Archive for the ‘Hurricane models’ Category

Gaston’s Remnant Could Redevelop Soon – 9-6-2010

RELEASED 8 AM EDT TODAY 9-6-2010

SHOWERS AND THUNDERSTORMS HAVE BECOME LESS ORGANIZED DURING THE PAST
FEW HOURS IN ASSOCIATION WITH THE REMNANT LOW OF GASTON...LOCATED
ABOUT 400 MILES EAST OF THE NORTHERN LEEWARD ISLANDS.  ENVIRONMENTAL
CONDITIONS ARE EXPECTED TO BECOME MORE CONDUCIVE FOR DEVELOPMENT
OVER THE NEXT DAY OR SO AS THE SYSTEM MOVES WESTWARD AT ABOUT 15
MPH.  THERE IS A HIGH CHANCE...70 PERCENT...OF THIS SYSTEM BECOMING
A TROPICAL CYCLONE AGAIN DURING THE NEXT 48 HOURS.  HEAVY RAINS AND
GUSTY WINDS SHOULD BEGIN TO AFFECT PORTIONS OF THE LEEWARD ISLANDS
LATER TODAY AND TONIGHT...AND INTERESTS IN THOSE ISLANDS SHOULD
MONITOR THE PROGRESS OF THIS SYSTEM.

The remains of Gaston don’t look like much this morning on the satellite imagery, but as you just read, there is a strong chance that it will redevelop into a tropical cyclonic system soon.  It is already cyclonic (loop imagery has been showing rotation for several hours now) but Weather Service experts are not ready to declare it a tropical depression on the basis of the very limited amount of current thunderstorm development.  But that is likely to change soon.  My feeling is that since it is of tropical origin and it is rotating – it should be designated a depression at this moment – but what do I know?  LOL

Unfortunately, as you can see, the models seem to favor its moving south of Hispaniola and Cuba.  This means, of course, that it’s bound for the Gulf of Mexico unless a decidedly sharp turn to the north were to occur before entering that body.  As usual, I recommend that you ignore the CLP5 model. The bottom line is that former Gaston deserves our attention.

97L could be the future Bonnie. It’s worth watching.

TWO SEPARATE CLICKS ON IMAGE WILL ENLARGE TO THE FULLEST

NOTE: THESE PLOTS ARE TIME-SENSITIVE.

Though there are many uncertainties at this time, a system currently out there (7-20-2010) might turn into a tropical storm.  It would be named Bonnie should that occur.

The GFDI* model (orange line) takes the system decidedly north of the other models – it has gotten my attention for two reasons:

1.  I have been impressed by the GFDL* model’s accuracy over the last 4 years that I’ve been watching it (see note)

and –

2.  I live in Citrus County which is in West-Central Florida where the model suggests it might pay a visit.

*Special Note:  The GFDI and the GHMI models are, for all practical purposes, an “adjusted” GFDL.

If you live in Florida or plan to be traveling in Florida on Thursday, Friday, or Saturday (and maybe even Sunday) – I recommend that you keep an eye on reports on this system.

If you would like to view current GFDL animations here is a link to a tutorial which, in turn, provides a link to the model.

https://cloudman23.wordpress.com/2008/08/30/gfdl-model-a-great-source-for-an-animation/

To see updated model plot comparisons I recommend going to  http://moe.met.fsu.edu/~acevans/models/

If anything is going on there will be a small “display” button to click on.

Ida’s Current Model Forecasts – 11-7-09

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

11-7-09Ida

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A Tropical Wave Worth Watching Has Formed

-l eft click to enlarge this TIME SENSITIVE image -
-left click twice to enlarge this TIME SENSITIVE image –

The chart above, acquired from the tropical page of Weather Underground at http://www.wunderground.com/tropical/ shows computer model “notions” of the future path of Investigation 91 which currently has the status of a tropical wave.  The wave (or tropical disturbance) is currently showing no signs of cyclonic circulation.  When, or if, if does it will become a tropical depression.

The red pathway is from the GFS image.  This is the one I’m tending to value the most in this specific case since the GFDL does not take it far enough.  In any case, it is believed that the leading half of an anticyclone moving from the west toward the east will prevent the system from continuing its rightward turning and will eventually cause it to move generally toward the west.

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ERIKA – KEEP A WATCHFUL EYE ON THE EAST COAST

z 9-3-09 Erika

Graphic courtesy of Jonathan Vigh, Colorado State.

LEFT CLICK GRAPHIC TO ENLARGE

and a second time to enlarge even further.

The models have a “ways to go” in order to reach what I consider a healthy agreement on Erika’s future path.  My “gut-level” feeling, for what it’s worth, is that even though the storm is likely to be disturbed a great deal by shear aloft, there is a strong chance that it could reorganize (come back to life) once that shear diminishes.  On the basis of some of the projections, I would not be surprised to see Erika sneeking up to near North Carolina around the 10th or 11th.  Of course I hope I’m wrong.  My wish, always, is that our tropical systems give us needed moisture without doing damage or causing stress and anxiety.  Perhaps that’s asking too much but as the old (1938) standard song says, “I can dream, can’t I?”

THIS IS A TIME-SENSITIVE POSTING

NEW TROPICAL DISTURBANCE IN SOUTHERN CARIBBEAN

11-3-08-93l

A tropical disturbance is in the Southern Caribbean.  The National Hurricane Center has it labeled 93L.  My arrow is not intended to pinpoint a spot but rather to point out the impressive assemblage of clouds which already seems to show some organization.  The system takes up the entire top/middle third of the image.  Presently the NHC gives it a medium potential for further development.  I recommend that interests in Jamaica and Cuba take notice.  Also, South Florida and Bahamian residents should be mindful of its existence.

The image above is not sharp and crisp because it is an unenhanced infrared image completed late in the day after the sunlight had slipped to the west.  Left click to enlarge.

The image  below is from Florida State University.  It shows the forecast location 120 hours beyond 7 AM EST today (11-3-2008).  Projecting forward 5 days would make it 7 AM EST Saturday (11-8-2008).

THIS IS NOT A SURFACE ANALYSIS.  PLEASE, IF YOU ARE NOT FAMILIAR WITH VORTICITY OR 500 MILLIBAR ANALYSES, DON’T WORRY – I’M SHOWING YOU THIS GRAPHIC MERELY TO ILLUSTRATE FORECAST POSITIONING FROM A MODEL I ENJOY CONSULTING.

AS IN MOST IMAGES IN THIS WEB-LOG,

LEFT CLICKS SHOULD RESULT IN ENLARGEMENT.

IN THIS CASE, AS IN MANY OTHERS

TWO LEFT CLICKS SHOULD GIVE YOU MAXIMUM ENLARGEMENT.

11-3-08-93l-plus-120hr

Tropical Storm Omar Has Developed From Tropical Depression 15

LEFT CLICK TO ENLARGE NATIONAL HURRICANE CENTER IMAGE

LEFT CLICK TO ENLARGE NATIONAL HURRICANE CENTER IMAGE

THE IMAGE ABOVE AND THE TEXT BELOW ARE TIME SENSITIVE

Tropical storm Omar is likely to be hurricane Omar in the morning.  Conditions are favorable for intensification.  Puerto Rico and the Northern Leeward Islands must be alert and ready.  I recommend you use these two links to keep updated on the storm’s progress:

http://www.nhc.noaa.gov/index.shtml

http://www.wunderground.com/tropical/

PUERTO RICO REPORTS – MORE FLOODING, LANDSLIDES – TROPICAL DISTURBANCE LIKELY TO HEAD NORTHWARD

“Plot provided courtesy of Jonathan Vigh, Colorado State University. For more information about this graphic, click here.”

THIS IS A TIME-SENSITIVE POST

FROM SEPTEMBER 22, 2008

Dr. Jeff Masters of http://www.wunderground.com/tropical/ reports flash floods and mudslides in Puerto Rico from the tropical disturbance in their vicinity.  Please check it out.  His weather blog is excellent.  You will find it on the right side of the page.

The models are all over the place today.  The GDFL model has been, in my opinion, the best performer over the last couple of years at least.  Please disregard the CLP5 model and the XTRP model.  They are no-skill models that do have a useful purpose but they are not meant to convey an actual forecast.  One day I may write about those models to explain their function but if you are bugged by it and can’t wait, I suggest a Google search.

Please visit the rest of this web-log at https://cloudman23.wordpress.com/.  If you are interested in weather, there are some tutorial items scattered about and more will be added in time.  At the end of this page there is a cue to click to the previous page or the next page.

Galveston Occupants and Others Along That Coast – GET OUT OF THERE

I learned while watching the Weather Channel around 12:15 pm EDT that about half of the residents of Galveston are still there.  That is not good news.  I suspect that the wind speeds and category of the hurricane are within the range of what many people feel they can handle – but that is not sound thinking.  What I fear they are failing to consider is the size of the storm.  According to Dr. Jeff Masters from WeatherUnderground, the “Integrated Kinetic Energy” for Ike is 30% higher than was that of Katrina.  So – a huge amount of water is being pushed (and pulled) ashore by the storm.  It is not merely the wind velocity that determines the magnitude of the surge; the size of the storm is a very important factor.  It’s as if you were the quarterback and you had your choice of being sacked by the fastest defender or being “stopped and stomped” by the entire front line.  The linemen would represent far more total energy, even though each is slower than the fastest defender.

IT IS NOT WISE TO FOCUS ON ONE MODEL.  THE FOLLOWING IMAGE IS USED FOR SAKE OF PROVIDING A GENERAL IDEA ONLY.  HOWEVER, THE MODELS ARE ALL IN GREAT AGREEMENT OVER THE NEXT 32 HOURS OF MOVEMENT.

PLEASE, IF YOU ARE IN HARMS WAY – SURELY YOU HAVE BEING WARNED.  IT DOESN’T ALWAYS HAPPEN TO THE OTHER GUY!  THIS TIME YOU COULD BE THAT OTHER GUY!  IF YOU ARE NOT ALONE AND ARE THE DECISION-MAKER WITHIN YOUR GROUP – DON’T BE MR. OR MS. MACHO!  GET THE HECK OUT OF THERE!  IF YOU ARE NOT THE DECISION-MAKER IN YOUR GROUP, IT’S TIME FOR A NON-VIOLENT MUTINY!  GET YOUR POSTERIORS OUT OF THERE!

TWO LEFT CLICKS ON THE IMAGE BELOW SHOULD MAKE IT LARGER.

Source = PSU Department of Meteorology

Source = PSU Department of Meteorology