Archive for the ‘Caribbean Weather’ Category
This is the 4 pm EDT advisory for August 30, 2012.
Two left clicks on the image will enlarge it fully.
By the time you see this posting, the forecast graphic for what remains of Isaac (above) will probably be obsolete. Here is where to go to get a comparable update (however, the advisory above might be the last):
In spite of modern technology the tasks of the National Hurricane Center’s forecasters are not easy and I guarantee they burned the midnight oil as this event unfolded. They have so many variables and unknowns to deal with. I think they do a wonderful job.
Where I live, in west-central Florida about 18 miles inland from where the tiny Crystal River flows into the Gulf of Mexico, there are long-term concerns about our fresh water supply. So I had hoped that Isaac would provide just the right amount of water WITHOUT damaging and costly winds and flooding. Like most humans, I want all of the good but none of the bad that can come from Nature’s wonders. At this time, Thursday evening, 8-30-2012, we are still getting some rain directly related to Isaac even though its center is about to move into Arkansas. Hopefully the system will provide needed rain to drought stricken areas in it’s predicted path. My retired-farmer uncle in Indiana indicates that it’s probably too late for the field corn but could be helpful to the soybeans. As I write, flooding and potential flooding in certain areas of Louisiana are creating real headaches there. There are some places claiming to have more water than with Katrina, albeit for different sets of circumstances.
There is so much information available today and I understand the great value of our acquired knowledge about tropical weather since I first began studying it formally (over 50 years ago) but sometimes, I confess, I think fondly of the days when we had little notion of what was going on until much later in a tropical cyclone’s life cycle. Now, it seems that the media devotes an inordinate amount of time telling us about the negatives and potential negatives that are going on all over the world and I can no longer bask in my ignorance as I used to because I haven’t the will-power or inclination to ignore the resources that are available. But, I concede, there are limits to the notion that ignorance is bliss.
I wish you peace, good health, and happiness.
By the time you read this, May of 2011 will have ended and the Northern Hemisphere Atlantic, Caribbean, and Gulf of Mexico hurricane season will have begun. The following link will take you to a summary of the NOAA outlook for this season:
Please be prepared if you live in hurricane territory.
The loop above illustrates nicely that a tropical system does not have to be a hurricane in order to cause significant problems including fatalities. TO ACTIVATE YOU MUST LEFT CLICK ON THE IMAGE. Here is what Wikipedia has to say about the 2008 storm: Tropical Storm Fay was a tropical storm and the sixth named storm of the 2008 Atlantic hurricane season. Fay formed from a vigorous tropical wave on August 15 over the Dominican Republic. It passed over the island of Hispaniola, into the Gulf of Gonâve, across the island of Cuba, and made landfall on the Florida Keys late in the afternoon of August 18 before veering into the Gulf of Mexico. It again made landfall near Naples, Florida, in the early hours of August 19 and progressed northeast through the Florida peninsula, emerging into the Atlantic Ocean near Melbourne on August 20. Extensive flooding took place in parts of Florida as a result of its slow movement. On August 21, it made landfall again near New Smyrna Beach, Florida, moving due west across the Panhandle, crossing Gainesville and Panama City, Florida. As it zigzagged from water to land, it became the first storm in recorded history to make landfall in Florida four times. Thirty-six deaths were blamed on Fay. The storm also resulted in one of the most prolific tropical cyclone related tornado outbreaks on record. A total of 81 tornadoes touched down across five states, three of which were rated as EF2. Damage from Fay was heavy, estimated at $560 million.
Here is a link to Wikipedia’s coverage of that storm:
Here is a link to my list of 23 Misconceptions About Hurricanes:
Though Tomas has weakened to a tropical depression, indications are that intensification to at least a category 1 hurricane will occur in the predicted journey northward. But, even as a lesser storm (tropical depression or tropical storm) the system can cause severe problems with fatalities. Just last month 23 people died in Haiti from the results of regular seasonal rainfall events, according to Dr. Jeff Masters’ blog this morning! The pitiful deforestation of that country allows for rapidly flooding streams and mass wasting events (e.g. mud slides) which can be deadly.
Certain deadly diseases can be spread by contaminated water which is a likely outcome of the flooding that Tomas will trigger. Cholera is probably the greatest current concern.
I am alarmed by the projected probability path of the storm (see this morning’s cone of uncertainty above) because, if it turns out this way, Haiti will be under the influence of the right hand leading quadrant of Tomas. That quadrant is typically the one possessing the strongest winds, most prominent storm surges, and greatest probability for imbedded mesoscale tornadic systems.
Of course, Haiti is not the only place that should be concerned. For example, the Dominican Republic, Jamaica, and the Bahamas need to be “ready.”
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.
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:
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!
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 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.
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.
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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.
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).
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.