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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786. OrchidGrower
6:21 PM GMT on August 01, 2012
re: #754 - immense wave poised to come off Africa
Member Since: September 24, 2002 Posts: 0 Comments: 398
785. mcluvincane
6:21 PM GMT on August 01, 2012
Quoting VAbeachhurricanes:


Reclass at 5?
Quoting VAbeachhurricanes:


Reclass at 5?



I would bet my house on it
Member Since: June 2, 2010 Posts: 0 Comments: 1404
784. KendallHurricane
6:20 PM GMT on August 01, 2012
very likely we will have TD 5 either at 5pm or 11pm
Member Since: August 14, 2008 Posts: 0 Comments: 498
783. RitaEvac
6:20 PM GMT on August 01, 2012
Quoting Grothar:
I believe the circulation is much further North than the last position.



Close to 12N 48W
Member Since: July 14, 2008 Posts: 2 Comments: 9686
782. HurricaneDean07
6:20 PM GMT on August 01, 2012
AL05 [coming soon]
YES! score! xD
Member Since: October 3, 2010 Posts: 40 Comments: 4129
781. louisianaboy444
6:20 PM GMT on August 01, 2012
Quoting yoboi:


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???


Well I am not in emergency management so I really do not know. I believe this will be put out to the news networks in plenty of time for coastal residents to heed warnings though.
Member Since: August 29, 2006 Posts: 22 Comments: 1352
780. robintampabay
6:20 PM GMT on August 01, 2012
Quoting DrMickey:

This look familiar?


Yeah that was VMFA 312, they were in the hanger next to us in Beaufort
Member Since: September 16, 2010 Posts: 0 Comments: 173
779. Bluestorm5
6:20 PM GMT on August 01, 2012
Quoting SLU:
01/1745 UTC 12.0N 48.3W T2.0/2.0 99L
Should be tropical depression at 5 pm.
Member Since: August 1, 2011 Posts: 28 Comments: 8075
778. CybrTeddy
6:20 PM GMT on August 01, 2012
Quoting TropicalAnalystwx13:
This should be enough for classification.

01/1745 UTC 12.0N 48.3W T2.0/2.0 99L -- Atlantic


It's possible. I'd much like to see a fresh ASCAT pass.
Member Since: July 8, 2005 Posts: 259 Comments: 24575
777. Patrap
6:20 PM GMT on August 01, 2012
Very Cool, they fine Aircraft..and they were just coming on-line when I was at School in EL Toro as Mag-13 was still flying F-4's in 80'.

MMS | Photography: Aircraft &emdash; U S Marine Corps Fighter Attack Squadron 312 FA 18 Hornet 205 II
Member Since: July 3, 2005 Posts: 428 Comments: 129844
776. HurricaneDean07
6:19 PM GMT on August 01, 2012
Quoting Grothar:
I believe the circulation is much further North than the last position.


Last coordinates were around 10.8 north... It has then moved WNW or a little north of that to 12.4 N
Member Since: October 3, 2010 Posts: 40 Comments: 4129
775. Bluestorm5
6:19 PM GMT on August 01, 2012
Quoting GeorgiaStormz:


POLL TIME!!!

Should 99L be a TS?:

A) Yes
B) No
No, not yet. Winds isn't strong yet.
Member Since: August 1, 2011 Posts: 28 Comments: 8075
774. NoLa86
6:19 PM GMT on August 01, 2012
Quoting Patrap:
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.
Is this guy okay?
Member Since: August 21, 2008 Posts: 0 Comments: 18
773. KendallHurricane
6:18 PM GMT on August 01, 2012
remember the further north 99L gets the harder its going to be to get strong, but i am very concerned for Jamaica and the Caymans some computer models are indicating a streghthing Hurricane moving close or
over them
Member Since: August 14, 2008 Posts: 0 Comments: 498
772. TropicalAnalystwx13
6:18 PM GMT on August 01, 2012
Quoting Grothar:
I believe the circulation is much further North than the last position.


Yeah.

AL, 99, 2012080118, , BEST, 0, 120N, 482W, 30, 1008, LO
Member Since: July 6, 2010 Posts: 113 Comments: 32825
771. AllStar17
6:18 PM GMT on August 01, 2012
Right on cue...August 1st and it looks like we will be dealing with a storm that will threaten land. Buckle in over the next 2 months and be prepared.
Member Since: June 29, 2009 Posts: 13 Comments: 5315
770. 954FtLCane
6:18 PM GMT on August 01, 2012
Quoting nigel20:
Thanks Dr. Masters...good afternoon and happy emancipation day to everyone in the British west indies.


Hello Nigel. Saw a great show on ESPN about the West Indies Cricket team last night. I had no idea how much they affected to many aspects not related to sports. It was called "Fire in babylon".

Now back to weather. Will be interesting to see where the models take 99L (per Ernesto) once we have a depression/TS.
Member Since: September 30, 2008 Posts: 0 Comments: 108
769. tropicfreak
6:18 PM GMT on August 01, 2012
Quoting GeorgiaStormz:


POLL TIME!!!

Should 99L be a TS?:

A) Yes
B) No


B) No, its winds aren't quite that strong, but I believe it at least should be TD 5.
Member Since: September 2, 2006 Posts: 110 Comments: 6878
768. ILwthrfan
6:17 PM GMT on August 01, 2012
Quoting GeorgiaStormz:


POLL TIME!!!

Should 99L be a TS?:

A) Yes
B) No


B) It needs to cook just a bit more, but it's going to be at least tropical depression by tomorrow morning IMO.
Member Since: February 2, 2010 Posts: 0 Comments: 1540
767. Patrap
6:17 PM GMT on August 01, 2012
AL992012 - INVEST

2km Natural Color Imagery

Green Estimated

Earlier..

Member Since: July 3, 2005 Posts: 428 Comments: 129844
766. wunderkidcayman
6:17 PM GMT on August 01, 2012
Quoting hurricanehunter27:
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.

shear will be 5-10kts so shear is out dry air if any 99L/PRE-TD5 would have a big enough moisture field to compinsate
Member Since: June 13, 2009 Posts: 2 Comments: 12716
765. VAbeachhurricanes
6:17 PM GMT on August 01, 2012
Quoting SLU:
01/1745 UTC 12.0N 48.3W T2.0/2.0 99L


Reclass at 5?
Member Since: September 6, 2007 Posts: 0 Comments: 6704
764. robintampabay
6:17 PM GMT on August 01, 2012
Quoting Patrap:


Very cool ,I was at Camp Hansen in Okinawa Sept 82-83 and the day I got my orders to fly home ,the Russians blew that 747 KAL Flight with the US Congressman on board outta da sky with the Mig.

Thank you for your service to Americas and Semper Fi.


Same to you Semper Fi Marine
Member Since: September 16, 2010 Posts: 0 Comments: 173
763. DrMickey
6:17 PM GMT on August 01, 2012
Quoting Patrap:


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.

This look familiar?
Link
Member Since: May 22, 2005 Posts: 0 Comments: 162
762. TropicalAnalystwx13
6:16 PM GMT on August 01, 2012
This should be enough for classification.

01/1745 UTC 12.0N 48.3W T2.0/2.0 99L -- Atlantic
Member Since: July 6, 2010 Posts: 113 Comments: 32825
761. AllStar17
6:16 PM GMT on August 01, 2012
Quoting SLU:
01/1745 UTC 12.0N 48.3W T2.0/2.0 99L


Should be classified at 5.
Member Since: June 29, 2009 Posts: 13 Comments: 5315
760. SLU
6:16 PM GMT on August 01, 2012
01/1745 UTC 12.0N 48.3W T2.0/2.0 99L
Member Since: July 13, 2006 Posts: 13 Comments: 5367
759. ILwthrfan
6:15 PM GMT on August 01, 2012
Quoting sunlinepr:
Taiwan will take a real punch... Not only the wind (125mph) in the north but all that tail and S moisture



Looks like it's tracking a little to the left of the forecast track too. That storm could very well make a full landfall on Taiwan.

Member Since: February 2, 2010 Posts: 0 Comments: 1540
758. 7544
6:15 PM GMT on August 01, 2012
hmmm found this interesting could the cmc be right after all
AS IT MOVES WEST-NORTHWESTWARD AT NEAR 20 MPH.
Member Since: May 6, 2007 Posts: 0 Comments: 6874
757. ackee
6:15 PM GMT on August 01, 2012
Quoting GeorgiaStormz:


POLL TIME!!!

Should 99L be a TS?:

A) Yes
B) No
YES
Member Since: July 15, 2008 Posts: 0 Comments: 1376
756. kwgirl
6:15 PM GMT on August 01, 2012
Good afternoon. While trying to catch up on the blog, I have had to add a few to my list. I don't know what is up, but I have no patience for some people. Would rather not hear them blather. Old Age? Pretty soon I will be talking to only the handful I respect, that is, if they have not ignored me! Oh, I just remembered, it's the full moon!
Member Since: March 28, 2008 Posts: 0 Comments: 1532
755. nigel20
6:14 PM GMT on August 01, 2012
Quoting yoboi:


he might be putting shutters up...

Hey! That would be very bad for us.
Member Since: November 6, 2010 Posts: 12 Comments: 8472
754. Patrap
6:14 PM GMT on August 01, 2012
Storm Relative 16km Geostationary Water Vapor Imagery

Member Since: July 3, 2005 Posts: 428 Comments: 129844
753. 1900hurricane
6:13 PM GMT on August 01, 2012
Quoting MississippiWx:


With that strong of a vort, it is separated enough. You only see that with a tropical cyclone.

Plus, with the NW movement over the past few hours, it may have put it far enough north to separate from the ITCZ, and if not, it is awfully close.
Member Since: August 2, 2006 Posts: 47 Comments: 11709
752. islander101010
6:13 PM GMT on August 01, 2012
Quoting KendallHurricane:
Indications looks like we may have TD 5 later today, for those in Jamaica and the windward islands need to be prepared for a moderate to strong Tropical Storm
leewards.first
Member Since: September 11, 2010 Posts: 1 Comments: 5001
751. DeValk
6:13 PM GMT on August 01, 2012
The longer it keeps it's current pace, the further West it will go before moving North...which should bring it South of PR. I think it is going to get beat up in the Carib., and either 1.)weakly push onto shore of the Yucatan, 0r 2.) slip just North of the Yucatan as a TS and thrive on the favorable conditions of the Southern GOM. Once in the "Hot Tub", TX to Destin,FL better look out...Most likely Galveston to Pensacola.
Member Since: June 26, 2012 Posts: 0 Comments: 15
Quoting robintampabay:



I was apart of VMFA-533 FA-18, was in Beaufort, Okinawa, Iwakuni, and then spent 4 months at an old Soviet Mig base in Hungry during the Kosovo Conflict in 99. While there the weather was dramatic, hot as hell during the day and very cold at night.


Very cool ,I was at Camp Hansen in Okinawa Sept 82-83 and the day I got my orders to fly home ,the Russians blew that 747 KAL Flight with the US Congressman on board outta da sky with the Mig.

Thank you for your service to Americas and Semper Fi.
Member Since: July 3, 2005 Posts: 428 Comments: 129844
Quoting tropicfreak:


As long as it has a well defined surface circulation, and is organized, which 99L is in this case, then it should be classified.


POLL TIME!!!

Should 99L be a TS?:

A) Yes
B) No
Member Since: February 11, 2012 Posts: 0 Comments: 9760
Quoting sunlinepr:
NHC/TAFB takes it directly to Jamaica....


Hey sunline! Not good for us if that scenario pans out.
Member Since: November 6, 2010 Posts: 12 Comments: 8472
gfdl.soon?
Member Since: September 11, 2010 Posts: 1 Comments: 5001
Indications looks like we may have TD 5 later today, for those in Jamaica and the windward islands need to be prepared for a moderate to strong Tropical Storm
Member Since: August 14, 2008 Posts: 0 Comments: 498
99L
Member Since: November 6, 2010 Posts: 12 Comments: 8472
Old eyes will do dat.

: )
Member Since: July 3, 2005 Posts: 428 Comments: 129844
743. ackee
I think we will see TD#5 later today
Member Since: July 15, 2008 Posts: 0 Comments: 1376
Quoting Patrap:


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.



I was apart of VMFA-533 FA-18, was in Beaufort, Okinawa, Iwakuni, and then spent 4 months at an old Soviet Mig base in Hungry during the Kosovo Conflict in 99. While there the weather was dramatic, hot as hell during the day and very cold at night.
Member Since: September 16, 2010 Posts: 0 Comments: 173
I believe the circulation is much further North than the last position.

Member Since: Posts: Comments:
99L Storm Relative 1km Geostationary Visible Imagery loop
Member Since: July 3, 2005 Posts: 428 Comments: 129844
new images came out location 11.8N 48.2W last was 11.8N 47.8W so that would mean its moving W
Member Since: June 13, 2009 Posts: 2 Comments: 12716
737. ackee
Quoting sunlinepr:
NHC/TAFB takes it directly to Jamaica....

I think warm water around jamaica could cause future Earnesto to be moderate TS or stronger by time it reach us
Member Since: July 15, 2008 Posts: 0 Comments: 1376
Thanks Dr. Masters...good afternoon and happy emancipation day to everyone in the British west indies.
Member Since: November 6, 2010 Posts: 12 Comments: 8472

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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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