Archive for the ‘Tropical activity in the Caribbean’ Category

Tomas May Invade Haiti as a Hurricane

Plot Courtesy of Jonathan Vigh - Colorado State University

Even when you left click twice to get full enlargement, most of the individual model forecast plots are hard to read individually because of the “cluster” of agreement in anticipated general trend.  The only glaring exception you see is the CLP-5 which should be no surprise to those who study these spaghetti charts.  CLP-5 is the “CLImatology-PERsistance model 5-day” of the National Hurricane Center and is sometimes referred to as the CLIPER model for obvious reasons.  It tends to project the path of tropical systems as though they were going to conform to their “past track.”  So, more often than not, when there are changes in the steering influences the storms actually stray significantly from the persistence route.  Most other models account for anticipated steering changes.  This does not mean that the CLP-5 is of no value.  To the contrary, it is very useful tool particularly in accessing forecast accuracy of other models.

It appears that Tomas could become a serious problem for Haiti.  The country is over 98% deforested and that opens up a whole can of worms with regard to flooding, mud slides, and soil erosion.  Some small fraction of the deforestation has been due to natural causes (e.g. Hurricane Hazel in 1954) but the vast majority has been due to the impact of humans and their practices upon the environment, the poor management of same, and the general human and political condition. It is my sincere hope that the storm weakens significantly but the National Hurricane Center currently has the “weighted mean” plot (within the cone of uncertainty) taking it through Haiti as a hurricane.

I copied this 2002 image below using my free Google Earth download.  With yellow it shows a small part of the border between Haiti and the Dominican Republic at the Artibonite river.  The greater amount of deforestation on the side of Haiti (west or left side of the river) is clearly evident.  The eye altitude is 26,293 feet; a horizontal scale appears on the lower left.

Image Courtesy of Google Earth

My dear, long-time friend, Chuck Knighton, and his wife, Helen, are residents of northern Barbados and as of yet I have heard no news.  I do know that they have frequent power interruptions with ordinary thunderstorm weather – so communication could be down for quite a while.

Update on that 1:40 pm EDT 11-1-2010 – An e-mail from Chuck’s mother:

“Hi Toney,
Thanks so much for calling about the situation in Barbados! I have just recently spoken with Chuck’s sister in law who lives in the south of Barbados. She reports that they are all OK and the property sustained fallen trees and lots of rain! They do have household water, AND electricity (praise be!) and no one sustained injuries. Great news! They do not have phone service as yet, and I was really glad to have touched bases with someone!
Thanks again!!”



Left click to enlarge (which also may trigger motion).


Hopefully you are able to see the counterclockwise rotation of Paula in the radar loop above.  Computer models are in general agreement that this storm is not likely to survive much longer.  Most models have the storm continuing to turn to eventually head toward the southeast – but in a very weakened state.  A combination of shear aloft and movement over Cuba is likely to spell the end of her.  However, it is never safe to assume such predictions as Gospel truth.  Interests in the area (including South Florida) should remain alert.


98L Becomes Tropical Storm Paula

98L intensified to a tropical storm late yesterday.  This morning’s graphic below is from the National Hurricane Center for 7 am CDT.  Note that the weighted mean forecast path looks a bit like a backwards comma.  Following that is Jonathan Vigh’s compilation of computer model tracks in what is referred to often as a spaghetti chart.  This one is very busy but a quick glance will give you the general idea.


Two left clicks should enlarge to the fullest.



Two left clicks should enlarge to the fullest.


CLP-5 is a persistence model which, in my opinion, is not likely to represent the true path the storm takes.  The BAMS model considers where the storm is likely to travel IF it is moved mainly by shallow (lower level) forces.  In my opinion this is unlikely.

98L – SPAGHETTI CHART – 10-10-2010


Two left clicks enlarge to the fullest


To see all postings go to the

blog tag at the top left of this page.

Tropical Low 98L – October 9, 2010

The graphic below shows this morning’s computer model forecast tracks for the low (98L) that is currently developing and under investigation in the Western Caribbean.


Two left clicks will enlarge to the fullest



Left click image twice to fully enlarge

Having a daughter and two grandsons living not far south of Jacksonville, I have been somewhat concerned about the current tropical weather.  A few days ago the GFDL model showed the Jacksonville area getting tropical storm winds from Nicole but that is no longer in the forecast.  However, interestingly, this morning’s GFDL model shows another storm moving along almost the same track as Nicole off to the east of Miami 5 days from now!  We shall see.

In the U.S. Navy plot above, the two nearly identical figures that look like oddly altered letter D’s represent the 34 knot line.  In other words, sustained wind velocities outside of those figures are expected to be less than 34 knots (nautical miles per hour).

Yours Truly,

Tonie Toney

Today’s Three Named Storms – Color Image – 9-14-2010

Cropping and yellow insertions by T. Ansel Toney. Left click twice for full enlargement.

Dear Tropical Weather Watchers,

I cropped the image above from a full disk image.  It was taken from the 4:45 pm (EDT) transmission of the GOES-13 weather satellite which is positioned at an altitude of 22,300 miles above the Equator at longitude 75 West.  At that altitude it orbits earth with the same period of revolution as the earth’s spin on its axis.  Therefore it stays over the same point (though it can be moved either east or west if desired).  By contrast, the International Space Station orbits at only 236 miles above the surface and the U.S. Shuttle crafts fly lower than that sometimes but have also gone higher – up to 365 miles or so above the surface to the Hubble Telescope.  It should be noted that neither the Space Station, the Shuttles, nor the Hubble are on equatorial orbits like the GOES Weather Satellites but instead they are at an inclination of 51.6 degrees to the equator.

In this image provided the sun had gone well past zenith and therefore you can see the bright eastern side of Igor’s eye wall.  It’s a very impressive storm.



More information about the three tropical weather systems depicted here can be found at the following site:

Click on each for printed reports.

Tropical Disturbance 92L Is A Problem – Not Much Model Agreement


Some computer models are not developing this tropical disturbance at all – and the ones that are, as you can see, have it all over the place.  We must wait and see for there is very little agreement here.  Obviously, it should not be forgotten – not yet.

Igor is still out there and the model forecast tracks have not changed much from yesterday’s.  I recommend the National Hurricane Center’s site for the latest at:

Hermine and Former Gaston Today – 9-7-2010

Yellow insertions by T. Ansel Toney

Here is a recent satellite image showing Hermine and the remnants of Gaston.