Archive for the ‘Tropical Disturbances’ Category

97AL – Tropical System May Become a Threat to Florida

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:

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Forecast Model Plots for Our First Tropical System of the Season – 2011

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.

Click on Image to Enlarge

98L – SPAGHETTI CHART – 10-10-2010

 

Two left clicks enlarge to the fullest

 

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THREE TROPICAL SYSTEMS ARE OF INTEREST THIS EVENING – 9-12-2010

LEFT CLICK THIS IMAGE TO ENLARGE.

More information about the three tropical weather systems depicted here can be found at the following site:

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

Click on each for printed reports.

Tropical Disturbance 92L Is A Problem – Not Much Model Agreement

THANKS TO JONATHAN VIGH OF COLORADO STATE U. FOR THIS GRAPHIC

Some computer models are not developing this tropical disturbance at all – and the ones that are, as you can see, have it all over the place.  We must wait and see for there is very little agreement here.  Obviously, it should not be forgotten – not yet.

Igor is still out there and the model forecast tracks have not changed much from yesterday’s.  I recommend the National Hurricane Center’s site for the latest at:  http://www.nhc.noaa.gov/index.shtml

Gaston Is Likely to Strengthen – 9-4-2010

Two independent left clicks will fully enlarge.

RELEASED BY THE NATIONAL HURRICANE CENTER AT 8 AM EASTERN DAYLIGHT TIME, SEPT. 4, 2010.

“SHOWER AND THUNDERSTORM ACTIVITY ASSOCIATED WITH THE REMNANTS OF
GASTON CONTINUE TO SHOW SIGNS OF ORGANIZATION THIS MORNING.
ENVIRONMENTAL CONDITIONS ARE CONDUCIVE FOR RE-DEVELOPMENT OF THIS
SYSTEM AND A TROPICAL DEPRESSION COULD RE-FORM IN THIS AREA LATER
TODAY OR TONIGHT. THERE IS A HIGH CHANCE...70 PERCENT...OF THIS
SYSTEM BECOMING A TROPICAL CYCLONE AGAIN DURING THE NEXT 48 HOURS
AS IT MOVES WESTWARD AT ABOUT 10 MPH.”

The color image above was completed at 7:45 am EDT today.
This black and white image below at 12:15 pm EDT (4.5 hours later).
Information inserted in yellow print was done by me, Tonie Ansel Toney.



A big thanks and a God bless to the U.S. Navy for this graphic!

LATEST ON GASTON – 9-3-2010

Gaston has weakened to the point where it has lost its closed rotation.  This means it has returned to the status of tropical wave (synonymous with tropical disturbance).  However, some of the more dependable computer models expect it to regain strength soon.  My advice is to ignore the CLP5 track in the chart above; it is a baseline derived from recent directional tendencies and is used as a tool “after the fact” to evaluate the accuracy of the more analytical models.

You have probably noticed that I tend to focus on those storms which could be a threat to Florida and the Gulf Coast and once that threat passes I generally assume that you get plenty of continuous information from television news.  Though it is quite repetitive and there is some “drama” I still highly recommend the Weather Channel.  Here is a link to their Hurricane Central page:  http://www.weather.com/newscenter/hurricanecentral/

We have friends in our West-Central Florida neighborhood, wonderful people, who are currently in Nova Scotia.  Therefore, since some of my concerned neighbors consult this site, I’m including this current statement about Earl’s expected effect upon Canada.  This comes verbatim from the WeatherUnderground website, appearing in Dr. Jeff Masters’ web-log (11:54 am EDT):

Impact of Earl on Canada

“Winds will begin to rise on the southwest coast of Nova Scotia late Friday night and early Saturday morning. By late morning Saturday, Earl is expected to make landfall somewhere between the Maine/New Brunswick border and central Nova Scotia. At that time, Earl will probably be a strong tropical storm with 55 – 60 mph winds. Earl will be moving at a very rapid 25 – 30 mph when it arrives in Canada, and regions on the right side of the eye can expect winds 15 – 20 mph greater than on the left side, due to the fast forward motion of the hurricane. Earl’s impact is likely to be less than 2008’s Hurricane Kyle, the last hurricane to hit Nova Scotia. Kyle hit near Yarmouth, Nova Scotia, as a Category 1 hurricane with 75 mph winds. Kyle produced a storm surge of 2.6 feet, and did $9 million in damage to Canada. The 11am EDT NHC wind probability forecast is calling for a 15% chance of hurricane-force winds in Yarmouth, and 3% in Halifax.”

IMAGE OF ATLANTIC TROPICAL WEATHER – 9-1-2010

Two independent left clicks will fully enlarge

Remember, tropical systems of this scale move generally from east to west if they have an entire ocean over which they can travel.  The reason for that tendency is multifaceted but it has to do more with the forces that dominate the general large-scale circulation of the atmosphere than anything else.  I will produce a posting with diagrams on that subject soon.

The lineup shown in the satellite image above is impressive to say the least though it is not unusual for this part of the Atlantic Hurricane Season.  Let’s hope that nothing serious comes of any of these systems.  However – I imagine that is wishful thinking.

Besides – everything is relative.  For example:  Since hurricane Andrew was relatively dry and part of the roof over the living room stayed on we were able to salvage some of our furniture.  The closest place I could find a truck to rent and storage was 100 miles north in Boynton Beach.  When my wife and I were up there we stopped at a Publix to purchase some provisions.  In the checkout lane we overheard a lady seriously complaining because her hair stylist was in Dade County and her standing weekly appointment had to be canceled because there was no electricity at the shop due to the hurricane.  Those of you who know me probably find it hard to believe that I kept my mouth shut – but I did.  In fact, I smiled over it as we moved on.  Our house had just been literally destroyed a few days earlier so this ladies concerns seemed a bit trivial to me.  However, for some reason – perhaps gratitude for being alive and having no one in my family injured – I felt that I needn’t bother to waste my time trying to convince her that her “problem” was not worth verbalizing in front of total strangers at a grocery store.  On the other hand, I’m sure some of my complaints seem trivial in the whole scheme of things.

AFRICAN LOWS 8-27-2010

For those of you who might be “old school” (like me) and enjoy surface pressure plots, I’m posting this current one that shows a line of lows over Northern Africa and Saudi Arabia – all of which are slowly migrating toward the west – which is typical for this time of year.  I’ve marked the cores of these lows in red. They are hot and dry but as soon as they move over the Atlantic they characteristically sweep up great amounts of moisture through evaporation.  Paradoxically, the addition of water vapor lowers the pressure and because of that the systems usually “deepen.”  Increasing winds make waves which increases the water surface for evaporation and whitecaps with bursting bubbles produces ejection filaments which break apart by gravity and cause even more surface to be available for evaporation.  During this phase of the hurricane season for some of these it’s “off to the races” as  tropical cyclonic systems evolve and track across the Atlantic.  Typically, the warmer the water, the higher the evaporation rates and the stronger the storms become.   NOTE:  Remember, the more water vapor in the air the less it weighs per unit volume – therefore the lower the pressure upon the surface. The opportunity for intensification is great because of the great length of ocean over which they can travel.  Once this happens – as long as they are over warm water about the only thing that can make them fade involves the air aloft (its temperature, velocity, and flow pattern).