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 kwgirl:
Mosquito repellant
..oh yes thats a biggie alright
Member Since: August 6, 2011 Posts: 4 Comments: 38396
The center of Invest 99L has become very visible at 47.8 °W 11.9 °N. Looks closed.

Developing convection south of the LLC should obscure it again soon.
Member Since: July 6, 2010 Posts: 113 Comments: 31984
Quoting wxchaser97:
Vorticy max is increasing with pink showing up.


Notice too that the "tail" of vorticity off to the SW that has existed for several days is now almost gone. This suggests consolidation which should lead to a closed low very soon, if not already. The overall appearance is still somewhat ragged though and it seems to be fighting off less than ideal upper air conditions at the moment.
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Quoting stormchaser19:


Yes, but they are been so conservatives this year.

Are we watching the same hurricane season, in the same basin?

3 TS and 1 category 1 by July 1 is hardly "conservative"
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circulation looks to be around 12 N 47.5 W
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Quoting LargoFl:
Make sure your hurricane kit includes:

Flashlights & extra bulbs
Battery-operated radio
Battery-operated lanterns
Batteries (in different sizes!)
Matches
First aid kit
Duct tape
Rain gear
Clock (wind-up or battery-powered)
Plastic garbage bags
Fire extinguisher
Scissors
Can Opener
Clean clothes
Extra blankets
Heavy gloves
Mosquito repellant and for those who refuse to evacuate, a magic marker.
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Quoting wxchaser97:
Vorticy max is increasing with pink showing up.
Ya, NS is getting nailed right now.
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Levi, this is what I was referring to on satellite when I said it looked like that 850mb vort trough was losing its influence on 99L. New 850 map shows that as well. Not sure I've ever seen an 850 vort sig this strong in the deep tropics without having a tropical cyclone.

Member Since: July 15, 2006 Posts: 17 Comments: 10244
Quoting ncstorm:


You forgot an Ax

Axe or saw are both recommended, but not required. I have a utility saw in my house (it can handle anything up to about 5" in diameter, at which point I'd go to my neighbor who has a chainsaw). I have several 3 and 4 cell LED Maglites for flash lights - they are excellent on both battery usage and bright light, but also handy clubs.

Don't forget canned goods and non-perishable foods. Camp stoves are awesome, along with propane BBQ grills (with an extra full tank at all times).
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277. ryang
Hey Stormchaser, how close is the Kalvin Wave to 99L right now?
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The center of the circulation is at risk of becoming exposed, probably due to the impact of higher shear values on its Northern edge as a consequence of the change in direction of travel. This image below shows what I am referring to.

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Quoting jeffs713:
I was just talking about TD5. And what difference does it make for being in the night? Weather doesn't take a break based on our personal diurnal cycles. If it meets the criteria at 11pm, it should be tagged as TD5 at 11pm. Not wait for when it is convenient.


Yes, but they are been so conservatives this year.
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Quoting MississippiWx:
A CIRCULATION CENTER IS LOCATED
NEAR 10.8N 47.0W.


Huh? Give me some of whatever this author is drinking...


simmlar here I have 10.8N 47.4W
Member Since: June 13, 2009 Posts: 2 Comments: 11947
Vorticy max is increasing with pink showing up.
Member Since: March 16, 2012 Posts: 127 Comments: 7942
Quoting AussieStorm:
>>>>>>> Test test <<<<<<<

Congrats, you made an "A".
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>>>>>>> Test test <<<<<<<
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Quoting LargoFl:
I think its wonderful, how its not even a depression yet and people all over are talking about it..thinking about it..its a good thing..people now are awake and watching for any development and danger ahead..the blog here is doing a wonderful job with this..and I for one..thank you, I am sure there are MANY lurkers out there reading and watching what you folks discover and all the model runs and alerts..again..ty for all your hard work


Better this than the GW bickering that is always prevalent when the tropics is slow.
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IMO an excellent look at the structure of 99L, which has continued to improve with each passing hour.
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Quoting stormchaser19:


11:00 PM is so late in the nigth, if they do something, is at 5:00 PM today or maybe wait 11:00 PM tomorow for T.S
I was just talking about TD5. And what difference does it make for being in the night? Weather doesn't take a break based on our personal diurnal cycles. If it meets the criteria at 11pm, it should be tagged as TD5 at 11pm. Not wait for when it is convenient.
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Quoting MississippiWx:


Sure, but not directly under the spin. Lol.


Super hi-res MODIS pass from an hour ago. (Click for full-res)


Im stuck trying to get some work done, but I'll let you play around with it for a while.



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Quoting LargoFl:
..yep..it would be amazing if it came ashore here, no mountain ranges or really HIGH ground to stop a huge storm surge if it came directly in huh..whew


Whew is right I don't even like to think about that. The tiny cottage we moved into in Dec is just behind the Church By The Sea which fronts Gulf Blvd...but it was built in 1947 and has survived so far :) fingers crossed it stays that way.
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Link

Link
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Quoting Waltanater:
isn't it too south to catch it?
Dean and Felix both came in pretty far south but Dean moved WNW while Felix maintained a more westerly movement.
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Quoting MississippiWx:


It's easily a degree off. Should be 11.8, not 10.8.

That is what I thought and what it looks like and convection is still firing near the center.
Member Since: March 16, 2012 Posts: 127 Comments: 7942
Quoting jeffs713:

I think 11pm for TD would be more likely. 5pm would be just hitting dmin, so the system could still be in the falling apart stage of the cycle. By 11pm, the NHC will have a better handle on how strong the system really is.

I really think they will go TD then TS on this, as there isn't any imminent impacts to land or DoD assets (which is a TCFA criteria), and the NHC is going to want to fly a plane through it first, before upgrading. That said, it looks darn good for being just an invest at this stage.


11:00 PM is so late in the nigth, if they do something, is at 5:00 PM today or maybe wait 11:00 PM tomorow for T.S
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Quoting LargoFl:
Make sure your hurricane kit includes:

Flashlights & extra bulbs
Battery-operated radio
Battery-operated lanterns
Batteries (in different sizes!)
Matches
First aid kit
Duct tape
Rain gear
Clock (wind-up or battery-powered)
Plastic garbage bags
Fire extinguisher
Scissors
Can Opener
Clean clothes
Extra blankets
Heavy gloves


You forgot an Ax
Member Since: Posts: Comments:
Quoting TropicalAnalystwx13:
According to what I've heard over the past few weeks (and Levi just mentioned it in his tidbit), the FIM model is expected to replace the GFS model over the next few years.

Maybe we need to find one to replace the CMC and NOGAPS.

could just combine them and call it the COMNGAPS(i:e Common Gaps).
Member Since: Posts: Comments:
Make sure your hurricane kit includes:

Flashlights & extra bulbs
Battery-operated radio
Battery-operated lanterns
Batteries (in different sizes!)
Matches
First aid kit
Duct tape
Rain gear
Clock (wind-up or battery-powered)
Plastic garbage bags
Fire extinguisher
Scissors
Can Opener
Clean clothes
Extra blankets
Heavy gloves
Member Since: August 6, 2011 Posts: 4 Comments: 38396
Quoting Stormchaser2007:


That puts it directly under the developing convection.


Sure, but not directly under the spin. Lol.
Member Since: July 15, 2006 Posts: 17 Comments: 10244
Quoting nrtiwlnvragn:


Not replace the GFS but part of a multi-model to create an ensemble to replace the GEFS:







Link


Thanks!
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Quoting 7544:


must be a td by now hmmm and looks to be jumping more to the north


Just working out where it wants the center to be, IMO.
Member Since: August 19, 2005 Posts: 5 Comments: 5395
Quoting jeffs713:

Based on spiral banding, that isn't a bad estimate. Without a HH fix, it is close enough.


It's easily a degree off. Should be 11.8, not 10.8.
Member Since: July 15, 2006 Posts: 17 Comments: 10244
I think its wonderful, how its not even a depression yet and people all over are talking about it..thinking about it..its a good thing..people now are awake and watching for any development and danger ahead..the blog here is doing a wonderful job with this..and I for one..thank you, I am sure there are MANY lurkers out there reading and watching what you folks discover and all the model runs and alerts..again..ty for all your hard work
Member Since: August 6, 2011 Posts: 4 Comments: 38396
Quoting Neapolitan:
Sounds like fun. But you should know that if you were to play the same game while simultaneously reading other blogs written by other scientists equally as knowledgeable about weather and climate as Dr. Masters, you'd drink yourself into a coma within minutes. Seconds, maybe... ;-)

FWIW, it's not the increasing use of the terms "extreme" or "record" that should be bothering anyone, but rather the fact that worsening climate and more severe weather are forcing them to be used. They are, after all, the only terms that fit.

Theoretically, if TAZ were to play his game, I would hate to see what his blogs would be like then! LOL! I know...bad joke.
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Quoting MississippiWx:
A CIRCULATION CENTER IS LOCATED
NEAR 10.8N 47.0W.


Huh? Give me some of whatever this author is drinking...



That puts it directly under the developing convection.
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The next generation of the U.S.-based global model, the Flow-following finite-volume Icosahedral Model (FIM), began in experimental operation in 2008 and will replace the GFS at an undetermined point several years in the future.

why dont we keep the GFS and the FIM and leave a few old guys to try to update the GFS after the FIM takes over?
No reason to get rid of the GFS....
Member Since: February 11, 2012 Posts: 0 Comments: 9727
Quoting TropicalAnalystwx13:
According to what I've heard over the past few weeks (and Levi just mentioned it in his tidbit), the FIM model is expected to replace the GFS model over the next few years.

Maybe we need to find one to replace the CMC and NOGAPS.


Not replace the GFS but part of a multi-model to create an ensemble to replace the GEFS:







Link
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Quoting MississippiWx:
A CIRCULATION CENTER IS LOCATED
NEAR 10.8N 47.0W.


Huh? Give me some of whatever this author is drinking...


Based on spiral banding, that isn't a bad estimate. Without a HH fix, it is close enough.
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Quoting Waltanater:
What if there is more than one system of different categories out there...which takes precedence for your warnings? LOL

Ive never thought about that...

Lol, idk.
Member Since: July 6, 2010 Posts: 113 Comments: 31984
70 washingtonian115 All 99L needs to do is close off it's circulation and we could have T.D 5.

Unless its travel-speed of 20knots(23mph)37km/h drops by a significant amount, it's more likely to go directly from Invest99L to TropicalStormErnesto
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Quoting TropicalAnalystwx13:
According to what I've heard over the past few weeks (and Levi just mentioned it in his tidbit), the FIM model is expected to replace the GFS model over the next few years.

Maybe we need to find one to replace the CMC and NOGAPS.


The GFS is one of the best so hopefully the FIM model is an improvement or evolution of the GFS model. Do you know if that's the case or is it a completely new model?
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A CIRCULATION CENTER IS LOCATED
NEAR 10.8N 47.0W.


Huh? Give me some of whatever this author is drinking...

Member Since: July 15, 2006 Posts: 17 Comments: 10244
Quoting trumpman84:
I've made a drinking game out of reading Dr. Master's blogs. Feel free to play along! One shot for every instance of 'extreme' or 'record.' Double shots if the blog includes the phrase 'record amount of records'
Sounds like fun. But you should know that if you were to play the same game while simultaneously reading other blogs written by other scientists equally as knowledgeable about weather and climate as Dr. Masters, you'd drink yourself into a coma within minutes. Seconds, maybe... ;-)

FWIW, it's not the increasing use of the terms "extreme" or "record" that should be bothering anyone, but rather the fact that worsening climate and more severe weather are forcing them to be used. They are, after all, the only terms that fit.

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The overview of the Atlantic:

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Quoting WeatherNerdPR:
99L's surface circulation seems to be becoming better defined. I can definitely see this being classified at 5PM. Time will tell, of course.

I think 11pm for TD would be more likely. 5pm would be just hitting dmin, so the system could still be in the falling apart stage of the cycle. By 11pm, the NHC will have a better handle on how strong the system really is.

I really think they will go TD then TS on this, as there isn't any imminent impacts to land or DoD assets (which is a TCFA criteria), and the NHC is going to want to fly a plane through it first, before upgrading. That said, it looks darn good for being just an invest at this stage.
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Quoting icmoore:


Yeah and the widest part of FL is about 160 miles...
..yep..it would be amazing if it came ashore here, no mountain ranges or really HIGH ground to stop a huge storm surge if it came directly in huh..whew
Member Since: August 6, 2011 Posts: 4 Comments: 38396
239. 7544
Quoting SFLWeatherman:
99L is now up to 35MPH!!


must be a td by now hmmm and looks to be jumping more to the north
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Quoting wxchaser97:
There are two typhoons ready to hit China


It's karma from the badminton scandal...LOL
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Quoting TropicalAnalystwx13:

It stays red until it appears that the United States will suffer a direct impact from a major hurricane.
What if there is more than one system of different categories out there...which takes precedence for your warnings? LOL
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this is the FIM model on 99L


or


anyway I expect 99L to track like this
Member Since: June 13, 2009 Posts: 2 Comments: 11947

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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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