Archive for the ‘Spaghetti models for today’ Category
Compare this to the previous posting which was 24 hours earlier and you will see some change in the tracking model forecasts – which is to be expected.
I have greatest confidence in the TVCA run which is a consensus of 5 other models which have been good performers over the last few years. Generally, the TVCA model is very close to the National Hurricane Center’s “official” track that is the basis for the “uncertainty” cones released to the public. If you are one to pay attention to which models get mentioned or shown in weather reports you have surely heard of the “European model” which is labeled ECMWF. You won’t find it on these spaghetti illustrations; Data from this model is restricted from being redistributed according to international agreement. However, the National Weather Service official track runs very close to being the same as the ECMWF. The BAMM and related models are still useful for long term runs but in this case I think you can pretty much ignore them (the ones that run off toward the west).
Suppose you lived along the Nature Coast of Florida, (e.g. Citrus County) then you might feel that you have nothing to be concerned about because the tracks seem to be shifting northward. But please remember, these tracks are merely forecasting the storm’s center. In most cases the strongest winds are at the right hand, leading quadrant of such storms, which, in this case might cause Citrus County some concerns.
Please be sure to click on the graphic for enlargement.
REMINDER: THIS IS A TIME-SENSITIVE REPORT
As of late this afternoon, 8-29-2016, Invest 99L has strengthened to a tropical depression. For up-to-date information on the system, I recommend Dr. Jeff Masters’ weblog (blog). See link below:
Go to the top of the page and click on News & Blogs.
As of the time of this writing, Dr. Masters expresses reasonable confidence that the system will track in such a way that a landfall will occur somewhere in the Florida coast north of Tampa. I urge all interested persons to pay close attention to Dr. Masters’ postings, the Weather Channel tropical reports, and your local news.
Here is the most recent version from my favorite spaghetti chart source, the National Center for Atmospheric Research in Boulder, Colorado (CLICK ON IMAGE TO ENLARGE):
THIS IS A TIME-SENSITIVE POSTING SUBMITTED 8-22-2011 AFTER 11 PM EASTERN TIME.
Hurricane Irene is now of GREAT CONCERN to the Bahamas. Based upon my observation of the ECMWF (European Centre for Medium-Range Weather Forecasting) model – it now looks as though South Carolina or North Carolina could be the landfall site though the statistical mean mid-line continues to “windshield-wiper” to the east.
Here is Jonathan Vigh’s spaghetti chart effort releases at 8 pm Eastern Daylight Time, 8-22-2011. The numbers along the forecast model tracks are “hours from the forecast release time.” OFCL is the designation for “official.” The OFCL is remarkably close to the ECMWF model track which does not show on this graphic. To observe it, go to my “Tropical Weather” links to the right of this page and click on “Penn. State U. Models Page.”
THIS IS NOW A SERIOUS CAT. 2 HURRICANE WITH POTENTIAL FOR STRENGTHENING.
– LEFT CLICK THE GRAPHIC TWICE FOR MAXIMUM ENLARGEMENT –
THIS IS A TIME-SENSITIVE POSTING SUBMITTED 8-21-2011 AFTER 11 PM EASTERN TIME.
IT IS NOW OUT OF DATE. PLEASE CLICK ON THE BLOG TAB AT THE TOP LEFT OF THIS PAGE AND SCROLL DOWN TO LOOK FOR A MORE RECENT REPORT ON THIS STORM WHICH IS NOW A SERIOUS HURRICANE (posted 8-22-2011 near midnight EDT).
Invest (investigation) 97L (or 97AL) has become Tropical Storm Irene. My concerns for Florida remain and it looks to me as though the east coast is the part of Florida most likely to be influenced by the system. If it does skirt the coast at least that region will be subjected to the left-hand leading quadrant which is almost always less powerful than the right-hand leading quadrant. Based upon my observation of the ECMWF (European Centre for Medium-Range Weather Forecasting) model – it now looks as though South Carolina could very well be the landfall site. Of course many changes can occur over the next few days and much depends upon the movement and strength of a trough dipping down over the Eastern U.S.A. One of my favorite sources, Dr. Jeff Masters wrote yesterday:
“The best model for predicting the timing and strength of such troughs over the past two years has been the ECMWF (European Center model). The European Center does not permit public display of tropical storm positions from their hurricane tracking module of their model, so we are unable to put ECMWF forecasts on our computer model forecast page that plots positions from the other major models. Remember that a 7-day forecast by even our best model will be off by an average of over 700 miles, so it is too early to tell what part of the U.S. might be most at risk from a strike by 97L. This weekend would be a good time to go over your hurricane preparation.”
In the future, if you wish to view the ECMWF model loops go to the right of this page and under the heading of “Tropical Weather” click on the link to Penn. State U. Models Page. Scroll down until you find it.
Here is Jonathan Vigh’s spaghetti chart effort releases at 8 pm Eastern Time, 8-21-2011.
THIS IS A TIME-SENSITIVE POSTING SUBMITTED 8-20-2011 LATE MORNING EASTERN TIME.
Though there is more than one system out there today, my attention is east of the Lesser Antilles Islands where there is a system that currently has the status of a tropical wave. However, there is an 80% chance that it will become cyclonic within the next 48 hours. The Spaghetti chart below is courtesy of Jonathan Vigh. His efforts to put the model forecasts together produce my favorite renditions. Notice that the islands between its present location and Florida will be effected if this early visual is close to being correct. The storms ability to sustain itself as it moves over land might be touch and go. Frankly, this one really has my attention.
If you left click the image should enlarge – a second left click might enlarge it even further:
Here is the forecast plot for our first tropical disturbance of the season – released at 1200 Greenwich Time (7AM Eastern Time) June 1, 2011 – the first official day of the season. These are sometimes called spaghetti charts. Please ignore the “straight line” projection into the Gulf which is an extrapolation of movement were there to be no change in course. Already, I’ve detected rightward deflection in its actual track. Two left clicks should fully enlarge this image for you.
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!
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.