Archive for the ‘Atlantic hurricane season’ Category

HURRICANE SEASON FOR 2010 HAS ENDED FOR THE NORTHERN HEMISPHERE ATLANTIC.

 

Graphic courtesy of http://www.wunderground.com/

 

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.

http://www.wunderground.com/blog/JeffMasters/comment.html?entrynum=1703

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:

http://hurricane.atmos.colostate.edu/Forecasts/2010/nov2010/nov2010.pdf

HAITI IS NOT LIKELY TO ESCAPE TOMAS

Two independent left clicks will enlarge to the fullest.

Though Tomas has weakened to a tropical depression, indications are that intensification to at least a category 1 hurricane will occur in the predicted journey northward.  But, even as a lesser storm (tropical depression or tropical storm) the system can cause severe problems with fatalities.  Just last month 23 people died in Haiti from the results of regular seasonal rainfall events, according to Dr. Jeff Masters’ blog this morning!  The pitiful deforestation of that country allows for rapidly flooding streams and mass wasting events (e.g. mud slides) which can be deadly.

Certain deadly diseases can be spread by contaminated water which is a likely outcome of the flooding that Tomas will trigger.  Cholera is probably the greatest current concern.

I am alarmed by the projected probability path of the storm (see this morning’s cone of uncertainty above) because, if it turns out this way, Haiti will be under the influence of the right hand leading quadrant of Tomas.  That quadrant is typically the one possessing the strongest winds, most prominent storm surges, and greatest probability for imbedded mesoscale tornadic systems.

Of course, Haiti is not the only place that should be concerned.  For example, the Dominican Republic, Jamaica, and the Bahamas need to be “ready.”

Tomas May Invade Haiti as a Hurricane

Plot Courtesy of Jonathan Vigh - Colorado State University

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.

Image Courtesy of Google Earth

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:

“Hi Toney,
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!
Thanks again!!”

Bermuda Is Experiencing a Weakened Igor – 9-19-2010

THANKS TO GOOGLE EARTH FOR THIS IMAGE - LEFT CLICK TWICE TO FULLY ENLARGE

Part of the image  above was done in 2007 and part in 2008.  I copied this from Google Earth this morning to give you an idea of the size and configuration of the beautiful British Overseas Territory of Bermuda.  Notice the 5 mile long scale at the lower left.  Latitude and longitude are also shown at the bottom margin.  This view is from an altitude of over 17 miles.  I recommend Google Earth for those of you who might be interested in more detail which is readily available.  There is a free version available.  With practice you can have great fun exploring the earth. 

http://www.google.com/earth/explore/products/desktop.html The free version of Google Earth 5 is the one that appears first on the page.

Yesterday Hurricane Hunter aircraft crews found that the inner 23-mile wide eyewall had collapsed during what seemed like a fairly typical eyewall replacement cycle.  A very large 92-mile wide eye was the result and, and as usually happens in such events the hurricane weakened.  Currently hurricane force winds are now spread out over a larger area but Igor is “down” to a category 1 hurricane.  Much of the big eye wall has collapsed and though that is good news, Bermuda is still in for some strong winds of long duration – and intensification is still a possibility.  In any event, there is likely to be considerable damage to beaches and some structures.  I am under the impression that residents of Bermuda are “hurricane savvy” and probably better prepared than those who live along Eastern coastal U.S. A.

According to a 9-17-2010 posting on Air-Worldwide.com, “Homes in Bermuda are typically one or two stories and constructed of ‘Bermuda Stone,’ a locally quarried limestone, or of concrete blocks. Roofs are commonly made of limestone slate tiles cemented together. Commercial buildings, typically of reinforced concrete construction, rarely exceed six stories. In both residential and commercial buildings, window openings are generally small and window shutters are common. These features make Bermuda’s building stock quite resistant to winds, and homes are designed to withstand sustained winds of 110 mph and gusts of up to 150 mph.”

HURRICANE IGOR IN MOTION !

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.

Yours Truly,

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.)”

Today’s Three Named Storms – Color Image – 9-14-2010

Cropping and yellow insertions by T. Ansel Toney. Left click twice for full enlargement.

Dear Tropical Weather Watchers,

I cropped the image above from a full disk image.  It was taken from the 4:45 pm (EDT) transmission of the GOES-13 weather satellite which is positioned at an altitude of 22,300 miles above the Equator at longitude 75 West.  At that altitude it orbits earth with the same period of revolution as the earth’s spin on its axis.  Therefore it stays over the same point (though it can be moved either east or west if desired).  By contrast, the International Space Station orbits at only 236 miles above the surface and the U.S. Shuttle crafts fly lower than that sometimes but have also gone higher – up to 365 miles or so above the surface to the Hubble Telescope.  It should be noted that neither the Space Station, the Shuttles, nor the Hubble are on equatorial orbits like the GOES Weather Satellites but instead they are at an inclination of 51.6 degrees to the equator.

In this image provided the sun had gone well past zenith and therefore you can see the bright eastern side of Igor’s eye wall.  It’s a very impressive storm.

IGOR FORECAST TRACK – 8 AM EDT – 9/9/2010

Left clicks will enlarge.

Here is the 8 am EDT forecast track for Tropical Storm Igor.

Hermine and Former Gaston Today – 9-7-2010

Yellow insertions by T. Ansel Toney

Here is a recent satellite image showing Hermine and the remnants of Gaston.

TROPICAL STORM HERMINE FORECAST, 9-9-2010

NOTE: the CDO to which the following report refers to is “Central Dense Overcast.”

THE FOLLOWING REPORT WAS TAKEN VERBATIM FROM THE NATIONAL HURRICANE CENTER’S WEBSITE.  IT WAS RELEASED AT 10 PM EASTERN DAYLIGHT TIME, 9-9-2010

000WTNT45 KNHC 070235TCDAT5TROPICAL STORM HERMINE DISCUSSION NUMBER 5NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL102010

1000 PM CDT MON SEP 06 2010

THE CENTER OF HERMINE MADE LANDFALL ON THE COAST OF NORTHEAST MEXICOAROUND 0130 UTC. PRIOR TO LANDFALL…SATELLITE DATA SHOWED THEFORMATION OF A CDO-LIKE FEATURE…WITH A LARGE AREA OF CONVECTIONALSO LOCATED NORTHEAST OF THE CENTER. THE LAST AIRCRAFT FIX AT 2333UTC SHOWED A PEAK 850-MB WIND OF 61 KT…WITH SFMR VALUES UP TO 56KT. DATA FROM THE BROWNSVILLE WSR-88D RADAR EARLIER INDICATED PEAKWINDS OF ABOUT 75 KT AT 4000 FT. THESE DATA SUGGEST THE LANDFALLINTENSITY WAS ABOUT 55 KT. SINCE LANDFALL…THE VELOCITIES FROM THEBROWNSVILLE RADAR HAVE DECREASED…AND THE INITIAL WIND SPEED ISLOWERED TO 50 KT. AS HERMINE WEAKENS…THE BIGGEST THREAT WILLSHIFT TO FLASH FLOODING FROM HEAVY RAINS AS THE CYCLONE MOVES INTO TEXAS.

THE INITIAL MOTION IS 330/12. THERE IS NO CHANGE TO THE FORECASTREASONING FROM THE PREVIOUS PACKAGE. HERMINE SHOULD MOVENORTH-NORTHWESTWARD AND THEN NORTHWARD AROUND THE WESTERN PERIPHERYOF A RIDGE OVER THE SOUTHEASTERN UNITED STATES FOR THE NEXT DAY ORSO. THEREAFTER…THE REMNANTS OF HERMINE WILL LIKELY TURN TOWARDTHE NORTHEAST AND EAST OVER THE CENTRAL UNITED STATES IN A COUPLEOF DAYS AS THE CYCLONE RIDES AROUND THE NORTHERN SIDE OF THATRIDGE. THE NHC FORECAST IS SHIFTED SLIGHTLY TO THE EAST IN GOODAGREEMENT WITH THE GFS AND ECMWF MODELS.


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!