Caribbean disturbance slow to develop; 5 EF-5 tornadoes this year confirmed
The tropical disturbance (Invest 93L) that crossed over Florida on Wednesday, bringing welcome rains of 1 - 3 inches, is now a naked swirl of low clouds over the central Gulf of Mexico. The disturbance is embedded in a large area of dry air associated with an upper level low pressure system, and this dry air is discouraging development. 93L is also moving into a region of moderate wind shear of 10 - 20 knots, and NHC is giving 93L a 0% chance of developing into a tropical depression before the storm makes landfall in Mexico south of Brownsville on Saturday. There are a few heavy thunderstorms trying to fire up near the center of 93L's fairly well-formed circulation, but I don't think this storm is going to bring more than 1 - 2 inches of rain to the coast on Saturday.

Figure 1. Morning satellite image of the Central Caribbean disturbance.
Central Caribbean disturbance 94L
Disorganized heavy thunderstorm activity continues in the region between Central America and Jamaica. Wind shear has fallen to the moderate range, 10 - 20 knots, and is predicted to continue to fall over the next two days. This should allow the disturbance, dubbed Invest 94L by NHC on Friday afternoon, to increase in organization, though it will take many days for it to approach tropical depression status, since it is so large and poorly organized. The last two runs of the NOGAPS model have developed the disturbance into a tropical depression or storm by early next week, with the system moving northwards into Jamaica, the Cayman Islands, and eastern Cuba. The other major models do not show the disturbance developing during the coming week. NHC is giving the disturbance a 10% of developing into a tropical depression by Sunday. A surge of moisture accompanying a tropical wave may aid development when the wave arrives in the Western Caribbean on Sunday. Water temperatures in the Central Caribbean are about 1°C above average, 29°C, which is plenty warm enough to support development of a tropical storm. Residents of Jamaica, eastern Cuba, the Cayman Islands, Haiti, and the Dominican Republic should anticipate the possibility that heavy rains of 2 - 4 inches may affect them today through Sunday.
Five EF-5 tornadoes confirmed in 2011
The National Weather Service in Oklahoma City announced Wednesday that the violent tornado that hit Binger, El Reno, Peidmont, and Guthrie, Oklahoma on May 24, killing nine people, was an EF-5 with winds greater than 210 mph. The rating was given based on measurements made by a University of Oklahoma portable "Doppler on wheels" radar. The long track, large wedge tornado caused extensive damage, with well built houses cleanly swept from their foundation and trees debarked. This tornado brings the total number of EF-5 tornadoes this year to five, tying 2011 with 1953 for 2nd place for greatest number of these top-end tornadoes in one year. Only 1974 (six) had more. The EF-5 tornadoes of 2011:
1) The April 27, 2011 Neshoba/Kemper/Winston/Noxubee Counties, Mississippi tornado (3 killed, 29 mile path length.)
2) The April 27, 2011 Smithville, Mississippi tornado (22 killed, 15 mile path length.)
3) The April 27, 2011 Hackleburg, Alabama tornado (71 killed, 25 mile path length.)
4) The May 22, 2011 Joplin Missouri tornado (138 killed, 14 mile path length.)
5) The May 24, 2011 Binger-El Reno-Peidmont-Guthrie, Oklahoma tornado. (9 killed, 75 mile path length.)

Figure 2. Aerial view of damage from the May 22, 2011 Joplin, Missouri tornado. Image credit: Wikipedia.
A few other remarkable statistics on the tornado season of 2011, compiled from NOAA's official press release and Wikipedia's excellent tornado pages:
- The April 25 - 28 tornado outbreak, with 330 tornadoes, was the largest tornado outbreak of three days or less duration on record. The previous record was 148 tornadoes, set during the April 3 - 4, 1974 Super Outbreak.
- For April 27, 186 tornadoes have been confirmed. This is the largest 1-day tornado total on record, beating the 148 recorded in 24 hours on April 3 - 4, 1974.
- The April 14 - 16 tornado outbreak, with 162 confirmed tornadoes, ranks as the fourth largest tornado outbreak of three days or less duration on record.
- The May 21 - 26 tornado outbreak, with 158 confirmed tornadoes, ranks as the 5th largest 6-day or shorter tornado outbreak on record. A May 2003 6-day outbreak had 289 tornadoes, and a May 2004 6-day outbreak had 229 tornadoes. The year 2011 now has three of the top five tornado outbreaks on record.
- April confirmed tornado total was 683, making it the busiest tornado month on record. The previous record was 542 tornadoes, set in May 2003. The previous April record was 267 tornadoes, which occurred in April 1974. The 30-year average for April tornadoes is 135.
- If the three deaths in Massachusetts from Wednesday's tornadoes are confirmed, this year's tornado death toll will be 522, beating 1953 as the deadliest tornado year since modern tornado records began. That year, 519 people died, and three heavily populated cities received direct hits by violent tornadoes. Waco, Texas (114 killed), Flint, Michigan (115 killed), and Worcester, Massachusetts (90 killed) all were hit by violent F-4 or F-5 tornadoes. A similar bad tornado year occurred in 1936, when violent tornadoes hit Tupelo Mississippi (216 killed), and Gainesville, Georgia (203 killed.) During that time period, the tornado death rate per million people was 60 - 70 times as great as in the year 2000 (Figure 4), implying that this year's tornadoes would have killed many thousands of people had we not had our modern tornado modern warning system.
- The May 22, 2011 Joplin, Missouri tornado killed 138 people and injured 1150, making it the deadliest U.S. tornado since 1947, and 8th deadliest in history. The $1 - $3 billion estimate of insured damage makes it the most expensive tornado in history.
- Damage from the April 25 - 28 super tornado outbreak was estimated at $3.5 - $6 billion, making it the most expensive tornado outbreak of all-time.
- The tornado that hit Springfield, Massachusetts on June 1 was at least an EF-3 with 136 - 165 mph winds. It was only the 9th EF-3 or stronger tornado to hit Massachusetts since 1950, and the third deadliest, with three deaths.
- The year 2011 now ranks in 3rd place behind 1974 and 1965 for highest number of strong to violent EF-3, EF-4, and EF-5 tornadoes (Figure 3.)

Figure 3. Number of strong to violent EF-3, EF-4 and EF-5 tornadoes from 1950 to 2011. The year 2011 now ranks in 3rd place behind 1974 and 1965. There is not a decades-long increasing trend in the numbers of these most dangerous of tornadoes. Image credit: NOAA/National Climatic Data Center (updated using stats for 2008 - 2011 from Wikipedia.)

Figure 4. Death rate per million people per year in U.S., 1875-2000. Thin line with dots is raw rate, curved thick line is death rate, filtered by 3-point median and 5-point running mean filter, and straight solid lines are least squares fit to filtered death rate for 1875-1925 and 1925-2000. Dashed lines are estimates of 10th and 90th percentile death rates from 1925-2000. The death rate fell from 8 per million to .12 per million between 1940 and 2000. Image credit: A Brief History of Deaths from Tornadoes in the United States, Harold Brooks and Charles Doswell III.
Joplin tornado the 7th U.S. billion-dollar weather disaster of 2011
The Joplin tornado is the 7th U.S. weather disaster of 2011 costing more than a billion dollars. With a major flooding disaster coming on the Missouri River, and hurricane season still to come, 2011 has an excellent chance of beating 2008's record of nine billion-dollar weather disasters. The billion dollar weather disasters of 2011 so far:
1) 2011 Groundhog Day's blizzard ($1- $4 billion)
2) April 3 -5 Southeast U.S. severe weather outbreak ($2 billion)
3) April 8 - 11 severe weather outbreak ($2.25 billion)
4) April 25 - 28 super tornado outbreak ($3.5 - $6 billion)
5) Mississippi River flood of 2011 ($9 billion)
6) Texas drought ($1.2 billion)
7) Joplin tornado ($1 - $3 billion)

Figure 5. River flood outlook for the U.S. Image credit: NOAA.
The next U.S. billion-dollar weather disaster: a Missouri River flood?
A great 100-year flood has arrived along the Missouri River and its tributaries from Montana to Nebraska. Record spring rains, combined with snow melt from record or near-record winter and spring snows, brought the Missouri River at Williston, North Dakota to 27.9' yesterday, just an inch short of the highest crest on record (28.0' on 4/01/1912.) Tributaries to the Missouri, such as the Souris River in North Dakota and the North Platte River in Nebraska, are already flooding at all-time record heights. With warm summer temperatures and additional rainfall expected over much of the area during the coming week, snow melt and rain runoff will swell area rivers even further, creating a damaging 100-year flood. Wunderground weather historian Christopher C. Burt has the details in his latest post, and I will be writing more on this latest epic flood next week.
I'll have a new post on Monday, or earlier if the Caribbean disturbance shows significant development.
Jeff Masters
Here it is turning into a monster.
Reader Comments
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 | 66 | 67 | 68 | 69 | 70 | 71 | 72 | 73 | 74 | 75 — Blog Index
i was posting raw footage of monstrous joplin tornado
But mother nature has way's of making man look foolish
"Sneaky she can be"
empty space created
thats enough of that
As we march through June, climatologically the TUTT starts developing in the central Atlantic during this month. Its signature in the 200mb height field is quite distinguished on average during the June 10-30th period. The latest runs of the GFS ensembles are also showing what appears to be a TUTT developing in the western Atlantic and reaching down into the eastern Caribbean. (see first two images below)
With the above-average amount of heat in the western Caribbean, Gulf of Mexico, and SW Atlantic Basin, these regions are prone to upper ridging developing aloft, west of the TUTT. Such ridges can provide very favorable conditions for monsoonal tropical development, provided that central America doesn't get in the way. We saw this with Hurricane Alex in June of 2010. The same pattern is observable during the typhoon season in the western and central Pacific (see the last image below). An upper ridge develops west of the TUTT over the western Pacific warm pool. This sets up a strong equatorward outflow channel from northeast to southwest, a signature characteristic of monsoonal depressions. The same setup can occur in the Atlantic over the west hemisphere warm pool, allowing the monsoon trough to spawn the same type of systems in the western Caribbean or the Gulf of Mexico. Again, Hurricane Alex last year was the text-book example of this.
Atlantic June 10-30 Climatological Average 200mb Heights:
GFS Ensemble Average 250mb Winds Day 15:
Pacific June-September Climatological Average 200mb Heights:
Kinda like an old tractor, can be hard to get started but once you get it running it'll run forever.
Agreed. I never had confidence that it would develop. I wouldn't be surprised to see it open up into a trough of low pressure.
Why is this set up so favorable for monsoonal lows? What does this mean for tropical waves coming off of Africa? Does this mean anything for the Azores high or NAO? What exactly causes this set up? And finally, what does this set up look like on a satellite image?
Sorry for so many questions, please understand I am only curious and wishing to learn
It was a joke, because he made a good call earlier on saying it would weaken.
Agreed, we can kiss the old COC goodbye.
It's Dmin that is inhibiting it, hasn't shown signs of it dying, just weakening.
Not again....
Don't look to me for instructions though. Some times I can get it to work, sometimes I clog up the blog mostly I just get frustrated. Why I mostly stick to links.
Impressive Low...
Great, more destruction, more loss of lives, more like the Tuscaloosa and Joplin tornadoes...
Remember how long Hurricane Alex took to get itself organized last year. This will be similar.
Not in anyones mind to go through that nightmare again... Anyhow, prevention is the best action for now...
Evening Aussie. Or for you, morning!
Good point there, most people gave up hope on 93L (pre Alex) because it took so long to develop and kept fluctuating in organization and also the organization of the COC changed a lot. Plus it formed under similar conditions, it was under a monsoonal trough or whatever you call it.
We can only take what we learned from the previous tornado outbreak and apply it to the next one...
HRWF model takes it into the hot GOM as a moderate TS, not good, it can explode in an instant!
Still morning just. 11:45am. the cloud from overnight has cleared and there is a full blanket of blue sky above.
Parramatta, Sydney, Australia
Now
60.4°F rising
Clear
Updated at 11:40 EST
ELT, EPIRB or PLB
COSPAS-SARSAT Rescues as of: May 27, 2011
Number of People Rescued (in 2011) in the United States: 88
Rescues at sea: 42 people rescued in 13 incidents
Aviation rescues: 9 people rescued in 4 incidents
Terrestrial PLB rescues: 37 people rescued in 20 incidents
Worldwide – Over 28,000+ People Rescued (since 1982)
United States – 6,617 People Rescued (since 1982)
Total Rescues in 2010: 295
Link
May want to double check that. The HWRF has continually sent the system northeast and across Hispanola out to sea as a minimal hurricane. Its the GFDL that sends the system into the GOM as a weak to at best moderate tropical storm.
Hopefully levi will respond.
This is nothing - wait till we get later in the season and especially when we get a TS/cane. It's like Bourbon on Mardi Gras - you just let the blog crowd carry you if you pick your feet up.
Harold Camping may be wrong about the date, but he is certainly not wrong about the events that would take place. LOL
It is favorable for them because it is the upper pattern that Pacific monsoonal systems exhibit. When the monsoon trough is allowed to lift north into the Caribbean in full glory, an upper ridge is usually situated over or just north of it, and the result is a strong equatorward channel that is not always observed in the Caribbean unless a strong hurricane enters the region.
Regarding tropical waves, they leave Africa within the African monsoonal circulation, which has some similar properties, but is centered over land as opposed to over a warm water pool. Conditions in the Caribbean don't have any direct baring on tropical waves and Africa.
The NAO is not directly affected by the monsoonal circulation in the Caribbean.
This setup can happen in any season, but it is aided by a warmer than normal western hemisphere warm pool (Caribbean/GOM), and a favorable ENSO pattern (neutral/La Nina).
As for what this setup looks like on a satellite image, what better example than Hurricane Alex last year. This was one of the best examples of an upper-level high pressure system centered over an Atlantic tropical cyclone that I had ever seen:
Notice the strong northeasterly upper winds everywhere south of 15N, a very well-defined equatorward outflow channel.
I remember being very frustrated that I couldn't explain his lack of development for days and days. Then all of a suddenly - bam, off he went.
Thx
Interesting system in the WPAC.
The TUTT is usually identifiable as a positively-tilted trough (oriented southwest to northeast) at the 200mb level, extending across the subtropical Atlantic, and sometimes the tropical Atlantic as well. The wind flow around it would be similar to any other kind of upper trough. Winds on the west side will be out of the north or northwest, curving around the axis of the trough and coming up out of the southwest on the eastern side of the trough.
Here is an example from today's GFS 200mb 15-day forecast, which is showing the development of the first real TUTT of this season:
Whoops, I keep getting those 2 models mixed up. Grrrr. Gotta work on model memory. LOL
I wish that big alien fly would move out of the way.
Viewing: 2851 - 2901
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 | 66 | 67 | 68 | 69 | 70 | 71 | 72 | 73 | 74 | 75 — Blog Index