Karl hits the Yucatan; two simultaneous Cat 4s in the Atlantic for 2nd time in history

By: Dr. Jeff Masters , 2:37 PM GMT on September 15, 2010

Share this Blog
5
+

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.)


Figure 1. A rare double feature: two simultaneous Category 4 hurricanes in the Atlantic, for only the second time in recorded history.

Karl
Tropical Storm Karl made landfall as a strong tropical storm with 65 mph winds and a central pressure of 991 mb at 8:45am EDT this morning on Mexico's Yucatan Peninsula, just north of the Belize border. Karl took advantage of nearly ideal conditions for intensification, and in just fifteen hours intensified from a tropical disturbance to a strong tropical storm with 65 mph winds. Had Karl managed to get its act together just one day earlier, it could have been a major hurricane at landfall this morning. Fortunately, Karl has a relatively small area of strong winds--tropical storm force winds extend out just 45 miles from the center of the storm, and wind damage is not the main concern. Heavy rains are the main concern, and Belize radar shows heavy rain bands from Karl spreading ashore over northern Belize near the border with Mexico. Cancun radar shows that heavy rains are relatively limited, though, near the tourist havens of Cancun and Cozumel.


Figure 2. Radar image of Karl at landfall this morning near the northern Belize/Mexican border. Image credit: Belize National Meteorological Service.

Forecast for Karl
Karl will traverse the Yucatan Peninsula today and emerge into the Gulf of Mexico's Bay of Campeche Thursday morning as a much weakened tropical storm, with perhaps 40 - 45 mph top winds. Once in the Gulf, conditions for intensification are ideal, with wind shear is expected to be low, 5 - 10 knots, SSTs will be warm, 29°C - 30°C, and the atmosphere very moist. These conditions, combined with the topography of the surrounding coast which tends to enhance counter-clockwise flow, should allow Karl to intensify into a strong tropical storm or a Category 1 hurricane before making landfall between Tampico and Vercruz, Mexico on Saturday morning. However, since Karl is a small storm, it is possible that passage over the Yucatan will disrupt the storm enough so that it will be much weaker. The ridge of high pressure steering Karl westwards is quite strong, and it is very unlikely that the storm will turn northwest and hit Texas. NHC is giving Brownsville, Texas, an 10% chance of receiving tropical storm force winds of 39+ mph.

Igor
Hurricane Igor put on a burst of intensification last night to put it at its strongest yet, a top-end Category 4 hurricane with 155 mph winds. Igor has weakened slightly this morning, but remains a formidable presence in the Central Atlantic with its 145 mph winds. Igor continues to show the classic appearance of a major hurricane on satellite imagery, with a well-formed eye, symmetrical cloud pattern, plenty of low-level spiral bands, and solid upper-level outflow on all sides.


Figure 3. Hurricane Igor as captured at 18 UTC Tuesday September 14, 2010, from the International Space Station. Image credit: Douglas Wheelock, NASA.

Intensity forecast for Igor
Wind shear is low, 5 - 10 knots, and is expected to remain low for the next 2 - 3 days. Waters are warm, 29°C, and will remain 29°C for the next 2 - 3 days. Igor is well armored against any intrusions of dry air for at least the next three days. These conditions should allow Igor to remain at major hurricane status for the next three days. The hurricane will probably undergo one of the usual eyewall replacement cycles intense hurricanes commonly have, where the eyewall collapses and a new eyewall forms from an outer spiral band. This will weaken the hurricane by 10 - 20 mph when it occurs, and may be responsible for the 10 mph weakening Igor experienced early this morning. Igor may regain its lost intensity over the next 36 hours. By Saturday morning, 36 hours before the core of Igor is expected to pass Bermuda's latitude, the trough of low pressure steering Igor northwestwards should bring moderate wind shear of 10 - 20 knots to the storm, weakening it. The SHIPS models predicts shear will rise to the high range, 20 - 30 knots, during the final 24 hours of the storm's approach to Bermuda. Igor will also be tracking over cooler 28°C waters during this period, and substantial weakening by perhaps 20 - 30 mph can be expected. Igor will still probably be at least a Category 2 hurricane on its closest pass by Bermuda on Sunday. NHC is giving Bermuda a 13% chance of experiencing hurricane force winds from Igor, but this probability is likely too low. The Bermuda Weather Service is calling for Category 1 or 2 hurricane conditions for the island on Sunday, with 20 - 25 foot waves in the offshore waters.

Track forecast for Igor
The track forecast for Igor remains unchanged. Igor has made its long-anticipated turn to the west-northwest, in response to the steering influence of a broad trough of low pressure moving across the Western Atlantic. This trough will steer Igor several hundred miles to the northeast of the Lesser Antilles, and high waves should be the only impact of Igor on the islands. Igor appears likely to be a threat to Bermuda, and that island can expect tropical storm force winds as early as Saturday. Igor will be moving at about 12 - 15 mph as it approaches Bermuda. Tropical storm force winds of 39+ mph will probably extend out about 250 miles to the north of Igor on Saturday, so Bermuda can expect 18 hours of tropical storm force winds before the core of Igor makes its closest pass. In all, Bermuda is likely to experience a very long pounding of 24 - 36 hours with winds in excess of tropical storm force.

The models have been in substantial agreement over multiple runs that Igor will miss the U.S. East Coast, and the danger to the U.S. will probably only come in the form of high waves. Large swells from Igor have arrived in the Northern Lesser Antilles Islands, and will spread westwards over the next few days, reaching the U.S. East Coast on Friday. By Saturday, much of the East Coast from northern Florida to Cape Cod Massachusetts can expect waves of 3 - 4 meters (10 - 13 feet), causing dangerous rip currents and significant beach erosion. These waves will continue through Sunday then gradually die down. The latest NOAA marine forecast for Cape Hatteras, North Carolina calls for 8 - 10 foot waves on Saturday, and 9 - 12 foot waves on Sunday.

Igor may pass very close to Newfoundland, Canada, but it is too early too assess the likelihood of this happening.

Julia
Hurricane Julia put on a remarkable and unexpected burst of intensification this morning to become the season's fourth Category 4 storm. Julia's 135 mph winds make it the strongest hurricane on record so far east; the previous record was held by the eighth storm of 1926 which was only a 120 mph Category 3 hurricane at Julia's current longitude. Julia's intensification was a surprise, since SSTs in the region are about 27.5°C, which is just 1°C above the threshold needed to sustain a Category 1 hurricane. Julia is headed northwest, out to sea, and it is unlikely that this storm will trouble any land areas. SSTs will steadily cool to 26.5°C today, and further intensification today is unlikely. Shear will be moderate, 10 - 20 knots, over Julia during the next two days, then rise sharply to 30 knots 3 - 5 days from now, as Julia moves within 1000 miles of Igor and begins to experience strong northwesterly winds from her big brother's upper level outflow. This should substantially weaken Julia.

Elsewhere in the tropics
The GFS and ECMWF models develop a new tropical depression a few hundred miles off the coast of Africa 3 - 6 days from now. The GFS also develops a tropical depression in the eastern Caribbean 6 - 7 days from now.

Portlight's 2-year anniversary
On September 14, 2008, the devastation wrought by Hurricane Ike on Texas and Louisiana moved members of the wunderground community to put into action their own impromptu relief effort. From this humble beginning has grown a disaster-relief charity I have been proud to support--Portlight.org. We've been blessed this hurricane season with relatively few landfalling storms, so Portlight's new disaster relief trailer (Figure 4), financed with a $21,500 grant from the Christopher and Dana Reeve Foundation, has yet to be deployed. With five weeks of peak hurricane season still to come, the new trailer may yet get a call to action. The mobile kitchen in the trailer will be able to feed several hundred people per day, and the trailer is equipped with portable ramps to help with shelter accessibility, as well as durable medical equipment to facilitate mobility and independence for survivors. The trailer is mobile, and Portlight is willing to load it up and fly it to Bermuda, if Igor ends up making a mess there!

The lack of landfalling storms has allowed Portlight to continue to concentrate their efforts on Haiti, where their assistance has been a tremendous boost for those most in need, the disabled. Portlight is working on constructing steel shelters out of shipping containers for homeless Haitians, as detailed in the Haitian Relief Recap blog post. Please visit the Portlight.org web site or the Portlight blog to learn more and donate. A few other items of note:

Portlight has been able to facilitate providing assistance to people with disabilities in Pakistan, where the worst natural disaster in their history has left 4 million homeless. While not directly involved in delivering relief, Portlight has been able to connect local Disabled People's Organizations with important sources of food, water, filtration systems, and medical equipment.

ABC News4 in Charleston broadcast a story about the Portlight relief trailer, and Portlight has also been featured on the Pacifica Radio Network.

Portlight launched a quarterly newsletter, The Portlight View, which can be seen on the newly redesigned website.


Figure 4. The new Portlight disaster relief trailer, funded by their $21,500 grant from the Christopher and Dana Reeve foundation.

I'll have an update Thursday morning.

Jeff Masters

Reader Comments

Comments will take a few seconds to appear.

Post Your Comments

Please sign in to post comments.

or Join

Not only will you be able to leave comments on this blog, but you'll also have the ability to upload and share your photos in our Wunder Photos section.

Display: 0, 50, 100, 200 Sort: Newest First - Order Posted

Viewing: 1236 - 1186

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 | 41 | 42 | 43 | 44 | 45 | 46 | 47 | 48 | 49 | 50 | 51 | 52 | 53 | 54 | 55 | 56 | 57 | 58 | 59 | 60 | 61 | 62 | 63 | 64 | 65 | 66Blog Index

Thanks, Storm.

So one can sumize that the reduced signal beginning in Aug can be associated with La Niña gaining strength that month? Does that mean the MJO has reduced or that it's signature is being masked by the ENSO, and it is just as influential in the tropics as neutral years? I'm asking because there's a major shift in velocity potential and moisture coming in the next couple of weeks which happens to coincide with some models showing the GOM lighting up...
Member Since: Posts: Comments:
1235. marmark
Quoting Patrap:
Description of computer models

By Dr. Jeff Masters
Timely...thanks.
Member Since: Posts: Comments:
UKMET is definitely a conservative model, probably somewhat more conservative than the EURO. NOGAPS is actually somewhat of a conservative model also (for systems outside of the SW Caribbean). GFS varies.
Member Since: Posts: Comments:
Quoting Hurricanes101:
the UKMET is reliable?

Yea for downcasters LOL, considering that if it were up to the UKMET, we would only have about 8 storms every season because that is all it develops lol


We're a nation of downcasters, after all.
Member Since: Posts: Comments:
1232. xcool


Member Since: Posts: Comments:
1230. Patrap
Description of computer models

By Dr. Jeff Masters
Member Since: Posts: Comments:
Quoting Hurricanes101:
the UKMET is reliable?

Yea for downcasters LOL, considering that if it were up to the UKMET, we would only have about 8 storms every season because that is all it develops lol
LOL, it's a rare occasion that the UKMET develops a system...not saying it isn't reliable, it's just a rare thing.
Member Since: September 2, 2009 Posts: 130 Comments: 21194
1227. tkeith
Quoting Patrap:


See it here tkeith,

Northern Gulf of Mexico (Updated every ~10-15 mins)
yeah, he's got a long reach for a TS over land.
Member Since: November 1, 2004 Posts: 25 Comments: 8937
1226. scott39
Quoting MiamiHurricanes09:
Hyperactive seasons are categorized in ACE. A hyperactive season needs to have at least 153% of average of ACE. Currently, the 2010 season is rounded to 95% of average.

Season total ACE thus far

01L (Alex): 6.7825
03L (Bonnie): 0.3675
04L (Colin): 1.9450
06L (Danielle): 21.7950
07L (Earl): 27.7750
08L (Fiona): 2.9400
09L (Gaston): 0.3675
10L (Hermine): 1.2725
11L (Igor): 23.8525
12L (Julia): 6.9850
13L (Karl): 0.9950
-------------------------------------
Total: 95.0775
thanks
Member Since: Posts: Comments:
Quoting cat5hurricane:
Roger that. Hard to knock them at this stage of the game.


I've stopped knocking them since FLOYD.
Member Since: Posts: Comments:
the UKMET is reliable?

Yea for downcasters LOL, considering that if it were up to the UKMET, we would only have about 8 storms every season because that is all it develops lol
Member Since: Posts: Comments:
Anywhere from Florida to the Gulf of Mexico will likely be affected by a tropical cyclone over the next two weeks.

12Z CMC Ensemble Mean
Member Since: July 19, 2008 Posts: 43 Comments: 4051
1221. Patrap
Gulf and Tropics (Updated every ~1/2 hour)
Member Since: Posts: Comments:
I'm not so sure Karl weakens to a TD before moving over water. Looks to be maintaining itself well over land. Still well-organized.
Member Since: Posts: Comments:
1216. Patrap
Quoting tkeith:
looks like these clouds over us are movin with the bands from Karl.


See it here tkeith,

Northern Gulf of Mexico (Updated every ~10-15 mins)

Member Since: Posts: Comments:
Quoting scott39:
How many TCs does it take to have a hyperactive season?
wow.....that's a line crying out for an answer, but a tough nut to crack, eh Dewey? For me it is.
Member Since: Posts: Comments:
Or, you can do it via ACE.

A blend is probably best (As ACE can distort the overall picture a bit towards Cape Verde-hurricanes as opposed to actual numbers).
Member Since: Posts: Comments:
Quoting HurricaneGeek:


jajajaja. lol.
That's may 400 comment forecast. It's to be taken with a grin of salt. =)


A "grin" of salt.
indeeeed.
Member Since: Posts: Comments:
1210. Patrap
Outflow from Karl is Impressive


Member Since: Posts: Comments:
Lets see if Igor makes that NW turn.
Member Since: Posts: Comments:
1208. xcool


12z cmc Ensemble
Member Since: Posts: Comments:
1207. tkeith
Quoting Patrap:
Karl

Rainbow

looks like these clouds over us are movin with the bands from Karl.
Member Since: November 1, 2004 Posts: 25 Comments: 8937
Quoting IKE:


I know exactly how far it goes out and I know the GFS shows something there at 120 hours. The UKMET doesn't.

12Z GFS @ 120 hours...





UKMET simply just doesn't develop it at the 120 hour period. May not be til later on if it ends up showing development, but too soon to tell.
Member Since: Posts: Comments:
Quoting scott39:
How many TCs does it take to have a hyperactive season?
Hyperactive seasons are categorized in ACE. A hyperactive season needs to have at least 153% of average of ACE. Currently, the 2010 season is rounded to 95% of average.

Season total ACE thus far

01L (Alex): 6.7825
03L (Bonnie): 0.3675
04L (Colin): 1.9450
06L (Danielle): 21.7950
07L (Earl): 27.7750
08L (Fiona): 2.9400
09L (Gaston): 0.3675
10L (Hermine): 1.2725
11L (Igor): 23.8525
12L (Julia): 6.9850
13L (Karl): 0.9950
-------------------------------------
Total: 95.0775
Member Since: September 2, 2009 Posts: 130 Comments: 21194
1203. BDAwx
I was certain that a hyper-active season was defined by an ACE value greater than 153, not by how many storms formed.
Member Since: Posts: Comments:
Quoting weathermancer:


"1559" - wow - you have forecasting abilities.
lol.


jajajaja. lol.
That's may 400 comment forecast. It's to be taken with a grin of salt. =)
Member Since: Posts: Comments:
Link
I'd say despite moving farther west than anticipated , Igor has stayed within in the cone of uncertainity and that is what counts, Its really hard to do any better than that, great job NHC.
Member Since: Posts: Comments:
1199. IKE
Quoting OctoberToRemember:


The UKMET is not a long range model; therefore, that would be expected, now wouldn't it?


The UKMET is a reliable model.
Member Since: Posts: Comments:
1197. Patrap
Member Since: Posts: Comments:
1196. IKE
Quoting MiamiHurricanes09:
Only goes out to 120 hours. The system doesn't materialize until 144+ hours on the models that develop it.


I know exactly how far it goes out and I know the GFS shows something there at 120 hours. The UKMET doesn't.

12Z GFS @ 120 hours...



Member Since: Posts: Comments:
Quoting MiamiHurricanes09:
Only goes out to 120 hours. The system doesn't materialize until 144+ hours on the models that develop it.


GFS tries to organize it a bit sooner, but yeah most of it happens 144+ hours out. However as the NWS in PR said, the models have a bit of a slow bias on developing storms.
Member Since: Posts: Comments:
Quoting HurricaneGeek:


I think 20 and up.
But I am not 100% sure. It could be 18 and up.


But for the C. PAC., it would be like 5. LOL.
Member Since: Posts: Comments:
Quoting scott39:
How many TCs does it take to have a hyperactive season?


Depends if you believe the 10-6-2 average or not. (As a way of measuring what has happened before based on what we know, fine. As a figure to detail actual reality, adjusted and otherwise, I don't believe it as it is).

Hyperactive, as said in the Doc's hurricane haven, is an extra 50% on top of the average. So, that'd be 15 storms. (15-9-3, roughly).
Member Since: Posts: Comments:
1191. Ldog74
Quoting jdj32:
I have been lurking for a few years, but I rarely post. I have a question. Does anyone know how accurate Doppler Radar is in accurately determining the strength of a Hurricane? Have their been any HH Recon Missions that have found Pressure and Winds that were either much higher, or lower than Dopper Radar was indicating at the time of the HH Recon. I only ask because we are getting fixed numbers for Hurricane Igor (based on radar estimates), but I know that a Hurricane such as Igor is continually fluctuating. Any answers would be appreciated. Thanks in advance. Jeff


I can think of one instance off the top of my head, but it is probably not going to play a factor in the immediate future. The satellite intensity estimates for Wilma were never all that impressive. Keep in mind were comparing "impressive" with the strongest known storm in the Atlantic ever. This was due to two factors. One, the satellite pictures of Wilma were not as pretty as say, Rita, or Gilbert. Two, the pinhole eye of Wilma was so small that satellites could not get an accurate eye temp reading, so the wind estimates were deflated. One pixel on the satellite was larger than the eye itself if i remember correctly. However, the Hurricane Hunters in that instance were unable to locate the true center with a dropsonde either.

An opposite example can be Cyclone Monica in the South Pacific. Intensity estimates based on satellite pictures were as low as 858 if i remember correctly (in other words, a pure 8.0 on Dvorak), and yet officially the storm never dropped below 900 MB in pressure.
Member Since: Posts: Comments:
Quoting scott39:
How many TCs does it take to have a hyperactive season?


I think 20 and up.
But I am not 100% sure. It could be 18 and up.
Member Since: Posts: Comments:
Quoting Cotillion:


Correct. I think in a single day Dog has the lead in most ACE (6th September, 1950; 10.0825), though the most ACE in a 24 hour period by one storm alone was Camille in 1969.


OK thanks.
Bueno, ACE only takes into account the windspeed?
Member Since: Posts: Comments:
1187. scott39
How many TCs does it take to have a hyperactive season?
Member Since: Posts: Comments:

Viewing: 1236 - 1186

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 | 41 | 42 | 43 | 44 | 45 | 46 | 47 | 48 | 49 | 50 | 51 | 52 | 53 | 54 | 55 | 56 | 57 | 58 | 59 | 60 | 61 | 62 | 63 | 64 | 65 | 66Blog Index

Top of Page

About

Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.

Local Weather

Overcast
28 °F
Overcast