An Atlantic tropical wave worth watching

By: Dr. Jeff Masters , 2:46 PM GMT on October 04, 2009

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A large tropical wave near 9N 40W, midway between Africa and the Lesser Antilles Islands, is generating a considerable amount of heavy thunderstorm activity as it moves west to west-northwest at 15 mph. The wave is under about 10 - 15 knots of wind shear, and this morning's QuikSCAT pass showed a large and disorganized region of converging winds in the region, with top winds of 25 mph. There is very little dry air in the vicinity, and conditions appear favorable for some slow development of this wave. None of the computer models develop the wave, but they do show relatively low wind shear along the wave's path for the next five days. The wave should reach the Lesser Antilles Islands by Wednesday.


Figure 1. The large tropical wave in the middle Atlantic.

In the Philippines, Tropical Storm Parma continues to linger offshore the northern tip of the Philippines' Luzon Island, bringing heavy rain. The storm has been blamed for the deaths of 17 people in the Philippines, but has not not had the devastating impact that was earlier feared. Parma's heaviest rains will stay offshore of the Philippines today (Figure 2).


Figure 2. Forecast rain amounts for Parma for the 24-hour period ending at 06 UTC October 5 (2am EDT Monday). This forecast is based on satellite measurements of Parma's current rainfall rate, plus a projection of the storm's path. Four to eight inches of rain (yellow colors) is expected along the extreme northwest tip of Luzon Island. Image credit: NOAA Satellite Services Division.

Super Typhoon Melor hits Cat 5 strength
Super Typhoon Melor has become the second Category 5 tropical cyclone of the year. Melor is expected to recurve to the north pass just south of the coast of Japan later this week.

Jeff Masters

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Quoting Skyepony:



It pretty much ran over a weather station in the heat of the day & managed a high of 71F, high wind of 31mph, gust to 44mph, 997mb was the lowest as it past through the S side of the COC. 0.08 in / 0.2 cm. 71F isn't warm core..


A warm core is not a warm temperature. A warm core is where the temperature is warmer than the surroundings. So you are saying the temperature has to be above a certain temperature for it to be warm-core? No. A warm core is when the temperature at the center of a system is warmer than the surrounding temperature.

Member Since: July 24, 2005 Posts: 407 Comments: 19076
Quoting GeoffreyWPB:
Drak...as you see it now...do you think we will have a named system approaching the Islands in three or so days?


If it can organize a surface low. Upper level winds appear most conducive south of 15N in the forecast and then becomes marginal above 15N. The models track the 850mb vorticity maximum towards the WNW towards the northern Lesser Antilles where the system would approach and deep-layered trough. The 850mb trough axis is what they expect will be enough to steering this system away from the Caribbean. I, however, am skeptical of this. If the system remains at a low latitude and bypasses the trough axis, then it will come under a ridge while moving into the Caribbean.
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AL 90 2009100500 BEST 0 402N 213W 40 992 EX


SHIPS Text
Member Since: September 23, 2005 Posts: 13 Comments: 10469
585. Skyepony (Mod)
Quoting Weather456:


It is unlikely phase diagrams are correct with 90L. 90L is a meso-scale feature and thus cannot be accurately measured and analyzed on global models, the two spatial resolution are not the same, thus there is error involved. In addition, the error is so evident that the phase of 90L differs from model to model.

It is unlikely that such convection is not generating some level of latent heat. Also 90L is non-frontal.



It pretty much ran over a weather station in the heat of the day & managed a high of 71F, high wind of 31mph, gust to 44mph, 997mb was the lowest as it past through the S side of the COC. 0.08 in / 0.2 cm. 71F isn't warm core..
Member Since: August 10, 2005 Posts: 156 Comments: 36156
583. beell
Check out the MIMIC loop on that Azores Low.
MIMIC_TPW

Member Since: September 11, 2007 Posts: 137 Comments: 15353
Quoting stormwatcherCI:
I think you need to go do your homework. Drak knows quite a bit and is also rated by StormW.


first time I ever got an ignore list, I placed him on it. *headaches*
Member Since: July 24, 2005 Posts: 407 Comments: 19076
Drak...as you see it now...do you think we will have a named system approaching the Islands in three or so days?
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Quoting hurricaneseason2006:


Drak you said this feature won't develop convection and will have trouble getting a surface circulation earlier today. You have proven on many accounts that you don't what you talking about. Leave it to the experts and go do your homework.
I think you need to go do your homework. Drak knows quite a bit and is also rated by StormW.
Member Since: October 9, 2008 Posts: 0 Comments: 8242
People need to chill on here and respect everybodys opinion. If it's wrong who cares? They tried.
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actually, the CATL has been supporting some pretty fiesty looking waves for a little over a week now...or has it been all summer?
i lose track.
kept thinking something would develop near the caribbean and nothing did.
so, going with my first thought, am not going to speculate on this one.
Member Since: July 11, 2006 Posts: 14 Comments: 11047
577. jipmg
Quoting Drakoen:
The evening's quickscat pass showed two areas at which the AOI is trying to bend the surface flow one near 42-43W and another near 46W. The inverted-V pattern is more distinct near 42W-43W.


link my friend
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Definitely looking good…Future 91L
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573. Skyepony (Mod)
Quoting Weather456:
Thats best tropically looking extratropical storm ever.




I think it's relative..from this view the swirl around 30n25w looks more impressive..



Member Since: August 10, 2005 Posts: 156 Comments: 36156
Quoting VAbeachhurricanes:


hey, whats your thought on the Azores low?


Same as the NHC
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TornadoDude - And not a moment too soon, I might add.
Member Since: March 10, 2006 Posts: 0 Comments: 9753
Quoting Drakoen:
The evening's quickscat pass showed two areas at which the AOI is trying to bend the surface flow one near 42-43W and another near 46W. The inverted-V pattern is more distinct near 42W-43W.



Link
Member Since: July 11, 2006 Posts: 14 Comments: 11047
This upper level divergence is looking very favorable for something to get going at the surface. Improving MJO evidence?

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Quoting tornadodude:
It appears that the ITCZ seems to be migrating farther south, possibly putting an end to the Cape Verde season

cv season is done till we meet again in 2010
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Quoting Drakoen:
The evening's quickscat pass showed two areas at which the AOI is trying to bend the surface flow one near 42-43W and another near 46W. The inverted-V pattern is more distinct near 42W-43W.


hey, whats your thought on the Azores low?
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The evening's quickscat pass showed two areas at which the AOI is trying to bend the surface flow one near 42-43W and another near 46W. The inverted-V pattern is more distinct near 42W-43W.
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Quoting kmanislander:
Dinner time so out for a while. Will be back a bit later.
Enjoy your meal and look forward to your input.
Member Since: October 9, 2008 Posts: 0 Comments: 8242
It appears that the ITCZ seems to be migrating farther south, possibly putting an end to the Cape Verde season

Member Since: June 28, 2006 Posts: 24 Comments: 8185
563. beell
Quoting Weather456:
Thats best tropically looking extratropical storm ever.




It is a very fine looking tiny feature embedded in a North Atlantic Low Pressure System trailing a cold front behind it.
(j/k)
Member Since: September 11, 2007 Posts: 137 Comments: 15353
Quoting Skyepony:
Bet those air temps in the upper 60s make ex-90L feel more like a nor'easter. No wonder it's currently cold core. Notice how weak when at all warm core.


It is unlikely phase diagrams are correct with 90L. 90L is a meso-scale feature and thus cannot be accurately measured and analyzed on global models, the two spatial resolution are not the same, thus there is error involved. In addition, the error is so evident that the phase of 90L differs from model to model.

It is unlikely that such convection is not generating some level of latent heat. Also 90L is non-frontal.
Member Since: July 24, 2005 Posts: 407 Comments: 19076
Thats best tropically looking extratropical storm ever.


Member Since: July 24, 2005 Posts: 407 Comments: 19076
Evening wunderblogfolk. Hope everyone's had a nice weekend. Do we have in invest in the making?
Member Since: July 11, 2006 Posts: 14 Comments: 11047
Unfortunately (in some way) every system is named in the European Union, every high, every low. So how could you differ?
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latest still AOI 13n/39w
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557. Skyepony (Mod)
Bet those air temps in the upper 60s make ex-90L feel more like a nor'easter. No wonder it's currently cold core. Notice how weak when at all warm core.
Member Since: August 10, 2005 Posts: 156 Comments: 36156
Quoting barbamz:
Wow, I'm really proud of our cute little European Hurricane. Perhaps we should have our own NHC? Good night. It's very late in Germany. It has been an interesting evening together with you. Barbara


Maybe the European Union can get together and figure out what to call it. No harm meant, of course.
Member Since: August 25, 2009 Posts: 20 Comments: 6785
Dinner time so out for a while. Will be back a bit later.
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Quoting OracleDeAtlantis:
Interesting .... ....



That's actually old from around 5 this morning
Member Since: July 24, 2005 Posts: 407 Comments: 19076
Extratropical AL90 is back

AL 90 2009100418 BEST 0 388N 239W 40 994 EX
Member Since: September 23, 2005 Posts: 13 Comments: 10469
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Wow, I'm really proud of our cute little European Hurricane. Perhaps we should have our own NHC? Good night. It's very late in Germany. It has been an interesting evening together with you. Barbara
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Interesting .... ....

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from 8pm TWD
...TROPICAL WAVES...

AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 40W/41W TO THE SOUTH OF
15N MOVING WESTWARD 15 KT. A LARGE CYCLONIC ENVELOPE FROM THE
SURFACE UPWARD COVERS THE AREA FROM THE ITCZ TO 17N BETWEEN 35W
AND 47W. IT LOOKS LIKE TWO OR THREE DISTINCT AXES OF LOW
PRESSURE MAY BE SPOTTED IN VISIBLE IMAGERY. STRONG SHOWERS AND
THUNDERSTORMS FROM 9N TO 15N BETWEEN 39W AND 45W. SCATTERED
MODERATE SHOWERS TO ISOLATED STRONG THUNDERSTORMS FROM 5N TO 10N
BETWEEN 31W AND 37W.
Member Since: June 13, 2009 Posts: 2 Comments: 9595
Quoting wunderkidcayman:

well at least we got a welcoming soaking in west bay


WB always gets a good soaking LOL
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Thanks Dr. Masters for your update today. Hope everyone is having a good day :0). As always peace and be blessed all.

Looks like 2 yellow markers, AOI's; the area W of the Cape Verde Islands looking a bit better this evening, the Azores AOI will most likely be a subject for debate for many. I won't touch that one with a 10' pole.

TS Parma looks like that trough to the NW "took a BIG bite out of it", as it's scheduled to meander around/move SW in the S China Sea, for 5 days. People in Vietnam are probably watching it closely. Where it goes, my bet is $10 on 24 red please, not sure.

Super TY Melor is probably beginning his weakening cycle, hopefully it follows the forecasted track and gives Japan a break. They do NOT need any of that Typhoon.

I'm here in Nashville, TN helping family. It's 55F raining, and I'm used to Ft Worth, TX weather, which is 85F and sunny. Gonna buy some real bright light bulbs to light my daughter's house up, it getting me down. I couldn't imagine living in AK, it would drive me insane. Enough rambling, I'll be around folks! Peace.
Member Since: August 25, 2009 Posts: 20 Comments: 6785
Quoting stormwatcherCI:
You notice the small area south of Jamaica ? Anything there ?

I see that small area it is prob. from the wave 77/78w
Member Since: June 13, 2009 Posts: 2 Comments: 9595
545. JRRP

see u later
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Quoting stormwatcherCI:
You notice the small area south of Jamaica ? Anything there ?


I don't think so. Looks like upper level diffluence on the S side of a ULL that is near the base of a trough. See WV loop
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543. Skyepony (Mod)
Parma weakens, Melor strengthens.
DATE/TIME LAT LON CLASSIFICATION STORM
04/2030 UTC 20.4N 119.3E T2.5/3.5 PARMA -- West Pacific
04/2030 UTC 18.1N 137.0E T7.0/7.0 MELOR -- West Pacific
04/1430 UTC 20.2N 119.5E T3.0/4.0 PARMA -- West Pacific
04/1430 UTC 17.7N 138.5E T6.5/7.0 MELOR -- West Pacific
04/0857 UTC 19.6N 119.7E T4.0/4.0 PARMA -- West Pacific

Member Since: August 10, 2005 Posts: 156 Comments: 36156
Wow - that 90L is a MICROSTORM. It is really small. I've seen several mesocyclones bigger than that.
Member Since: April 5, 2007 Posts: 83 Comments: 12345
The NHC sure like yellow, don't they.
Member Since: August 9, 2009 Posts: 10 Comments: 4504
Member Since: July 24, 2005 Posts: 407 Comments: 19076
Quoting kmanislander:
That's weird. When I first looked at the QS pass half the data was missing but the link I posted now shows a full download of data. LOL
You notice the small area south of Jamaica ? Anything there ?
Member Since: October 9, 2008 Posts: 0 Comments: 8242

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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.