Hurricane Hunters find 50 - 60 mph winds in disturbance 92L north of Puerto Rico

By: Dr. Jeff Masters , 8:54 PM GMT on August 25, 2009

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The tropical wave (92L) a few hundred miles north of Puerto Rico is generating a large area of surface winds of 50 - 60 mph, according to the latest information from the Hurricane Hunters. Top winds seen so far at their flight level of 1,000 feet were 69 mph, which would make 92L a strong tropical storm if it had a surface circulation.
However, the aircraft has not found a surface circulation, and the satellite appearance shows virtually no change in the amount, intensity, or organization of the storm's thunderstorm activity. Wind shear has dropped to the moderate range, 15 - 20 knots this afternoon, but the upper low 92L is moving underneath is dumping cold, dry air into the region. Dry air continues to get ingested into 92L's thunderstorms, creating strong downdrafts that are robbing 92L of heat and moisture. These downdrafts are creating surface arc clouds that spread out from where the downdraft hits the ocean surface. NHC continues to give 92L a high (greater than 50% chance) of developing into a tropical depression by Thursday afternoon.

The forecast for 92L
As 92L moves underneath the center of the upper low on Wednesday morning, the upper low is expected to weaken, and wind shear is expected to decline to the low range, 5 - 10 knots. However, the upper-level low will continue to dump dry, cold air into 92L through Thursday afternoon, slowing down development. By Thursday night, when 92L should be several hundred miles off the coast of northern Florida, the upper-level low may be weak enough and far enough away that 92L will find itself in a region with light upper level anticyclonic winds, which would favor more rapid development. However, this favorable environment will not last long, since a strong trough of low pressure will be approaching the U.S. East Coast on Friday. This trough will bring high wind shear of 20 - 30 knots by Friday night. This trough should be strong enough to turn 92L to the north. The models disagree substantially on how close 92L will be to the coast at that time. One camp of models, including the NOGAPS, Canadian, UKMET, and ECMWF models, predict 92L will pass very close to the Outer Banks of North Carolina on Friday night or Saturday morning. The GFS, GFDL, and HWRF models keep 92L several hundred miles out to sea. Both sets of models bring 92L north-northeastwards on Saturday, with a track over Massachusetts or Nova Scotia. The intensity forecast for 92L is problematic, since it's eventual strength depends upon how quickly it manages to become a tropical depression. Given that 92L will find itself in a favorable environment for strengthening for about 36 hours this week, and marginal for the remainder of the week, I give the system these odds:

10% chance of never getting a name.
20% chance of becoming a weak tropical storm (40 - 50 mph winds).
40% chance of becoming a strong tropical storm (55 - 70 mph winds).
30% chance of attaining hurricane strength.

Elsewhere in the Atlantic
The ECMWF and UKMET models predict the development of a tropical wave coming off the coast of Africa late this week. The GFS model no longer shows this.

I'll have an update Wednesday morning.

Jeff Masters

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Quoting eddye:
due west towards florida



No the Bahama's
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Well the NHC said we will most likely be issuing advisories today, I think either TS, or possibly even STS Danny will form at 11 a.m. Too bad I won't be back till 3, should definitely be Danny by then if organization continues. I see the quickscat has found a well defined circulation and you can see it on the visible. What could make this Subtropical is that Dannys center is displaced from the convection, making it a hybrid storm at best. Some models turn it into a Hurricane. I still see a WNW movement which leads me to believe all models may be off because most models already have it turning by later on today which will probably not happen. at least till tomorrow.
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Quoting IKE:
Floater loop on 92L...


hey IKE
saved ya some pancakes and sausage LOL
Ok bout how close mile wise are the models bringin this thingy to you know where?
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Quoting IKE:
Looks like it's moving almost due west.


"West Caster"

LOL, agree.
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835. eddye
due west towards florida
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813. kmanislander : 24N 70W

Station 41046 (Requested) - E Bahamas 23.867 N 70.870 W

Member Since: August 19, 2008 Posts: 6 Comments: 2490
Quoting WxLogic:


Hehe... I would give it a .5N deviation.

I don't really buy the solution of a LLC closer to the convection as it's being enhanced still by the TUTT to its SSW.

Also, this kind of proves the system is not self sufficient enough to produce deep enough convection as long as that TUTT still there.


I was " rounding up " LOL
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It should begin to wrap in that convection later today as the environment becomes more favorable
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830. IKE
Looks like it's moving almost due west.
Member Since: June 9, 2005 Posts: 23 Comments: 37858
Quoting kmanislander:


It is somewhat elongated to the SSW but looks tight enough near 24N 70W to be considered closed IMO.

Given the winds out there I would expect this to be classified given the current state of organization.

I would too, but more because of its location and its proximity to land and the u.s. I really think it is a very broad llc, on the sw side of the convection and I agree with whoever said, sts looking.
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827. IKE
Floater loop on 92L...
Member Since: June 9, 2005 Posts: 23 Comments: 37858
Quoting kmanislander:


24N 70W


Hehe... I would give it a .5N deviation.

I don't really buy the solution of a LLC closer to the convection as it's being enhanced still by the TUTT to its SSW.

Also, this kind of proves the system is not self sufficient enough to produce deep enough convection as long as that TUTT still there.
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we should know by later today where the closed circulation will be..if and when it develops, based on the models, majority of the strong winds will be towards the east side of the storm, brushing the east coast.
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Quoting TheCaneWhisperer:


Maybe broad / elongated SW to NE a bit.


It is somewhat elongated to the SSW but looks tight enough near 24N 70W to be considered closed IMO.

Given the winds out there I would expect this to be classified given the current state of organization.
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Quoting TheCaneWhisperer:


Wouldn't that throw a wrench in things.

Ahun! Eyes Open -might have a trickster here
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Quoting MahFL:
I see a clear coc, and convectiom moving SW over it.



I think your looking at the MLC sheared off unstacked system.
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my best guess from this is 24.84 69.89



based on cloud imagery
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818. IKE
Quoting P451:
Good Morning. The invest is a mess still I see. If there is a LLC I would say I see it on the south west corner of the western-most blob of convection. Not exactly conducive for intensification.





This thing looks more like a gale center trying to become an STS than anything else.


I agree. Rather messing looking.
Member Since: June 9, 2005 Posts: 23 Comments: 37858
Quoting kmanislander:


24N 70W


Maybe broad / elongated SW to NE a bit.
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816. MahFL
I see a clear coc, and convectiom moving SW over it.
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815. IKE
Looks like near 20 knots of westerly shear is partially exposing the center of 92L....

Member Since: June 9, 2005 Posts: 23 Comments: 37858
Quoting nrtiwlnvragn:
Recon found a w e a k center circulation at flight level, well away from convection, ~22.6 70.6. They are now flying towards the heaver convection, where they might find a stronger center.


Hmmm... a bit further south than what I expected as noted on my previous post(s)... but I guess we'll see.
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Quoting nrtiwlnvragn:


Just looked at it, and agree. Recon is now heading back to where they found that weak center. Maybe they will descend to a lower level, last time was at 12,500 ft.


24N 70W
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Quoting kmanislander:


Good morning

Based on the quikscat pass this morning they will likely find enough of a closed low to classify the system


Just looked at it, and agree. Recon is now heading back to where they found that weak center. Maybe they will descend to a lower level, last time was at 12,500 ft.
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Hi Res Quikscat
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Quoting TheCaneWhisperer:


Last night Steve Weagle in West Palm indicated that he thought the surface low was there instead of by the convection. We'll see if he is right, looking at maps tell me the center may have relocated up to 24ish 68ish


Wouldn't that throw a wrench in things.
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Quoting IKE:


Most of them are offshore w/92L...that's the lowdown..

6Z HWRF...

6Z GFDL...




LOL.


Thanks Ike
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If they find something, will that info be fed into the 12Z?
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Quoting nrtiwlnvragn:
Recon found a w e a k center circulation at flight level, well away from convection, ~22.6 70.6. They are now flying towards the heaver convection, where they might find a stronger center.


Last night Steve Weagle in West Palm indicated that he thought the surface low was there instead of by the convection. We'll see if he is right, looking at maps tell me the center may have relocated up to 24ish 68ish
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Quoting nrtiwlnvragn:
Recon found a w e a k center circulation at flight level, well away from convection, ~22.6 70.6. They are now flying towards the heaver convection, where they might find a stronger center.


Good morning

Based on the quikscat pass this morning they will likely find enough of a closed low to classify the system
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would a shallower/developing system not be influenced by the trough like 92L would 92L continue to move WNW towards the bahamas ??????
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803. IKE
Quoting justalurker:
any changes in the models since last night?


Most of them are offshore w/92L...that's the lowdown..

6Z HWRF...

6Z GFDL...


Quoting SeVaSurfer:
Our local Yocal weathermen keep saying " a little breezy this weekend" keep your eyes on the tropics. I give up on them. Nothing like a little advanced warning of an approaching storm, a whole 2 days and they still have no idea. IKE need a job?


LOL.
Member Since: June 9, 2005 Posts: 23 Comments: 37858
Since the blog is slow today...
A little listening with your coffee

Member Since: August 19, 2008 Posts: 6 Comments: 2490
Our local Yocal weathermen keep saying " a little breezy this weekend" keep your eyes on the tropics. I give up on them. Nothing like a little advanced warning of an approaching storm, a whole 2 days and they still have no idea. IKE need a job?
Member Since: August 30, 2006 Posts: 0 Comments: 104
Recon found a w e a k center circulation at flight level, well away from convection, ~22.6 70.6. They are now flying towards the heaver convection, where they might find a stronger center.
Member Since: September 23, 2005 Posts: 14 Comments: 11215
any changes in the models since last night?
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Quoting leftovers:
blog picking up now td forming


From the way it sounds probably ts forming.
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Quoting Engine2:
Slow blog this morning


good morning, yes its usually slow in the morning and all the kids are in school..till afternoon when it picks up.LOL
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25n 70w looks to be where an llc is booking it due west.
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Good Morning Guys.

I beleive when i get to the computer this afternoon...We'll have TS Danny.
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793. IKE
Drinking coffee.....at my house, this morning...


TROPICAL WEATHER OUTLOOK
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
800 AM EDT WED AUG 26 2009

FOR THE NORTH ATLANTIC...CARIBBEAN SEA AND THE GULF OF MEXICO...

SATELLITE IMAGERY INDICATES THAT THE AREA OF DISTURBED WEATHER
CENTERED ABOUT 470 MILES EAST OF NASSAU IN THE BAHAMAS IS
DEVELOPING A WELL-DEFINED CIRCULATION.
THE SYSTEM COULD DEVELOP
INTO A TROPICAL DEPRESSION...OR MORE LIKELY A TROPICAL STORM...AT
ANY TIME AS IT MOVES WEST-NORTHWESTWARD AT ABOUT 15 MPH...AND IF
CURRENT TRENDS CONTINUE ADVISORIES WILL BE INITIATED LATER TODAY.
THERE IS A HIGH CHANCE...GREATER THAN 50 PERCENT...OF TROPICAL
CYCLONE FORMATION DURING THE NEXT 48 HOURS. INTERESTS IN THE
BAHAMAS SHOULD MONITOR THE PROGRESS OF THIS SYSTEM. A NOAA
HURRICANE HUNTER AIRCRAFT IS CURRENTLY ENROUTE TO INVESTIGATE THIS
SYSTEM.

ADDITIONAL INFORMATION ON MARINE WARNINGS ASSOCIATED WITH THIS
SYSTEM CAN BE FOUND IN HIGH SEAS FORECASTS ISSUED BY THE NATIONAL
WEATHER SERVICE...UNDER AWIPS HEADER NFDHSFAT1 AND WMO HEADER
FZNT01 KWBC.

ELSEWHERE...TROPICAL CYCLONE FORMATION IS NOT EXPECTED DURING THE
NEXT 48 HOURS.

$$
FORECASTER BEVEN

Member Since: June 9, 2005 Posts: 23 Comments: 37858
Slow blog this morning
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Member Since: March 19, 2009 Posts: 0 Comments: 1421
re 787 will do and thanks of course =)
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yes I belive there are women that handle those waves. Basically I belive its more mental then physical in heavy days. There have been times I have seen even the saltiest guy get rattled and go back in for a break. Its amazing that heavy surf and big surf are not synonomus(sp).
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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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