Ophelia remains weak; TD 17 forms; dangerous Nesat headed for the Philippines

By: Dr. Jeff Masters , 4:54 PM GMT on September 24, 2011

Share this Blog
17
+

There's not much change to Tropical Storm Ophelia today, which continues to battle dry air and high wind shear. Satellite imagery shows that Ophelia has little heavy thunderstorm activity near its low level circulation center, which is mostly exposed to view. Most of the storm's heavy thunderstorms are to the east of the center, with just a few puffs of thunderstorms occasionally popping up near the center. An analysis from the University of Wisconsin CIMMS group shows a high 20 - 25 knots of wind shear due to strong upper-level southwesterly winds. Water vapor satellite images show Ophelia is at the eastern edge of large area of very dry air.


Figure 1. Afternoon satellite image of Ophelia showing the low-level center exposed to view, with all the storm's heavy thunderstorms in a band several hundred miles to the east and south. This is not a healthy-looking tropical storm.

Forecast for Ophelia
The latest SHIPS model forecast predicts that Ophelia will experience high wind shear of 20 - 40 knots over the next five days, and will move into a region with slightly drier air. This combination of shear and dry air may be enough to dissipate Ophelia, as predicted by several of the models. However, Ophelia has maintained itself better than the models have predicted, so the storm will probably survive until at least Sunday. Even it Ophelia does dissipate, it will have the chance to regenerate by Tuesday or Wednesday, when it may encounter a region of lower wind shear. At this time, it appears that Ophelia will only be a threat to Bermuda.

TD 17 forms
Tropical Depression 17 formed in the far eastern Atlantic off the coast of Africa last night, and is likely to intensify into Tropical Storm Philippe later today. TD 17 has some impressive low-level spiral bands and upper-level outflow, and is very close to tropical storm strength. The predicted west-northwest to northwest track of TD 17 will put it in a position where historically, very few storms have ever gone on to hit land.


Figure 2. MODIS satellite image of Hurricane Hilary at 4:05 pm EDT September 23, 2011. At the time, Hilary was a Category 4 storm with 145 mph winds. Image credit: NASA.

Powerful Hurricane Hilary remains at Category 4 strength
In the Eastern Pacific, Hurricane Hilary remains an impressive Category 4 hurricane with 140 mph winds. Hilary is headed west, away from Mexico, and the storm is small enough that its outer bands are not causing flooding problems for Mexico. A trough of low pressure expected to move over the Western U.S. by the middle of the week may be strong enough to turn Hilary to the north, eventually bringing Hilary to Mexico's Baja Peninsula. The timing of this event is highly uncertain, though. Hilary is small enough that it is unlikely to bring significant drought relief to Arizona, New Mexico, and Texas if the storm's remnants move north into those states. Hilary is the fourth Category 4 hurricane in the Eastern Pacific this year, and the second strongest, behind Hurricane Dora, which had 155 mph winds.

Invest 91L set to soak North Carolina
A moderate amount of heavy thunderstorm activity has developed over the Northwestern Bahamas in association with the tail end of an old stalled front. This disturbance, Invest 91L, is under a low 5 - 10 knots of wind shear, but water vapor loops show a considerable amount of dry air to the east and west of the disturbance that will likely interfere with development. In their 8 am Tropical Weather Outlook, NHC gave 91L a 20% chance of developing into a tropical depression by Monday. The disturbance has only a short window to develop, as it is headed northwards and is expected to make landfall in North Carolina by Sunday afternoon. The 8 am EDT SHIPS model forecast predicts 91L will hit 35 knots of wind shear by Sunday morning, when the storm will be approaching the coast of North Carolina. Heavy rains from 91L may cause localized flooding in Morehead City, NC and surrounding regions. A moist flow of tropical air over the region has already brought rainfall amounts of 1 - 3 inches to much of Eastern North Carolina today.

Dangerous Tropical Storm Nesat headed for the Philippines
What may be the season's most dangerous storm in the Western Pacific, Tropical Storm Nesat, has formed about 700 miles east of the Philippine Islands. Nesat is under a moderate 10 knots of wind shear, is embedded in a very moist environment, has very warm sea surface temperatures of 30°C under it, and a very favorable upper-level outflow pattern above it. Nesat has plenty of time to intensify into a major typhoon before its expected landfall on Luzon Island in the Philippines on Tuesday morning.

I'll have an update before 2 pm Sunday afternoon.

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: 463 - 413

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19Blog Index

463. PlazaRed
10:55 PM GMT on September 24, 2011
Quoting EYEStoSEA:

Evening Eyes:-
This north Atlantic circulation that keeps getting reflected in your visually informative posts might just be a sign of what is to come.Summers might just go round in endless circles in the north Atlantic!
Thinking about it as best I can not being any form of expert but a good observer then I do feel,"rather than think," that we might be experiencing the calm before the storms that are to come in the next few seasons?
So many systems have formed only to be neutralised by sheer or bad alignments to lack for a better word. With a bit of bad luck we could have be moaning about disasters right now; not boredom.
"Keeper," said months ago this would be a season to remember! not that I remember his exact words but I do think that we should count ourselves lucky that we got this far and nothing went the way it could have done.
Our thoughts go out out to all that continue to suffer in the Southern US from droughts and we wish that you should soon get some relife.
Oh almost forgot,"Evening All"
Member Since: January 21, 2011 Posts: 0 Comments: 2189
459. Levi32
10:41 PM GMT on September 24, 2011
Quoting wxgeek723:


This season managed to push a 960 mb hurricane (although the winds didn't correlate) into coastal New Jersey. That's more than enough to impress me.


The season is a very long way from over too. We still have the possibility for a threat from the Caribbean or Gulf of Mexico during early October, and possibly more than one threat before that month is over.

I'm out for now. Back later.
Member Since: November 24, 2005 Posts: 635 Comments: 26700
457. CaneFreeCR
10:40 PM GMT on September 24, 2011
It seems that a very large amount of dry air has been coming South from the Arctic -- across North America, brought South probably by the jet stream. I suspect this will be a more persistent pattern as the Arctic warms and the warmer, but still cold and dry, Arctic air drains South, creating the vertical stability we've seen this year. That may cause a lot more seasons like this one -- many tropical storms and few hurricanes.
Member Since: August 12, 2011 Posts: 0 Comments: 319
456. j2008
10:40 PM GMT on September 24, 2011
Quoting JLPR2:
Ophelia looks like half of a storm.

Yea put philippe together with her and you might get a whole storm! I think it shall be called TC matchmakeing. Seriously, one quality the storms havnt lacked this year has been stubborness, they just dont want to give up.
Member Since: December 19, 2008 Posts: 1 Comments: 224
455. wxgeek723
10:38 PM GMT on September 24, 2011
Quoting Levi32:
It should be noted that the calls for increased danger to the United States this year relative to last year have been completely correct so far. We may not have had a true major hit, but 950mb Hurricane Irene was essentially a major hurricane that cost us 10+ billion dollars and several lives. Lee caused massive flooding damage. If folks want to be picky about whether we get one big hurricane hit or two, then ok, but this season has been bad for the United States.


This season managed to push a 960 mb hurricane (although the winds didn't correlate) into coastal New Jersey. That's more than enough to impress me.
Member Since: August 28, 2008 Posts: 79 Comments: 3714
453. FrankZapper
10:36 PM GMT on September 24, 2011
Quoting CANTTRUSTTHEM:
thge entire atlantic has been covered with dry air and shear all season
Why did no one forecast it?
Member Since: May 26, 2011 Posts: 0 Comments: 1193
451. wunderweatherman123
10:34 PM GMT on September 24, 2011
Quoting Levi32:


Wind shear has been normal to below normal in the tropical Atlantic this year.

Next season, no matter what, should be less active than this year, just as this year has been less active than last year. A La Nina could mean a near-normal to slightly above normal season. 3rd-year La Ninas are not commonly big seasons. We only have a couple of examples during warm AMOs. 1956 had only 7 storms. 2000 had 15 storms and 3 major hurricanes. That's not a large sample, but all 3rd year La Ninas had fewer storms and a smaller ACE than the previous year.
levi you do remember models showed the la nina of 2010 in the winter staying moderate till july of 2011 then in the spring they showed neutral conditions for the rest of the season. then in june they showed la nina reforming. now same thing again. models show la nina again by spring and early summer. this could all change. given the fact that we are going into another la nina and the PDO is still negative, i could take an educated guess and say el nino wont be forming ANYTIME SOON. thanks for the answers Levi
Member Since: August 23, 2011 Posts: 0 Comments: 1728
Quoting Levi32:


I say that because moisture levels have been above-normal in the entire tropical Atlantic all season long based on analysis. The reason that might not make sense is because almost every storm so far has struggled with dry air. The reason for that is not because there is an abnormally large amount of dry air around, but because the lack of instability makes the storms more vulnerable to the dry air that is already there.



Well here in FL instability has not been the same during our rainy season either. I mean we've had some bad storms here and there, but a lot less lightning this year, a lot less intense storms for the most part, kinda strange to see that occur basin wide.
Member Since: Posts: Comments:
447. JLPR2
Ophelia looks like half of a storm.
Member Since: September 4, 2007 Posts: 7 Comments: 8747
Activity since the active era of 1995. Note the different enso condtions and NUMBER OF NAMED STORMS
1995-19-la nina
1996-13- cool neutral
1997-8-EL NINO
1998-14-la nina
1999-12-la nina
2000-15-cool neutral/weak la nina
2001-15- warm neutral
2002-12- EL NINO
2003-16-warm neutral
2004-15-warm neutral
2005-28-neutral
2006-10-EL NINO
2007-15-la nina
2008-16-neutral
2009-9-EL NINO
2010-19-la nina
2011- 16 (So Far) cool neutral/la nina
Reason behind the low numbers for hurricanes is low instability... overall all el nino years have the fewest number of storms and either are average to below average seasons. An average season has 10 to 11 storms. Above Average generally has 13 or more. As you can tell 95% of neutral/la nina season had 13 or more storms. if 2012 wont be el nino then we could say that the 2012 season will be active BUT we are 9 months away from june 2012 and in 9 months the enso conditions could be different. now we are weak la nina
Member Since: August 23, 2011 Posts: 0 Comments: 1728
Quoting charlottefl:


The only other thing I can think of is dry air. SAL hasn't been a huge factor this year. And I know you say dry air hasn't been a huge factor, but maybe mid level dry air has done the trick this year. Just a thought.



I say that because moisture levels have been above-normal in the entire tropical Atlantic all season long based on reanalysis. That might not make sense because almost every storm so far has struggled with dry air. The reason for that is not because there is an abnormally large amount of dry air around, but because the lack of instability makes the storms more vulnerable to the dry air that is already there, as well as self-produced dry air within collapsing thunderstorms.
Member Since: November 24, 2005 Posts: 635 Comments: 26700
444. j2008
Quoting charlottefl:

Yea Irene gave the fishcasters a bit of their own medicine. Philippe will probably become a Cat 2-3 cane if nothing gets in his way, Ophelia may become a Cat 1 similar to Maria and affect Bermuda and possibly the eastern coastline of Canada. Do I have to point out to everybody that we are getting to th time of year where the carrebean takes over on makeing storms, just look at water temps; they are in the 90's. Recipe for disaster if you ask me.
Member Since: December 19, 2008 Posts: 1 Comments: 224
It should be noted that the calls for increased danger to the United States this year relative to last year have been completely correct so far. We may not have had a true major hit, but 950mb Hurricane Irene was essentially a major hurricane that cost us 10+ billion dollars and several lives. Lee caused massive flooding damage. If folks want to be picky about whether we get one big hurricane hit or two, then ok, but this season has been bad for the United States.
Member Since: November 24, 2005 Posts: 635 Comments: 26700
Quoting Levi32:


Models and satellite data fill in the gaps over the ocean where we don't have weather balloons. The best tool that we have to look at that is through NCEP reanalysis. I did have a temperature crossection to show but ESRL's scripts are down right now. However, according to the reanalysis, so far there hasn't been an anomalous inversion layer in the Atlantic that would explain the lack of instability. Some dry air has been present between 45W and 65W, but mostly oriented to the south of the climatological precipitation belt, which would normally imply a northerly displaced ITCZ, a sign of an active season.



The only other thing I can think of is dry air. SAL hasn't been a huge factor this year. And I know you say dry air hasn't been a huge factor, but maybe mid level dry air has done the trick this year. Just a thought.

Member Since: Posts: Comments:
You can't have a strong BH when you have monster troughs one after another breaking it down. It looks like November out there. This is the most unusual neutral to La Nina hurricane season i have ever witnessed. I am sure all the experts are scratching their heads right now.
Member Since: Posts: Comments:
Member Since: Posts: Comments:
Quoting charlottefl:


Do you know anyone that has access to lapse rates over the Atlantic, that would be interesting to see...


Models and satellite data fill in the gaps over the ocean where we don't have weather balloons. The best tool that we have to look at that is through NCEP reanalysis. I did have a temperature crossection to show but ESRL's scripts are down right now. However, according to the reanalysis, so far there hasn't been an anomalous inversion layer in the Atlantic that would explain the lack of instability. Some dry air has been present between 45W and 65W, but mostly oriented to the south of the climatological precipitation belt, which would normally imply a northerly displaced ITCZ, a sign of an active season.

Member Since: November 24, 2005 Posts: 635 Comments: 26700
Quoting FrankZapper:
I would say this season has been a Fishcaster and Downcaster's near dream year. We started out hearing how we would have about 10 to 12 hurricanes and 5 or 6 major hurricanes with high chances for 2 or more major hits on the US. Everybody got their popcorn, then Wap! Wimpy little fish and poofouts. And all the cards were supposed to be lined up. You tell me. What happened?

And Phillipe. Biggest fish of them all.



LOL!
Maybe global warming is actually killing hurricanes? (Just a joke, Nea...)
Maybe the government actually can control a cane?
Maybe we don't understand the Earth like we think we do?

I honestly have no idea, LOL!
Member Since: Posts: Comments:
Quoting FrankZapper:
I would say this season has been a Fishcaster and Downcaster's near dream year. We started out hearing how we would have about 10 to 12 hurricanes and 5 or 6 major hurricanes with high chances for 2 or more major hits on the US. Everybody got their popcorn, then Wap! Wimpy little fish and poofouts. And all the cards were supposed to be lined up. You tell me. What happened?

And Phillipe. Biggest fish of them all.


With the exception of Irene...
Member Since: Posts: Comments:
Quoting Levi32:


This year is active but remains near-normal in ACE, making it nothing extraordinary outside of the record number of tropical storms without hurricanes. Although lack of atmospheric instability is likely to blame, it remains an open question as to why instability is so much lower than normal, given the fact that dry air hasn't really been an issue in the Atlantic this year, though storms have struggled with it due to the abnormal stability.


Do you know anyone that has access to lapse rates over the Atlantic, that would be interesting to see...
Member Since: Posts: Comments:
Quoting luigi18:


take it easy ! it will move west soon!


I'll believe it when I see it...Texas ain't getting squat from anything out there right now :(

Bring on the cold fronts.
Member Since: Posts: Comments:
Quoting muddertracker:
Borrrr-ing. Still. Snooze button *on* What happened to that huge ridge that was going to drive everything west? Didn't happen?


take it easy ! it will move west soon!
Member Since: September 21, 2008 Posts: 0 Comments: 483
Quoting wunderweatherman123:
someone at WSI mentioned the vertical instability at a very low level... what about ULL and inverted troughs that increased shear? is that to blame as well? and my final question. if the enso during hurricane season is NOT an el nino will activity be above average beacause since 1995 EVERY SINGLE NEUTRAL OR LA NINA season was ABOVE AVERAGE i think the lowest numbers was 12 named storms from 98 and the highest 28 from 05. thanks for the explanations


Wind shear has been normal to below normal in the tropical Atlantic this year.

Next season, no matter what, should be less active than this year, just as this year has been less active than last year. A La Nina could mean a near-normal to slightly above normal season. 3rd-year La Ninas are not commonly big seasons. We only have a couple of examples during warm AMOs. 1956 had only 7 storms. 2000 had 15 storms and 3 major hurricanes. That's not a large sample, but all 3rd year La Ninas had fewer storms and a smaller ACE than the previous year.
Member Since: November 24, 2005 Posts: 635 Comments: 26700
Borrrr-ing. Still. Snooze button *on* What happened to that huge ridge that was going to drive everything west? Didn't happen?

NOT rooting for death and destruction...just some drought relief.
Member Since: Posts: Comments:
Quoting JLPR2:
But then we have Ophelia.


she is looking like a Chick!
Member Since: September 21, 2008 Posts: 0 Comments: 483
Quoting TropicalAnalystwx13:


Errr...



Lets just say for the recurve god (GFS) to take this west, the Bahamas should keep an eye on Ophelia. the BAMS are also bringing her further west.
Member Since: Posts: Comments:


Satellite estimates(ADT and CI) are coming into an agreement of 45 kt Philippe... Interesting... Final T#'s are 3.3, and Raw is 3.4
Member Since: Posts: Comments:
Quoting reedzone:
I mentioned this last night and models are backing me up here.. I am SKEPTICAL of Ophelia recurving until it reaches the Bahamas. The High Pressure looks to be strong enough to steer Ophelia westward NEAR not to, but near Florida, though a trough will eventually recurve it. The question is where that recurve takes place and 91L is very interesting. No recurve until Long Island, similar to Irenes track.


Errr...

Member Since: Posts: Comments:
Quoting Levi32:


This year is active but remains near-normal in ACE, making it nothing extraordinary outside of the record number of tropical storms without hurricanes. Although lack of atmospheric instability is likely to blame, it remains an open question as to why instability is so much lower than normal, given the fact that dry air hasn't really been an issue in the Atlantic this year, though storms have struggled with it due to the abnormal stability.
someone at WSI mentioned the vertical instability at a very low level... what about ULL and inverted troughs that increased shear? is that to blame as well? and my final question. if the enso during hurricane season is NOT an el nino will activity be above average beacause since 1995 EVERY SINGLE NEUTRAL OR LA NINA season was ABOVE AVERAGE i think the lowest numbers was 12 named storms from 98 and the highest 28 from 05. thanks for the explanations
Member Since: August 23, 2011 Posts: 0 Comments: 1728
I mentioned this last night and models are backing me up here.. I am SKEPTICAL of Ophelia recurving until it reaches the Bahamas. The High Pressure looks to be strong enough to steer Ophelia westward NEAR not to, but near Florida, though a trough will eventually recurve it. The question is where that recurve takes place and 91L is very interesting. No recurve until Long Island, similar to Irenes track.
Member Since: Posts: Comments:
wonder if 99's ex "leftover" energy might combine with 91 to form a new spin in the straights of fl.
Member Since: Posts: Comments:
417. JLPR2
Lesser Antilles getting some showers courtesy of Ophelia.
Member Since: September 4, 2007 Posts: 7 Comments: 8747
416. j2008
Quoting CybrTeddy:
I still think there's a good chance that Ophelia will become a hurricane north of Bermuda very similarly to Maria. Seems that Philippe will beat it to hurricane though first.
Exactly what I was thinking, depends on how fast Philippe intensifys, if hes pretty speedy he might become a major even. After all he does have a center in the center of convection, thats a quality many storms have lacked this year.
Member Since: December 19, 2008 Posts: 1 Comments: 224
The NHC , though I have deep respect for them can be defiant in the face of real time in favor of their cherished computer models, though admittingly things usually pan out in their favor I've seen them bend the rules a few times to suit their model concensus, jmo, just saying...... PLz just wait for me to get my bulletproof vest on before the attacked is lauched :)
Member Since: Posts: Comments:
Quoting wunderweatherman123:
Levi! your back! levi would you call the 2011 season active and do you know why we dont have that many hurricanes/majors? also if an enso is not el nino does that mean an above average season? thanks :)


This year is active but remains near-normal in ACE, making it nothing extraordinary outside of the record number of tropical storms without hurricanes. Although lack of atmospheric instability is likely to blame, it remains an open question as to why instability is so much lower than normal, given the fact that dry air hasn't really been an issue in the Atlantic this year, though storms have struggled with it due to the abnormal stability.
Member Since: November 24, 2005 Posts: 635 Comments: 26700
413. JLPR2
The Atl isn't producing anything amazing.

This is amazing.


Lets not forget about this too:
Member Since: September 4, 2007 Posts: 7 Comments: 8747

Viewing: 463 - 413

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19Blog 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.

JeffMasters's Recent Photos

Lake Effort Snow Shower Over Windsor, Ontario
Sunset on Dunham Lake
Pictured Rocks Sunset
Sunset on Lake Huron