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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Quoting MississippiWx:


Step #1 of what I was trying to prove after Debby. The GFS only made sense to Florida wishcasting when it was the only model bringing it to them. Now, one storm later, Floridians are bashing the GFS already for taking it away from them. Lol. Priceless.

Happy model-watching. I'm out for a while since that should really stir the pot. :-D


I'm not bashing the GFS infact the GFS shifted north big time this run. Also Myself and 2 or 3 others were the only ones saying Debby was going to FL. While the rest of the Blog was going by what Levi was telling them would happen. Myself, Grother, and ncstorm posted countless graphics of why this would happen and got bashed for it. Either way this looks like another Debby set up.

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poof to that image
Member Since: August 6, 2011 Posts: 4 Comments: 42266
GOES just failed misserably.

Member Since: June 9, 2007 Posts: 4 Comments: 15950
I'll second Patrap's comment about the heat. Heat exhaustion was killing people with Rita, too. Adrenaline, a lack of planning and heat are a bad combination.
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First, we got to see if 99L develops into tropical storm AND recon mission into the storm before guessing where it'll go.
Member Since: August 1, 2011 Posts: 28 Comments: 8075
99L looks to be organizing quickly now and headed WNW straight toward Barbados.
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Quoting doabarrelroll:


As it happens I have been in an eywall for hours and feared for my life. Woke up the next morning and saw a field where a neighborhood once stood. I resent this remark. You are not special because of Katrina. You suffered as I have.

I am allowed to my opinion on the buses bit you are not allowed to stifle it.


Dont you know his experience is the only one that counts..

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577. wpb
hmrf 70 mph,gfdl nothing go figure???
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Remember people.. on developing systems... any path right now in the models are not worth going by. Once it becomes a TD and the models start it out as a TD and not a open wave, then they will consolidate more on a path.
Right now.. from looking at data.. this is close to being a TD and could be a Tropical Storm if he gets better organized tonight into Thurs. The GFS is alittle too far south in the first 72hrs... expect a path closer to Dominica by Friday night-Saturday.
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Debby part 2? Very possible FL could get hit by it's 3rd Tropical system in just 9 weeks.

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..............................in florida..we sure remember Debby alright
Member Since: August 6, 2011 Posts: 4 Comments: 42266
Quoting floridaboy14:
well the GFS run makes NO SENSE AT ALL the trough is digging but there is a HURRICANE in the NW carribean! should it move NW towards the weakness or west into the yucatan?


Step #1 of what I was trying to prove after Debby. The GFS only made sense to Florida wishcasting when it was the only model bringing it to them. Now, one storm later, Floridians are bashing the GFS already for taking it away from them. Lol. Priceless.

Happy model-watching. I'm out for a while since that should really stir the pot. :-D
Member Since: July 15, 2006 Posts: 17 Comments: 10284
Quoting TropicalAnalystwx13:

With a trough over the Northeast, I have a hard time believing it would continue west.


look at the isobars, there is not much of a passage to the NW but it may hit texas.

From Mexico to NOLA is the range im thinking.

come to think of it, the GFS has this in the bay of campeche on the 12th, 4 days too early for farmer's almanac.......
but if it slows or goes over there and recurves its possible...
lol jk
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Quoting TropicalAnalystwx13:

With a trough over the Northeast, I have a hard time believing it would continue west.
dont forget GFS shows a HURRICANE in the NW Carribean. i didnt say the trough will curve it into florida like a charley but if the ridge WEAKENS will it move NW AROUND IT OR DUE WEST INTO MEXICO?
Member Since: July 25, 2011 Posts: 0 Comments: 1102
Just got back from lunch.

Really not impressed by the sheared presentation on IR.

Might need 12-18 more hours to get together.
Member Since: June 9, 2007 Posts: 4 Comments: 15950
Ignorance is Bliss as well.


Calamity will find folks, like in LA on a clear summer day after a Verdict, or a Cat 1 like Irene did the Nasty in the Neast.

Yada, yada, yada...do a barrlel roll, but be careful not to invert and auger in.

Body bags are best made with 2 Large Garbage Bags and Duct Tape.

I still cant use neither.

So thanks for the cordial disco.

I fade..away today, but not fade away.

Peace.
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Houston bugged out in the middle of the night early Thursday before any hurricane warnings were issued. I know of people who tried to leave at 5 am but turned around and went back home after spending two hours trying to get out of their subdivision. A hurricane warning was not issued until 10 am that morning. There was no food and no gasoline available by Thursday morning. The storm made landfall early on Saturday. I don't know of anyone being caught on the highways because of traffic when the storm made landfall.
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Quoting StormTracker2K:


Yeah but in reality it will be much stronger than that.


How can anyone know for sure at this time?
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Quoting jeffs713:

Locked up is an understatement. The traffic system in Houston is not designed for 1/2 to 2/3 of the population to get out of town at the same time. Lots of people evacuated who shouldn't have, and that held up a lot of people who should have evacuated. Also, speaking from a local perspective, like NOLA, Houston has done quite a bit to prevent the same thing from happening again.


Jeff you are correct, a lot of people evacuate who shouldn't but I don't think there's anything you can do to prevent that, some people just get scared even if they're 30 miles inland on top of a hill!
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Quoting Chiggy:

I'm looking at that weakness over the central plains, and whether that will draw "Ernesto" towards the north...
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990mbs is a Tropical Storm in most cases....70mph... when it gets to about 988 or 987 is when we say it's a hurricane.
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560. yoboi
Quoting 69Viking:


You miss my point too, when your told to evacuate do it. They shouldn't have been there, they could have easily walked out of there before Katrina arrive but chose not to and went against the evacuation orders. I guess some people listen better than others, maybe next time the ones stranded on the rooftops will listen to the evacuation orders and heed them before the storm arrives and not after.


alot of people did walk to the superdome and convention center....
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Quoting StormTracker2K:


Yeah but in reality it will be much stronger than that.

990 millibar on the GFS is a minimal Category 1...maybe.
Member Since: July 6, 2010 Posts: 113 Comments: 32862
Quoting StormTracker2K:
This trough here across the east could play a big role on 99L down the road. Looks like a Debby set up all over again. Very interesting in seeing the other 12Z models later.



well the GFS run makes NO SENSE AT ALL the trough is digging but there is a HURRICANE in the NW carribean! should it move NW towards the weakness or west into the yucatan?
Member Since: July 25, 2011 Posts: 0 Comments: 1102
Quoting washingtonian115:
GFS turns Ernesto into a beast :(.All though IMO I think it'll be a little further east.
I thought a little farther N and E but the gfs has been showing a similar set up for a few runs now.
Member Since: March 16, 2012 Posts: 127 Comments: 7972
Quoting floridaboy14:
cody it doesnt make sense. wouldnt a stronger system like the GFS is showing would move into the gulf and move NW and a weaker system head west into the yucatan? whats your prediction?

With a trough over the Northeast, I have a hard time believing it would continue west.
Member Since: July 6, 2010 Posts: 113 Comments: 32862
Quoting osuwxguynew:
Structure continues to improve on MIMIC TPW as well, thought the ITCZ feature is also evident...

MIMIC TPW


In climate related news, the SOI has plummeted which should provide another step up in ocean heat content/El Nino development

1 Aug 2012 1010.36 1014.75 -36.48

Daily SOI


GFS nailed it, the high is past tahiti so pressure falls again and the soi, plummets
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Quoting Bluestorm5:
990 mb is a Category 1...


Yeah but in reality it will be much stronger than that.
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Wave train in full swing. If you look close, one can see the one that temporarily has no convection.
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the GFS and its consistency with 99L..
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Quoting doabarrelroll:

it is quite hard and not everyone should evacuate but many of the folks who died did so because the city failed to use their buses. I have seen cities do this where it works and cities where they failed.


Buses was BS, we had plenty o Buss's, but the Decision was made to Shelter in Place at the Superdome as time was critical.

Here's a fact, Folks didnt even have to leave but 7-8 miles from the Dome to Jefferson Parish on the Dry side,as I lived one mile West from the 17th St Canal at the time.

If we had just known that the Breeches were to happen, we wouldn't have lost no one.


There was 80 different failures of Levee's.

But K was K, and if you were not in K's Eyewall for 9 Hours, well you havent a clue How Big and different she was.

But 7 years later and 14 Billion Dollars, were better protected, but still Vulnerable to a Cat 4.

Or a Surge 17-20 ft...plus.
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...................EAST COAST OF FLORIDA GET READY, THE SEA BREEZE STORMS ARE COMING
Member Since: August 6, 2011 Posts: 4 Comments: 42266
Quoting wxchaser97:
GFS buries 99L in the boc as a strong TS/minimal hurricane and then weakens it without major landfall.

This is too far out to put much faith in.
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546. yoboi
Quoting jeffs713:

Locked up is an understatement. The traffic system in Houston is not designed for 1/2 to 2/3 of the population to get out of town at the same time. Lots of people evacuated who shouldn't have, and that held up a lot of people who should have evacuated. Also, speaking from a local perspective, like NOLA, Houston has done quite a bit to prevent the same thing from happening again.


yeah i think the gov in texas will not evac houston ever again, even with contra flow ya cant move that many people out, it would take about 96hrs -120 hrs to move that many people out and with 120hrs from landfall still hard to tell where storm will make landfall....
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This trough here across the east could play a big role on 99L down the road. Looks like a Debby set up all over again. Very interesting in seeing the other 12Z models later.



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ha ha..the bloggers removed my trashcan pic..I must have touched some nerves..
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Expanding in coverage, and becoming better organized, and is probably a TD already.
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GFS buries 99L in the boc as a hurricane and then weakens it without major landfall.
Member Since: March 16, 2012 Posts: 127 Comments: 7972
Quoting TropicalAnalystwx13:
This is the first time since the GFS sniffed out 99L that it has taken the pressure below 1000 millibars.

cody it doesnt make sense. wouldnt a stronger system like the GFS is showing would move into the gulf and move NW and a weaker system head west into the yucatan? whats your prediction?
Member Since: July 25, 2011 Posts: 0 Comments: 1102
Quoting yoboi:


i was there in a boat for 5 days not much walking going on plus the water was nasty with sewer, oil, gas


You miss my point too, when your told to evacuate do it. They shouldn't have been there, they could have easily walked out of there before Katrina arrive but chose not to and went against the evacuation orders. I guess some people listen better than others, maybe next time the ones stranded on the rooftops will listen to the evacuation orders and heed them before the storm arrives and not after.
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Quoting StormTracker2K:


Probably a cat 3 or 4 right here on the GFS.


990 mb is a Category 1...
Member Since: August 1, 2011 Posts: 28 Comments: 8075
Quoting wunderkidcayman:


as I say the track is perfect not going anymore N


Lol. I've seen it all now.
Member Since: July 15, 2006 Posts: 17 Comments: 10284

Saola


Damrey
Member Since: July 11, 2006 Posts: 14 Comments: 11424

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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.

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