Disturbance 99L more organized; record melting in Austrian Alps

By: Dr. Jeff Masters , 2:02 PM GMT on August 01, 2012

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A tropical wave (Invest 99L) near 11°N 47°W, about 1000 miles east of the Lesser Antilles Islands, is showing increasing organization, and has the potential to develop into a tropical depression today or tomorrow as it moves westward at 15 - 20 mph. Visible satellite loops show that the disturbance now has two respectable low-level spiral bands, one to the north and one to the south, and a moderate amount of heavy thunderstorms near the center. The thunderstorm activity has not changed much in intensity this morning. A well-defined surface circulation is not evident on satellite images, but last night's 8:30 pm EDT pass from the ASCAT satellite showed a broad, elongated center with light winds had formed. Water vapor satellite loops show that 99L has a reasonably moist environment, and the latest Saharan air layer analysis shows that the dry air from the Sahara is not present in large quantities over the central tropical Atlantic. WInd shear over the disturbance has increased some since Tuesday, and is now at the moderate level, 10 - 15 knots. Ocean temperatures are 28°C, (82°F) which is about 0.5°C above average for this time of year.


Figure 1. Morning satellite image of Invest 99L.


Figure 2. Vertical instability over the tropical Atlantic in 2012 (blue line) compared to average (black line.) The instability is plotted in °C, as a difference in temperature from near the surface to the upper atmosphere. Thunderstorms grow much more readily when vertical instability is high. Instability has been lower than average, due to an unusual amount of dry, sinking air in the atmosphere, reducing the potential for tropical storm formation. Image credit: NOAA/NESDIS/CIRA.

Forecast for 99L
Wind shear is expected to remain light to moderate, 5 - 15 knots, through Friday, ocean temperatures will remain near 28°C, and mid-level moisture will be a moderate 60 - 70%, according to the 8 am EDT run of the SHIPS model. The disturbance has gained a bit of latitude and is now at 11°N, which will help it leverage the Earth's spin more to acquire its own spin. These conditions are probably sufficient for 99L to become Tropical Depression Five, with Thursday being the most likely day for this to happen. However, the reliable computer models are not very eager to develop 99L, and none show it becoming a hurricane over the next five days. This is probably because the atmosphere over the tropical Atlantic is unusually stable for this time of year (Figure 2), with large-scale areas of dry, sinking air present. Climatologically, we see very few Cape Verdes-type hurricanes forming near the Lesser Antilles Islands this early in August, and I expect 99L will struggle at times over the next few days. This is particularly likely if 99L goes north of 13°N, where a band a high wind shear of 20 - 40 knots associated with the subtropical jet stream lies. At 8 am Wednesday, NHC gave 99L a 60% chance of developing into a tropical depression by Friday morning. Residents and visitors to the Lesser Antilles Islands should anticipate heavy rains and strong winds from 99L beginning to affect the islands as early as Friday morning. The long-range fate of 99L next week is uncertain, but a track west to west-northwest through the Caribbean is the most popular solution from the models.


Figure 3. Typhoon Saola (bottom) and Typhoon Damrey (top) perform a pincer maneuver on Shanghai, China in this MODIS photo from NASA's Terra satellite taken at 02 UTC August 1, 2012. Image credit: NASA.

Two typhoons headed towards China
In the Western Pacific, typhoon season is in full swing with two typhoons headed towards China. The more dangerous of the two is Category 2 Typhoon Saola, which is predicted to skirt the northern coast of Taiwan and hit mainland China 300 miles south of Shanghai on Friday as a Category 3 typhoon. Typhoon Damrey, a Category 1 storm located just south of Japan, is expected to hit China about 150 miles north of Shanghai on Thursday at Category 1 strength.

Extreme heat in Oklahoma
The withering heat in America's heartland continued on Tuesday, with the prize for most ridiculous heat a 113° temperature recorded in Chandler, Oklahoma. A close second: Tulsa hit 112°, just 3° below the city's all-time high of 115° set on August 10, 1936. The low temperature in Tulsa was 88° Tuesday morning, tying the record for warmest low temperature in city history set just the previous day. Six locations in Oklahoma hit 112° or hotter Tuesday, and the forecast calls for highs near 112° again today over portions of Oklahoma.

Extreme dryness in the Central U.S.
A few final tallies for July precipitation are in, and several U.S. cities in the heart of the drought region set new records for driest July:

Joplin, MO: 0.00" (ties record set in 1946)
Springfield, MO: 0.32" (previous record 0.33" in 1953)
Sioux Falls, SD: 0.24" (previous record, 0.24" in 1947, normal is 3.09")

Record early snow melt in the Austrian Alps
One of the longest meteorological data records at high altitude comes from Sonnblick, Austria, on a mountaintop in the Alps with an elevation of 3106 meters (10,200 feet.) The observatory typically sees maximum snow depths of 3 - 4 meters (10 - 13 feet) during winter. According to weather records researcher Maximiliano Herrera, the snow had never completely melted at Sonnblick until the summer of 1992. Complete snow melt did not happen again until August 12, 2003, and has happened an average of once every two years since then--but always in September. Yesterday, on July 31, the snow completely melted at Sonnblick, the earliest melting since record keeping began in 1886. It's been an exceptionally hot summer in Austria, which experienced its 6th warmest June since record keeping began in 1767. Sonnblick Observatory recorded its all-time warmest temperature of 15.3°C (60°F) on June 30. Vienna hit 37.7°C (100°F) that day--the hottest temperature ever measured in June in Austria. Note that the two mountains in the Alps with long climate records, Saentis in Switzerland and Zugspitze in Germany, beat their records for earliest melting last year in 2011 (Saentis beat the previous record of 2003, and Zugspitze tied the record set in 2003.)


Figure 4. The Sonnblick Observatory in Austria on April 26, 2010. Image credit: Michael Staudinger.

Jeff Masters

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Thanks Dr. Masters...good afternoon and happy emancipation day to everyone in the British west indies.
Member Since: November 6, 2010 Posts: 11 Comments: 8164
Quoting RitaEvac:
This would be an epic location, because it's landlocked and bound to move into GOM

That location is in a bad area. Very high TCHP. Hope that shear and dry air are available to keep it from turning into a monster.

Member Since: Posts: Comments:
Quoting CybrTeddy:


'Might' be a little attached to the ITCZ still. You can tell though it's starting to split fully.



With that strong of a vort, it is separated enough. You only see that with a tropical cyclone.
Member Since: July 15, 2006 Posts: 17 Comments: 10284
Storm Relative 1km Geostationary Visible Imagery

Member Since: July 3, 2005 Posts: 426 Comments: 128766
Quoting sunlinepr:
GFS now takes it into GOM



GFS trending further north and CMC trending further south. I'm thinking somehow a storm crossing Cuba around the periphery of the high is not out of the question It all depends on the position of the high and how much lat this storm gains.
Too many factors though and still way too early but there does seem to be a little consensus going on here.
Member Since: September 30, 2008 Posts: 0 Comments: 108
Quoting Stormchaser2007:
I'd go with 70%

Looks like it's getting nailed by shear now.



Structure wise it isn't looking too shabby.
Member Since: September 2, 2006 Posts: 110 Comments: 6878
http://www.ssd.noaa.gov/PS/TROP/floaters/99L/flash- vis-long.html
Looks like an LLC has formed in the NW quadrant, should see it reclassified to a TD at any moment today.
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Quoting TropicalAnalystwx13:
Looks organized enough for classification to me.



'Might' be a little attached to the ITCZ still. You can tell though it's starting to split fully.

Member Since: July 8, 2005 Posts: 259 Comments: 24199
728. yoboi
Quoting louisianaboy444:
Just wanted everyone to know...I am a weather intern at KATC out of Lafayette. The station has offered me to stay in the weather lab in the instance of a Louisiana hurricane to answer the phones and help with social media. So if anyone from South Louisiana would have questions before or during a hurricane you could call the KATC weather-lab and talk to moi ;)


i have a question for ya, if louisiana has another coastal evacuation like they did for gustav, how will the phase evacuation take place???? and what are the timelines for each phase???
Member Since: August 25, 2010 Posts: 7 Comments: 2348
This would be an epic location, because it's landlocked and bound to move into GOM

Member Since: July 14, 2008 Posts: 1 Comments: 9630
Quoting robintampabay:



Havelock in my opinion is much better than MCAS Beaufort SC


My first duty Station was Beaufort , after El Toro School, I was there for the Great Santini Premiere in 81,saw and met Robert Duvall, a real nice guy too.
I was with H &HS there,shucks cant remember the Squadron now, VMFA-312 Maybe, Checkerboards.
Member Since: July 3, 2005 Posts: 426 Comments: 128766
Looks organized enough for classification to me.

Member Since: July 6, 2010 Posts: 113 Comments: 32291
Quoting ncstorm:
I am really not to get into a "which storm was the worst for someone" contest..but if I did, the Haitians got everyone beat here..dont ever say you had it worst because there is always someone going through a harder struggle than you are ..I'll be back later
My good friend just got back from her mission in Haiti today. She told me that it'll take Haitians 50 years or more to recover from that earthquake, yet they are one of the nicest people she have ever met. She said that they are very graceful that they are still alive through the struggles from hurricanes and earthquakes. She plans to tell me more from her trip later, but her life seems to be changed forever after visiting Haiti.
Member Since: August 1, 2011 Posts: 28 Comments: 8031
"Patience is a virtue"
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Repost in the event no one saw it.
Tropical Disturbance 99L a threat to develop - 8/1/12
Member Since: July 8, 2005 Posts: 259 Comments: 24199
Quoting GeorgiaStormz:


thats not reasonable.

At that rate a lot of swirls could be TSs after jose, beryl(in the beginning) etc


As long as it has a well defined surface circulation, and is organized, which 99L is in this case, then it should be classified.
Member Since: September 2, 2006 Posts: 110 Comments: 6878
Quoting sunlinepr:
NHC/TAFB takes it directly to Jamaica....



Oh boy,where is nigel? I haven't seen him today.
Member Since: April 29, 2009 Posts: 75 Comments: 14344
GFS now takes it almost into GOM

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99L's LLCOC is currently located at 11.8N 47.8W
Member Since: June 13, 2009 Posts: 2 Comments: 12168
Quoting RitaEvac:


Hey that term is trademarked....


lol...sorry Rita :)
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Quoting AllStar17:
I've seen worse-looking tropical storms than 99L. This should be classified at 5.


thats not reasonable.

At that rate a lot of swirls could be TSs after jose, beryl(in the beginning) etc
Member Since: February 11, 2012 Posts: 0 Comments: 9731
Quoting muddertracker:


Yeah...Houston learned from the Rita Evac...(which was a nightmare)...and did a "better" job with Ike.


Hey that term is trademarked....
Member Since: July 14, 2008 Posts: 1 Comments: 9630
Just wanted everyone to know...I am a weather intern at KATC out of Lafayette. The station has offered me to stay in the weather lab in the instance of a Louisiana hurricane to answer the phones and help with social media. So if anyone from South Louisiana would have questions before or during a hurricane you could call the KATC weather-lab and talk to moi ;)
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NHC/TAFB takes it directly to Jamaica....

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712. yoboi
Quoting muddertracker:


Yeah...Houston learned from the Rita Evac...(which was a nightmare)...and did a "better" job with Ike.



very true..
Member Since: August 25, 2010 Posts: 7 Comments: 2348
711. wxmod
North Pole. MODIS today
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The difference in the Bermuda High between the CMC & GFS 12Z runs seems substantial...
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Red Alert!

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what about this thing off the eastern seaboard? warm-core?
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Quoting yoboi:



best thing with previous storms is look at the mistakes that were made and try to learn from them...

most people seem to forget with what went wrong and when ya discuss things people either don't read what ya are saying or they just don't care....


Yeah...Houston learned from the Rita Evac...(which was a nightmare)...and did a "better" job with Ike.

Many people died during the Rita evacuation:

Link
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I've seen worse-looking tropical storms than 99L. This should be classified at 5.
Member Since: June 29, 2009 Posts: 13 Comments: 5313
Quoting HurricaneDean07:
99L gaining latitude at a good pace now...
Near 13N, and should continue a WNW motion now.
It appears it gained latitude a little too quickly though, and has ran into an increased amount of wind shear, and almost caused it to expose its better defined circulation. New blow up convection over the center should keep it going, for now. It needs to organize more though, it has become assymetric with this WSWerly shear. I say it will be called Ernesto at 11pm. It is much better defined, and should be getting better as the shear lessens further west.
I give 99L a 99% chance of forming into Ernesto in the next 36 hours.


I'm pretty sure 99L, will slow down at any time, the ridge will take place again,looks like will take the cmc right now, but for this reason is because the tropic is very complex place, Divergence a convergence occur
Member Since: June 20, 2012 Posts: 0 Comments: 2159
Quoting TropicalAnalystwx13:

New burst. Should see it fire more later as that Kelvin wave you have talked about moves closer.


Gonna sit down later tonight and really hit the books on that one. There are three different situations in which the CCKW will enhance convection. Just have to really figure out which one is taking place now.

The Kelvin Wave may have to really battle it out with the TUTT in the short term, but I'll have more details once I'm able to really sit down and look at things some more.

Quote from the Met who described this whole event:

. We are still in the middle of a battle for synoptic pattern dominance. In one corner, we have a strong upper level trough thats still inducing significant westerly shear over the Atlantic basin, especially between 40-60W 15N and above. On the other, we have a significant convectively coupled kevin wave (CCKW) which should enhance upper level easterlies after its passage.




Member Since: June 9, 2007 Posts: 4 Comments: 15921
Good grief.
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702. yoboi
Quoting ncstorm:



best thing with previous storms is look at the mistakes that were made and try to learn from them...

most people seem to forget with what went wrong and when ya discuss things people either don't read what ya are saying or they just don't care....
Member Since: August 25, 2010 Posts: 7 Comments: 2348
canadian.hasnt.read.the.farmers.alm.
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canadians.persistant...
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698. JLPR2
I'm finding the sudden rise in latitude a little intimidating.




But anyways I'm going out today, see you all at night.
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I am really not to get into a "which storm was the worst for someone" contest..but if I did, the Haitians got everyone beat here..dont ever say you had it worst because there is always someone going through a harder struggle than you are ..I'll be back later
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99L appears to be moving into an area that is slightly more favorable for development than it is in now. It appears to be near the southern edge of the Tropical Upper Tropospheric Trough at the moment and should be moving away from the axis as it continues to the west.

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Taiwan will take a real punch... Not only the wind (125mph) in the north but all that tail and S moisture

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692. yoboi
Quoting VAbeachhurricanes:


Yeah 9/11 only affected two blocks! my god.... the ignorance

Anyway, 99L seems to be making strides, it's still connected to the ITCZ though is it not?


reread i said world trade center bombings....logistics only 2 blocks...
Member Since: August 25, 2010 Posts: 7 Comments: 2348


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Quoting hurricanehunter27:


70% chance in the next 48 hours not 12.



whoops.
thx
Member Since: February 11, 2012 Posts: 0 Comments: 9731
convection has almost fully wrapped around the circulation and the circulation seem to be slowing it North movement I am not sure yet still wait for a few more sat images to come out
Member Since: June 13, 2009 Posts: 2 Comments: 12168
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Quoting Stormchaser2007:

New burst. Should see it fire more later as that Kelvin wave you have talked about moves closer.
Member Since: July 6, 2010 Posts: 113 Comments: 32291
Chances of landfall at any intensity
according to FSU

invest 99L.
Cuba (13%↑↑) in 7.9 days
Louisiana (11%) in 12 days
Bermuda or w/i 1 deg (11%) in 8.9 days


big blob of convection firing up near the center
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Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.