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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What a difference a few hours make. Pre-Ernesto is very persistent and seems to be back on track after some convection loss earlier in the day. Assuming Ernesto does form from this CV wave, the next question (per the historical climatology) is whether we will get an early "cluster" of CV storms over the next 5 weeks, or, whether this storm is an early August anomaly and there will be a break in the action until the late-August/early-September period.

Starting to look, at this point, like a possible unfavorable steering pattern going into August that favors these types of trajectories as metioned by Dr. M a few days ago as opposed to fish storms for the time being. Not good if this general AB-High pattern continues in the next 4-6 weeks.


Member Since: August 8, 2006 Posts: 0 Comments: 8278
Quoting CybrTeddy:
Surprised they went ahead and upgraded 99L to TD5.

Now the real fun begins, we have a tropical cyclone. Got to admit, if TD5 becomes Ernesto we're still well ahead of schedule.

We're on par with 2011...exactly. Tropical Storm Emily developed on this day last year. Just a tad farther west too..
Member Since: July 6, 2010 Posts: 108 Comments: 30254
TS watches will need to be posted for the islands, as the system is already producing 40mph gusts and heavy rain, this warrants TS advisories as of now
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Improvement on the winds as well
Member Since: March 16, 2012 Posts: 123 Comments: 7886
1132. BDAwx
Meanwhile, in the West Pacific, the eye of Typhoon Damrey is now on radar out of Shanghai.
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Quoting Neapolitan:
As Dr. Masters noted above, Chandler, Oklahoma, reached 113 yesterday. It reached 115 just a bit ago:

hot

...and many other areas around the state are very toasty; some all-time highs are in jeopardy of falling:

hot

hot

It's strange to think that it is so hot not so far away from where I am, where we have had a cooler than average July.
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Can we please stop criticizing the experts now on their choice of when to classify things?
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Quoting doabarrelroll:


ok... creeper...

All im saying is we are entitled to our opinion. I am in no way diminishing those that died during Katrina. But please dont act like you are the only one to have seen a true disaster on this blog. I still have nightmares.


mean!
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Surprised they went ahead and upgraded 99L to TD5.

Now the real fun begins, we have a tropical cyclone. Got to admit, if TD5 becomes Ernesto we're still well ahead of schedule.
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Quoting Grothar:


Gee, thanks for remembering me, TA? :P

It's okay Gro, we'll find a better category for you.
Member Since: July 6, 2010 Posts: 108 Comments: 30254
Quoting 19N81W:
center fully exposed now? looks like it may come back down to 30%....who knows but like I said yesterday not doing anything quickly this one....
Hello? It already did, it's a TD...
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Quoting Grothar:


Gee, thanks for remembering me, TA? :P

You have your own category.
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Quoting 19N81W:
center fully exposed now? looks like it may come back down to 30%....who knows but like I said yesterday not doing anything quickly this one....
you know it is a td right?
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Quoting StormTracker2K:
13N and moving WNW and even NW at times. I think the CMC or UKMET will win out on this one. Stronger storm getting pulled north. Those in North or South Carolina neead to really watch this as well as we remember very well what happened with Hurricane Irene.

Yeah...I highly doubt that.
Member Since: July 6, 2010 Posts: 108 Comments: 30254
Quoting StormTracker2K:


What's that Gro 13N. I better run before the TX peeps come out with spears. LOL!

My spear is currently being sharpened. Had to use it too much yesterday with #$Q^%^#%$^# car salesmen.
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Quoting StormJunkie:


Nice Bluestorm. I use to love breaking out the paper maps...And listening to the marine radio to get updates between the new broadcasts.

Hey Chuctown, good to see ya.


What's up SJ, gotta keep Ernesto along that southern track. That's all we need is a TS along the SE US coast during the PGA next week.
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1120. Grothar
Quoting TropicalAnalystwx13:

I don't know...I think Kori and I would be good candidates as well.


Gee, thanks for remembering me, TA? :P
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Tropical Depression FIVE.
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13N and moving WNW and even NW at times. I think the CMC or UKMET will win out on this one. Stronger storm getting pulled north. Those in North or South Carolina need to really watch this as well as we remember very well what happened with Hurricane Irene.
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1117. KEEPEROFTHEGATE (Mod)
05L/TD/E/CX
MARK
11.03N/47.68W
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Quoting TropicalAnalystwx13:

I don't know...I think Kori and I would be good candidates as well.

I'll toss my hat in there, too.
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1115. Grothar
Quoting StormTracker2K:


What's that Gro 13N. I better run before the TX peeps come out with spears. LOL!


Big LOL!
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Quoting MississippiWx:


LOL. You still haven't heard of one doing it because I'm not sure I fall under the expert or well-respected blogger category. If you had a smarta## category, I'd be tops.

You know, it is possible to be in both the well-respected AND smarta** category.

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Quoting Stormchaser2007:


Hey NRT (Thanks for the BAM confirmation this morning BTW)

Yes I saw that. I plotted it out earlier when it came out.




I like this track maybe a tad to the north IMO
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Quoting MississippiWx:


LOL. You still haven't heard of one doing it because I'm not sure I fall under the expert or well-respected blogger category. If you had a smarta## category, I'd be tops.

I don't know...I think Kori and I would be good candidates as well.
Member Since: July 6, 2010 Posts: 108 Comments: 30254
As Dr. Masters noted above, Chandler, Oklahoma, reached 113 yesterday. It reached 115 just a bit ago:

hot

...and many other areas around the state are very toasty; some all-time highs are in jeopardy of falling:

hot

hot
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1110. SLU
172

WHXX01 KWBC 012009

CHGHUR

TROPICAL CYCLONE GUIDANCE MESSAGE

NWS NATIONAL HURRICANE CENTER MIAMI FL

2009 UTC WED AUG 1 2012



DISCLAIMER...NUMERICAL MODELS ARE SUBJECT TO LARGE ERRORS.

PLEASE REFER TO NHC OFFICIAL FORECASTS FOR TROPICAL CYCLONE

AND SUBTROPICAL CYCLONE INFORMATION.



ATLANTIC OBJECTIVE AIDS FOR



TROPICAL CYCLONE FIVE (AL052012) 20120801 1800 UTC



...00 HRS... ...12 HRS... ...24 HRS. .. ...36 HRS...

120801 1800 120802 0600 120802 1800 120803 0600



LAT LON LAT LON LAT LON LAT LON

BAMS 12.0N 48.2W 12.7N 51.4W 13.4N 54.4W 14.0N 57.5W

BAMD 12.0N 48.2W 12.5N 50.1W 13.0N 51.9W 13.4N 53.7W

BAMM 12.0N 48.2W 12.6N 50.6W 13.2N 52.9W 13.7N 55.2W

LBAR 12.0N 48.2W 12.6N 50.7W 13.4N 53.4W 14.0N 56.1W

SHIP 30KTS 33KTS 37KTS 41KTS

DSHP 30KTS 33KTS 37KTS 41KTS



...48 HRS... ...72 HRS... ...96 HRS. .. ..120 HRS...

120803 1800 120804 1800 120805 1800 120806 1800



LAT LON LAT LON LAT LON LAT LON

BAMS 14.7N 60.6W 16.6N 67.0W 18.7N 73.9W 20.2N 79.9W

BAMD 14.1N 55.6W 15.7N 59.3W 16.6N 62.5W 16.0N 64.6W

BAMM 14.5N 57.9W 16.7N 63.5W 19.0N 69.8W 21.0N 75.5W

LBAR 14.8N 58.8W 17.0N 64.3W 19.1N 69.9W 20.9N 73.6W

SHIP 46KTS 54KTS 59KTS 64KTS

DSHP 46KTS 54KTS 59KTS 64KTS



...INITIAL CONDITIONS...

LATCUR = 12.0N LONCUR = 48.2W DIRCUR = 290DEG SPDCUR = 16KT

LATM12 = 10.9N LONM12 = 45.3W DIRM12 = 290DEG SPDM12 = 16KT

LATM24 = 9.7N LONM24 = 41.7W

WNDCUR = 30KT RMAXWD = 50NM WNDM12 = 25KT

CENPRS = 1008MB OUTPRS = 1012MB OUTRAD = 150NM SDEPTH = M

RD34NE = 0NM RD34SE = 0NM RD34SW = 0NM RD34NW = 0NM



$$

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Quoting 1031.MississippiWx:
For the first time today, it appears that the center is underneath the cloud canopy.
Looks like Foghorn Leghorn
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Quoting Bluestorm5:
My favorite thing during hurricane season? Marking the current position down on hurricane tracking maps :) I thought I would use my new graphics for my tracking map. What y'all think?



And I see that it's now a Tropical Depression 5... whoops!



Nice Bluestorm. I use to love breaking out the paper maps...And listening to the marine radio to get updates between the new broadcasts.

Hey Chuctown, good to see ya.
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Quoting 19N81W:
center fully exposed now? looks like it may come back down to 30%....who knows but like I said yesterday not doing anything quickly this one....

It's a tropical depression...
Member Since: July 6, 2010 Posts: 108 Comments: 30254
Quoting Grothar:
Getting very close to 13 as well.




What's that Gro 13N. I better run before the TX peeps come out with spears. LOL!
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Quoting afj3:
Hello all!
When do advisories begin?

5pm EDT and they should be interesting for sure.
Member Since: March 16, 2012 Posts: 123 Comments: 7886
1104. GetReal


Hello TD #5... Still tracking just north of due west.
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Quoting tropicfreak:


I've never heard an expert or well respected blogger on here vent at the NHC ;). Guess they heard ya! :)


LOL. You still haven't heard of one doing it because I'm not sure I fall under the expert or well-respected blogger category. If you had a smarta## category, I'd be tops.
Member Since: July 15, 2006 Posts: 17 Comments: 10156
Quoting Matt1989:
Please can we keep the wishcasting to ourselves?? atleast until this thing is closer to actually hitting the US..


Technically, we are by talking about it in this blog.

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1101. 19N81W
center fully exposed now? looks like it may come back down to 30%....who knows but like I said yesterday not doing anything quickly this one....
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Quoting Stormchaser2007:


Tropical or GW related? :P
Well, climate and weather are related, much as some might wish things were otherwise... ;-)
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Quoting KEEPEROFTHEGATE:
one clue JFV


SHUT UP! Get out!

the blog is ready to go crazy now that we have a TD!!! yay!!
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New hand drawn keeps the storm further south, impacting the Yucatan by next week.
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Quoting Stormchaser2007:


Tropical or GW related? :P

He actually talked about tropical weather. They touched briefly on the developing El Nino and he said it hasn't had a significant impact on the hurricane season yet.
Member Since: July 6, 2010 Posts: 108 Comments: 30254
1096. afj3
Hello all!
When do advisories begin?
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1095. HadesGodWyvern (Mod)
Japan Meteorological Agency
Tropical Cyclone Advisory #1
TROPICAL DEPRESSION 12
3:00 AM JST August 2 2012
=============================================

SUBJECT: Tropical Depression Near Ogasawara Water

At 18:00 PM UTC, Tropical Depression (1002 hPa) located at 23.4N 146.3E has 10 minute sustained winds of 30 knots with gusts of 45 knots. The depression is reported as almost stationary.

Dvorak Intensity: T2.0

Forecast and Intensity
==========================

24 HRS: 23.4N 142.3E - 35 knots (CAT 1/Tropical Storm) - Ogasawara Waters

Japan Meteorological Agency
Tropical Cyclone Advisory #47
SEVERE TROPICAL STORM DAMREY (1210)
3:00 AM JST August 2 2012
=============================================

SUBJECT: Category Two Typhoon In East China Sea

At 18:00 PM UTC, Severe Tropical Storm Damrey (980 hPa) located at 31.7N 127.0E has 10 minute sustained winds of 50 knots with gusts of 70 knots. The cyclone is reported as moving northwest at 20 knots.

Dvorak Intensity: T3.0

Gale Force Winds
=================
210 NM from the center in east quadrant
150 NM from the center in west quadrant

Forecast and Intensity
==========================

24 HRS: 34.5N 120.1E - 45 knots (CAT 1/Tropical Storm) - Yellow Sea
48 HRS: 37.4N 116.8E - Tropical Depression Overland northern China

Japan Meteorological Agency
Tropical Cyclone Advisory #47
TYPHOON SAOLA (1209)
3:00 AM JST August 2 2012
=============================================

SUBJECT: Category Three Typhoon South Of Okinawa

At 18:00 PM UTC, Typhoon Saola (970 hPa) located at 24.2N 122.2E has 10 minute sustained winds of 65 knots with gusts of 95 knots. The cyclone is reported as moving west northwest slowly.

Dvorak Intensity: T4.0

Storm Force Winds
=================
50 NM from the center

Gale Force Winds
================
300 NM from the center in southeast quadrant
250 NM from the center in northwest quadrant

Forecast and Intensity
==========================

24 HRS: 26.7N 121.1E - 65 knots (CAT 3/Strong Typhoon) - East China Sea
48 HRS: 30.6N 116.6E - Tropical Depression Overland Central China
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1094. Grothar
Getting very close to 13 as well.


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Quoting Bluestorm5:
My favorite thing during hurricane season? Marking the current position down on hurricane tracking maps :) I thought I would use my new graphics for my tracking map. What y'all think?


You know I like the tracking map and forecast graphic!
Member Since: March 16, 2012 Posts: 123 Comments: 7886
Quoting StormTracker2K:


I'm talking in 8 days not in 2 to 3 days as 99L gets near Jamaica.



ST2K, I love your posts and you nailed Debby, but I just disagree with you here...respectfully.
Member Since: July 15, 2006 Posts: 17 Comments: 10156
1091. SLU
This shows you how conservative the TWO has been in the last couple of days.
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I told you guys now hello TD5
Member Since: June 13, 2009 Posts: 2 Comments: 9560
You all have to remember that along with persistent convection and a closed circulation, the next biggest factor in declaration of a tropical depression is blog activity and comments! The NHC had no choice.
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1088. GetReal


A good solid core of convection all day.
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My favorite thing during hurricane season? Marking the current position down on hurricane tracking maps :) I thought I would use my new graphics for my tracking map. What y'all think?



And I see that it's now a Tropical Depression 5... whoops!

Member Since: August 1, 2011 Posts: 23 Comments: 7463
1086. Chiggy
Quoting allancalderini:
we have tropical depression 5 the same day Emily form last year.coincidence.

LOL
Member Since: June 26, 2012 Posts: 0 Comments: 297

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About JeffMasters

Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.