you to his Wunderblog feature which usually appears on the right hand side of the page.

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but are unable,

please click on the “blog” tab

near the top of this page.

Clear Indications of Rotation with System 93L

I expect that before morning has ended tomorrow (November 5) 93L will be declared a tropical depression.  By definition, a tropical disturbance upgrades to a tropical depression once closed rotation at the surface is confirmed.

The first shows windfields from a Quiksat (satellite) pass.  The second depicts the movement of ocean waves, which for the most part, is a function of wind.

With regard to this notion/expectation that a tropical depression status will be designated, I am providing two graphics which I consider to be supportive.  Left clicks will enlarge the graphics.

Yours Truly,

Cloudman23 (Tonie Toney)

11-4-08-wind-field

11-4-08-wave-motion

NEW TROPICAL DISTURBANCE IN SOUTHERN CARIBBEAN

11-3-08-93l

A tropical disturbance is in the Southern Caribbean.  The National Hurricane Center has it labeled 93L.  My arrow is not intended to pinpoint a spot but rather to point out the impressive assemblage of clouds which already seems to show some organization.  The system takes up the entire top/middle third of the image.  Presently the NHC gives it a medium potential for further development.  I recommend that interests in Jamaica and Cuba take notice.  Also, South Florida and Bahamian residents should be mindful of its existence.

The image above is not sharp and crisp because it is an unenhanced infrared image completed late in the day after the sunlight had slipped to the west.  Left click to enlarge.

The image  below is from Florida State University.  It shows the forecast location 120 hours beyond 7 AM EST today (11-3-2008).  Projecting forward 5 days would make it 7 AM EST Saturday (11-8-2008).

THIS IS NOT A SURFACE ANALYSIS.  PLEASE, IF YOU ARE NOT FAMILIAR WITH VORTICITY OR 500 MILLIBAR ANALYSES, DON’T WORRY – I’M SHOWING YOU THIS GRAPHIC MERELY TO ILLUSTRATE FORECAST POSITIONING FROM A MODEL I ENJOY CONSULTING.

AS IN MOST IMAGES IN THIS WEB-LOG,

LEFT CLICKS SHOULD RESULT IN ENLARGEMENT.

IN THIS CASE, AS IN MANY OTHERS

TWO LEFT CLICKS SHOULD GIVE YOU MAXIMUM ENLARGEMENT.

11-3-08-93l-plus-120hr

Florida’s West Coast May Soon Be Visited By a Strong Weather System

I apologize to my few “regulars” (mostly in Central Florida) who rely on my postings of weather tips.  My on-line signal has been very weak and undependable up here in Nature’s Wonderland – the Southern Appalachians.  But these cool temperatures (below freezing in the early morning hours and with the beautiful Autumn colors make being without the Internet a trivial inconvenience in the whole scheme of things.  Conditions are allowing me to be on line this moment so I want to get this information out to you while I can.  Almost all of what I have learned about the tropical disturbance centered slightly north of Honduras has come from a quick check with Dr. Jeff Master’s statement found at Weather Underground.  Since I’m having difficulty getting on line, I strongly suggest you go there for updates.  Here is a link:

http://www.wunderground.com/tropical/

Though the weather system has been deadly in Central America, there does not seem to be cause for great alarm in Florida at this time but heavy rains with fairly strong winds (30-35 mph) might be expected for part of the state on Friday night – probably somewhere between Tampa and the Big Bend.  Strong wind shear over the Gulf of Mexico will probably prevent the storm from becoming any stronger – in fact, by the time it reaches Florida it will probably have taken on extratropical (mid-latitude) characteristics.  An example of such characteristics is the establishment of a front (or fronts).  It will be interesting to see if that happens.

My personal favorite with regard to the models is the GFDL which is shown in blue in the image below.  Since it is dated, and since nothing new yet appears today, I’m hoping that something has happened in the interim to further weaken the system.

If you would like to view the GFDL model animation and need instructions on how to do so, the last posting on my tutorials page will tell you how.  Here is a link: https://cloudman23.wordpress.com/weather-tutorials/

LEFT CLICK IMAGE TO ENLARGE

LEFT CLICK IMAGE TO ENLARGE

NANA, TROPICAL DEPRESSION 15, INVEST 90L, AND INVEST 99L.

FOR EASIER VIEWING, ENLARGE THE IMAGE WITH A LEFT CLICK.

There is “action” in the Atlantic basin today in-so-much as multiple systems are concerned.  The Gulf of Mexico and the Caribbean are considered to be a part of the Atlantic Basin.  The most immediate concerns reside in Puerto Rico, I should think, due to tropical depression 15 nearby.  If it moves northeastward, as predicted, the island will no doubt get precipitation that it doesn’t need considering the pelting it has already taken this season.

Storms do not get named until they “graduate” from tropical depressions to tropical storms.  But, there is a tropical depression out there today with a name, Nana.  She is “named” because she had reached tropical storm status earlier in her history and she retains that name even though she has now deintensified as was predicted.

That is not uncommon but there has been a very interesting occurrence with Nana.  Wind shear earlier on broke her into two distinct parts.  The northern segment (Nana) is not likely to survive but the southern segment, Invest 90L, stands a chance of intensifying.  Both Invest 90L and Invest 99L are tropical disturbances (also called tropical waves).  If you didn’t already know you might have guess that numbers are assigned to tropical disturbances and when under “investigation” they are labeled with the abbreviation, “invest.”

So, there are four systems out there being watched.

Classification of Synoptic-Scale Lows of Tropical Origin:

1. Tropical disturbance (tropical wave) – An area of organized convection, originating in the tropics and occasionally the subtropics, that maintains its identity for 24 hours or more. It is often the first developmental stage of any subsequent tropical depression, tropical storm, or hurricane.

2. Tropical depression – A tropical cyclone in which the maximum sustained surface winds are 38 miles per hour (33 knots) or less. Characteristically having one or more closed isobars, it may form slowly from a tropical disturbance or an easterly wave which has continued to organize.  NOTE FROM CLOUDMAN23 – By convention, it has been the practice of the National Hurricane Center to associate the beginning of “rotation” with the transition from disturbance to depression.  In fact, in some definitions rotation is an important element.  Generally, this causes no problem because once one or more closed isobars are needed to plot the pressure, rotation has almost always begun.

3. Tropical storm – A tropical cyclone in which the maximum sustained surface winds are from 39 miles per hour (34 knots) to 73 miles per hour (63 knots). At this point, the system is given a name to identify and track it.

4. Hurricane (or another name depending upon geographical location – e.g. typhoon) – The name for a tropical cyclone with sustained winds of 74 miles per hour (65 knots) or greater in the North Atlantic Ocean, Caribbean Sea, Gulf of Mexico, and in the eastern North Pacific Ocean. This same tropical cyclone is known as a typhoon in the western Pacific and a cyclone in the Indian Ocean.

(definitions source is the Weather Channel Glossary found at http://www.weather.com/glossary/a.html

During my long college teaching career I was asked from time to time why such a list was not labeled “Classification of Synoptic-Scale Cyclones of Tropical Origin” instead of Synoptic-Scale Lows. The reasoning is straight-forward.  The first member of the quartet, the tropical disturbance, is not cyclonic.  In order to be cyclonic there must be rotation.  Therefore, though all cyclones are lows, not all lows are cyclones.

FLORIDA MAY HAVE A TROPICAL VISITOR LATER THIS WEEK

Left click on image to enlarge.

Left click on image to enlarge.

From late September on through the remainder of the official hurricane season, systems that can develop into named storms begin to pop up in the Caribbean and Gulf of Mexico.  One such development may be occurring now.

An interesting area in the vicinity of the Yucatan is being watched by the National Hurricane Center.  I have marked the approximate center which is hard to pinpoint since there is no apparent closed surface circulation at this time.  I may have my blue dot positioned a bit too far to the east.  It’s easier to do when using loops rather than stills like this image.  If you want to try that, here is a good page to get some nice loops:

http://www.ssd.noaa.gov/PS/TROP/trop-atl.html

I have looked at some of the models on this one and there are indications that it could eventually move toward Florida and provide significant rainfall.  It is my opinion that interests along the West Coast of Florida should pay attention to this.  Right now the wind shear over the storm is about 20 mph.  There is some chance that it could slowly strengthen as it moves toward the northeast later this week.  Probably around the middle of the week it will be influencing some part of Florida.

Tonie A. Toney

12:50 PM EDT 9-28-08

PUERTO RICO REPORTS – MORE FLOODING, LANDSLIDES – TROPICAL DISTURBANCE LIKELY TO HEAD NORTHWARD

“Plot provided courtesy of Jonathan Vigh, Colorado State University. For more information about this graphic, click here.”

THIS IS A TIME-SENSITIVE POST

FROM SEPTEMBER 22, 2008

Dr. Jeff Masters of http://www.wunderground.com/tropical/ reports flash floods and mudslides in Puerto Rico from the tropical disturbance in their vicinity.  Please check it out.  His weather blog is excellent.  You will find it on the right side of the page.

The models are all over the place today.  The GDFL model has been, in my opinion, the best performer over the last couple of years at least.  Please disregard the CLP5 model and the XTRP model.  They are no-skill models that do have a useful purpose but they are not meant to convey an actual forecast.  One day I may write about those models to explain their function but if you are bugged by it and can’t wait, I suggest a Google search.

Please visit the rest of this web-log at https://cloudman23.wordpress.com/.  If you are interested in weather, there are some tutorial items scattered about and more will be added in time.  At the end of this page there is a cue to click to the previous page or the next page.

CARIBBEAN SYSTEM HAS MEDIUM POTENTIAL FOR FURTHER DEVELOPMENT.

TWO LEFT CLICKS WILL ENLARGE IMAGES A GREAT DEAL

According to the National Hurricane Center, the tropical wave in the Caribbean has a medium potential for tropical cyclone development.  For those of you who don’t understand that here is a brief explanation.

In order for a system to be cyclonic there must be a rotation of the wind around a low pressure center.  Presently there is no indication of a closed rotation in this otherwise impressive system.  A tropical wave (also called a tropical disturbance) becomes a tropical depression if rotation begins.  Ordinarily the rotation itself signals a maturing (growth) of the system.  Once rotation begins, the conservation of angular momentum kicks in such that as the wind spirals closer and closer to the center its velocity increases.  Tropical depressions can intensify into tropical storms (39-73 mph) and the latter can intensify into hurricanes (74 or more mph).  Here is the formal statement from the Hurricane Center:

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TROPICAL WEATHER OUTLOOK

NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL

800 PM EDT SAT SEP 20 2008

FOR THE NORTH ATLANTIC…CARIBBEAN SEA AND THE GULF OF MEXICO…

1. A TROPICAL WAVE…ACCOMPANIED BY A SURFACE LOW PRESSURE SYSTEM OVER THE NORTHEASTERN CARIBBEAN SEA…IS PRODUCING WIDESPREAD CLOUDINESS AND SHOWERS OVER THE LESSER ANTILLES…AND ADJACENT CARIBBEAN AND ATLANTIC WATERS.  THIS SYSTEM IS SHOWING SIGNS OF ORGANIZATION…AND UPPER-LEVEL WINDS ARE EXPECTED TO BECOME A LITTLE MORE FAVORABLE

FOR DEVELOPMENT OVER THE NEXT COUPLE OF DAYS.  A TROPICAL

DEPRESSION COULD FORM DURING THIS TIME AS THE SYSTEM MOVES SLOWLY NORTHWESTWARD.  AN AIR FORCE RESERVE UNIT RECONNAISSANCE AIRCRAFT IS SCHEDULED TO INVESTIGATE THE SYSTEM ON SUNDAY…IF NECESSARY.  REGARDLESS OF DEVELOPMENT…LOCALLY HEAVY RAINFALL AND STRONG GUSTY WINDS WILL AFFECT MUCH OF THE LESSER ANTILLES…THE VIRGIN ISLANDS AND PUERTO RICO THROUGH SUNDAY.

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On the infrared satellite image above from the U.S. Naval Research Lab, I have marked two islands that don’t need any more precipitation for a while due to recent tropical systems having dumped heavy (and deadly) loads upon them.  Flooding and mudslides are likely if this disturbance moves as expected, over the islands.  For the same reasons, Cuba also stands a risk of increased problems.

Please visit the rest of this web-log at https://cloudman23.wordpress.com/.  If you are interested in weather, there are some tutorials scattered about and more will be added in time.


Tropical Wave In Eastern Caribbean

“Plot below is provided courtesy of Jonathan Vigh, Colorado State University. For more information about the graphic, click here.”

FROM THE NATIONAL HURRICANE CENTER:
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
800 AM EDT SAT SEP 20 2008

1. A WESTWARD-MOVING TROPICAL WAVE ACCOMPANIED BY A SURFACE LOW PRESSURE SYSTEM OVER THE EASTERN CARIBBEAN SEA IS PRODUCING WIDESPREAD CLOUDINESS AND SHOWERS OVER THE LESSER ANTILLES AND ADJACENT CARIBBEAN AND ATLANTIC WATERS.  THIS SYSTEM IS SHOWING SIGNS OF IMPROVED ORGANIZATION THIS MORNING AND UPPER-LEVEL WINDS ARE EXPECTED TO BECOME SOMEWHAT MORE FAVORABLE OVER THE NEXT COUPLE DAYS FOR SOME ADDITIONAL DEVELOPMENT TO OCCUR.

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Well, it’s time.  More tropical activity is inevitable. Yes – the official hurricane season for the northern hemisphere Atlantic, the Caribbean and the Gulf of Mexico is 6 months long. It begins on June 1.  That means that we must wait until the beginning of December in order to realize that at least officially, it’s over for another 6 months.  For many of us, it goes with the territory.  Environmental hazards and/or natural disasters are but a few things many of us must face, sooner or later.

I remember so clearly, after Andrew, how grateful I was and how often I expressed that gratitude.  I suspect that those closest to me got a bit tired of hearing the same old – same old out of me.  But I was (and am) sincere.  At least we were unhurt – at least we had good insurance – at least I could swing the cost of a travel trailer to put in the driveway while the house was being rebuilt, at least I had a job and, at that time, an understanding employer.  The paychecks did not stop, though absenteeism was high, we were told to take care of our personal matters first.  The length of that Autumn term at the college where I taught was shortened. I seriously doubt that my former employer would be so kind today – the management is far different now.

Whether it’s hurricanes, earthquakes, wild fires, mass wasting (e.g. landslide), tsunamis, floods, heat waves, etc., a multitude of hazards exist out there for we humans to contend with – some which we enhance because of the way we have altered our natural environment.  In time, I will no doubt speak of each of those and others in this web-log. However, I’m not well informed about (nor do I pretend to understand) what I perceive to be the most dangerous of hazards – namely – many, if not most, humans.  One need not study or observe too long or hard to learn that we can be our own worst enemies (individually and as a species).