Potentially dangerous 92L steadily developing; Igor nears hurricane strength

By: Dr. Jeff Masters , 3:04 PM GMT on September 11, 2010

Share this Blog
0
+

A tropical disturbance (92L) over the Eastern Caribbean, a few hundred miles south of Puerto Rico, is steadily organizing and appears likely to develop into a tropical depression by tonight or Sunday morning. Satellite loops show an impressive and expanding region of heavy thunderstorms, with good spiral banding and respectable upper-level outflow on all sides. Long range radar out of Puerto Rico shows that heavy rains are now affecting that island, but there is no rotation to the radar echoes evident. However, the rain bands are becoming more intense and more organized. San Juan, Puerto Rico reported a heavy rain squall at 8:44 am this morning, and radar estimates suggest two inches of rain fell in this squall just southeast of San Juan. Wind shear over 92L is low, 5 - 10 knots. The waters beneath are at near-record warmth, 30°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-northwest at 11 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 Mexico's Yucatan Peninsula on Wednesday. The HWRF model has a more northwesterly track, taking 92L over the Dominican Republic, Haiti, and Cuba, but this model has been trending too far north in its tracks. I expect 92L will follow a path south of the islands, bringing it near or just south of Jamaica on Monday, then into the Yucatan Peninsula on Wednesday. On this track, the southern Dominican Republic can expect heavy rains of 3 - 6 inches tonight through Monday morning; southern Haiti can expect similar rains Sunday through Monday, and Jamaica and the Cayman Islands can expect heavier rains of 4 - 8 inches Monday and Tuesday. Eastern Cuba will probably escape 92L's heaviest rains in this scenario (Figure 2.)

Intensity forecast for 92L
I can't find any reason to doubt this will be a tropical storm by Sunday or Monday, and potentially a Category 1 or 2 hurricane by Wednesday, if 92L avoids passage over Hispaniola and Cuba. The SHIPS model predicts wind shear will remain low, 5 - 10 knots, through the period, and makes 92L a Category 1 hurricane by Monday night. 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. The first Air Force Hurricane Hunter mission into 92L is scheduled for Sunday afternoon, but there will be a research mission by the National Center for Atmospheric Research G-V jet today that will give us valuable information on 92L's large scale environment and potential for development.


Figure 2. Forecast rain amounts from 92L from the 2am EDT Saturday run of the GFDL model. This model predicts most of 92L's heaviest rains will miss Haiti, but will affect Jamaica, the Cayman Islands, and the Yucatan Peninsula. Image credit: Morris Bender, NOAA/GFDL.

Igor
Tropical Storm Igor is very close to hurricane strength, and appears destined to become a large and powerful major hurricane over the Central Atlantic in the days to come. Wind shear is moderate, 15 - 20 knots, waters are warm, 28°C, and Igor has moistened its environment enough to keep the dry air of the Saharan Air Layer (SAL) at bay. Igor will track west under the influence of a strong ridge of high pressure for the next three days, then turn more to the west-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 has a slight chance of making landfall on the U.S. East Coast or Canada. Climatology shows that about 10% 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 5% for Canada. The forecast steering pattern for the coming two weeks from the GFS model 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. The odds of Igor hitting land in the U.S. or Canada are probably close to their climatological 10% and 5% probabilities, respectively.

Elsewhere in the tropics
A new tropical wave (Invest 93L) emerged from the coast of Africa yesterday, and is already showing signs of organization. Most of the models predict 93L will develop into a tropical depression 2 - 4 days from now, and NHC is giving 93L a 30% chance of developing by Monday.

Next post
This may be my only post today; I'll have a new post Sunday morning.

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: 223 - 173

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 | 52Blog Index

Quoting plywoodstatenative:
Drak, whats the forecast path for all three systems?


92L should travel WNW through the Caribbean approaching the Yucatan Peninsula. The NHC track on Igor looks good. 93L looks to recurve up into the subtropical Atlantic.
Member Since: Posts: Comments:
Quoting Bordonaro:

wow
Member Since: July 7, 2010 Posts: 0 Comments: 5630
Quoting CosmicEvents:
The lot of rain part is right....but it's not explosive development of a cyclone. It's a lot of convection otherwise known as thunderstorms and commonly refered to as rain.
.
.
No explosive development is possible as we have no spin. If a spin develops, then things could pop rapidly.


That's why I say explosive development, and not explosive cyclone development.
Member Since: Posts: Comments:
219. beell
Igor should show a good response to the right in a couple of days from the current western ATL trough. Looks healthy this morning (the trough).

Photobucket
GOES N ATL WV LOOP
Member Since: Posts: Comments:
We are watching the birth phase of out "J" TC :o)


BULLETIN - IMMEDIATE BROADCAST REQUESTED
SPECIAL MARINE WARNING
NATIONAL WEATHER SERVICE SAN JUAN PR
1206 PM AST SAT SEP 11 2010

THE NATIONAL WEATHER SERVICE IN SAN JUAN HAS ISSUED A

* SPECIAL MARINE WARNING FOR...
COASTAL WATERS OF SOUTHERN USVI...VIEQUES AND EASTERN PUERTO RICO
OUT 10 NM...
COASTAL WATERS OF SOUTHERN PUERTO RICO OUT 10 NM...
CARIBBEAN WATERS OF PUERTO RICO FROM 10 NM TO 17N...

* UNTIL 200 PM AST

* AT 1155 AM AST...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
A SERIES OF THUNDERSTORMS...PRODUCING STRONG WINDS 34 KNOTS OR
GREATER OVER CARIBBEAN WATERS OF PUERTO RICO...MOVING WEST NORTHWEST
AT 25 KNOTS.


THESE THUNDERSTORMS WILL BE CAPABLE OF PRODUCING WIND GUSTS IN
EXCESS OF 40 KNOTS...TORRENTIAL RAINFALL...FREQUENT CLOUD TO GROUND
LIGHTNING AND SUDDEN WATERSPOUTS.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

MARINERS CAN EXPECT GUSTY WINDS...HIGH WAVES...DANGEROUS LIGHTNING...
AND HEAVY RAINS. BOATERS SHOULD SEEK SAFE HARBOR IMMEDIATELY...UNTIL
THIS STORM PASSES.

THUNDERSTORMS CAN PRODUCE SUDDEN WATERSPOUTS. WATERSPOUTS CAN EASILY
OVERTURN BOATS AND CREATE LOCALLY HAZARDOUS SEAS. SEEK SAFE HARBOR
IMMEDIATELY.

&&

LAT...LON 1700 6736 1794 6737 1793 6573 1807 6573
1807 6491 1700 6486
Member Since: Posts: Comments:
Quoting Jeff9641:
Now notice the steering becomes out of the SW or WSW if Julia is trapped near the Yucatan or BOC.

http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/12/fp0_156.shtml

Now thats some spurrious steering there Jones, gulf Fla come into play of that happens
Member Since: Posts: Comments:
If the trough that keeps all the storms recurve out to sea changes soon, I think we might see some kind of hurricane affect Florida or the US Gulf Coast shortly. I have some doubts Invest 92L will seriously threaten South Florida but I'm still keeping a close eye in case this gets in the Gulf and turns out to be another Ivan or Opal.
Member Since: Posts: Comments:
Quoting JLPR2:
And the rain starts again here. XD

Same here.
Member Since: July 7, 2010 Posts: 0 Comments: 5630
212. JLPR2
hm... 92L is cleaning my windows nicely, got a little wind with the rain. XD
Member Since: Posts: Comments:
Quoting JLPR2:
And the rain starts again here. XD

I'm jealous, it's 88 sunny and hot outside but atleast college football is on. Go FAU and UM!!
Member Since: Posts: Comments:
208. IKE
180 hour 12Z GFS....

Member Since: Posts: Comments:
Quoting bird72:
Explosive development in the caribbean. A lot of rain here in the north part of Puerto Rico.
The lot of rain part is right....but it's not explosive development of a cyclone. It's a lot of convection otherwise known as thunderstorms and commonly refered to as rain.
.
.
No explosive development is possible as we have no spin. If a spin develops, then things could pop rapidly.
Member Since: Posts: Comments:
Convection already waning in the southern quadrant. We'll see what happens.


Member Since: June 9, 2007 Posts: 4 Comments: 15790
205. JLPR2
And the rain starts again here. XD
Member Since: Posts: Comments:
Quoting bird72:
Explosive development in the caribbean. A lot of rain here in the north part of Puerto Rico.


none in ponce.
Member Since: August 22, 2006 Posts: 2 Comments: 1975
Quoting aislinnpaps:


Any remote chance it could stay that way for the rest of the season?


its forecast to change soon
Member Since: August 22, 2006 Posts: 2 Comments: 1975
Quoting PensacolaDoug:


Troughs coming off the east coast and a good ridge in the Carrib means "deflector shields up, Captain Kirk!" for Gulf Coast and SE US.


Any remote chance it could stay that way for the rest of the season?
Member Since: August 22, 2009 Posts: 0 Comments: 3115
Quoting MiamiHurricanes09:

I believe the 92L and Igor will become major hurricanes during their life cycles.
Member Since: Posts: Comments:
Explosive development in the caribbean. A lot of rain here in the north part of Puerto Rico.
Member Since: Posts: Comments:
Pretty odd to see a developing depression in the Eastern Caribbean.

Member Since: June 9, 2007 Posts: 4 Comments: 15790
Its the wave that Igor is currently ingesting
Member Since: Posts: Comments:
196. 7544
looks like igor maybe getting his eye
Member Since: Posts: Comments:
Quoting MiamiHurricanes09:
Anyone know what is that area of showers and thunderstorms located near 30N 50W? It's accompanied by an area of low pressure as noted on satellite loops.



Used to be a tropical wave ahead of Igor.
Member Since: June 9, 2007 Posts: 4 Comments: 15790
Quoting 7544:
u can call thgis wishcasting but i hope 92l could go a little more north and avoid hati they dont need the rain and floods this year then it could go wnw or nw twoard the bahamas are conditions favoable in the bahamas area for 92l tia

Thats hopecasting
Member Since: Posts: Comments:
192. JLPR2
Quoting MiamiHurricanes09:
Lol, it can't be. It looks like it's a surface trough, and an area of low pressure developed along it.

Back later.


LOL XD
It's a persistent one, after it degenerated it split into two, a very weak spin now at 20N 53W and the low you are speaking of, it has been interesting seeing it these past few days.
Member Since: Posts: Comments:
Quoting PensacolaDoug:


Troughs coming off the east coast and a good ridge in the Carrib means "deflector shields up, Captain Kirk!" for Gulf Coast and SE US.
Hi ya Doug good to see you on today....

Looks like 92L soon to be "Julia" might have a great chase coming....

Taco :o)
Member Since: Posts: Comments:
Yes, the dead zone producing life for a change....bad news.

Quoting atmoaggie:
Allows for much better surface and upper air obs than any CV system probably ever will.
Quoting Drakoen:
I see 92L is organizing nicely. Probably saw 93L coming off the coast of Africa and decided it wanted to be named first. It looks like it is pretty much a neck to neck race to see who gets named first. On another note, it is interesting to see 92L developing in the Eastern Caribbean.
Member Since: Posts: Comments:
Drak, whats the forecast path for all three systems?
Member Since: Posts: Comments:
Quoting MiamiHurricanes09:
Anyone know what is that area of showers and thunderstorms located near 30N 50W? It's accompanied by an area of low pressure as noted on satellite loops.

Remnant of Karen? Couldn't resist.
Member Since: Posts: Comments:
Surface observations and satellite-derived winds show that 93L already has a closed low level circulation.
Member Since: Posts: Comments:
Quoting Drakoen:
I see 92L is organizing nicely. Probably saw 93L coming off the coast of Africa and decided it wanted to be named first. It looks like it is pretty much a neck to neck race to see who gets named first. On another note, it is interesting to see 92L developing in the Eastern Caribbean.
Allows for much better surface and upper air obs than any CV system probably ever will.
Member Since: Posts: Comments:
I see 92L is organizing nicely. Probably saw 93L coming off the coast of Africa and decided it wanted to be named first. It looks like it is pretty much a neck to neck race to see who gets named first. On another note, it is interesting to see 92L developing in the Eastern Caribbean.
Member Since: Posts: Comments:
Curacao has some fairly dry air aloft, SW of the system, too. But, not that dry.

Member Since: Posts: Comments:
It's about time for PockyLips to rear his ugly head with some stupid crap about how its a conspiracy from the NHC to not let anybody know that the storm (or storms) is/are really going to Florida. Doesnt matter which storm. He'll have 'em both making landfalls as cat5's. He's a lot more predictable than the storms are!
Member Since: Posts: Comments:
Yah 92l track is a match to Deans path. Hope it wont be like Gilber or Dean. Both very strong Cat 5 storms.
Member Since: Posts: Comments:
Wind slowly picking up at St. Croix. (this is 1-minute time average, not the 8-minute version)

Member Since: Posts: Comments:
Quoting MiamiHurricanes09:
Anyone know what is that area of showers and thunderstorms located near 30N 50W? It's accompanied by an area of low pressure as noted on satellite loops.


thats the chupacabra storm
Member Since: Posts: Comments:
Quoting JLPR2:


part of ex-99L
Lol, it can't be. It looks like it's a surface trough, and an area of low pressure developed along it.

Back later.
Member Since: Posts: Comments:
177. JLPR2
Quoting MiamiHurricanes09:
Anyone know what is that area of showers and thunderstorms located near 30N 50W? It's accompanied by an area of low pressure as noted on satellite loops.



part of ex-99L
Member Since: Posts: Comments:
175. JLPR2


SE PR is in for a rainy day
Member Since: Posts: Comments:
Rather dry N of the system. Santo Domingo:

Member Since: Posts: Comments:
Anyone know what is that area of showers and thunderstorms located near 30N 50W? It's accompanied by an area of low pressure as noted on satellite loops.

Member Since: Posts: Comments:

Viewing: 223 - 173

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 | 52Blog 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.