The Atlantic is quiet; Russian heat wave ends; huge 926 mb South Indian Ocean storm

By: Dr. Jeff Masters , 2:09 PM GMT on August 19, 2010

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A tropical wave in the western Caribbean approaching Mexico's Yucatan Peninsula is generating disorganized thunderstorms. Wind shear is a moderate 10 - 15 knots over the region, and water vapor satellite images show that there is some dry air to the west that will interfere with any development that might occur. None of the reliable computer models develop this wave, and NHC is giving it a 10% chance of developing into a tropical depression.


Figure 1. Morning satellite image of the disturbed region of weather of the coast of Africa, south of the Cape Verdes Islands.

The GFS, NOGAPS, and ECMWF models continue to predict that a tropical storm will form between Africa and the Lesser Antilles Islands sometime in the period 3 - 6 days from now. There is an area of disturbed weather south of the Cape Verdes Islands, but there is no obvious organization to the cloud pattern. Wind shear is a hefty 20 - 30 knots in the region, and the disturbance is a 1 - 2 day journey away from reaching a lower shear area where development can occur. Preliminary indications are that if a storm did develop in this region, it would track west-northwest and pass well to the northeast of the Lesser Antilles Islands 7 - 8 days from now. However, 7-day forecasts of a storm that hasn't even formed yet are not to be trusted.


Figure 2. The cold front that brought an end to the Great Russian Heat Wave of 2010 lies east of Moscow in the NASA MODIS photo taken at 8:35 UTC August 19, 2010. Smoke from wildfires is visible over a wide swath of Russia east of the front. Image credit: NASA.

The Great Russian Heat Wave of 2010 ends
A powerful cold front swept through Russia yesterday and today, finally bringing an end to the Great Russian Heat Wave of 2010. Temperatures at Moscow's Domodedovo airport hit 25°C (77°F) today, which is still 4°C (7°F) above average, but the high temperature since late June. Moscow has seen 62 consecutive days with a high temperature above average, but the latest forecast for Moscow predicts that remarkable string will come to an end Friday, when the high will reach just 17°C (62°F).

Massive 926 mb extratropical storm generating huge waves off Antarctica
One of the most intense extratropical storms in recent years is churning up the waters near the coast of Antarctica in the South Indian Ocean. The powerful storm peaked in intensity yesterday afternoon with a central pressure of 926 mb--the type of pressure typically found in a Category 4 hurricane. Storms this intense form on average once per year, or perhaps less often, according to an email I received from Jeff Callaghan of the Australia Bureau of Meteorology. Since extratropical storms do not form eyewalls, the winds at the surface from this monster storm probably reached "only" 100 - 120 mph (equivalent to a Category 2 or 3 hurricane.) The storm is forecast to generate huge waves with a significant wave height of 13 meters (44 feet) today, according to the NOAA Wavewatch III model (Figure 3.) I have flown into an extratropical storm this intense--in 1989, I participated in a field project based in Maine that intercepted a remarkable extratropical storm that "bombed" into a 928 mb low south of the Canadian Maritime provinces. You can read my story of that somewhat harrowing flight here.


Figure 3. Satellite image taken at 8:10 UTC August 19, 2010, showing the intense extratropical cyclone that has weakened to 940 mb in the South Indian Ocean near the coast of Antarctica. Image credit: NASA.


Figure 4. Surface pressure analysis from 18 UTC August 18, 2010, showing a 926 mb low in the South Indian Ocean, just north of Antarctica. Image credit: Jeff Callaghan, Australia Bureau of Meteorology.


Figure 5. Predicted wave height from the NOAA Wavewatch III model for 2pm EDT (18 UTC) today, August 19, 2010. Peak wave heights of 13 meters (44 feet) are projected over ocean areas between Antarctica and Australia. Long-period waves (19 seconds between crests) up to 7 meters (22 feet) high are predicted to affect the southwest coast of Australia by Sunday. The waves are predicted to propagate eastwards to New Zealand 8 - 9 days from now, and be a respectable 4 - 5 meters high then.

Jeff Masters

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2377. scott39
westward
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2376. Jax82
Quoting StormW:
And looking at this "Supertrof" is at the least, 1 week away (west of the west coast)



Is that an ULL north of PR? If so, where is it expected to go?
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2375. wxhatt
Good Morning Storm,

I see things are geting more active again right on time. Should we be concerned about any potential future landfall with 95L?
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Quoting calder:


Hey, dunno if you can see my comments.. U based in scotland?


Not in Scotland, but in the UK, yes.
Member Since: August 23, 2008 Posts: 7 Comments: 5300
Is the High in the Central and Western Atlantic supposed to get stronger and move westward? Is there a weakness associated with this?

According to what I learned from Storm, if the high builds larger and encompasses a lot of the central and western atlantic with a weakness, it should increases chances of us land fall.
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2370. SQUAWK
Quoting StormW:


you can't have a deeper trof with a flat ridge or zonal flow. Period.


Got it! Thanks.
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Quoting StormW:
Adrian, you can't have a deeper trof with a flat ridge or zonal flow. Period.


Stormw let be the first to admit that this isn't my specialty.

However, It may also be related to tropical forcing from the westerly wind burst that occurred in the Pacific last week. That transfer of energy to the mid-latitudes will force the subtropical ridge back toward the Southern Plains/Four Corners and allow the trough to deepen over the Eastern U.S. With weak background flow near the Carolinas, it will also allow an upper low to cutoff temporarily. As the ridge shifts back eastward due to tropical WAA over the Southeast, the trough will kick out into the NW Atlantic.
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2313! KanKunKid!

Too funny dude!

I can't help but to wonder if somewhere in Japan, there is a Wunderblog type tropical weather discussion in Japanese. they're all looking at the west coast of Mexico and writing:
"It's a fish, I tell you!"
"What you saying? This is Pacific! They all fish!"
"No! No. Not this time Sakura1985! I have gut feeling!"
"NO! NO! Look at chart! See? It recurves and hit Hawaii!"
"You can't trust model so far out, I say it come here and knock socks off!"
" You crazy you drink too much saki last night"
" Well you...This comment cut off with samurai sword for being in violation of honor.
Member Since: July 25, 2006 Posts: 0 Comments: 563
Quoting StormW:


Yes..and here's the kicker...talk about models, the models take it out to sea quicker than 95L.


So that would mean it gets really strong, very quickly. Or, do you feel the same about it as 95L, that the models are reading into a trough more than they should? Thanks so much :)

Kelley
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2365. SQUAWK
Hey "killer," good to see you.

Quoting hurricane23:
Stormw i wanted to reply to a question you posted on the blog yesterday if you dont mind.

Here's your question...

The A/B high and Icelandic low. I'm looking at it in the manner of, if you have a ridge over the U.S., which should be pumping the trof east of it, which will be the one dipping down, the strength of the trof depends on the strength of that ridge. Then east of the trof, you have the A/B high. Look at he shallow layer mean...both centers of the Atlantic ridge are weaker, which correlates to the current NAO state...the trof in the middle is weak. So my question is, and hopefully you can shed some light, is, if the western portion of the A/B high is weak near the east coast, how do we have a stronger trof in place, as in the trof being wedged in between whatever ridge is over the U.S., and then the A/B high?

All the points bolded, generally correlate well together. However, in the modeling world:

A. The framework of the models doesn't always output what we tend to correlate with reality, epecially many days out.

B. The relationships in bold, especially in model world, can easily become weaker, because models inherently must interpolate grid points via adjacent data points, and then try and integrate them over time with their given physics packages. So what is the model to do when it gets data, interpolates them into their gridpoints, and it doesn't "fit" into our preconceived notions of "ridge pumping = deeper trough"?? Well, if it sees a "flatter ridge at initialization, BUT a deeper trough, that's what it is going to depict....and remember, we are talking days and days out. The representation of these features in detail will verify FAR differently than any one model can depict them now. So it's not a matter of a model "mistakenly" doing something that is "nonsense" vs. a previous run.....the model doesn't know it ran before!!!! It is all within the chaotic noise that outputs can be at these time ranges.

adrian
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Alot will depend on the ridge of high pressure eurpoean models are starting to hint to a stronger high next week
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2363. calder
Quoting Cotillion:


Yeah, of course.

We don't typically get these gales for another couple of months (this is supposed to reach a height of 985mb according to the UKMO's synoptic charts), but it happens.


Hey, dunno if you can see my comments.. U based in scotland?
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Quoting kshipre1:
Storm,

can you please briefly explain the four table NAO chart that you are saying ouch about?

I can not properly read it due to the letters being blurry.

Also, are you saying ouch because of the potential track of future storms?

Thanks


Hey I know this is kinda off subject but just thought I'd let cha know, you can hold down CTRL and press + no shift key is needed and it will make the text as big as ya need it and you can do the same to make it small but use the - key, I have to do it cause my poor contacts our wore out. LOL Just thought it might help.
sheri
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20/1145 UTC 11.0N 25.7W T1.0/1.0 95L -- Atlantic

SAB
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Stormw i wanted to reply to a question you posted on the blog yesterday if you dont mind.

Here's your question...

The A/B high and Icelandic low. I'm looking at it in the manner of, if you have a ridge over the U.S., which should be pumping the trof east of it, which will be the one dipping down, the strength of the trof depends on the strength of that ridge. Then east of the trof, you have the A/B high. Look at he shallow layer mean...both centers of the Atlantic ridge are weaker, which correlates to the current NAO state...the trof in the middle is weak. So my question is, and hopefully you can shed some light, is, if the western portion of the A/B high is weak near the east coast, how do we have a stronger trof in place, as in the trof being wedged in between whatever ridge is over the U.S., and then the A/B high?

All the points bolded, generally correlate well together. However, in the modeling world:

A. The framework of the models doesn't always output what we tend to correlate with reality, epecially many days out.

B. The relationships in bold, especially in model world, can easily become weaker, because models inherently must interpolate grid points via adjacent data points, and then try and integrate them over time with their given physics packages. So what is the model to do when it gets data, interpolates them into their gridpoints, and it doesn't "fit" into our preconceived notions of "ridge pumping = deeper trough"?? Well, if it sees a "flatter ridge at initialization, BUT a deeper trough, that's what it is going to depict....and remember, we are talking days and days out. The representation of these features in detail will verify FAR differently than any one model can depict them now. So it's not a matter of a model "mistakenly" doing something that is "nonsense" vs. a previous run.....the model doesn't know it ran before!!!! It is all within the chaotic noise that outputs can be at these time ranges.

adrian
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Thanks Storm. So, let me see if I can apply what you taught me and if I understand. That means a more positive NAO is coming? Thanks
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Is ex TD5 supposed to loop back into the Gulf for the 2nd time around?
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Quoting Jax82:


That is from yesterday evening.
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Quoting StormW:
Storm, are you concerned about this area because it will exit Africa lower or is there another reason? Thank you for you time.

Kelley
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Quoting weatherguy03:
Tropical Update Aug. 20th. 2010


Thanks for the update Bob!
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2351. SQUAWK
2313. KanKunKid 10:25 AM EDT on August 20, 2010

Funny!
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I am still not sold on the storm recurving out to sea, there are things that can mess up in a matter of days with the "recurvature" pattern, we are in a negative NAO, weaker highs, but doesn't mean the troughs are strong. This pattern reminds me of Frances in 2004.
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Tropical Update Aug. 20th. 2010
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Quoting hydrus:
Every time I see that satellite picture I remember the 1979 Fastnet disaster.


Yeah, of course.

We don't typically get these gales for another couple of months (this is supposed to reach a height of 985mb according to the UKMO's synoptic charts), but it happens.
Member Since: August 23, 2008 Posts: 7 Comments: 5300
2340

DestinJeff?!?!
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Quoting Hardcoreweather2010:


Looks a tad familiar to when Frances was an invest..
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NEW TROPICAL STORM FORECAST TO DEVELOP AFTER 60 HOURS
FORECAST POSITION AT T+ 60 : 14.6N 33.1W

VERIFYING TIME POSITION STRENGTH TENDENCY
-------------- -------- -------- --------
12UTC 22.08.2010 14.6N 33.1W WEAK
00UTC 23.08.2010 16.0N 36.3W WEAK LITTLE CHANGE
12UTC 23.08.2010 16.7N 39.2W WEAK LITTLE CHANGE
00UTC 24.08.2010 18.4N 42.7W WEAK INTENSIFYING SLIGHTLY
12UTC 24.08.2010 20.2N 45.6W MODERATE LITTLE CHANGE
00UTC 25.08.2010 22.2N 47.9W MODERATE INTENSIFYING SLIGHTLY
12UTC 25.08.2010 24.5N 49.8W STRONG LITTLE CHANGE
00UTC 26.08.2010 26.6N 50.9W STRONG INTENSIFYING SLIGHTLY


THIS INFORMATION IS PROVIDED AS GUIDANCE FOR TROPICAL CYCLONE
RSMCS. IT REQUIRES INTERPRETATION BY TROPICAL CYCLONE SPECIALISTS
AND SHOULD NOT BE CONSIDERED AS A FINAL PRODUCT


MET OFFICE, EXETER, UK

TOO 200458

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Difficult to describe this season...Barbarians at the(ULL)Gate?
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Howdy all...
Member Since: July 30, 2010 Posts: 0 Comments: 491
Quoting Jax82:


doh! missed again
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2335. Jax82
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2334. angiest
Quoting Stormchaser2007:
The BAMS suite has this going out to sea, but climatology disagrees somewhat.

Top 10 analog tracks for 95L



Donna, eh?
Member Since: August 26, 2006 Posts: 16 Comments: 4766
Quoting duajones78413:
How long until 95 is named?


I don't know (looks at watch) what time you got lol!
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2328....Now thats Funny!
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How long until 95 is named?
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2327. hydrus
Quoting 900MB:
HOLY SHIPS!

Ships has 95L up to 105mph in 96 hours. That would be impressive.

Storm- should East Coast (Montauk) be concerned?
Thx as always!
Montauk gets whacked by all kinds of storms. In September the Nor,Easters start. And some years the hurricanes..
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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.