Archive for the ‘Dr. Jeff Masters’ Tag
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.
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.
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.
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.
In an attempt to provide you variety in the storm track presentations, I’ve used Hurricane Alley’s version for this afternoon. Here is a link to their home page; http://www.hurricanealley.net/
One of my primary sources, Dr. Jeff Masters of Weather Underground posted the following at 4:40 pm EDT today (7-23-2010):
“The projected track will take Bonnie over the oil spill region, and the storm’s strong east to southeasterly winds will begin to affect the oil slick on Saturday morning. Assuming Bonnie doesn’t dissipate over the next day, the storm’s winds, coupled with a likely storm surge of 2 – 4 feet, will drive oil into a substantial area of the Louisiana marshlands. However, the current NHC forecast has Bonnie making landfall in Louisiana near 9pm CDT Saturday night. According to the latest tide information, this will be near the time of low tide. This will result in much less oil entering the Louisiana marshlands than occurred during Hurricane Alex in June. That storm brought a storm surge of 2 – 4 feet and sustained winds of 20 – 30 mph that lasted for several days, including several high tide cycles.”
A reference to Dr. Masters with a photograph is in the following outdated post from 2009: https://cloudman23.wordpress.com/2009/11/08/ida-forecast-11-8-09/
Here is a link to the Weather Underground Tropical Page: http://www.wunderground.com/tropical/
TO GET TO CLOUDMAN23’s HOME PAGE CLICK ON THE “BLOG” TAG ABOVE.
Some of the information on this site is published close to “real-time” particularly as it applies to tropical weather. But it is important to remember that the only “official” source of information is the National Hurricane Center. Decisions concerning life or death, property, and such should not be made based solely on the information found on this site or any other sites that are recommended here. unless they are official. Listen to your local authorities when conditions are life-threatening or there is possible loss of property.
If you wish to see other posts on this web-log
but are unable,
please click on the “blog” tab
near the top of this page.
THE ENTIRE FIRST PARAGRAPH THAT FOLLOWS IS A DIRECT QUOTE FROM DR. JEFF MASTERS (PICTURED BELOW) THAT WAS CUT AND PASTED FROM HIS WEATHER UNDERGROUND SITE; DR. MASTERS IS MY MOST RELIABLE AND DEPENDABLE SOURCE WHEN IT COMES TO TROPICAL WEATHER; HE IS A DEDICATED ‘WINNER:” ONE REASON WHY I DEPEND SO HEAVILY UPON HIS WORK IS THAT HE IS NOT OPERATING UNDER THE CONSTRAINTS OF NATIONAL WEATHER SERVICE FORECASTER BUT HE BENEFITS FROM THEIR INTERPRETATIONS AS WELL AS FROM OTHER NATIONAL WEATHER SERVICE RESOURCES. HE IS DEDICATED, “UP FRONT,” AND RESPONSIBLE.
The forecast for Ida –
Posted: 10:21 AM EST on November 08, 2009
“The high wind shear of 20 – 25 knots currently affecting Ida is forecast to persist at that level until Monday night. Some slow intensification is still possible while Ida remains over the exceptionally warm water of the Loop Current in the Gulf of Mexico, through tonight (Figure 2). Late tonight, Ida will be crossing over waters of 26°C, which is barely enough to support a hurricane. With shear still expected to be at 20 -25 knots, I expect weakening to begin early Monday morning and accelerate on Monday afternoon. At that time, Ida will encounter 40 knots of wind shear associated with a cold front over the Gulf of Mexico, and begin transitioning to an extratropical storm. Exactly how strong Ida will be when it reaches the coast early Tuesday morning–and indeed if Ida even does reach the coast–is a forecast with high uncertainty. The computer models have a tough time forecasting the evolution of a tropical cyclone into an extratropical cyclone, and the models are all over the place on what will happen. Most of the models foresee a landfall near 1 am EST Tuesday between Mississippi and Pensacola, Florida, then a path northeastward over the Southeast U.S. However, Ida could come to halt before reaching the coast and turn west towards Tampa (the UKMET model’s forecast), or turn south back over the Gulf of Mexico (the NOGAPS model’s forecast). In any case, storm surge and heavy rain appear to be the main hazards from Ida. The GFDL model (Figure 3) is forecasting rain amounts of 4 – 8 inches for a large swath of the Gulf Coast, and there is a risk of tornadoes if the warm air from the core of Ida pushes ashore.” END QUOTE
From my point of view, (this is Cloudman23 writing) everyone on the Gulf Coast from Mississippi to Key West should have a “heads up” mindset while Ida is out there. As Dr. Masters said, the computer models have a difficult time when the tropical to extratropical metamorphoses takes place. Furthermore, the chance of tornadoes (mentioned by Dr. Masters) in association with warm, moist air from Ida and its inherent instability in such situations, this storm should not be taken lightly.
The total amount of thermal energy at the surface in the Western Caribbean is high and wind shear aloft is relative low so it is anticipated that Ida will intensify before striking the Yucatan Peninsula. The Yucatan does not have the type of topography that we associate with significant weakening of a storm due to friction. But, read what Dr. Jeff Masters says this morning about the fate of Ida after she enters the Gulf of Mexico:
“Once Ida crosses into the Gulf of Mexico on Sunday night, the storm will encounter much cooler SSTs and a strong trough of low pressure that will dump cold air into the storm and bring 40 knots of wind shear. This will cause Ida to lose its tropical characteristics and become a powerful extratropical storm with 45 – 55 mph winds. It is highly unlikely that Ida will hit the U.S. as a tropical storm, but it could still bring tropical storm-force winds of 45 mph to the coast next week as an extratropical storm.”
As for me, I have been favoring the Geophysical Fluid Dynamics Laboratory Model (GFDL) for the path that Ida will take; currently, if I had to depend upon only one of the many models, that would be the one – in most instances anyway. I have no real science to back that up – only my perception based upon experience. Call it a “gut level” good feeling about the model’s past performance if you will. Therefore I expect Ida to eventually curve rightward as the GFDL shows in the plot below. By the time it does I expect it will have lost its tropical characteristics though the winds will still be strong. In other words, it will become extratropical. TO GET INSTRUCTIONS ON OBTAINING THE GFDL ANIMATION CLICK ON THE FOLLOWING LINK: https://cloudman23.wordpress.com/2008/08/30/gfdl-model-a-great-source-for-an-animation/https://cloudman23.wordpress.com/2008/08/30/gfdl-model-a-great-source-for-an-animation/
The prefix, extra, means “outside of” or “beyond.” Extratropical cyclones are sometimes called cold core lows whereas tropical cyclones are warm core lows. When a tropical cyclone draws in cold air (as usually happens when a front interferes with the storm) it becomes extratropical. The majority of the world’s extratropical cyclones develop in the middle latitudes (30 degrees to 60 degrees latitude) and for that reason are often referred to as middle latitude cyclones.
Graphic courtesy of Jonathan Vigh of the Department of Atmospheric Science at Colorado State University
If you wish to see other posts on this web-log
but are unable,
please click on the “blog” tab
near the top of this page.
Ida developed quickly – in fact at a record pace (see Jeff Master’s Weather Blog at http://www.wunderground.com/blog/JeffMasters/comment.html?entrynum=1372).
Though relatively high wind shear could prevent Ida from becoming a significant threat to the U.S. mainland it is a storm that is worth watching, partly because warm Gulf waters could nurture it.
Here is a recent forecast plot from the National Hurricane Center (left click to enlarge image):