An early start to hurricane season? And, tornado kills 3 in Missouri
The 2009 Atlantic hurricane season may get off to an early start. For the past two days, most of our reliable hurricane forecast models have been predicting the possibility of a subtropical depression forming near Florida or Western Cuba Monday - Thursday next week. An area of disturbed weather associated with a mid- to upper-level trough of low pressure near eastern Cuba and the southeastern Bahama Islands is predicted to slide west-northwest over the next few days. Wind shear over this low, current a prohibitively high 40 knots, is expected to relax to just 10 knots by Monday in the region surrounding Florida. This may allow a disturbance with a surface warm core to develop, according to phase space analyses from Florida State. However, since the upper atmosphere will still be cold, any development of this system will likely be subtropical in nature. If a subtropical storm does form, it may be fairly dry, like Subtropical Storm Andrea of May 2007. This storm ended up fanning fires in Florida, instead of putting them out. Water vapor loops show plenty of dry, continental air in the region, and it will take many days for the atmosphere to moisten enough to support formation of a subtropical depression.
Figure 1. Water vapor image showing moisture from a weak mid- to upper-level low of low pressure over the southeastern Bahama Islands, surrounded by a large area of dry air, and sandwiched between the polar and subtropical jet stream. Image credit: NOAA/SSD.
The GFS and NOGAPS models predict a subtropical depression could form by Tuesday, while the ECMWF shows development later in the week. The latest UKMET model forecast puts development Wednesday or Thursday near Haiti. The area of predicted development is sandwiched in a relatively narrow band of low wind shear between two branches of the jet stream. This is not a typical set-up for formation of a May tropical cyclone. With so much shear and dry air around, I put the probability of a subtropical depression forming next week at about 10%. Any developing system will also have to contend with the arrival Tuesday of a strong upper-level low pressure system that is expected to drop down over the northern Gulf of Mexico. The eventual track of any depression that forms is highly uncertain, and the models support tracks up the U.S. East Coast towards South Carolina, or up the west coast of Florida in the Gulf of Mexico.
Season's first tropical wave arrives
The season's first tropical wave rolled off the coast of Africa yesterday, and is now located near 10N 20W, a few hundred miles off the coast of Africa, according to total precipitable water loops. Mid-May is a fairly typical time for these waves to begin moving across the Atlantic, though they usually don't start developing into tropical depressions until August. Last year was an exception, when Hurricane Bertha formed from a July tropical wave. Wunderground blogger Weather456 has been tracking the date of the first African wave each year since 2004, and these dates have ranged from May 2 to May 21. With Sea Surface Temperatures near average this year in the tropical Atlantic, an early season major hurricane in the eastern Atlantic like Bertha is unlikely.
Figure 2. The line of severe thunderstorms that spawned the Kirksville, MO tornado.
A wild night in Tornado Alley
Northern Missouri took a hard hit by a powerful tornado last night, when a twister passed through Kirksville, killing three people. The tornado flipped cars and damaged 30 - 40 buildings as it tore through the north end of town. The Storm Prediction Center recorded 23 tornado reports across Missouri, Illinois, Oklahoma, and Kansas yesterday.
The Vortex2 field study, the world's largest-ever tornado research project, caught last night's tornado outbreak with its armada of 40 research vehicles and radars. You can read about yesterday's chase on our new featured Vortex2 blog. Our team of University of Michigan students caught some severe thunderstorms, but were forced by darkness to quit before the storms spawned tornadoes.
Portlight/wunderground shirts for sale
The portlight.org disaster relief charity is selling spiffy new shirts sporting the portlight and wunderground logos, to help raise funds for relief operations during the coming hurricane season. I expect that their services will be needed this year, and I encourage you to shell out the $20 to get this fine piece or wunderwear.
I'll have an update on the tropics Friday.
Jeff Masters
Most of the V2 convoy waited in Canton, OK for initiation.
Reader Comments
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Me?
All I did is ask him not to get in the middle of the situation and not to tell me when I will get banned. He decided to make a comment calling me a dick..So now he's on my ignore list. I need to get to bed though..your right though the blog doesent need this unneccessary drama..and I'm done with it all..Be back tomorrow :) bye all.
I TOLD YOU DON'T GET SUCKED IN
No, CaneAddict.
Hope the temperatures here on WU cool down, or its going to be a long hot tempered season!
Chill
and
Peace!
I must attest, I have been amazed at the amount of posts related to a non related subject matter of a who.
Get over it folks, you waste our time with your fictional controversy and posts of a non issue.
If you don't like it, ignore it and don't burden the rest of us with having to see your obvious problems that go beyond the item at hand.
As was said prior, if you want to deliberate someones being, do it via chat or email.
Stop wasting post space on the subject.
You look foolish doing so.
Yep, I said it and many others think it.
OK, soap box down for maintenance again. Think before you post.
Oh - I should've come up with a more unique name...there are way too many "cane" names on here.
The Saffir-Simpson Hurricane Wind Scale is a 1 to 5 categorization based on the hurricane's intensity at the indicated time. The scale provides examples of the type of damages and impacts in the United States associated with winds of the indicated intensity. In general, damages rise by about a factor of four for every category increase. The maximum sustained surface wind speed (peak 1-minute wind at 10 m [33 ft]) is the determining factor in the scale. The historical examples (one for the U.S. Gulf Coast and one for the U.S. Atlantic Coast) provided in each of the categories correspond with the intensity of the hurricane at the time of landfall in the location experiencing the strongest winds, which does not necessarily correspond with the peak intensity reached by the system during its lifetime. The scale does not address the potential for such other hurricane-related impacts, as storm surge, rainfall-induced floods, and tornadoes. These wind-caused impacts are to apply to the worst winds reaching the coast and the damage would be less elsewhere. It should also be noted that the general wind-caused damage descriptions are to some degree dependent upon the local building codes in effect and how well and how long they have been enforced. For example, recently enacted building codes in Florida, North Carolina and South Carolina are likely to somewhat reduce the damage to newer structures from that described below. However, for a long time to come, the majority of the building stock in existence on the coast will not have been built to higher code. Hurricane wind damage is also dependent upon such other factors as duration of high winds, change of wind direction, amount of accompanying rainfall, and age of structures.
Earlier versions of this scale - known as the Saffir-Simpson Hurricane Scale - incorporated central pressure and storm surge as components of the categories. The central pressure was utilized during the 1970s and 1980s as a proxy for the winds as accurate wind speed intensity measurements from aircraft reconnaissance were not routinely available for hurricanes until 1990. Storm surge was also quantified by category in the earliest published versions of the scale dating back to 1972. However, hurricane size (extent of hurricane force winds), local bathymetry (depth of near-shore waters), and topographic forcing can also be important in forecasting storm surge. Moreover, other aspects of hurricanes - such as the system's forward speed and angle to the coast - also impact the storm surge that is produced. For example, the very large Hurricane Ike (with hurricane force winds extending as much as 125 mi from the center) in 2008 made landfall in Texas as a Category 2 hurricane and had peak storm surge values of 15-20 ft. In contrast, tiny Hurricane Charley (with hurricane force winds extending at most 25 mi from the center) struck Florida in 2004 as a Category 4 hurricane and produced a peak storm surge of only 6-7 ft. These storm surge values were substantially outside of the ranges suggested in the original scale. Thus to help reduce public confusion about the impacts associated with the various hurricane categories as well as to provide a more scientifically defensible scale, the storm surge ranges, flooding impact and central pressure statements are being removed from the scale and only peak winds are employed in this revised version - the Saffir-Simpson Hurricane Wind Scale.
Category One Hurricane:
Winds 74-95 mph (64-82 kt or 119-153 km/hr). Damaging winds are expected. Some damage to building structures could occur, primarily to unanchored mobile homes (mainly pre-1994 construction). Some damage is likely to poorly constructed signs. Loose outdoor items will become projectiles,. causing additional damage. Persons struck by windborne debris risk injury and possible death. Numerous large branches of healthy trees will snap. Some trees will be uprooted, especially where the ground is saturated. Many areas will experience power outages with some downed power poles. Hurricane Cindy (pdf) (2005, 75 mph winds at landfall in Louisiana) and Hurricane Gaston (2004, 75 mph winds at landfall in South Carolina) are examples of Category One hurricanes at landfall.
Category Two Hurricane:
Very strong winds will produce widespread damage. Some roofing material, door, and window damage of buildings will occur. Considerable damage to mobile homes (mainly pre-1994 construction) and poorly constructed signs is likely. A number of glass windows in high rise buildings will be dislodged and become airborne. Loose outdoor items will become projectiles, causing additional damage. Persons struck by windborne debris risk injury and possible death.. Numerous large branches will break. Many trees will be uprooted or snapped. Extensive damage to power lines and poles will likely result in widespread power outages that could last a few to several days. Hurricane Erin (1995, 100 mph at landfall in northwest Florida) and Hurricane Isabel (2003, 105 mph at landfall in North Carolina) are examples of Category Two hurricanes at landfall.
Category Three Hurricane:
Winds 111-130 mph (96-113 kt or 178-209 km/hr). Sustained winds 111-130 mph (96-113 kt or 178-209 km/hr). Dangerous winds will cause extensive damage. Some structural damage to houses and buildings will occur with a minor amount of wall failures. Mobile homes (mainly pre-1994 construction) and poorly constructed signs are destroyed. Many windows in high rise buildings will be dislodged and become airborne. Persons struck by windborne debris risk injury and possible death. Many trees will be snapped or uprooted and block numerous roads. Near total power loss is expected with outages that could last from several days to weeks. Hurricane Rita (pdf) (2005, 115 mph landfall in east Texas/Louisiana) and Hurricane Jeanne (2004, 120 mph landfall in southeast Florida) are examples of Category Three hurricanes at landfall.
Category Four Hurricane:
Winds 131-155 mph (114-135 kt or 210-249 km/hr). Extremely dangerous winds causing devastating damage are expected. Some wall failures with some complete roof structure failures on houses will occur. All signs are blown down. Complete destruction of mobile homes (primarily pre-1994 construction). Extensive damage to doors and windows is likely. Numerous windows in high rise buildings will be dislodged and become airborne. Windborne debris will cause extensive damage and persons struck by the wind-blown debris will be injured or killed. Most trees will be snapped or uprooted. Fallen trees could cut off residential areas for days to weeks. Electricity will be unavailable for weeks after the hurricane passes. Hurricane Charley (2004, 145 mph at landfall in southwest Florida) and Hurricane Hugo (1989, 140 mph at landfall in South Carolina) are examples of Category Four hurricanes at landfall.
Category Five Hurricane:
Sustained winds greater than 155 mph (135 kt or 249 km/hr). Catastrophic damage is expected. Complete roof failure on many residences and industrial buildings will occur. Some complete building failures with small buildings blown over or away are likely. All signs blown down. Complete destruction of mobile homes (built in any year). Severe and extensive window and door damage will occur. Nearly all windows in high rise buildings will be dislodged and become airborne. Severe injury or death is likely for persons struck by wind-blown debris. Nearly all trees will be snapped or uprooted and power poles downed. Fallen trees and power poles will isolate residential areas. Power outages will last for weeks to possibly months. Hurricane Camille (pdf) (1969, 190 mph at landfall in Mississippi) and Hurricane Andrew (1992, 165 mph at landfall in Southeast Florida) are examples of Category Five hurricanes at landfall.
You will Like This Site
You've got everyone blocked.
or do i need to go find the Admin and have them come in here and have a pet talk??
Dido well said.
Your right and as I said..I'm done..I know I have been a part of the bickering and have let myself get sucked in but I am done..I'll do my part to keep the blog civil. Thanks for pointing this out. G'night everyone.
It is not their fault, it is that time of the month. TC development surge testosterone levels.
That sound like a lot.....LOL
Im done too.
Back to the Tropics!
I'm from Cooper City in Broward County, FL to answer your question.
Just anyone mentioning You know who
went thru gloria in 85 and bob in 91,lots of trees down,I mean alot.....oddly enough I was 8 and 14 years old at the time,those TC conditions were worse than any of the conditions I've been thru while living here in FL for the last 7 TC seasons!!!
Do subtropical systems get classified as invests?
Already..Good night!
yes
I can't see you either. Dam i must have you blocked also...LOL.....Whats up buddy.
Some just won't let it go....
its way past the point of being remotely humorous
Yeppers they do.
So, everyone is all excited about something that isn't even classified as an invest yet... I am really disagree with the models here. From what I am seeing, this has little potential to become anything more than a STD.
:)
This blog is not about "right", "wrong", or who is wishcasting (although I sincerely hope the wishcasting will be avoided this season). This blog is about spreading information about tropical cyclones, and helping teach those who want to know about those very same tropical systems.
I know there is quite a bit that I am not aware of with tropical systems. I am here to learn some of that information, and hopefully do a little teaching myself. If you feel a need to prove everyone wrong, please do so on your own blog, and stop wasting all of our time. Everyone has a blog for a reason. Dr. Jeff Masters is nice enough to post this blog to spread his wealth of expert knowledge (if anyone can be considered an expert that posts in here, its him). Please respect it, and respect each other.
Please read backwards!
Invest:
A weather system for which a tropical cyclone forecast center (NHC, CPHC, or JTWC) is interested in collecting specialized data sets (e.g., microwave imagery) and/or running model guidance. Once a system has been designated as an invest, data collection and processing is initiated on a number of government and academic web sites, including the Naval Research Laboratory (NRL) and the University of Wisconsin Cooperative Institute for Meteorological Satellite Studies (UW-CIMSS). The designation of a system as an invest does not correspond to any particular likelihood of development of the system into a tropical cyclone; operational products such as the Tropical Weather Outlook or the JTWC/TCFA should be consulted for this purpose.
Cough might want to rephrase that. cough.
STD = Sub Tropical Depression
Ok, now that was funny
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