The North Atlantic Hurricane Season officially ends today.
There were thirteen named storms, but only two hurricanes this year in the Atlantic.
Most interestingly, for the first time since 1994, there were no major hurricanes. There have only been 33 such seasons since 1851.
The Accumulated Cyclone Energy index (ACE) is a measurement of the wind energy over the lifetime of a tropical cyclone, measured in 6 hour increments. The 2013 North Atlantic Hurricane Season will go down as the 14th slowest since 1851 with an ACE of 30. It is the slowest ACE value since 1983, when a 17 was posted.
Here is a quick rundown of this season’s named storms:
Tropical Storm Andrea:
The only U.S. landfalling storm of 2013 brought heavy rain to the Florida Panhandle on June 6th. Andrea formed from a low pressure system in the Gulf of Mexico on June 5th. It strengthened to a 65 mph tropical storm with a central pressure of 992 mb just before landfall near Steinhatchee, Florida. Its biggest impact was rainfall of 3-5 inches from Florida to New England. A storm surge of 4.55 feet was observed at Cedar Key, Florida.
Tropical Storm Barry:
A tropical depression formed over the southwestern Caribbean on June 17th, made landfall in Belize, crossed the Yucatan, became a tropical storm over the southwestern Gulf of Mexico and made landfall in the Mexican state of Veracruz early on the 20th.
Tropical Storm Chantal:
Crossed Lesser Antilles as tropical storm on July 9th, but dissipated over the eastern Caribbean.
Tropical Storm Dorian:
Formed and weakened over the open Atlantic, but redeveloped near the Bahamas
Tropical Storm Erin:
Cape Verde storm that curved north prematurely and dissipated
Tropical Storm Fernand:
Formed over the SW Caribbean and moved inland in Mexico a short time later.
Tropical Storm Gabrielle:
Short-lived, weak tropical storm that formed and dissipated in the Caribbean Sea south of Puerto Rico, but reformed close to Bermuda.
Another Cape Verde storm for the fishes that had a split life.
Another Bay of Campeche storm that impacted Mexico.
Tropical Storm Jerry:
Formed and dissipated over the open Atlantic.
Tropical Storm Karen:
Threatened the northern Gulf Coast, but fizzled just before landfall.
Tropical Storm Lorenzo:
Another storm for the fishes over the open Atlantic.
Tropical Storm Melissa:
Named as a subtropical storm over the open Atlantic that acquired tropical characteristics.
It is still officially hurricane season until the end of the month. Systems can still develop in the Atlantic basin and that has happened this morning. The NHC has started issuing advisories on newly formed Subtropical Storm Melissa in the central Atlantic. Melissa is out in the middle of no where and will not impact any land areas, but could affect some of the shipping lanes. No worries for Alabama of the U.S. mainland with this system as it will remain out over the open waters.
…SUBTROPICAL STORM MELISSA DEVELOPS OVER THE CENTRAL ATLANTIC…
SUMMARY OF 1100 AM EDT…1500 UTC…INFORMATION
ABOUT 695 MI…1120 KM ESE OF BERMUDA
MAXIMUM SUSTAINED WINDS…50 MPH…85 KM/H
PRESENT MOVEMENT…NW OR 320 DEGREES AT 9 MPH…15 KM/H
MINIMUM CENTRAL PRESSURE…987 MB…29.15 INCHES
An interesting image created by our friends at the Cooperate Institute of Meteorological Satellite Studies in Madison, Wisconsin. The have superimposed Super Typhoon Haiyan into the Gulf of Mexico at the same location as Hurricane Katrina. Haiyan is on the left and Katrina is on the right.
A neat comparison of the two showing their similarities and differences. In the image, Katrina appears to be the better organized system with a very large eye, while Haiyan appears to be more compact with the smaller eye. Both systems are at a category 5 intensity right before landfall. Luckily for the Gulf Coast Katrina weakened before moving onshore. Not such great news for the Philippines as Haiyan maintained intensity at landfall. Both systems were responsible for widespread destruction and great loss of life.
Those in the Philippines call this historic storm “Yolanda”… here is a short Instagram video from Tacloban City, Philippines @macmalz.
Scroll down for more on this big storm…
This close-up of Super Typhoon Haiyan shows structural features rarely seen in such powerful storms. Because of the time difference these images are delayed a day, but these features continue to show up on other current satellite products. Haiyan is a very well organized system and it is amazing to be able to look down into this very powerful storm. From up above we can see down into the eye and we have a clear view down to the ocean’s surface. Within the eye, small vortices are rotating around a seemingly calm center and these small vortices are mini areas of circulation within the broader center of circulation.
Another beautiful feature with this storm are the towering thunderstorms that look like bubbling mud or the tops of cauliflower, especially in the outer bands. These overshooting tops are allowing for shadows to be cast in certain areas of the storm, which enhances their texture and causes them to stand out even more. As the sun sets towards the end of the animation, you will notice the sun still hitting the top of the eastern eyewall, showing just how tall the storms are at the center of circulation.
This is very dangerous storm with sustained winds of 195 mph with gust over 235 mph. Haiyan continues to move towards the west-northwest and will be crossing and likely devastating portions of the Philippines over the next 24 hours.
The weather story of the week and perhaps the year is Super Typhoon Haiyan. Haiyan is a very powerful super typhoon that will be impacting the island nation of the Philippines. Typhoons are notorious for being the strongest storm systems on earth, and Haiyan is no exception. Haiyan is the equivalent of a category 5 hurricane with maximum sustained winds of 190 mph with gust to over 230 mph. This is truly a monster and a very dangerous storm.
Haiyan is a very organized system as it has the classic buzz saw look of a very powerful tropical system. This system will move through the Philippines and will bring widespread destruction and likely loss of life. It will cross some heavily populated islands, but as of now, it looks as though the worst of the storm will miss the capital of Manila, which is the population center. The system will remain a very strong system as it continues to the west-northwest towards Vietnam.
Even though the Atlantic Basin is very quiet, that is not the case in the western Pacific. There are several tropical systems in the region, but the main storm that has everyone’s attention is Francisco. Francisco is a super typhoon which is the equivalent of a category 5 hurricane in the Atlantic. Sustained winds in Francisco are 160 mph with gust to 195 mph. This is a dangerous storm and very healthy looking as it has the classic buzz saw look of a very symmetrical storm. Francisco is expected to maintain this intensity for the next day or so as it continues a northwest track towards Japan. The system is expected to begin to weaken as it moves over cooler waters, but just like Typhoon Phailin last week, it will likely cause problems for the Japanese mainland early next week.
At 08:01 GMT (3:01 a.m. CDT) on October 19, 2005, Air Force Hurricane Hunters measured a central pressure of 884 millibars in Hurricane Wilma while it was over the western Caribbean.
Here is the vortex data message from the plane that early morning:
URNT12 KNHC 190835
VORTEX DATA MESSAGE
B. 17 deg 03 min N
082 deg 20 min W
C. 700 mb 2082 m
D. NA kt
E. NA deg nm
F. 320 deg 166 kt
G. 221 deg 003 nm
H. 884 mb
I. 10 C/ 3073 m
J. 24 C/ 3043 m
K. 10 C/ NA
N. 12345/ 7
O. 0.02 / 1 nm
P. AF308 0724A WILMA OB 16
MAX FL WIND 168 KT SE QUAD 06:10:20 Z
But the surface pressure when the dropsonde hit the ocean was still 23 knots, and meteorologists know that the device did not find the true center. So, the observation was adjusted to 882 millibars, which is the lowest barometric reading ever observed in an Atlantic Hurricane. Since the hurricane was intensifying at the time, it is likely that the pressure was even lower.
The record low pressure was measured at the end of a period of amazing strengthening that is also a record as the pressure dropped 97 millibars in 24 hours!
The eye of shrunk to an amazing 2.3 miles in diameter, also a record for any Atlantic tropical cyclone.
Top winds at the time were 185 mph. Just 24 hours before, the winds had been 70 mph.
Wilma would strike the Yucatan Peninsula on the 20th and 21st and become the worst disaster in the history of Mexico. Damages totaled $3 billion.
The storm weakened, but regained category Three status in the Gulf before striking southern Florida on the 24th. U.S. damages totaled $20.4 billion.
A total of 62 people were killed by the storm.
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