New African disturbance 96L likely to develop

By: Dr. Jeff Masters , 2:55 PM GMT on September 07, 2009

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A tropical wave (96L) that emerged off the coast of Africa yesterday has organized rather quickly, and will likely become a tropical depression by Tuesday night. Satellite imagery from the European satellite shows a well-organized circulation, but not enough heavy thunderstorm activity near the center of circulation to be considered a tropical depression. The storm is far enough south that the dry air of the Saharan Air Layer is not a major impediment to development. Wind shear is moderate, 10 - 15 knots, and ocean temperatures are 1 - 2°C above the threshold needed for tropical cyclone formation.


Figure 1. Morning satellite image of 96L, off the coast of Africa. The remains of disturbance 95L, which are under 30 - 40 knots of wind shear, can be seen at upper left.

The forecast for 96L
Most of the models develop 96L, and the chances are that this disturbance will become Tropical Storm Fred later this week. The system will initially move west-northwest, but by Thursday, a strong trough of low pressure passing to 96L's north will pull the storm to the northwest, and may be capable of fully recurving the storm to the northeast. However, most of the models foresee that 96L will not move far enough north for this to happen, and that the storm will have to wait for the next trough of low pressure. With the steering pattern for this year continuing to feature plenty of deep troughs of low pressure moving off the U.S. East Coast, the odds of 96L making it all the way across the Atlantic to threaten land areas appear low. Still, much that is unexpected can and does happen in the world of tropical meteorology, and 96L bears watching.

North Carolina low
An area of concentrated thunderstorms has developed off the North Carolina coast in association with the remains of an old cold front. This system is under about 20 - 30 knots of shear, and is not tropical. However, it will bring heavy rain to eastern North Carolina today and Tuesday, as the storm slides north-northeastward along the coast.

I'll have an update Tuesday.

Jeff Masters

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Awesome pictures of cold-air funnels today that were in the tri-state area.
Link

Note: I did not take the pictures.
Member Since: August 9, 2009 Posts: 10 Comments: 4902
Quoting TheDawnAwakening:
I think TD7 is moving WSW.


it is
Member Since: July 24, 2005 Posts: 407 Comments: 19076
1084. amd
Quoting Dakster:
Let's see if mothernature throws "us" a curve ball with TD7, too...



it's trying to get as far south as possible. Personally, I think the center is further south than any of the satellite fixes.

My evidence, continued SSE winds at buoy 13001 which would not be occurring if the center was north of 11.8 North (latitude of the buoy).

Link
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I think TD7 is moving WSW.
Member Since: October 21, 2008 Posts: 243 Comments: 3690
1082. Levi32
Quoting Weather456:


Saturday evening



It started a bit earlier than that with this tropical wave near the Bahamas when Erika got named on the 1st. By the 3rd (last Thursday), the front had gotten stalled out over the eastern seaboard with the tropical wave approaching. During the 4th and 5th their energies combined, and by yesterday you could see the low starting to form with thunderstorm activity increasing off the SE coast, which has now turned into our hybrid.

September 1st:



September 3rd:



September 6th:



This is the type of situation you look for in a season like this. Storms like Claudette and Danny that formed from tropical waves that didn't have a chance to develop anywhere until they got all the way west to the US coastline where they found the energy needed, sometimes with help from baroclinic systems, to develop.
Member Since: November 24, 2005 Posts: 635 Comments: 26548
Quoting Samantha550:


Hi there who is saying it will track towards us? 9-13 is not lucky for us!


Greg said it whatever it is will move this way towards the weekend. And that it should be watched for development. Channel 12 said it could move by us. And that the air is so moist that when it did we would likely see a lot more rain. He didn't think it would develop, at least he didn't seem too enthused about it developing. I think it's because the ECMWF has come off development. And you know how he is about the EURO. Lol.
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Quoting BurnedAfterPosting:


you are probably seeing that old ULL that was hanging out there before

Yes.
But it seems to be working it's way to the surface at that area as it falls apart generally.
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Quoting CosmicEvents:
weather456..are my eyes playing tricks on me?
Do you see something spinning(just beginning to) around 24-69.


remnants of an upper low
Member Since: July 24, 2005 Posts: 407 Comments: 19076
Quoting BurnedAfterPosting:


It is moving WSW then

NHC had the position at 12.4N I think before


I guess which models predicted that wsw motion just after 1800Z today - the model ensembles.
Member Since: July 24, 2005 Posts: 407 Comments: 19076
Taz, TS Linda was already at 50 knots and 997mb pressure as of the 5pm EDT advisory.
Member Since: October 21, 2008 Posts: 243 Comments: 3690
Quoting CosmicEvents:
weather456..are my eyes playing tricks on me?
Do you see something spinning(just beginning to) around 24-69.


you are probably seeing that old ULL that was hanging out there before
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Multi-platform satellite winds indicate 33 knots or 37 mph, which is normally rounded to 40 mph and that data supports an upgrade



Member Since: July 24, 2005 Posts: 407 Comments: 19076
weather456..are my eyes playing tricks on me?
Do you see something spinning(just beginning to) around 24-69.
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1073. Dakster
Let's see if mothernature throws "us" a curve ball with TD7, too...

Member Since: March 10, 2006 Posts: 0 Comments: 10034
Quoting Weather456:
I'm thinking the NHC kept 07L intensity at 30 knots due to the latest dvorak from SAB

07/2345 UTC 12.0N 25.5W T2.0/2.0 07L



It is moving WSW then

NHC had the position at 12.4N I think before
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I'm thinking the NHC kept 07L intensity at 30 knots due to the latest dvorak from SAB

07/2345 UTC 12.0N 25.5W T2.0/2.0 07L

Member Since: July 24, 2005 Posts: 407 Comments: 19076
Good evening!

07L is still looking very nice.

Member Since: August 9, 2009 Posts: 10 Comments: 4902
1069. Dakster
Quoting serialteg:


i guess you guys are watching the game too


Yeah. It has never been a boring game to watch. Of course, I prefer it when the canes win...

This should be the only Hurricane to hit the Panhandle this year.
Member Since: March 10, 2006 Posts: 0 Comments: 10034
Quoting homelesswanderer:
Good evening all. Just trying to catch up on things. Still watching the gulf. One local says it'll track by us. Another said towards us. One says it will or it won't develop the other maybe. Lol. At least one of them did say the same thing I said this morning...September 13th is not lucky for us. :)


Hi there who is saying it will track towards us? 9-13 is not lucky for us!
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Quoting serialteg:


maybe u can find it here


Great link thanks!
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Could that be the scattered ashes left from the remains of the remnants of Erika spinning up at 24N69W?
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Quoting P451:
Final Visible (4+ hours ago):





IR Loop:


Moving SE.
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Thunderstorms now moving through.....
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Quoting amd:


agreed. don't have a dog in this battle. Would like to see two acc teams play well considering the ACC as a whole has been atrocious this weekend.



i guess you guys are watching the game too
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Quoting P451:


I was about to go to that site to get a second opinion. But ya beat me.
Member Since: July 24, 2005 Posts: 407 Comments: 19076
1061. Relix
TD7 (FRED!!!) won't go west guys. It's nearly a fact that it will get pulled up. It's very hard, (like 1 in a million?) for it to miss that through and weakness. Don't expect Freddie to be anywhere near the Antilles, in fact with what I am seeing and what W456 posted (really man, you are doing a fantastic job lately) I could say this could be one for the Bermuda's or more possibly.. nope.
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Quoting Levi32:
Also this system was a tropical wave in the Bahamas last week while Erika was near the Antilles. It does have tropical origins tied to it.


Saturday evening

Member Since: July 24, 2005 Posts: 407 Comments: 19076
Quoting BurnedAfterPosting:
yea 456 that pic says 35
Quoting amd:


actually according to your picture, it looks like there was a sustained wind of 35 knots right on the coast just to the nne of the low pressure area. But, i could be reading that wrong.



becuz of image auto resizing it looks like 35 but its 15 knots


Open the image in another window or zoom in
Member Since: July 24, 2005 Posts: 407 Comments: 19076
1058. Patrap
NEXRAD Radar
Morehead City, Echo Tops Range 124 NMI




Member Since: July 3, 2005 Posts: 421 Comments: 127601
Quoting Seastep:


Would love a link to that ecmwf if possible, 456.


maybe u can find it here
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1055. will40
Link Levi go here and look at sat wind map
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Even the frogs outside are saying enough with the rain.

This system is nothing compared to a month or so ago when some training thunderstorms dumped 10"+ in a few hours in Havelock, NC.
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1053. Levi32
Also this system was a tropical wave in the Bahamas last week while Erika was near the Antilles. It does have tropical origins tied to it.
Member Since: November 24, 2005 Posts: 635 Comments: 26548
000
WHXX01 KMIA 080036
CHGE77
TROPICAL CYCLONE GUIDANCE MESSAGE
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0036 UTC TUE SEP 8 2009

DISCLAIMER...NUMERICAL MODELS ARE SUBJECT TO LARGE ERRORS.
PLEASE REFER TO NHC OFFICIAL FORECASTS FOR TROPICAL CYCLONE
AND SUBTROPICAL CYCLONE INFORMATION.

EAST PACIFIC OBJECTIVE AIDS FOR

TROPICAL CYCLONE LINDA (EP152009) 20090908 0000 UTC

...00 HRS... ...12 HRS... ...24 HRS. .. ...36 HRS...
090908 0000 090908 1200 090909 0000 090909 1200

LAT LON LAT LON LAT LON LAT LON
BAMS 15.3N 127.5W 15.5N 128.8W 15.8N 129.8W 16.2N 130.8W
BAMD 15.3N 127.5W 15.4N 128.4W 15.8N 129.2W 16.3N 130.1W
BAMM 15.3N 127.5W 15.5N 128.8W 15.8N 130.0W 16.0N 131.0W
LBAR 15.3N 127.5W 15.3N 128.7W 15.7N 129.9W 16.5N 131.5W
SHIP 50KTS 58KTS 63KTS 64KTS
DSHP 50KTS 58KTS 63KTS 64KTS

...48 HRS... ...72 HRS... ...96 HRS. .. ..120 HRS...
090910 0000 090911 0000 090912 0000 090913 0000

LAT LON LAT LON LAT LON LAT LON
BAMS 16.7N 131.7W 18.4N 133.3W 21.0N 134.0W 23.8N 133.5W
BAMD 17.2N 131.2W 20.0N 134.0W 24.0N 136.5W 27.8N 136.6W
BAMM 16.4N 131.9W 17.8N 133.8W 20.7N 135.5W 24.0N 136.0W
LBAR 17.6N 133.4W 20.8N 137.1W 25.9N 138.3W 28.5N 133.6W
SHIP 66KTS 55KTS 36KTS 0KTS
DSHP 66KTS 55KTS 36KTS 0KTS

...INITIAL CONDITIONS...
LATCUR = 15.3N LONCUR = 127.5W DIRCUR = 275DEG SPDCUR = 7KT
LATM12 = 15.2N LONM12 = 126.1W DIRM12 = 266DEG SPDM12 = 7KT
LATM24 = 15.2N LONM24 = 124.6W
WNDCUR = 50KT RMAXWD = 20NM WNDM12 = 30KT
CENPRS = 997MB OUTPRS = 1010MB OUTRAD = 150NM SDEPTH = D
RD34NE = 60NM RD34SE = 30NM RD34SW = 60NM RD34NW = 60NM


wnds going up too 50kt
Member Since: May 21, 2006 Posts: 5091 Comments: 114754
yea 456 that pic says 35
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1050. amd
Quoting Weather456:
Also no TD force winds observed yet, but a low pressure is evident which has been there since yesterday




actually according to your picture, it looks like there was a sustained wind of 35 knots right on the coast just to the nne of the low pressure area. But, i could be reading that wrong.
Member Since: Posts: Comments:
000
WHXX01 KWBC 080024
CHGHUR
TROPICAL CYCLONE GUIDANCE MESSAGE
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0024 UTC TUE SEP 8 2009

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 SEVEN (AL072009) 20090908 0000 UTC

...00 HRS... ...12 HRS... ...24 HRS. .. ...36 HRS...
090908 0000 090908 1200 090909 0000 090909 1200

LAT LON LAT LON LAT LON LAT LON
BAMS 12.4N 25.3W 12.8N 28.1W 13.5N 31.2W 14.0N 33.9W
BAMD 12.4N 25.3W 12.9N 27.7W 13.6N 29.7W 14.6N 31.6W
BAMM 12.4N 25.3W 12.9N 27.6W 13.7N 29.8W 14.5N 31.9W
LBAR 12.4N 25.3W 12.9N 27.8W 13.6N 30.4W 14.4N 33.0W
SHIP 30KTS 38KTS 46KTS 52KTS
DSHP 30KTS 38KTS 46KTS 52KTS

...48 HRS... ...72 HRS... ...96 HRS. .. ..120 HRS...
090910 0000 090911 0000 090912 0000 090913 0000

LAT LON LAT LON LAT LON LAT LON
BAMS 14.2N 36.0W 14.5N 36.8W 14.1N 33.8W 13.4N 32.2W
BAMD 15.8N 33.1W 19.0N 34.3W 22.1N 33.2W 25.0N 33.4W
BAMM 15.5N 33.6W 17.7N 35.1W 19.5N 34.0W 21.6N 33.5W
LBAR 15.7N 35.1W 19.7N 38.1W 23.4N 37.7W 27.1N 37.0W
SHIP 58KTS 61KTS 58KTS 45KTS
DSHP 58KTS 61KTS 58KTS 45KTS

...INITIAL CONDITIONS...
LATCUR = 12.4N LONCUR = 25.3W DIRCUR = 275DEG SPDCUR = 14KT
LATM12 = 12.1N LONM12 = 22.3W DIRM12 = 278DEG SPDM12 = 15KT
LATM24 = 11.8N LONM24 = 19.6W
WNDCUR = 30KT RMAXWD = 60NM WNDM12 = 25KT
CENPRS = 1004MB OUTPRS = 1008MB OUTRAD = 170NM SDEPTH = M
RD34NE = 0NM RD34SE = 0NM RD34SW = 0NM RD34NW = 0NM



this in no TS yet
Member Since: May 21, 2006 Posts: 5091 Comments: 114754
Quoting Dakster:
Hurricane Warnings just posted for Tallahassee...



Not for long
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1047. Levi32
Quoting Weather456:


I would like to see QS, but as I indicated before - Cyclone phase diagrams show a shallow warm-core system due to the injection of tropical air. But that was also the case with 98L.


True, and as I said before this system can never be thought of as truly fully tropical, but I do think it's worthy of TD classification. Just look at it on satellite and tell me it doesn't look like it's running at least mostly on tropical processes. The consistent deep thunderstorms near the circulation center and banding coming in from the south are not characteristic of an average frontal wave passing by in September, and keep in mind this is over 85F water.
Member Since: November 24, 2005 Posts: 635 Comments: 26548
1046. amd
Quoting Dakster:


LOL... Hopefully doesn't become a tropical wave at this point. Both teams playing well.


agreed. don't have a dog in this battle. Would like to see two acc teams play well considering the ACC as a whole has been atrocious this weekend.

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Quoting stormpetrol:
While fairly good guidance, models are overblown imo, too much faith in them, what ever happen to good old fashion forecasting, man has become to dependent on the very thing they invented, some may say yes, but the computer can do this 1000s of time faster than man, but the final question is the true answer who made the computers? or did they just evolve, just my thought for tonight.


i agree i just skip the model talk and images usually...

computers have done things that would take humans a lifetime and a great deal of manwork to do i.e. the human genome, yes we create them but it is for a reason. all computer work has to be checked by us because they right now are "as dumb as a brick" meaning the AI or intelligence we have is just not there in most systems

to me model technology right now is too much like gossip. they give different perspectives on what can happen, based on mathematical models of the atmosphere and i dont discredit at all those who took the effort to code it all in. it's a work in progress though and i will wait for further refinements before putting my moneys worth on it or paying too much serious attention to them

really sometimes i just wish they weren't available at all publicly lol ...
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Nice little band of rain coming in from the NC system, all the way to Raleigh-Durham. Feel bad for the coast, they don't need that much rain. However, we do.
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Also no TD force winds observed yet, but a low pressure is evident which has been there since yesterday


Member Since: July 24, 2005 Posts: 407 Comments: 19076
That BOC 'hint of a vortex/swirl' that I presume, and can be clearly seen on visible satellite appears to be near 20N 96W.
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.
Member Since: July 24, 2005 Posts: 407 Comments: 19076
1039. Seastep
Great to see you around Levi.
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1038. Dakster
Quoting amd:


just been downgraded to a tropical storm watch...


LOL... Hopefully doesn't become a tropical wave at this point. Both teams playing well.
Member Since: March 10, 2006 Posts: 0 Comments: 10034
looking for too the E PAC posts season,
Member Since: May 21, 2006 Posts: 5091 Comments: 114754

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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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