Dr. Jeff Masters' WunderBlog

92L still a threat to develop; Igor a hurricane; TD 12 forming near Africa
Posted by: Dr. Jeff Masters, 02:18 PM GMT del 12 Settembre 2010 +1
Tropical disturbance (92L) over the Central Caribbean, a few hundred miles south of the Dominican Republic, remains a threat to develop into a tropical depression. Satellite loops this morning show 92L may be starting to form a surface circulation, and an Air Force Hurricane Hunter aircraft will investigate 92L this afternoon to see if a tropical depression is forming.

The storm has only a modest area of heavy thunderstorm with limited low-level spiral banding and upper-level outflow, thanks to an infusion of dry air last night that disrupted the storm. Long range radar out of Puerto Rico shows that heavy rains are affecting that island, but there is no rotation to the radar echoes evident. Wind shear over 92L is low, 5 - 10 knots. The waters beneath are hot, 29.5°C, and these warm waters extend to great depth. Water vapor satellite loops show a large area of dry air lies to the north and west of 92L, and this dry air could interfere with development at times over the next few days.


Figure 1. Morning satellite image of 92L.

Track forecast for 92L
The disturbance is moving west to west-northwest at 15 mph, and steering currents favor a continuation of this motion for the next three days. Model support for development is scattered. The GFS and NOGAPS models do not develop 92L. The GFDL and ECMWF models predict development, with a track taking 92L into Belize or Mexico's Yucatan Peninsula on Wednesday. On this track, the southern Dominican Republic can expect heavy rains of 3 - 6 inches today through Monday morning; southern Haiti can expect similar rains tonight through Monday night, and Jamaica and the Cayman Islands can expect heavier rains of 4 - 8 inches Monday and Tuesday. Eastern Cuba can expect rains in the 2 - 4 inch range. Once 92L crosses the Yucatan, the ridge of high pressure steering it is expected to remain in place, forcing 92L to a second landfall in Mexico south of the Texas border.

Intensity forecast for 92L
NHC is putting the odds of 92L developing into a tropical depression by Tuesday at 50%; I'd put them higher, at 70%. However, time is running out for 92L to become a hurricane before hitting the Yucatan Peninsula on Wednesday. Given the current disorganized state of 92L, it would be difficult for it to intensify quickly enough to become a hurricane by then. The storm may also suffer another of its mysterious evening collapses, where it loses most of its heavy thunderstorm activity. However, the SHIPS model predicts wind shear will remain low, 5 - 10 knots, through the period, and water temperatures are certainly warm enough to support development. The main detriment to intensification is likely to be dry air, and 92L could wrap in some of the dry air to its northwest at times, slowing down development. There are a number of research flights being made into 92L this afternoon that should help long-term efforts to make better predictions in the future on whether or not disturbances like this will develop or not.


Figure 2. Morning satellite image of Igor.

Igor
Hurricane Igor appears destined to become a large and powerful major hurricane over the Central Atlantic in the days to come. Wind shear is low, 5 - 10 knots, and is expected to drop below 5 knots for the next five days. Waters are warm, 28°C, and will warm to 29°C by Wednesday. Igor has moistened its environment enough to keep the dry air of the Saharan Air Layer (SAL) at bay. Igor is undergoing a period of rapid intensification today, and will probably be a Category 3 or 4 hurricane by Monday.

The track forecast for Igor remains unchanged. Igor will move west under the influence of a strong ridge of high pressure for the next 2 - 3 days, then turn more to the west-northwest then northwest in response to the steering influence of a broad trough of low pressure moving across the Western Atlantic on Tuesday and Wednesday. This should allow Igor to pass several hundred miles to the northeast of the Lesser Antilles. In the longer range, Igor may be a threat to Bermuda, and does have a small chance of making landfall on the U.S. East Coast or Canada. Climatology shows that about 15% of all tropical cyclones that have existed at Igor's current position have gone on to hit the U.S. East Coast; these odds are about 10% for Bermuda and 10% for Canada. The forecast steering pattern for the period 5 - 12 days from now from the ECMWF and GFS models shows a continuation of the pattern we've seen all hurricane season, with regular strong troughs of low pressure moving off the U.S. East Coast. This pattern favors Igor eventually recurving out to sea without affecting any land areas. Recent runs of the ECMWF model indicate that these troughs may not be as intense as previously thought, so it is possible Igor has a higher chance than usual to hit land than climatology suggests. One wild card may be the possible development of TD 12 behind Igor. If TD 12 develops into a hurricane, and moves close to Igor, as some of the models are suggesting, the two hurricanes could rotate around a common center, forcing Igor more towards the coast of the U.S. The long term fate of Igor is difficult to predict at this point.

Tropical Depression Twelve forms
Tropical Depression Twelve formed between the Cape Verdes Islands and coast of Africa this morning, and is already affecting the Cape Verdes with winds near tropical storm strength; sustained winds of 35 mph were recorded in the northwest Cape Verdes this morning. You can follow the progress of TD 12 through the Cape Verdes today using our wundermap.

Next post
I'll have a new post Monday morning, and perhaps late this afternoon if events warrant.

Jeff Masters
Categories: Hurricane
  Permalink | A A A
Reader Comments
Display: 0, 50, 100, 200 Sort: Newest First - Order Posted
Viewing: 751 - 801

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 | 41 | 42 | 43 | 44 | 45 | 46 | 47 | 48 | 49 | 50 | 51 | 52 | 53 | 54 | 55 | 56 | 57 | 58 | 59 | 60 | 61 | 62 | 63 | 64 | 65 | 66 | 67 | 68 | 69 | 70 | 71 | 72 | 73 | 74 | 75 | 76 | 77 | 78 | 79 | 80 | 81 | 82 | 83 | 84 | 85Blog Index

751. Cotillion 05:55 PM GMT del 12 Settembre 2010    
Member Since: Agosto 23, 2008 Posts: 7 Comments: 5300
752. pottery 05:55 PM GMT del 12 Settembre 2010    
In the Meantime....
an afternoon thunder-thingy is building overhead here, with fireworks and cymbal-noises approaching.

I will be back, after I attack a large portion of cheese-cake I just remembered in the fridge...
Member Since: Ottobre 24, 2005 Posts: 0 Comments: 20708
755. Ameister12 05:56 PM GMT del 12 Settembre 2010    
Igor is probably a category 4 now. (135 mph)
Member Since: Agosto 9, 2009 Posts: 9 Comments: 3517
757. KimberlyB 05:56 PM GMT del 12 Settembre 2010    
Quoting Stormchaser2007:




WOW! WOW-WOW-WOW-WOW!!!!

(one for each image that was posted of Igor....but this one hit me the most)
Member Since: Ottobre 21, 2007 Posts: 27 Comments: 328
758. Levi32 05:56 PM GMT del 12 Settembre 2010    
Quoting Seastep:


Correct me if I am wrong, but I though the CMC performed best last year at 5 days.

Have no idea about this year. Link to that would be appreciated if anyone has it.

I think CyberTeddy posted it before?


Ya the CMC can have some good accuracy on track once it has locked on, but early in the game it can be rather foolish.
Member Since: novembre 24, 2005 Posts: 586 Comments: 25450
759. atmoaggie 05:57 PM GMT del 12 Settembre 2010    
I forget, which of the text advisories has the annular flag in it?

Anyone?
Member Since: Agosto 16, 2007 Posts: 6 Comments: 12461
760. dmaddox 05:57 PM GMT del 12 Settembre 2010    
Member Since: Maggio 5, 2007 Posts: 0 Comments: 445
761. stillwaiting 05:58 PM GMT del 12 Settembre 2010    
92l looks like its going to take a hwrf like path towards haiti/se cuba area,also sustaining convection,though no closed surface low yet,still waiting on west winds,probably a td at some point tonight
Member Since: Ottobre 5, 2007 Posts: 20 Comments: 4970
762. Levi32 05:58 PM GMT del 12 Settembre 2010    
Quoting StormW:
Levi, great update!

As (mets), couldn't ask for a prettier storm to look at this season.


Thanks Storm! Same to you.

Yes...Igor is eye-candy to us Mets right now.
Member Since: novembre 24, 2005 Posts: 586 Comments: 25450
763. MiamiHurricanes09 05:58 PM GMT del 12 Settembre 2010    
Quoting atmoaggie:
I forget, which of the text advisories has the annular flag in it?

Anyone?
SHIPS. Should come out in 30 minutes.
Member Since: Settembre 2, 2009 Posts: 129 Comments: 19976
764. Stormchaser2007 05:58 PM GMT del 12 Settembre 2010    
Quoting atmoaggie:
I forget, which of the text advisories has the annular flag in it?

Anyone?


SHIPS
Member Since: Giugno 9, 2007 Posts: 4 Comments: 15248
765. sailingallover 05:58 PM GMT del 12 Settembre 2010    
Quoting WeatherNerdPR:

2009 gave us a break, though.

Don't forget Ike..
Member Since: Settembre 1, 2009 Posts: 23 Comments: 982
766. kimoskee 05:58 PM GMT del 12 Settembre 2010    
Quoting Levi32:
The ECMWF starting to show northwest movement of 92L in the Bay of Campeche is a big clue to Igor's track. The Euro was showing south of west movement in the BOC with 92L just a couple days ago. If the storm instead fades northwest, that implies more of a trough digging into the west-central US which would force the Texan ridge to build further east, implying a more westerly track for Igor and a more northerly one for 92L.


Sounds like the caribbean islands need to sit up and take note
Member Since: Agosto 17, 2008 Posts: 0 Comments: 670
767. Ameister12 05:59 PM GMT del 12 Settembre 2010    
Quoting Cotillion:

Igor defiantly starting to look like Daniel.
Member Since: Agosto 9, 2009 Posts: 9 Comments: 3517
768. Stormchaser2007 05:59 PM GMT del 12 Settembre 2010    
Member Since: Giugno 9, 2007 Posts: 4 Comments: 15248
769. CybrTeddy 05:59 PM GMT del 12 Settembre 2010    
Miami, when do the T# come out?
Member Since: Luglio 8, 2005 Posts: 253 Comments: 20238
770. atmoaggie 05:59 PM GMT del 12 Settembre 2010    
Really, little banding apparent. (Less than I saw a bit ago)

Member Since: Agosto 16, 2007 Posts: 6 Comments: 12461
771. Neapolitan 05:59 PM GMT del 12 Settembre 2010    
Quoting NOLALawyer:


Because this seasons sucks, lacks excitement and has been painful to watch...especially watching CV storms traverse the entire Atlantic to recurve at the last minute. I have had to limit myself from coming here because these storms, and the frustration, tension and nervousness which they spawned in my psyche, were consuming me.

YMMV.


I'm terribly sorry you're so bored; by all means, please continue to limit yourself. ;-)
Member Since: novembre 8, 2009 Posts: 4 Comments: 11153
773. Stormchaser2007 06:00 PM GMT del 12 Settembre 2010    
Comrade Igor

Member Since: Giugno 9, 2007 Posts: 4 Comments: 15248
774. MiamiHurricanes09 06:00 PM GMT del 12 Settembre 2010    
Quoting CybrTeddy:
Miami, when do the T# come out?
Around the same time as the SHIPS text...30 minutes or so.
Member Since: Settembre 2, 2009 Posts: 129 Comments: 19976
775. plywoodstatenative 06:01 PM GMT del 12 Settembre 2010    
Cotillion that is about as perfect a major storm as you can get.
Member Since: novembre 15, 2005 Posts: 16 Comments: 4147
776. LightningCharmer 06:01 PM GMT del 12 Settembre 2010    
703. KanKunKid LOL
Member Since: Settembre 1, 2007 Posts: 0 Comments: 1111
777. atmoaggie 06:01 PM GMT del 12 Settembre 2010    
Quoting MiamiHurricanes09:
SHIPS. Should come out in 30 minutes.
Quoting Stormchaser2007:


SHIPS
Oh, right. *smack*
Member Since: Agosto 16, 2007 Posts: 6 Comments: 12461
778. TropicalAnalystwx13 06:01 PM GMT del 12 Settembre 2010    
Quoting Stormchaser2007:


LMAO!

I was scrolling down the page, reading, and that scared me. it made me jump!

LMAO!
Member Since: Luglio 6, 2010 Posts: 89 Comments: 25284
779. HurricaneSwirl 06:01 PM GMT del 12 Settembre 2010    
Quoting StSimonsIslandGAGuy:
Maybe the NHC will issue a special advisory, although I don't see the need for it. Last night the NHC issued a special Tropical Weather Outlook to raise the probability of development for 92L to 90% at 11 pm and I didn't see the necessity for that either.

Igor is looking like a Cat 4 to me.


92L got upped to 90% last night? Now it's all the way down to 50%
Member Since: Luglio 7, 2008 Posts: 2 Comments: 3237
781. MiamiHurricanes09 06:02 PM GMT del 12 Settembre 2010    
Quoting HurricaneSwirl:


92L got upped to 90% last night? Now it's all the way down to 50%
No, that was 93L...got upped to 12L this morning.
Member Since: Settembre 2, 2009 Posts: 129 Comments: 19976
782. Stormchaser2007 06:02 PM GMT del 12 Settembre 2010    
Quoting TropicalAnalystwx13:


LMAO!

I was scrolling down the page, reading, and that scared me. it made me jump!

LMAO!


LOL

My bad.
Member Since: Giugno 9, 2007 Posts: 4 Comments: 15248
783. caneswatch 06:03 PM GMT del 12 Settembre 2010    
Quoting Drakoen:


No because you have an incoming trough


An incoming trough that looks flattening.
Member Since: Ottobre 8, 2008 Posts: 14 Comments: 4473
785. Ameister12 06:03 PM GMT del 12 Settembre 2010    
Igor is 100% not a category 2 anymore.
Member Since: Agosto 9, 2009 Posts: 9 Comments: 3517
787. FloridaTigers 06:03 PM GMT del 12 Settembre 2010    
Quoting Chicklit:
Cracks me up that every time a hurricane forms, someone asks if it's annular.
"Annular hurricanes are very rare."

Please see wiki article on them below.
annularhurricane


Well, Igor could very well be becoming annular, there isn't a need for snark here.
Member Since: Maggio 17, 2009 Posts: 0 Comments: 559
788. NCHurricane2009 06:04 PM GMT del 12 Settembre 2010    
Quoting CosmicEvents:
That's why I suggested that next time around they go with something like Isaiah, or even Ishkabble.


Yo, they've got Isias lined up for 2014, that's the name they used to replaced Ike.

http://www.nhc.noaa.gov/aboutnames.shtml

Thats really close to Isaiah.
Member Since: Settembre 15, 2009 Posts: 277 Comments: 3357
789. earthlydragonfly 06:04 PM GMT del 12 Settembre 2010    
Repost......

Afternoon StormW... I'm sitting here watching the Dolphins game (big fish fan here) and was reflecting on all that preaching you did this year... Looks to be coming to fruition my friend. Starting to look ominous out in the Atlantic and with all of that heat potential out there (even with some of it released into the Russian heat wave and Europe) Looks like this season could be a 2005 type season (not in number of storms) in length of season.. Everything is so hot storms are turning into tropical situations as soon as they dip thier toe in the water from Africa.... Hope we can keep dodging bullets here in Florida but with the patterns setting up the way they seem Im thinking the clock is ticking on us here in the South East.
Member Since: Luglio 1, 2005 Posts: 10 Comments: 1649
790. Chicklit 06:04 PM GMT del 12 Settembre 2010    
Member Since: Luglio 11, 2006 Posts: 14 Comments: 10253
791. JupiterFL 06:04 PM GMT del 12 Settembre 2010    
I hope this thing stays away from any land mass. Looks really peeved right now. Over open water its a beautiful show.
Member Since: Agosto 10, 2005 Posts: 0 Comments: 2146
793. leo305 06:04 PM GMT del 12 Settembre 2010    
I think it's nearing moderate CAT 4 strength 140-145MPH

the eye isn't completely clear, and the structure isn't completely perfectly circular for it to be a CAT 5 but it can get there by tonight especially with DMAX just giving it even more fuel
Member Since: Aprile 17, 2010 Posts: 0 Comments: 1752
794. Bordonaro 06:04 PM GMT del 12 Settembre 2010    
Quoting Ameister12:
This is 100% not a category 2 anymore.

Probably a low end CAT 4 w/135MPH winds, w/min central pressure around 945mb!!!!
Member Since: Agosto 25, 2009 Posts: 20 Comments: 6785
795. DDR 06:04 PM GMT del 12 Settembre 2010    
Quoting pottery:
In the Meantime....
an afternoon thunder-thingy is building overhead here, with fireworks and cymbal-noises approaching.

I will be back, after I attack a large portion of cheese-cake I just remembered in the fridge...

Hey,tell me about it!
Its been raining by the buckets for an hour an a half,possibly some floding going right now
Member Since: Aprile 27, 2007 Posts: 13 Comments: 1473
796. breald 06:04 PM GMT del 12 Settembre 2010    
Quoting Neapolitan:


I'm terribly sorry you're so bored; by all means, please continue to limit yourself from coming here. ;-)


++++++++++
Member Since: Maggio 28, 2008 Posts: 38 Comments: 5298
797. BahaHurican 06:05 PM GMT del 12 Settembre 2010    
Quoting Seflhurricane:
dear god that is one monster approaching the central bahamas !!!!!!!!!!
U know, u could have NOT said that.......

Hoping CMC is on crack 2day.... especially since this is 12z and not one of the more suspect "interim" runs....

Quoting StSimonsIslandGAGuy:
I also think that Igor may become the first true annular hurricane in the Atlantic since Isabel.
Yeah, was thinking this earlier this morning when I saw that very solid structure even though cloud tops had not yet cooled to where they are now...

Quoting hurricane23:
Anything is possible but i doupt the 12z CMC comes even close to verifying.
Thank u for ur support.... lol Really REALLY not liking even the idea of that right now.

Quoting Levi32:
Freaking Beautiful.

Like, that's why I haven't changed my avatar.... like the most beautiful storm of our time... lol

Want to see if Igor can match that.
Member Since: Ottobre 25, 2005 Posts: 19 Comments: 17632
799. Stormchaser2007 06:05 PM GMT del 12 Settembre 2010    
Member Since: Giugno 9, 2007 Posts: 4 Comments: 15248
800. PensacolaDoug 06:05 PM GMT del 12 Settembre 2010    
IGOR lookin good, like the 'FINS!
Member Since: Luglio 25, 2006 Posts: 0 Comments: 4827

Viewing: 751 - 801

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 | 41 | 42 | 43 | 44 | 45 | 46 | 47 | 48 | 49 | 50 | 51 | 52 | 53 | 54 | 55 | 56 | 57 | 58 | 59 | 60 | 61 | 62 | 63 | 64 | 65 | 66 | 67 | 68 | 69 | 70 | 71 | 72 | 73 | 74 | 75 | 76 | 77 | 78 | 79 | 80 | 81 | 82 | 83 | 84 | 85Blog Index

New Comment
Community Standards Policy Comments will take a few seconds to appear.
Post Your Comments
Please sign in to post comments.
Not only will you be able to leave comments on this blog, but you'll also have the ability to upload and share your photos in our Wunder Photos section.
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.

Local Weather
Partly Cloudy
84 °F
Parzialmente nuvoloso
Community Activity