92L still a threat to develop; Igor a hurricane; TD 12 forming near Africa

By: Dr. Jeff Masters , 2:18 PM GMT on September 12, 2010

Share this Blog
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

Reader Comments

Comments will take a few seconds to appear.

Post Your Comments

Please sign in to post comments.

or Join

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.

Display: 0, 50, 100, 200 Sort: Newest First - Order Posted

Viewing: 2796 - 2746

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

2776...ROFLMAO!!!!
Member Since: Posts: Comments:
2795. KEEPEROFTHEGATE (Mod)
011L/MH/I/C4
MARK
17.65N/47.48W

Member Since: Posts: Comments:
Cant wait till Hurricane Vladamir.
Member Since: Posts: Comments:
2793. mbjjm
Goldenblack looking at the wrong chart, and wrong levels of the atm
Member Since: Posts: Comments:
2792. Seastep
Quoting mbjjm:
Igor no concern for the Islands. Igor is already at the latitude of the Islands while over 1000 miles away, will gain latitude and keep at least 400 miles north. Could directly impact Bermuda


Irresponsible statement.
Member Since: Posts: Comments:
2790. sopla2o
Okay... "IF" everything goes according to plan it looks like will miss all land.

Now, what needs to happen for the expected curve not to occur. Or is the curve a given, just a matter of time.

Just prepping to the "just in case" variable for south Florida.
Member Since: Posts: Comments:
2789. xcool




interesting
Member Since: September 26, 2009 Posts: 2 Comments: 15624
Quoting MZT:


Katrina is a very common Russian name too.

Somebody tell the tropics that the cold war is over!
Member Since: Posts: Comments:
2787. pottery
Quoting angiest:


Specs

:):)
Member Since: Posts: Comments:
Quoting RecordSeason:
2765:

No, those coordinates are absurd.

Igor is no farther north than 17.6N, and moving WSW now...

17.6N 47.4W

Moving WSW (~245 degrees) @ ~13mph


Will be interesting to see what the "official" NHC position and heading are at the next update...


The pic I looking at is not the correct one?
Member Since: Posts: Comments:
2785. MZT
Quoting MoltenIce:
What makes it more interesting that both names are of Russian origin


Katrina is a very common Russian name too.
Member Since: Posts: Comments:
what i am seeing now is that the apart from the deepayer steering which has Igor moving south of west, Igor is such a powerful storm that it is creating a strong high to its north which is beginning to neutralise any weakness that may come about as a result of any troughs. Igor will continue on a south of west track for a few hrs before returning to awest track. l cannot see that sudden recurvature happening as the models want to put and i believe islands yo the east of the system will come under the gun tomorrow.. i expect the models to shift south on the next avisory
Member Since: Posts: Comments:
I keep on forgetting that Igor isn't a huge storm.
Member Since: Posts: Comments:
Quoting pottery:
Just had a chance to look at some images and 'specs' on Igor.
What have you guys been feeding him?


Monster eat good master...lol
Member Since: Posts: Comments:
I am kinda disagreeing....

Unless I am reading this wrong...looks like he might (albeit it could be temporary) be caught under a tongue of deep layer high pressure....Please correct me if I am looking at this wrong. I'd much rather be proven incorrect on this one.



Quoting mbjjm:


It is just a wobble.will resume west soon, not significant enough to change the model consesus
Member Since: Posts: Comments:
Quoting pottery:

Defiantly...
Good evening, Pottery.
Member Since: Posts: Comments:
2779. angiest
Quoting pottery:
Just had a chance to look at some images and 'specs' on Igor.
What have you guys been feeding him?


Specs
Member Since: Posts: Comments:
I was looking at the African weather. I didn't know that the NWS went international especially in Africa. http://weather.noaa.gov/weather/EG_cc.html
Member Since: Posts: Comments:
Quoting will40:


yea at current speed it will be tuesday before they can go in
How come they cant fly a P3 from Puerto Rico from the Naval Air Station there, seems odd?
Member Since: Posts: Comments:
Quoting CosmicEvents:
That's what we thought when we saw btwntx08's chart.
.
.
.
This Igor does look Cat5 now, but knowing the NHC as I do I suspect that they're waiting for a 7.0 Dvorak if they're to make some special advisory before 11. It's just a matter of time anyway, from the looks of it. We could go 7.5 here before all is said and done..


You know what they say Big Chart, Big....
Member Since: Posts: Comments:
2774. pottery
Just had a chance to look at some images and 'specs' on Igor.
What have you guys been feeding him?
Member Since: Posts: Comments:
Quoting Herbertsbox:


Good Lord man...that things looks bigger than most countries
That's what we thought when we saw btwntx08's chart.
.
.
.
This Igor does look Cat5 now, but knowing the NHC as I do I suspect that they're waiting for a 7.0 Dvorak if they're to make some special advisory before 11. It's just a matter of time anyway, from the looks of it. We could go 7.5 here before all is said and done..
Member Since: August 3, 2005 Posts: 10 Comments: 5531
Quoting Stormchaser2007:
Comrade Ivan


Comrade Igor
What makes it more interesting that both names are of Russian origin.

Comrade Igor again.
Member Since: Posts: Comments:
2771. mbjjm
Quoting weatherlover94:
defiantly wsw im waiting for the new model runs to come in


It is just a wobble.will resume west soon, not significant enough to change the model consesus
Member Since: Posts: Comments:
These two almost belong in a Vodka commercial together....

As in we need some while watching.

Quoting Stormchaser2007:
Comrade Ivan


Comrade Igor
Member Since: Posts: Comments:
Missed this release earlier

Met Service of Jamaica

NEWS RELEASE
September 12, 2010 at 5:00 p.m.

*** FLASH FLOOD *** FLASH FLOOD WATCH IN EFFECT FOR LOW-LYING AND FLOOD PRONE AREAS OF ALL PARISHES ***

*** LARGE AND POWERFUL IGOR MOVING WESTWARD OVER THE CENTRAL TROPICAL ATLANTIC***

The Meteorological Service has issued a Flash Flood Watch Low-lying and Flood prone areas of all parishes until 5:00 pm tomorrow.

FLASH FLOOD WATCH means flash flooding is possible and residents are advised to check precautionary measures, keep informed by listening to further releases from the Meteorological Service and be ready for quick action if flooding is observed or if a warning is issued.

A broad area of Low Pressure is now located south of Hispaniola and is moving toward the west.

Satellite imagery indicates that the cloudiness and thunderstorms associated with the Low Pressure system remain disorganized. Conditions are, however, favourable for gradual development and a tropical cyclone could still form during the next day or two as the system moves toward the western Caribbean Sea.

As the system progress closer to Jamaica, heavy showers and flash flooding are possible.

Due to the current potential for the system to strengthen while moving westward, marine interests are advised that weather conditions will gradually deteriorate today and tomorrow. Thundershowers and strong, gusty winds are forecast over southern waters and small craft operators, especially fishers on the cays and banks, should exercise extreme caution. Those in port are urged not to venture far from the mainland.

The Meteorological Service will continue to monitor the progress of this system and all interests should pay special attention to subsequent Releases.





Meanwhile…


At 4:00 p.m. the centre of Hurricane Igor was located near latitude 17.7 degrees north and longitude 46.9 degrees west or about 1,715 kilometres east of the northern Leeward Islands.

Igor is moving toward the west near 22 km/hr. A turn toward the west-northwest is expected on Tuesday.

Maximum sustained winds have increased to near 220 km/h, with higher gusts. Igor is a category four Hurricane on the Saffir-Simpson scale. Some Additional strengthening is forecast during the next couple of days.


Meanwhile…

At 4:00 p.m. the centre of Tropical Depression Twelve was located near latitude 13.3 degrees north and longitude 22.8 degrees west or about 240 kilometres southeast of the southernmost Cape Verde islands.

The depression is moving toward the west near 22 km/hr. A turn toward the west-northwest is expected on tonight and Monday and, a turn toward the northwest with a decrease in forward speed are expected on Tuesday. On the forecast track, the centre of the depression is expected to pass near the southernmost Cape Verde Islands tonight and Monday.



Maximum sustained winds have increased to near 55 km/hr, with higher gusts. Some strengthening is forecast during the next couple of days and the depression is expected to become a Tropical Storm tonight or Monday.


Hurricane Igor and Tropical Depression Twelve are not a threat to Jamaica.




nch
Member Since: August 17, 2008 Posts: 0 Comments: 672
2767. hercj
Quoting Levi32:


Everything is not right. Upper-level conditions are less than ideal. Development will be gradual but I think it still has a decent shot at becoming a storm eventually.

Thanks Levi.
Member Since: Posts: Comments:
Which is truly one of nature's more interesting and potentially deadly wonders...

Quoting Levi32:


Not sure what you mean. A powerful hurricane can be rather unpredictable as they can to some extent manipulate their own environment.
Member Since: Posts: Comments:
Link

Can anyone verify the linl. I think Igor is located 18N and 47. Please let me know
Member Since: Posts: Comments:
Thanks, Chief. Good show tonight!
Member Since: Posts: Comments:
Comrade Ivan


Comrade Igor
Member Since: Posts: Comments:
2761. Levi32
Quoting breald:


so an annular storm still stays on the projected track?


Not sure what you mean. A powerful hurricane can be rather unpredictable as they can to some extent manipulate their own environment.
Member Since: Posts: Comments:
2760. djdanik
Quoting breald:


so an annular storm still stays on the projected track?


quote from wikipedia:
Annular hurricanes also tend to persist, even when encountering environmental conditions which easily dissipate most other hurricanes. Forecasters have difficulty predicting the behavior of annular hurricanes; they are a recently recognized phenomenon, and as such, little is known about their tendencies. Because of this, they can be more dangerous than typical hurricanes

complete article
http://en.wikipedia.org/wiki/Annular_hurricane
Member Since: Posts: Comments:
2759. pottery
Quoting weatherlover94:
good night all i bet we have a cat 5 by ll if not 11 then defiantly 5 am

Defiantly...
Member Since: Posts: Comments:
2756. hydrus
Igor fills the grid square entirely.
Member Since: Posts: Comments:
2755. Levi32
Quoting hercj:

Levi, what is your take on 92L? Everything is right but it just won't fire.


Everything is not right. Upper-level conditions are less than ideal. Development will be gradual but I think it still has a decent shot at becoming a storm eventually.
Member Since: Posts: Comments:
Link

Wow; Had to look twice at this.
Member Since: August 23, 2008 Posts: 0 Comments: 1918
Quoting MississippiBoy:
hey don't want anything to do with Igor,I remember Ivan.

Yeah, Ivan was really bad.

Good thing is Igor won't have a huge affect to land, like Ivan.
Member Since: Posts: Comments:
good night all i bet we have a cat 5 by ll if not 11 then defiantly 5 am
Member Since: Posts: Comments:
defiantly wsw im waiting for the new model runs to come in
Member Since: Posts: Comments:
Quoting weatherwart:


Wow. How strong is this sucker going to get?
I bid 163 now before 11
Member Since: Posts: Comments:
2749. mbjjm
Quoting DarIvy959810:

the northernmost islands is Anguilla at around 18.5 N

Agreed, Northern most of the Lesser Antilles
Member Since: Posts: Comments:
2748. Seastep
Quoting angiest:


What's the farthest east they do recon?


55W
Member Since: Posts: Comments:
Quoting Levi32:


1. Yes.

2. Igor is nearly annular, which means he has a structure that is highly resistant to EWRCs. In other words, unless he is exposed to a negative factor (dry air, wind shear, cold water), he likely won't undergo an EWRC. He will simply remain this way, either annular or nearly annular, and maintain a nearly constant intensity once he peaks, with minor fluctuations until he begins recurving. Hurricane Isabel in 2003 trekked for days across the Atlantic at Cat 4/5 intensity with little change in structure when she was annular.


Thanks for the update Levi.. Very good information!!
Member Since: Posts: Comments:
Quoting MississippiBoy:
hey don't want anything to do with Igor,I remember Ivan.

IGOR, the IVAN comrade
Member Since: Posts: Comments:

Viewing: 2796 - 2746

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

Top of Page

About

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

Overcast
62 °F
Overcast