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 Chicklit:

Weather456, you deserve a lot of credit and a huge pat on the back for hanging in there. Plus, you had several mentions by Dr. Masters himself! You made it interesting all along the way. I'm not writing the epitaph of the season, especially since Dr. Masters mentioned we could see something in the latter part of October, and in fact we do have two named storms in one week with Grace and Henri...both rather tenuous, but 456 you have really been consistent. This was no easy feat with so little developing. Shear may relax and we may finally see something materialize, but at this point, we'll just have to wait until the end of November. And until then, we do depend on you Weather456 to keep us all on track. So hang in there. You are appreciated.
je


Well thank you for those kind thoughts.
Member Since: July 24, 2005 Posts: 407 Comments: 19076
Quoting Relix:
So, the NHC track is dead on. Does WU agree on this? =P


This year, the NHC did well with Bill. They didn't do well with any other storm.

My $.02 is to watch Henri carefully! Computer models and shear forecasts haven't been real good this season. IF shear decreases, he might ramp up quick.

Member Since: August 25, 2009 Posts: 20 Comments: 6785
Still poof in two days...

TROPICAL STORM HENRI DISCUSSION NUMBER 2
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL102009
1100 PM AST TUE OCT 06 2009

CONVECTION HAS CONTINUED TO PULSATE NEAR THE CENTER OF HENRI THIS
EVENING AND THE AREA OF COLD CLOUD TOPS HAVE EXPANDED CONSIDERABLY.
DVORAK T-NUMBERS HAVE INCREASED...SUGGESTING AN IMPROVEMENT IN
ORGANIZATION. A 2151 UTC QUIKSCAT PASS SHOWED SOME 40 KT WIND
VECTORS TO THE NORTHEAST OF THE CENTER THAT SEEM BELIEVABLE.
ON THIS BASIS...THE INITIAL INTENSITY IS RAISED TO 40 KT. THE
LOW-LEVEL CENTER IS LOCATED NEAR THE WESTERN EDGE OF THE CONVECTION
DUE TO STRONG SOUTHWESTERLY VERTICAL WIND SHEAR. THE SHEAR IS
EXPECTED TO REMAIN STRONG OVER THE NEXT COUPLE OF DAYS AND SHOULD
CAUSE THE CYCLONE TO DECOUPLE AND WEAKEN. THE INTENSITY FORECAST
IS SIMILAR TO THE PREVIOUS ADVISORY AND CALLS FOR HENRI TO WEAKEN
TO A TROPICAL DEPRESSION IN ABOUT 24 HOURS AND DEGENERATE TO A
REMNANT LOW SHORTLY THEREAFTER. THIS IS IN GOOD AGREEMENT WITH THE
DYNAMICAL MODELS WHICH ALL WEAKEN THE CYCLONE DURING THE NEXT DAY
OR TWO.

THE INITIAL MOTION IS 290/15...A LITTLE TO THE LEFT OF THE PREVIOUS
ESTIMATE. HENRI IS CURRENTLY LOCATED ALONG THE SOUTHWESTERN
PERIPHERY OF A MID-LEVEL RIDGE OVER THE EASTERN ATLANTIC. THE
CYCLONE IS EXPECTED MOVE IN A GENERAL WEST-NORTHWESTWARD TO
NORTHWESTWARD HEADING UNTIL DISSIPATION. THE NEW NHC TRACK
FORECAST IS SLIGHTLY SOUTH OF THE PREVIOUS ADVISORY...MAINLY
TO ACCOUNT FOR THE INITIAL POSITION AND MOTION.

FORECAST POSITIONS AND MAX WINDS

INITIAL 07/0300Z 18.4N 55.3W 40 KT
12HR VT 07/1200Z 19.3N 57.3W 35 KT
24HR VT 08/0000Z 20.5N 59.7W 30 KT
36HR VT 08/1200Z 21.8N 61.9W 25 KT...REMNANT LOW
48HR VT 09/0000Z...DISSIPATED



Member Since: September 10, 2007 Posts: 0 Comments: 11271
A dud of a hurricane season is not a totally bad thing except I am worried about aquifers and birds and trees having enough water. That's the issue for me. Tropical storms are normal. Not to have any make landfall just doesn't seem right.
Member Since: July 11, 2006 Posts: 14 Comments: 11348
Quoting 7544:
and the blob south of henri also building more convection aniother one to watch a dmax tonight


I'm carefully monitoring that poorly organized but large convective band currently attached to the south side of Henri. If it persists or expands, locally heavy rainfall will be a possibility across the islands over the next 24 hours or so.
Member Since: Posts: Comments:
Quoting JRRP:
well at least we have more storms than 1997
this is not the smallest season since 1995


You are forgetting about the unnamed subtropical storm that developed on May 31. So, number wise, we are currently tied with 1997.
Member Since: Posts: Comments:
351. nrtiwlnvragn
2:40 AM GMT on October 07, 2009
342. cchsweatherman

However SHIPS also shows Henri moving into a dry environment, realtive humidity in the mid twenty percent range after 48 hours.
Member Since: September 23, 2005 Posts: 14 Comments: 11215
350. Chicklit
2:39 AM GMT on October 07, 2009
Quoting Weather456:


It seems I'm the only who took time to track and learn from the 8 systems we had. It might not been 2005 but its been a hurricane season regardless, and once there is tropical activity there is always something to learn. And I am sure others here have learn quite a lot. the season has been inactive yes but not boring.

Weather456, you deserve a lot of credit and a huge pat on the back for hanging in there. Plus, you had several mentions by Dr. Masters himself! You made it interesting all along the way. I'm not writing the epitaph of the season, especially since Dr. Masters mentioned we could see something in the latter part of October, and in fact we do have two named storms in one week with Grace and Henri...both rather tenuous, but 456 you have really been consistent. This was no easy feat with so little developing. Shear may relax and we may finally see something materialize, but at this point, we'll just have to wait until the end of November. And until then, we do depend on you Weather456 to keep us all on track. So hang in there. You are appreciated.
je
Member Since: July 11, 2006 Posts: 14 Comments: 11348
349. Cavin Rawlins
2:39 AM GMT on October 07, 2009
Quoting ElConando:


One more and 2009 is tied with 2006 two more and its 3rd lowest since 1995.


2006 had 10 systems, so it would be tied for named storms but not overall activity since we had the un-named storm of July that year.
Member Since: July 24, 2005 Posts: 407 Comments: 19076
348. ElConando
2:38 AM GMT on October 07, 2009
456 you got mail!!!
Member Since: September 6, 2009 Posts: 2 Comments: 3759
347. Relix
2:38 AM GMT on October 07, 2009
So, the NHC track is dead on. Does WU agree on this? =P
Member Since: August 3, 2006 Posts: 0 Comments: 2725
346. Bordonaro
2:37 AM GMT on October 07, 2009
The Japanese Times, their English online webpage, mentioned NOTHING about Typhoon Melor, very interesting?
Member Since: August 25, 2009 Posts: 20 Comments: 6785
345. ElConando
2:36 AM GMT on October 07, 2009
Quoting JRRP:
well at least we have more storms than 1997
this is not the smallest season since 1995


One more and 2009 is tied with 2006 two more and its 3rd lowest since 1995.
Member Since: September 6, 2009 Posts: 2 Comments: 3759
344. 7544
2:35 AM GMT on October 07, 2009
and the blob south of henri also building more convection aniother one to watch a dmax tonight
Member Since: May 6, 2007 Posts: 0 Comments: 6857
343. DVG
2:35 AM GMT on October 07, 2009
four
Member Since: August 29, 2007 Posts: 0 Comments: 264
342. cchsweatherman
2:34 AM GMT on October 07, 2009
Nice to see when I get home that we have a new cyclone in the Atlantic: Tropical Storm Henri. In analyzing satellite imagery and data, this remains a rather sheared tropical storm with the circulation center struggling to remain coincided with the intense convective mass to the north and east. Will admit that the convective bursts have been quite impressive considering the rather unfavorable upper level winds that continue to impact the system. In looking at the SHIPS wind shear forecast, it would seem the next 24 hours will be the most critical for Henri as wind shear is expected to remain unfavorable for the next 24 hours but become rather favorable beyond that time. If Henri can hold together for the next 24 hours and the rather favorable upper level environment forecast by the SHIPS model does materialize, the storm could become a bigger threat down the road.
Member Since: April 14, 2007 Posts: 8 Comments: 5169
341. JRRP
2:34 AM GMT on October 07, 2009
Quoting farhaonhebrew:
bulding more and more convection araund the center...amazing!

yeah.. and stronger
Member Since: August 16, 2007 Posts: 0 Comments: 5974
340. JRRP
2:33 AM GMT on October 07, 2009
well at least we have more storms than 1997
this is not the smallest season since 1995
Member Since: August 16, 2007 Posts: 0 Comments: 5974
339. farhaonhebrew
2:32 AM GMT on October 07, 2009
Quoting JRRP:
bulding more and more convection around the center...amazing!
Member Since: July 14, 2008 Posts: 0 Comments: 248
338. 7544
2:31 AM GMT on October 07, 2009
another nice burst at this hour for henri might surpise us all at dmax tonight if it holds this energey till then we can see a much stronger ts in the am stay tuned
Member Since: May 6, 2007 Posts: 0 Comments: 6857
337. DVG
2:29 AM GMT on October 07, 2009
Quoting GeoffreyWPB:
How The Earth Was Made...on the History Channel....talking about the Loch Ness Monster. Wasn't that famous picture already proved a fraud?



Yes I believe those who made it came forward.

But...I believe Google earth had a sat photo of the Loch Ness with something large on the surface. A fuzzy picture of something that looked like it had for appendages.
Member Since: August 29, 2007 Posts: 0 Comments: 264
336. JRRP
2:29 AM GMT on October 07, 2009
Member Since: August 16, 2007 Posts: 0 Comments: 5974
335. cchsweatherman
2:27 AM GMT on October 07, 2009
Quoting hurricane23:


Lol...Not a fun season for those that like to track tc's across the atlantic thats for sure,no complaining on this end.


I completely agree with you on that point. Everyone in the Atlantic basin needs a break from tropical cyclones since the past several seasons have been brutal for different parts of the basin. This year it has very much been a season dominated by wind shear and troughs coming off the Eastern Seaboard which are classic for a moderate El Nino event like we have been experiencing. Even though admittedly I love tracking tropical cyclones, I'm enjoying every day with very little action and no threats to land.
Member Since: April 14, 2007 Posts: 8 Comments: 5169
334. Dakster
2:25 AM GMT on October 07, 2009
Quoting GeoffreyWPB:


Was he horney? I know...bad joke...:)


Which one? WS or the Triceratop?
Member Since: March 10, 2006 Posts: 0 Comments: 10436
333. Cavin Rawlins
2:25 AM GMT on October 07, 2009
Quoting hurricane23:


Lol...Not a fun season for those that like to track tc's across the atlantic thats for sure,no complaining on this end.


It seems I'm the only who took time to track and learn from the 8 systems we had. It might not been 2005 but its been a hurricane season regardless, and once there is tropical activity there is always something to learn. And I am sure others here have learn quite alot. the season has been inactive yes but not boring.
Member Since: July 24, 2005 Posts: 407 Comments: 19076
332. hurricane23
2:24 AM GMT on October 07, 2009
Without visibles but looks exposed right now as shear continues to impinge on the circulation.
Member Since: May 14, 2006 Posts: 8 Comments: 13804
331. Chicklit
2:24 AM GMT on October 07, 2009
Quoting GeoffreyWPB:


Think how bad tacoman feels right now.
Kinda like how Pittsburg felt after the steel market went overseas. Was it the EPAC?
Member Since: July 11, 2006 Posts: 14 Comments: 11348
330. Bordonaro
2:23 AM GMT on October 07, 2009
Quoting Chicklit:

I believe you.
Looks like Melor plans to pay a visit to Toyoko.

Thankfully for Japan,Typhoon Melor is weakening a bit faster than the JTWC expected.

On the other hand, on her projected track, she may effect about 75 million residents of Japan, with TS force winds and plenty of rain. Hope they're ready!

I know Typhoons are a regular part of Japanese weather, but Melor used to be a STY and it's still pretty good sized storm.
Member Since: August 25, 2009 Posts: 20 Comments: 6785
329. GeoffreyWPB
2:22 AM GMT on October 07, 2009
Quoting Chicklit:

Oh c'mon Adrian. Be real. It's been a very disappointing season. I don't think Ike can recover without Xanax. LOL.


Think how bad tacoman feels right now.
Member Since: September 10, 2007 Posts: 0 Comments: 11271
328. Chicklit
2:21 AM GMT on October 07, 2009
Quoting hurricane23:


Lol...Not a fun season for those that like to track tc's across the atlantic thats for sure,no complaining on this end.

Oh c'mon Adrian. Be real. It's been a very disappointing season. I don't think Ike can recover without Xanax. LOL.
Member Since: July 11, 2006 Posts: 14 Comments: 11348
327. ElConando
2:20 AM GMT on October 07, 2009
Quoting GeoffreyWPB:


Was he horney? I know...bad joke...:)


*Facepalm* LOL
Member Since: September 6, 2009 Posts: 2 Comments: 3759
326. hurricane23
2:20 AM GMT on October 07, 2009
Quoting Chicklit:

I believe you.


Lol...Not a fun season for those that like to track tc's across the atlantic thats for sure,no complaining on this end.
Member Since: May 14, 2006 Posts: 8 Comments: 13804
325. Chicklit
2:20 AM GMT on October 07, 2009
Take a break, AtlantaMet. It's been a depressed season.
Member Since: July 11, 2006 Posts: 14 Comments: 11348
324. GeoffreyWPB
2:19 AM GMT on October 07, 2009
---
Member Since: September 10, 2007 Posts: 0 Comments: 11271
323. ElConando
2:18 AM GMT on October 07, 2009
I once saw a Weather Student but it was just a figment of my imagination, it was actually Orca holding a cardboard cutout of JFV.
Member Since: September 6, 2009 Posts: 2 Comments: 3759
321. Chicklit
2:16 AM GMT on October 07, 2009
Quoting hurricane23:
I saw a triceratop moving through downtown on the way home.

I believe you.
Looks like Melor plans to pay a visit to Toyoko.
Member Since: July 11, 2006 Posts: 14 Comments: 11348
320. Chicklit
2:16 AM GMT on October 07, 2009
Parma is still hanging around, being goofy.

Member Since: July 11, 2006 Posts: 14 Comments: 11348
319. ElConando
2:15 AM GMT on October 07, 2009
ADT is going up for now. We shall we what will become of Henri.
Member Since: September 6, 2009 Posts: 2 Comments: 3759
318. hurricane23
2:15 AM GMT on October 07, 2009
I saw a triceratop moving through downtown on the way home.
Member Since: May 14, 2006 Posts: 8 Comments: 13804
317. Seastep
2:15 AM GMT on October 07, 2009
Quoting 19N81W:
2009, Caribbean and US...am I wrong? did we have something named make landfall this year? wow if we did what a storm it must have been!...


Irrelevant to the bet. LMAO.
Member Since: September 9, 2008 Posts: 6 Comments: 3414
316. swatkins
2:14 AM GMT on October 07, 2009
Quoting 19N81W:
I did make a bet back in I think June/July saying no named storms would make landfall in the US or Caribbean...how do you check post history?? I think a couple guys took the bet...obviously its not going to happen as the active period seems to be ending....anyone want to pay up??


You said OR in this post,,,, Not Both. Good try though :)
315. Cavin Rawlins
2:13 AM GMT on October 07, 2009
Quoting GeoffreyWPB:
Hydrus believes that the Loch Ness monster was real. Interesting.


Geeze, I thought he was joking.
Member Since: July 24, 2005 Posts: 407 Comments: 19076
314. SouthALWX
2:13 AM GMT on October 07, 2009
Quoting 19N81W:
2009, Caribbean and US...am I wrong? did we have something named make landfall this year? wow if we did what a storm it must have been!...

claudette .. pay me =P
Member Since: August 27, 2008 Posts: 0 Comments: 1497
313. GeoffreyWPB
2:12 AM GMT on October 07, 2009
Hydrus believes that the Loch Ness monster was real. Interesting.
Member Since: September 10, 2007 Posts: 0 Comments: 11271
312. Cavin Rawlins
2:09 AM GMT on October 07, 2009
Ex-Danny also affected the Mid-Atlantic states.
Member Since: July 24, 2005 Posts: 407 Comments: 19076
311. Chicklit
2:09 AM GMT on October 07, 2009
Quoting 19N81W:
2009, Caribbean and US...am I wrong? did we have something named make landfall this year? wow if we did what a storm it must have been!...

no nuthin. imbalance of nature imo regardless of shabby building codes. we're supposed to have something happen. rain, wind...tropical storms making landfall. nothing tho. it seems weird. i don't trust it. there's something bad about our good fortune. like drought. the birds and trees need rain. it's just not right.
Member Since: July 11, 2006 Posts: 14 Comments: 11348
310. Cavin Rawlins
2:08 AM GMT on October 07, 2009
Quoting hydrus:
No, (Nessie) was killed in a extra-tropical cyclone in the early 1950,s. It was unable to come up for air do to heavy wave action.


LMAO
Member Since: July 24, 2005 Posts: 407 Comments: 19076
309. hurricane23
2:08 AM GMT on October 07, 2009
Another name to the list....Henri will likely not be around to long as some stronger westerlies should begin to impact the system as pending trof shoots to the NE.
Member Since: May 14, 2006 Posts: 8 Comments: 13804
308. GeoffreyWPB
2:08 AM GMT on October 07, 2009
302...am I setting myself up? Didn't Claudette hit the U.S.?
Member Since: September 10, 2007 Posts: 0 Comments: 11271
307. Cavin Rawlins
2:07 AM GMT on October 07, 2009
Quoting 19N81W:
2009, Caribbean and US...am I wrong? did we have something named make landfall this year? wow if we did what a storm it must have been!...


Ana and Erika went through the Leewards

Claudette made landfall on the Gulf coast of Florida

and the remnants of Fred was the main caused the 2009 Georgian floods
Member Since: July 24, 2005 Posts: 407 Comments: 19076

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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.