Disturbance 90L close to tropical depression strength; TD 2 may rise again

By: Dr. Jeff Masters , 2:02 PM GMT on August 14, 2009

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A strong tropical wave (90L), with a large circulation and a moderate amount of heavy thunderstorm activity, is a few hundred miles southwest of the Cape Verdes Islands, off the coast of Africa. This morning's QuikSCAT pass shows that 90L has a large circulation, but this circulation is not yet well-formed, as it is elongated along an east-west axis. Satellite imagery from the European METEOSAT satellite show that the heavy thunderstorms associated with 90L are gradually becoming better organized, with some spiral banding evident on the south side of the storm. Satellite intensity estimates from NOAA already put 90L at tropical depression strength with 30 mph winds, but the storm does not yet have a well enough formed circulation to be classified as a depression. Water vapor imagery shows that since 90L is forming several hundred miles south of the dry air of the Saharan Air Layer (SAL), the storm should not be affected by dry air and dust as much as Tropical Depression Two was. However, there is some dry air from the SAL being sucked into the circulation of 90L, and this is retarding its development.

Wind shear is moderate, about 10 - 15 knots, but is forecast to fall to the low range, 5 - 10 knots, later today. Shear is then forecast to remain low for the next five days. Sea Surface Temperatures are about 28°C, and will remain in the 27 - 28°C range the next five days. The combination of low wind shear and sufficiently warm SSTs should allow 90L to develop into a tropical depression by Saturday, and potentially reach hurricane strength by Wednesday. Most of our reliable models strengthen 90L into a hurricane by Wednesday, when the storm is expected to be near the northern Lesser Antilles Islands. One important outlier is the ECMWF model, which has 90L passing to the north of the islands, and eventually recurving out to sea east of Bermuda. The ECMWF was by far the most reliable model for forecasting hurricane tracks last year. However, all of our models are pretty unreliable going out 5 days in advance for systems that have yet to reach tropical depression strength. Once 90L becomes a tropical depression and develops a well-formed circulation, the models will have a better handle on forecasting where it will go.


Figure 1. The remnants of Tropical Depression Two (left side of image) and tropical wave 90L (right side of image).

Tropical Depression Two may come back
Tropical Depression Two died yesterday, but may rise again. Satellite loops of the remnants of the storm show that heavy thunderstorms are again attempting a comeback near the axis of what is now a tropical wave. However, dry air continues to interfere with the development of the thunderstorm activity, and moderately high wind shear of 15 - 20 knots is also inhibiting the process. Wind shear over the remnants of TD 2 is expected to remain in the moderate range, 10 - 20 knots, over the next four days. Sea Surface Temperatures (SSTs) are 27°C, but will warm to 28°C two days from now. There is plenty of dry, stable air from the Saharan Air Layer (SAL) to the north and west that will continue to cause the storm problems. The relatively cool SSTs and dry air mean that any re-development of the storm will be slow to occur. NHC has given the system a medium (30 - 50% chance) of becoming a tropical depression again by Sunday morning. Only one reliable model, the NOGAPS, is predicting regeneration of TD 2. The NOAA Hurricane Hunters are flying research missions into the remnants of TD 2 today and Saturday.

I'll have an update Saturday morning, or earlier, if significant developments occur.

Jeff Masters

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Quoting hurricanelover236:
I told you guys. Yuo should listen to me. Im always right about this stuff. I said ana woulsd die due to dry air and shear and its already happening. Both of these storms will amount to nothing. Florida can breath easy. Whoever is getting their hopes up for getting ana or potential Bill are gonna be very disapointed.


Why do I think StormTop is here but actually being a bit more clever by not doing CAPS LOCK ON EVERYTHING?
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4683. JRRP
Link
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Quoting Cotillion:
Hah, ADT's thrown the raw T# back to 1.0 again.

Ana's got problems.
Again.
------------------------------------------------
15/1145 UTC 14.3N 47.2W T2.0/2.5 ANA -- Atlantic


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Quoting TheCaneWhisperer:


One of the things I love about this place is your always one step ahead of the masses. I always chuckle as I drive my massive lines at gas stations and brawls in the grocery store over the last can of beanie weanies, lol.
Last year a day before Ike my wife sent me to CVS to buy some vitamins of all things for our baby. The place was a mad house. Some guys was in there verbally assaulting the pharmacist behind the counter. It looked like it was going to turn bad quick. I turned around and just left. Luckily for me I work in a hospital pharmacy so I just went to work and got some. People become insane when a storm is approaching. It is good to be several steps ahead of the idiots.
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4461. hurricanelover236 12:29 PM GMT on August 15, 2009
I can assure you that florida is safe from Ana. It is so weak its going to stay west and in my opinion be a gulf storm. It will also stay weak if it survuves because it has a alot of shear and dry air to battle. florida u can breath easy because ana is not coming. Im telling you.

you can assure us? LMAO. sorry, but your "assurances" dont mean squat here. i prefer to rely on the NHC instead of downcasters like yourself who speak in absolutes. consider yourself #15 on my ignore list
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Quoting Hurricane4Lex:
PSSS: Thanks Cotillion for earlier but are you sure the Fujiwara Effect won't have too much of a role?

Also don't the models get confused when that happens


More than likely. Though some models have tried to show it in the past, like the CMC (I think), but that had Ana practically stalling.

No, I don't think it will because a.) Neither storm will be strong enough, and b.) Ana's supposed to pick up in speed in a couple of days or so, which means the distance will be too large.

Member Since: August 23, 2008 Posts: 7 Comments: 5300
Quoting Tazmanian:
i think the E PAC now has other cat 4


000
WHXX01 KMIA 151253
CHGE77
TROPICAL CYCLONE GUIDANCE MESSAGE
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1253 UTC SAT AUG 15 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 GUILLERMO (EP102009) 20090815 1200 UTC

...00 HRS... ...12 HRS... ...24 HRS. .. ...36 HRS...
090815 1200 090816 0000 090816 1200 090817 0000

LAT LON LAT LON LAT LON LAT LON
BAMS 18.8N 132.6W 19.5N 135.7W 20.3N 138.8W 21.2N 141.9W
BAMD 18.8N 132.6W 19.8N 135.1W 21.1N 137.4W 23.1N 139.4W
BAMM 18.8N 132.6W 19.9N 135.6W 21.0N 138.3W 22.5N 141.0W
LBAR 18.8N 132.6W 19.7N 135.1W 21.3N 137.5W 23.2N 139.8W
SHIP 110KTS 105KTS 88KTS 72KTS
DSHP 110KTS 105KTS 88KTS 72KTS

...48 HRS... ...72 HRS... ...96 HRS. .. ..120 HRS...
090817 1200 090818 1200 090819 1200 090820 1200

LAT LON LAT LON LAT LON LAT LON
BAMS 22.1N 144.8W 24.2N 150.3W 26.6N 155.9W 29.6N 161.5W
BAMD 25.4N 141.0W 30.4N 142.2W 30.1N 140.2W 25.1N 144.1W
BAMM 24.4N 143.4W 28.9N 147.9W 31.9N 150.6W 32.3N 152.0W
LBAR 25.5N 141.7W 30.4N 143.4W 31.9N 140.8W 29.3N 139.7W
SHIP 56KTS 35KTS 20KTS 0KTS
DSHP 56KTS 35KTS 20KTS 0KTS

...INITIAL CONDITIONS...
LATCUR = 18.8N LONCUR = 132.6W DIRCUR = 285DEG SPDCUR = 14KT
LATM12 = 18.2N LONM12 = 129.7W DIRM12 = 284DEG SPDM12 = 15KT
LATM24 = 17.6N LONM24 = 126.7W
WNDCUR = 110KT RMAXWD = 15NM WNDM12 = 95KT
CENPRS = 954MB OUTPRS = 1008MB OUTRAD = 165NM SDEPTH = D
RD34NE = 100NM RD34SE = 80NM RD34SW = 70NM RD34NW = 100NM



I thought it was weakening.
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Quoting P451:


They just number them in order.

90 through 99 and then start over.

Except this year they skipped from 93L to 96L and nobody seems to know why.

99L--->TD2---->Ana
90L--->soon to be TD3---->likely to be Bill

next invests will be 91L and 92L - probably the south florida convection - and/or - possibly the Africa wave.



we had 91L so the next one will be 92L
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4676. jipmg
I feel a tropical depression ana coming in at 11..
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Quoting TheCaneWhisperer:


One of the things I love about this place is your always one step ahead of the masses. I always chuckle as I drive my massive lines at gas stations and brawls in the grocery store over the last can of beanie weanies, lol.


My son and I consider it a spectator sport, we get ourselves ready in advance and then go out at the last minute and laugh at the antics - LOL!!
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It's another way of saying to have a slice of humble pie except they say eat crow or crow pie.
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It does look as if the wave just south of Florida is beginning to spin, but I read on the Accuweather site that the GOM has too much shear and dry air to be conducive to hurricane formation.
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Good morning everyone!

Checking in from the USVI! Looks like we're going to have an exciting week. I'll be watching and waiting. Thank you all, as always, for keeping me informed.
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Quoting sullivanweather:
This morning's cold spot - Horse Ridge, Oregon - 22°F


sounds great for a morning jog in speedos.

i once went to old forge, NY, it was like -15F and people were out jogging in shorts. no surprise they were white folks, probably insane, as i am from puerto rico and was covered by roughly 78 layers of thick raw animal wool
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I told you guys. Yuo should listen to me. Im always right about this stuff. I said ana woulsd die due to dry air and shear and its already happening. Both of these storms will amount to nothing. Florida can breath easy. Whoever is getting their hopes up for getting ana or potential Bill are gonna be very disapointed.
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GOM Pressure Trend
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what about the blob around the keys, wheres it headed?
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Quoting serialteg:


i wont answer you.

kidding hehe... they go thru 90-99, 99L just means they've gone thru 90-98 and are up to 99. i guess the L means low but that's just me talking.


Thanks all for the answer!
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Quoting StormW:


Awesome pic, Storm.

"Don't Mess With Bill"

http://www.youtube.com/watch?v=K8t3PO7ZOfQ
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i think the E PAC now has other cat 4


000
WHXX01 KMIA 151253
CHGE77
TROPICAL CYCLONE GUIDANCE MESSAGE
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1253 UTC SAT AUG 15 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 GUILLERMO (EP102009) 20090815 1200 UTC

...00 HRS... ...12 HRS... ...24 HRS. .. ...36 HRS...
090815 1200 090816 0000 090816 1200 090817 0000

LAT LON LAT LON LAT LON LAT LON
BAMS 18.8N 132.6W 19.5N 135.7W 20.3N 138.8W 21.2N 141.9W
BAMD 18.8N 132.6W 19.8N 135.1W 21.1N 137.4W 23.1N 139.4W
BAMM 18.8N 132.6W 19.9N 135.6W 21.0N 138.3W 22.5N 141.0W
LBAR 18.8N 132.6W 19.7N 135.1W 21.3N 137.5W 23.2N 139.8W
SHIP 110KTS 105KTS 88KTS 72KTS
DSHP 110KTS 105KTS 88KTS 72KTS

...48 HRS... ...72 HRS... ...96 HRS. .. ..120 HRS...
090817 1200 090818 1200 090819 1200 090820 1200

LAT LON LAT LON LAT LON LAT LON
BAMS 22.1N 144.8W 24.2N 150.3W 26.6N 155.9W 29.6N 161.5W
BAMD 25.4N 141.0W 30.4N 142.2W 30.1N 140.2W 25.1N 144.1W
BAMM 24.4N 143.4W 28.9N 147.9W 31.9N 150.6W 32.3N 152.0W
LBAR 25.5N 141.7W 30.4N 143.4W 31.9N 140.8W 29.3N 139.7W
SHIP 56KTS 35KTS 20KTS 0KTS
DSHP 56KTS 35KTS 20KTS 0KTS

...INITIAL CONDITIONS...
LATCUR = 18.8N LONCUR = 132.6W DIRCUR = 285DEG SPDCUR = 14KT
LATM12 = 18.2N LONM12 = 129.7W DIRM12 = 284DEG SPDM12 = 15KT
LATM24 = 17.6N LONM24 = 126.7W
WNDCUR = 110KT RMAXWD = 15NM WNDM12 = 95KT
CENPRS = 954MB OUTPRS = 1008MB OUTRAD = 165NM SDEPTH = D
RD34NE = 100NM RD34SE = 80NM RD34SW = 70NM RD34NW = 100NM

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Quoting Hurricane4Lex:
Explain the Fujiwara Effect and what effect it could have on our 2 starting stars? TIA ^_^



A few sets of examples can be found in the busy 1995 Atlantic hurricane season. During the height of the season, Hurricane Humberto and Hurricane Iris took part in a brief Fujiwara interaction. Iris then began interacting with a third storm, Tropical Storm Karen, which orbited and later merged with the more intense Iris. In the 1994 Pacific typhoon season, Typhoon Pat and Tropical Storm Ruth completed a full orbit around their centroid before collapsing into a single cyclone. In 1997, Ivan and Joan were a pair of super typhoons that interacted through the Fujiwara effect. The interaction affected their motion as Ivan was steered to the west, and Joan was steered more northerly.

The most recent example in the Atlantic is Alpha being absorbed by Wilma in 2005. One year earlier, Lisa absorbed a tropical disturbance as described in the Tropical Cyclone Report. The most recent example in Eastern North Pacific is Lidia being absorbed by Max in 2005. Another recent example occurred when Tropical Storm Wukong absorbed Tropical Storm Sonamu in the 2006 Pacific typhoon season south of Japan. In 2007, Tropical Storm Hagibis made a recurvature in South China Sea towards Typhoon Mitag, northeast of the Philippines. In 2008, in the South Indian Ocean, Tropical Cyclone Fame began orbiting Tropical Cyclone Gula with the stronger storm, Gula, absorbing Fame.

Fujiwhara Wiki

I think they interact, but i don't know if this will be enough for absorbing or lets say a north push for bill.
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PSSS: Thanks Cotillion for earlier but are you sure the Fujiwara Effect won't have too much of a role?

Also don't the models get confused when that happens
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4662. IKE
Quoting wantsnow:
Ike,

I cannot get your link to come up.
Somethings blocking it on my in end.
I've tried turing of my popup blocker etc.


I clicked it....same results....I'll delete the link.....
Member Since: June 9, 2005 Posts: 23 Comments: 37858
4661. 7544
gfs dosent even show anna is that bill ???

Link
Member Since: May 6, 2007 Posts: 0 Comments: 6690
Quoting Cotillion:
Hah, ADT's thrown the raw T# back to 1.0 again.

Ana's got problems.

Again.


Yesterday it was a remnant low so all things considered, she's doing quite well.
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Quoting Cotillion:
Hah, ADT's thrown the raw T# back to 1.0 again.

Ana's got problems.

Again.


Honestly - I want Ana to carry on being a TS before weakening and killing itself before doing anything damage-worthy. She will support the big event. Bill - who I feel will be a fish.
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4657. JRRP
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Quoting sullivanweather:
This morning's cold spot - Horse Ridge, Oregon - 22°F


Hey Sully!

Seem to recall you saying 19/10/5 for the EPac? Well you're halfway there!
Member Since: August 23, 2008 Posts: 7 Comments: 5300
Quoting TampaSpin:
I don't have time this morning to do an update but, all the Graphics stay current Here. It appears a Surface Low if forming just off the Coast of the tip of Florida at 23.5N 82W moving into the GOM......i gotta go and will be back late this evening.



To my untrained eye, it's not dissipating. Been watching this wave for two days. Haven't noticed west winds on any Florida Keys buoys yet.
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Quoting Cotillion:
Hah, ADT's thrown the raw T# back to 1.0 again.

Ana's got problems.

Again.


LOL!
Member Since: March 19, 2009 Posts: 0 Comments: 1421
Quoting SwirlOfDoom:
Lurk Mode OFF

How does the NHC come up with the various codes for Invests? Like what does 99L mean? Thanks for answering!

Lurk Mode ON


i wont answer you.

kidding hehe... they go thru 90-99, 99L just means they've gone thru 90-98 and are up to 99. i guess the L means low but that's just me talking.
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I think one of these hits the east coast, and the other one hits the gulf coast. recurvature is looking less likely with Ana, but could still happen(though unlikely with 90 L/TD3). What do you guys think?
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4649. 7544
90l may just follow anna track wise that high is in place for it too
Member Since: May 6, 2007 Posts: 0 Comments: 6690
Ike,

I cannot get your link to come up.
Somethings blocking it on my in end.
I've tried turing of my popup blocker etc.

Nevermind I had to install java for 32 bit and 64 bit windows....dummyme
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This morning's cold spot - Horse Ridge, Oregon - 22°F
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Hah, ADT's thrown the raw T# back to 1.0 again.

Ana's got problems.

Again.
Member Since: August 23, 2008 Posts: 7 Comments: 5300
Quoting polarcane:
Miami time to check your supplies. If it were me I would buy gas, food and water now. Beat the rush. I always figure you will burn the gas, eat the food and drink the water if it does not come.


One of the things I love about this place is your always one step ahead of the masses. I always chuckle as I drive my massive lines at gas stations and brawls in the grocery store over the last can of beanie weanies, lol.
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Quoting serialteg:


rofl hey man... can someone explain to me the crow deal... lololol i dont get it! haha


Don't ask - in my 3 or 4 seasons of being here, I never understood it. (under various not used handles)
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PS Mornin all!

PSS the SFWMD has TD3 on their map
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Quoting BenBIogger:
Ana is center is exposed again. lol


Ana should stop flashing herself.
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Morning everyone!
I see that 02L regenerated into TS Ana, and 90L might be forming a depression.
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Could we have Claudette too? Look at the keys to Florida's west side on the models.

Explain the Fujiwara Effect and what effect it could have on our 2 starting stars? TIA ^_^
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4638. JRRP
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4637. jipmg
Quoting AussieStorm:

I could see Ana making a path for 90L and laying it with moisture


that's what its doing, its sucking up all the dry air that was there and leaving a path left with moisture for bill
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Lurk Mode OFF

How does the NHC come up with the various codes for Invests? Like what does 99L mean? Thanks for answering!

Lurk Mode ON
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Quoting willdunc79:
I don't think they'll skip TD yet I think they'll go to TD 3 to be safe and wait & watch and then if things stay good go to TS Bill later this evening tonight at the latest.


Most likely they will issue a special statement for TD3 and Upgrade to Bill @ 11.
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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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