Archive for the ‘Dr. Jeff Masters’ Category
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):
The graphic above is the Friday, October 4, 2013 10 a.m CDT (advisory #6) from the National Hurricane Center.
Those who follow this web-log know that my primary source of information regarding tropical weather is Dr. Jeff Masters of Weather Underground. His blog can be found by clicking on the “community” tab once you open the following page: http://www.wunderground.com/
It would be a waste of my time and yours for me to try to explain it any better. Here is his verbatim forecast report posted at 1:44 PM GMT on October 04, 2013
Forecast for Karen
Wind shear for the next three days is expected to stay high, around 20 – 30 knots, according to the 8 am EDT SHIPS model forecast. The atmosphere is quite dry over the Western Gulf of Mexico, and this dry air combined with high wind shear will retard development, making only slow intensification possible until landfall. A trough of low pressure and an associated cold front will be moving through Louisiana on Saturday, and the associated upper-level westerly winds will bring higher wind shear near 30 knots and turn Karen more to the northeast as it approaches the coast on Saturday. The higher shear, combined with ocean temperatures that will drop to 28°C, may be able to induce weakening, and NHC has sharply reduced its odds of Karen achieving hurricane strength. The 5 am EDT Friday wind probability forecast from NHC put Karen’s best chance of becoming a hurricane as a 23% chance on Sunday at 2 am EDT. This is down from the 41% odds given in Thursday afternoon’s forecast. Most of the models show Karen intensifying by 5 – 10 mb on Saturday afternoon and evening as the storm nears the coast, as the storm interacts with the trough of low pressure turning it to the northeast. This predicted intensification may be because of stronger upper-level outflow developing (due to diverging winds aloft sucking up more air from the surface.) We don’t have much skill making hurricane intensity forecasts, so I wouldn’t be surprised to see Karen do the opposite of what the models predict, and decay to a weak tropical storm just before landfall, due to strong wind shear. In any case, residents of New Orleans should feel confident that their levee system will easily withstand any storm surge Karen may generate, as rapid intensification of Karen to a Category 3 or stronger hurricane has a only a minuscule probability of occurring (1% chance in the latest NHC forecast.)
Since Karen is expected to make a sharp course change to the northeast near the time it approaches the south coast of Louisiana, the models show a wide range of possible landfall locations. The European and UKMET models are the farthest west, with a landfall occurring west of New Orleans. The GFS model is at the opposite extreme, showing a landfall about 400 miles to the east, near Apalachicola, Florida. NHC is splitting the difference between these extremes, which is a reasonable compromise. Most of Karen’s heavy thunderstorms will be displaced to the east by high wind shear when the storm makes landfall, and there will likely be relatively low rainfall totals of 1 – 3″ to the immediate west of where the center. Much higher rainfall totals of 4 – 8″ can be expected to the east. NHC’s 5 am EDT Friday wind probability forecast shows the highest odds of tropical storm-force winds to be at the tip of the Mississippi River at Buras, Louisiana: 66%. New Orleans, Gulfport, Mobile, and Pensacola have odds ranging from 47% – 51%.
Since I began this site on August 24 2008, it’s been averaging about 12 “hits” per hour. So, I’m not setting the Internet world on fire. I’m sure that many of my “followers” are either friends and neighbors, family, or former students. Of course a number of people reach this site as a consequence of a search term that blends with something I’ve discussed.
This is my first posting in over three months. That might be strange for a site devoted mostly to tropical meteorology but those who know me understand that I devote most of my tropical weather attention to those systems that cause alarm to folks in Central Florida where I now reside.
The six month long official hurricane season whose last day was November 30 was an active one but not for Central Florida. There were some storms in the Atlantic, Caribbean, and Gulf that caused concern but, if you have been following this site you have no doubt noticed that I ignored most of them. I choose to refrain from alarming anyone unnecessarily when I deduce that a storm in question is not likely to bother us. On the other hand, the National Weather Service errs on the side of caution and consequently the “coverage” was vigorous and reports were easily obtained through the media. Though I think that the media does a good job, generally speaking, I am inclined to suspect that they are spectacularizing their reports. There were times when it appeared that a storm would be coming our way here in West-Central Florida but my information and gut-level feelings indicated a very low probability. SPECIAL NOTE: It appears that in using “spectacularizing” I’ve used a word whose acceptance is debatable; it appears to be a mere colloquialism but that fits me well.
This year’s hurricane season was very active! An average northern hemisphere Atlantic/Caribbean/Gulf of Mexico season has 11 named storms, 6 hurricanes, and 2 intense hurricanes.
For the 2011 season there were 19 named storms, 7 hurricanes, and 3 intense hurricanes.
But for the U.S.A. specifically – the season was unusually timid. In his summary of the season, Dr. Jeff Masters (one of my important sources) wrote: “Only two named storms made landfall, Tropical Storm Lee, which hit Louisiana with 60 mph winds, and Hurricane Irene, which hit North Carolina on August 27 with 85 mph winds, and made two additional landfalls in New Jersey and New York the next day.” By the time tropical storm Don reached Texas it had weakened to a tropical depression. There seems to be general agreement that favorable steering currents were the principle reason for our good fortune in the U.S.
I made no entries concerning Irene, in spite of the scare in New York because we were being flooded with media information and for those with cable or satellite, the Weather Channel was right on top of things. Since it wasn’t threatening our Central Florida region I held back in the wake of such comprehensive coverage.
The way our season luckily turned out has indeed caused me some considerable concern over the tendency that we humans have toward complacency. In the 6+ years I’ve lived in Citrus County, Florida there have been no tropical systems of any severe nature but the year before I arrived, 2004, was a busy one with Jeanne, Ivan, Frances, and Charlie. None of those named storms were strong enough to create a county-wide wake-up call. Some people were without power for a few days but the storms did not create events comparable to those which reverberate in our heads for years to follow – like Andrew, for example, which destroyed my home (in Homestead, Florida) in 1992.
I have heard tales of real estate agents in the area boasting that Citrus County possesses some sort of special immunity for whatever reason. I refute that notion absolutely. There is nothing about the environment that affords it the luxury of special protection other than the high sand ridges that minimize storm surge potential for those who live far enough inland from the Gulf. For example, my house sits at an elevation of 55′ above mean sea level so I don’t anticipate storm surge events. However, high water from heavy rains is a distinct possibility.
In any event I urge you who live in my area to NOT ignore the fact that you live in hurricane country. There are so many things about hurricanes that should not be discounted. For example, doubling the wind velocity actually quadruples it’s potential force. So a 60 mph wind has four times the ability to do harm compared to a 30 mph wind. Here is a link to a site which I put together regarding “hurricane misconceptions.” http://ztechzone.net/learningzone/science/science55/hurricanes.html
Coming next: My Christmas Greeting and Reflections.
Shortly before noon Eastern Daylight Time today (8-30-2011) Dr. Jeff Masters published this statement:
“Gulf of Mexico development possible late this week”
“Several of our best computer models for predicting formation of tropical cyclones, the GFS and ECMWF, are predicting that an upper level pressure interacting with a tropical wave now over the the Western Caribbean could combine to spawn a tropical depression in the Gulf of Mexico late this week or early next week. The formation location is likely to be off the coast of Louisiana or Texas, but the track of the system is hard to predict at this point.” (end quote) –
Though this is far too early to tell, here is a six day look into the ECMWF model’s “take” on our tropical weather. It was released at 8 pm EDT, 8-29-2011 and projects out six days (144 hours).
Notice, in addition to the system in the Gulf of Mexico, the position northeast of Puerto Rico of what is currently Tropical Storm Katia. Some are predicting that she will be of hurricane strength by the time 6 days pass.
The error 6 days out can be enormous so take this for what it’s worth. I recommend your being mindful that the ECMWF has been doing well for the last couple of years. For instructions on viewing the model in animated form on WeatherUnderground.com, please use the following link: https://cloudman23.wordpress.com/2011/08/25/ecmwf-model-run-the-european-model/
NOTE: ECMWF = European Center for Medium -Range Weather Forecast
When the European Center for Medium-Range Weather Forecast model is running, here is my favorite site for viewing:
For a lot of different reasons, but mainly because I enjoy the insights of Dr. Jeff Masters in his weather blog, I use WeatherUnderground.com. For future reference, a link to his blog is under the Blogroll category at the right margin of this page. In fact, it’s the first listed.
For the ECMWF Model Run, click on the following link and then follow my instructions exactly: NOTE: YOU MIGHT WANT TO COPY THE INSTRUCTIONS BECAUSE ONCE YOU CLICK ON THE LINK THIS PAGE WILL BE GONE UNLESS YOU CLICK BACK –
- At the upper left of the image, click on the “continent” tab.
- Scroll down the menu on the right margin and click in the box labeled “model data”.
- Another menu dropped down. Click on the “model” arrow and select ECMWF.
- Make sure the “map type” remains on MSL which stands for “mean sea level.”
- Click on the “forecast” arrow and wait patiently for the load.
- After it has loaded fully it should loop. If you want it to stop click on the button at “forecast.”
Though the European Model is not always right (none of them are) it has done the best job for the last two years in situations akin to this one with hurricane Irene. The National Weather Service gives credence to this model though you will not see it indicated on the official spaghetti charts and such. In fact, lately, the NWS official forecasts have been close to that of the ECMWF model runs or, if you please, the ECMWF model runs have been close to the official forecasts of the NWS. To be sure, there will be times when there is little agreement – at which time I expect to lean toward the NWS advisories.
FOR THE RECORD:
The “official” hurricane season is 6 months long – beginning June 1 – ending November 30.
An Atlantic hurricane was observed on March 7, 1908. That’s quite a number of days before June 1.
An Atlantic hurricane was observed December 31, 1954. That’s quite a number of days after November 30.
The earliest hurricane to strike the United States since 1900 was Alma which struck northwest Florida on June 9, 1966 and the latest was near the end of the day on November 30, 1925 near Tampa, Florida.
Here is a wonderful hurricane season summary by Dr. Jeff Masters of Weather Underground. Dr. Masters is one of my primary resources when it comes to tropical weather. At the end of his summary he links to the Klotzbach-Gray report which I have also linked you to below. But – for those interested in the “season” I recommend reading the Master’s report first.
Here’s the link to the comprehensive summary of the 2010 Atlantic/Gulf of Mexico/Caribbean hurricane season by Philip J. Klotzbach and William Gray. Gray is the renowned long-term forecaster from Colorado State University and Klotzbach, after a great deal of experience working with Gray, has taken over the primary responsibility. It is in the PDF format:
LEFT CLICK ON THE IMAGE ABOVE
AND THEN WAIT PATIENTLY FOR AN ANIMATION.
I RECOMMEND YOU READ THE INTRO. BELOW FIRST.
I’m posting this on the afternoon of Wednesday, 9-15-2010. What you will be looking at as you view the animation above is, to my mind, fantastic. I would have loved to have had such a tool to use in the college classroom when I was a full-time meteorology professor. Even though this is jerky, it gives a wonderful view of things which I and my students could only imagine back before my retirement from the profession. The stream will quickly get to mid-day (of Monday, Sept. 13) and the sun will quickly reach the western horizon marking sunset. If you focus upon the eye in the afternoon you will see the shadow created by the wall cloud’s western margin as it creeps eastward. Also watch the boiling cumuliform tops in various places. I was fascinated by the way the clouds moved within the eye of the storm as it rotated. ENJOY!
SPECIAL NOTE: For those of you who understand hurricane circulation in more detail than most, notice the lower level clouds converging cyclonically (counterclockwise in the Northern Hemisphere) and look hard enough at the more diffuse high clouds and you will detect the anticyclonic divergence (clockwise in the Northern Hemisphere). The latter is easiest to see on the west side of the storm where you can envision the feathered cirrus moving toward the north or northwest. If they seem to you to be standing still that is because the ice crystals are sublimating at the leading edges of the clusters (turning from solid to gas) whereas deposition (gas to solid) is occurring at the trailing edges.
Watch the digital clock at the bottom margin of the image and you will note that after the initial spurt of one frame per 15 minutes, it settles down to a nicer one frame per minute.
* * * * * * *
This hurricane is a very strong one and potentially dangerous – particularly for the 65,000 or so people in Bermuda. Let’s hope that they escape unharmed. I’m hoping that Igor takes a surprisingly sharper right turn than anticipated in order to spare those fine people.
However, no matter the outcome, it’s difficult not to be in awe of this beautiful beast. It’s also important, I think, to recognize that there are some good things about this storm especially when coupled with the impending effects of Julia which is positioned further to the east. A certain amount of energy MUST be transformed over the Atlantic in order that it not be all released at once. An analogy: It’s better to have one tiny earthquake per year along an active fault than wait for 100 years before all of that stored energy is released as one gigantic earthquake.
The fact that Igor and Julia are both releasing huge amounts of latent heat into the atmosphere is good – particularly when that is happening over relatively uninhabited places. Generally such long fetches over such long periods of time will move warm, tropical water such that it is replaced from below by cooler upwelling water. That is good because the next system to move by is less likely to have as much oceanic heat to stoke it.
At the time I’m writing this (about 5 pm EDT, 9-15-2010) Igor is a category 4 hurricane and Julia is a category 3. However, not many hours ago Julia was also a 4 and she might intensify to that category again. According to my sources, this is only the second time in history that we have had two category 4 storms in the Atlantic at the same time.
Dr. Jeff Masters of WeatherUnderground.com wrote of that fact in his weblog today. Rather than mimic what he has said, I’m placing his well-written statement below in blue.
T. Ansel Toney
e-mail = ProfToney@gmail.com
“The Atlantic hurricane season of 2010 kicked into high gear this morning, with the landfall of Tropical Storm Karl in Mexico, and the simultaneous presence of two Category 4 hurricanes in the Atlantic, Igor and Julia. Tropical Storm Karl’s formation yesterday marked the fifth earliest date that an eleventh named storm of the season has formed. The only years more active this early in the season were 2005, 1995, 1936 and 1933. This morning’s unexpected intensification of Hurricane Julia into a Category 4 storm with 135 mph winds has set a new record–Julia is now the strongest hurricane on record so far east. When one considers that earlier this year, Hurricane Earl became the fourth strongest hurricane so far north, it appears that this year’s record SSTs have significantly expanded the area over which major hurricanes can exist over the Atlantic. This morning is just the second time in recorded history that two simultaneous Category 4 or stronger storms have occurred in the Atlantic. The only other occurrence was on 06 UTC September 16, 1926, when the Great Miami Hurricane and Hurricane Four were both Category 4 storms for a six-hour period. The were also two years, 1999 and 1958, when we missed having two simultaneous Category 4 hurricanes by six hours. Julia’s ascension to Category 4 status makes it the 4th Category 4 storm of the year. Only two other seasons have had as many as five Category 4 or stronger storms (2005 and 1999), so 2010 ranks in 3rd place in this statistic. This year is also the earliest a fourth Category 4 or stronger storm has formed (though the fourth Category 4 of 1999, Hurricane Gert, formed just 3 hours later on today’s date in 1999.) We’ve also had four Cat 4+ storms in just twenty days, which beats the previous record for shortest time span for four Cat 4+ storms to appear. The previous record was 1999, 24 days (thanks to Phil Klozbach of CSU for this stat.)”
We are entering the peak of the Atlantic hurricane season. If you have not been influence by tropical activity thus far this year you might be under the impression that it’s an inactive season. That would not be true. Statistically, it has been about average to date. Though we cannot “plan the future” I feel strongly that we should plan “FOR” certain eventualities in the future. I urge you to be prepared and alert in the event that a tropical system comes your way.
The following statement in “blue” was taken Verbatim Thursday morning (8-19-2010) from the Dr. Jeff Masters web-log found at http://www.wunderground.com/tropical/.
“The GFS, NOGAPS, and ECMWF models continue to predict that a tropical storm will form between Africa and the Lesser Antilles Islands sometime in the period 3 – 6 days from now. There is an area of disturbed weather south of the Cape Verdes Islands, but there is no obvious organization to the cloud pattern. Wind shear is a hefty 20 – 30 knots in the region, and the disturbance is a 1 – 2 day journey away from reaching a lower shear area where development can occur. Preliminary indications are that if a storm did develop in this region, it would track west-northwest and pass well to the northeast of the Lesser Antilles Islands 7 – 8 days from now. However, 7-day forecasts of a storm that hasn’t even formed yet are not to be trusted.”
I have taken the liberty of trimming the latest full disc color satellite image down to a manageable size where you can still easily find Florida and thus look across the Atlantic to see the area of disturbed weather off Africa to which Dr. Masters refers. Two independent left clicks on this image will enlarge it fully. This image was taken from a distance over three earth diameters away from the surface yet there is considerable detail. I hope you enjoy it.