Tropical Storm Henri forms

By: Dr. Jeff Masters , 9:37 PM GMT on October 06, 2009

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The tropics spawned another October surprise today, when Tropical Storm Henri formed in the face of adverse levels of wind shear. Henri is under about 20 - 25 knots of wind shear, which ordinarily prevents rapid development like we witnessed this afternoon. However, the environment is quite moist, and Henri is over warm waters, 29°C. An ASCAT pass from 11:37am EDT showed Henri had winds of 40 mph. Satellite loops show that Henri has managed to rapidly develop a large area of intense thunderstorms with cold cloud tops in just a few hours, though the high shear is keeping any thunderstorms from developing on the west side of the center. Water vapor satellite images show that there is some dry air to Henri's northwest, and this dry air will act to slow Henri's growth some. The dry air is creating strong downdrafts that are apparent on visible satellite images as arcs of cumulus clouds spreading out from where the downdraft hits the ocean surface, along the northwest side of Henri's center.

None of the reliable global computer models showed Henri would develop, and the models all favor weakening and dissipation of Henri by Thursday, due to high wind shear of 20 - 25 knots. The official NHC forecast goes along with this scenario, but think there is a medium (30 - 50% chance) that Henri will not dissipate. By Friday, wind shear in the vicinity of Henri (or its remains) is predicted to fall to the low to moderate range. Even if Henri has dissipated by that point, regeneration into a tropical storm may occur. The track of Henri after Friday is problematic, as the storm will be in an area of weak steering currents. Several of the models favor a track to the west-southwest into the Caribbean, across Hispaniola. Residents of the Dominican Republic and Haiti should anticipate that Henri or its remains may bring flooding rains to Hispaniola by Saturday. It is also possible that Henri will get pulled northwards and recurved out to sea, and not affect the Caribbean at all, though.


Figure 1. Latest satellite image of Henri.

A little tropical weather for England
The remnant circulation of Tropical Storm Grace is currently making landfall in Southwest England. Grace's remains brought sustained winds of tropical storm force--41 mph--to one buoy off the coast last hour, and 38 mph to the Sevenstones Lightship buoy. you can track the progress of Grace via our wundermap for the region.


Figure 2. The remnant circulation of Tropical Storm Grace scoots by to the south of Ireland in this visible satellite image taken at 1pm EDT 10/06/09. Image credit: UK Met Office.

Jeff Masters


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Quoting AtlantaMET:


Good morning Ike. Glad to see you. I have flagged and reported the jerk.
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556. IKE
Quoting AtlantaMET:


It's the plain truth and many of us know it. You might not like it but I am honest. It's like saying Obama is black and people might not like it but it is the truth. Same concept here. What you are doing is not contributing the blog's education or welfare and you know it as much as I do. Stop being so subborn and listen to when poeple say these things because they are not telling a lie on you.


????????????????????????????????????????????

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Henri continues to look very impressive, I would think 60MPH winds at 11AM, imo. I'm also watching that vigorous looking tropical wave to its SE, shear will most likely tear it apart, but it should be highlighted yellow, imo.



As you can see, Henri's 850MB circulation is strong, and the wave to its SE is also strengthening.



With the latest steering currents I'm seeing (1000-1010 MSLP), I think that if Henri can survive the very strong shear, I think this will most likely end up somewhere near SFLA.



I'm out, Have a great Morning/Afternoon!

-MiamiHurricanes09
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553. IKE
AtlantaMET.

Listen to a little Robert Plant..In The Mood.

Maybe that'll help you out...you need it.
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Good morning..
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Quoting leftovers:
beautiful rose sunrise here in e cent florida i live for this time of day


I took your advise. I am going to return to surfing during the off-season but I hope we do get some decent waves from frontal waves passing to our north.
Member Since: July 24, 2005 Posts: 407 Comments: 19076
BBL

Blog Update

Tropical Storm Henri and the area to its southeast
Member Since: July 24, 2005 Posts: 407 Comments: 19076
post 544 - LOL

Ike - not only are you rooting against Henri, but you are rooting for another invest eh? Trying to get yelled at by all bloggers?

Seriously - nice observation.
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545. Mikla
Henri w/ mid and upper shear. He still faces a good deal of shear 20-30 over the next day or two...
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544. IKE
Henri under 20-30 knots of shear(downcaster).

Blob SE of Henri has a high over it(wishcaster).

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I see a coc near 17.8N 56.3W
Member Since: October 6, 2007 Posts: 0 Comments: 5581
Member Since: June 29, 2009 Posts: 13 Comments: 5238
Good Morning

Blog Update

Tropical Storm Henri and the area to its southeast
Member Since: July 24, 2005 Posts: 407 Comments: 19076
539. JRRP
may be im wrong but the shear is beginning to destroy

see you later
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Parma looks like it just moved East of the Philippines, If it restrengthens or even just get convection Luzon will be in big trouble.
Member Since: March 29, 2008 Posts: 0 Comments: 2338
To me it doesn't look any better or worse. Still looks like a sheared mess like Ana and Danny. I have to say it does look better than Danny right now. The first good clear visible should tell us how bad of shape Henri is in.
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534. JLPR
also we have a stronger Henri

200910070600 18 -55.6 45
200910070000 18.1 -54.7 35
200910061800 17.7 -53.4 35

and with that im off to bed :0)
Member Since: September 4, 2007 Posts: 36 Comments: 5223
533. JLPR
Member Since: September 4, 2007 Posts: 36 Comments: 5223
532. JLPR
By what im seeing it appears Henri has been moving mostly west with the center barely under the convection right on the edge of it

and its satellite presentation has improved like I never thought it would

Member Since: September 4, 2007 Posts: 36 Comments: 5223
531. 7544
Quoting silverstripes:
Blackout has ended already.



got it now hmmm he really is starting to get a good shape at this hour could be 50 mph by what he looks like right now they may still bump him up again at 5am
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Blackout has ended already.

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529. 7544
blackout ends in 30 minutes then we can see how henri looks imo we might see a red ball
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Quoting stormsurge39:
If it keeps a more westerly route wouldnt that keep it away from strong wind shear and over the islands into the Carribean for futher developement?

It would have to stay at a due west movement here on out and then have to go wsw at some point to dodge Hispaniola and make it into the southern Caribbean. I don't see that happening right now. Shear is not as bad in the southern Caribbean. That is probably the only way Henri would survive.
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Quoting markymark1973:
Models say Henri bends back to the wsw and then eventually dies over Hispaniola or maybe Cuba. If the shear doesn't kill him first that will.
If it keeps a more westerly route wouldnt that keep it away from strong wind shear and over the islands into the Carribean for futher developement?
Models say Henri bends back to the wsw and then eventually dies over Hispaniola or maybe Cuba. If the shear doesn't kill him first that will.
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If Henri makes it to the Carribean, what will wind shear be like?
524. JLPR
Quoting KoritheMan:


Regardless of whether or not Henri relocates his low-level center, the relentless southwesterly shear will ensure that it quickly becomes exposed again. I'll be surprised if this survives the next 48 hours.


I agree it will have to continue to fight if it wants to survive
Member Since: September 4, 2007 Posts: 36 Comments: 5223
523. xcool


Member Since: September 26, 2009 Posts: 2 Comments: 15603
Quoting JLPR:


it looks too good
maybe a LLC relocation?
well cant tell till we get some visible images in the Morning


Regardless of whether or not Henri relocates his low-level center, the relentless southwesterly shear will ensure that it quickly becomes exposed again. I'll be surprised if this survives the next 48 hours.
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Quoting stormsurge39:
Wont wind shear decrease the father W henri goes? It looks like hes going to miss current forecast points!


Indeed, it's something to closely watch.
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520. JLPR
Quoting ElConando:


I'm not too sure the convection has been moving west with it.


it looks too good
maybe a LLC relocation?
well cant tell till we get some visible images in the Morning
Member Since: September 4, 2007 Posts: 36 Comments: 5223
Wont wind shear decrease the father W henri goes? It looks like hes going to miss current forecast points!
518. xcool
Link

model runs.!!
Member Since: September 26, 2009 Posts: 2 Comments: 15603
517. xcool


5.30 utc
Member Since: September 26, 2009 Posts: 2 Comments: 15603
Quoting JLPR:


thanks =)


I really do hope the center is to the west of that convection xD


I'm not too sure the convection has been moving west with it.
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GFS showed this split happening the other day. One part of the energy headed NW towards the Bahamas and the southern part headed toward the Caribbean. Big props for the GFS if that were to pan out.
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woah! there is nothing at 200mb voracity wise with Henri. Nothing...
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513. JLPR
Quoting Bordonaro:
Link
Link above to Navy Microwave Image, click on 91L link on left. It will show you TS Henri pic from 0400 UTC, about 11PM CDT.


thanks =)


I really do hope the center is to the west of that convection xD
Member Since: September 4, 2007 Posts: 36 Comments: 5223
didn't Tampa post that shear in the last 24 hrs around Henri has generally decreased?
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Quoting JerseyFisher:
And also for participants and lurkers Henri is pronounced Ah-n-ree.



I also found out the hard way, Henri is French for Henry. I thought is was a female variation of Henry?!?
Member Since: August 25, 2009 Posts: 20 Comments: 6785
Link
Link above to Navy Microwave Image, click on 91L link on left. It will show you TS Henri pic from 0400 UTC, about 11PM CDT.
Member Since: August 25, 2009 Posts: 20 Comments: 6785
508. JLPR
Quoting TampaSpin:


I realize that but the loop from then shows a very exposed Henri....i doubt much has changed when looking at the shear.


well yeah
according to this it was really close to being exposed before blackout :)
Member Since: September 4, 2007 Posts: 36 Comments: 5223
And also for participants and lurkers Henri is pronounced Ah-n-ree.

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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.