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

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

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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

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Sounds about right to me:

AL, 17, 2011092418, , BEST, 0, 110N, 274W, 35, 1006, TS, 34, NEQ, 40, 0, 0, 40, 1011, 180, 40, 0, 0, L, 0, , 0, 0, SEVENTEEN, M,
Member Since: November 8, 2009 Posts: 4 Comments: 13799
Quoting cat5hurricane:

Now THAT is a storm good people of the blog. It's thousands of miles away from the U.S. though.


Ya the outflow channels Nesat has developed is really going to let it bomb out. Those are some really cold cloud tops. Anti-Cyclone centered right over the top of her. Hopefully Nesat peaks and starts to weaken before landfall or takes a more northerly track.

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Quoting cat5hurricane:

West Big Guy. Going West. C'mon. where else petrol???

lmao!!!
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Quoting MiamiHurricanes09:
Who gives if it's away from the U.S?? The people of the Philippines and China aren't superior to those of the U.S.


Ignore cat5hurricane, just please. He isn't stating an opinion, he's bashing everyone else and wanting storms to hit the USA.. its ridiculous.
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Quoting cat5hurricane:

Now THAT is a storm good people of the blog. It's thousands of miles away from the U.S. though.
Who gives if it's away from the U.S?? The people of the Philippines and China aren't superior to those of the U.S in any way, shape, or form.
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guys this Ignore CANTTRUSTTHEM he likey the others we have Ignore
Member Since: May 21, 2006 Posts: 5091 Comments: 115454
Nesat in the Western Pacific means business.



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Ophelia is roughly 2 degrees south of the next forecast, i wonder what this does in terms of track?
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Quoting TropicalAnalystwx13:


This pattern is very dangerous come late season, because, while storms coming from the east likely curve, the ones that form in the Gulf and Caribbean are pulled north and NE towards the USA.


Something has to make it into that area first. :)
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Quoting CANTTRUSTTHEM:
its so exciting out there .... 3 fish storms





if 91L froms it wont be a fish storm


Ophelia is heading for Bermuda wish would all so not make it a fish storm



the olny ture fish storm we have boy do i hate uesing that word fish storm is TD 17
Member Since: May 21, 2006 Posts: 5091 Comments: 115454
144. Gorty
Quoting robert88:


I agree. I see nothing in the long range models that show any indication of a pattern change in October. This season has been very boring. Look at all those weak pathetic struggling systems out there. It amazes me as well...because we are in a neutral to La Nina season.


People like this should be banned because they wish for death and destruction to have an "interesting" season.
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Quoting robert88:


I agree. I see nothing in the long range models that show any indication of a pattern change in October. This season has been very boring. Look at all those weak pathetic struggling systems out there. It amazes me as well...because we are in a neutral to La Nina season.


This pattern is very dangerous come late season, because, while storms coming from the east likely curve, the ones that form in the Gulf and Caribbean are pulled north and NE towards the USA.
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The tail connected to 91L to the north all the way into the USA is steeling convergence away from 91L, causing the disorganization. For storms like 91L, you want all the convergence to be over it, not strung out like it is. Its not exactly a sure thing it wont develop, but seems pretty slim to me IMO.
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Quoting cat5hurricane:

It really has been bogus. Very uneventful this year. Same upper-level steering pattern not likely to change until at least the middle of Nov. And by then, Who cares.

Another 2010. Another Earl. What can I say. More of the same. Very boring. zzzzzzz.


I agree. I see nothing in the long range models that show any indication of a pattern change in October. This season has been very boring. Look at all those weak pathetic struggling systems out there. It amazes me as well...because we are in a neutral to La Nina season. All the experts sure didn't see this coming.
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140. HCW
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139. Gorty
Quoting cat5hurricane:

It really has been bogus. Very uneventful this year. Same upper-level steering pattern not likely to change until at least the middle of Nov. And by then, Who cares.

Another 2010. Another Earl. What can I say. More of the same. Very boring. zzzzzzz.


At least I don't wish death and destruction for people to have a non-bogus season...
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A T-number of 2.6, and the center position a little off?

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We've been having on and off T storms over on the West coast of Fl. It looks like Miami is getting a nice T storm at the moment.
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Quoting Cotillion:


No worries :)

Btw, while a lot of these storms have been weak (as we see from the hurricane numbers) as well as seeing the ACE low numbers, we've actually only had two storms lower than 1 value in ACE so far.

2010 had 3, 2009 had 2, 2008 had 3, 2007 had 6 (inc STS Andrea), 2006 had 1, 2005 had 5.


And our highest almost produced 25 values in ACE, followed by another one producing a little over 20 values in ACE.

Total for the season is approaching 80.
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Quoting MiamiHurricanes09:
Dang, you're right. Either way, it's going to be difficult for moisture to make it into south Florida with subsidence from the longwave over the eastern U.S pumping dry air southeastward.




yes it will be a close call it seems
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Quoting will40:



may need to read that again. to me it sounds like the Mets are saying moisture not the storm will be across south fla
Dang, you're right. Either way, it's going to be difficult for moisture to make it into south Florida with subsidence from the longwave over the eastern U.S pumping dry air southeastward.

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Buy land in Canada. New Foundland the Florida of 2012.

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Quoting mossyhead:
I was not criticizing you and I am sorry if it seems that way.


No worries :)

Btw, while a lot of these storms have been weak (as we see from the hurricane numbers) as well as seeing the ACE low numbers, we've actually only had two storms lower than 1 value in ACE so far.

2010 had 3, 2009 had 2, 2008 had 3, 2007 had 6 (inc STS Andrea), 2006 had 1, 2005 had 5.
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Center Fix Coordinates: 17°07'N 57°23'W (17.1167N 57.3833W)

SOUTH WEST WOBBLE?
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128. Gorty
Quoting atl134:


Considering the storms we've had this year, probably several of them would have been missed without satellites.


So what, that's irrelevant, we have them now.
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Quoting mossyhead:
You have to realize that until we had satellites we were blind and there could have been more fish storms and hurricanes. Repeat, we were blind and how many did we miss.


Considering the storms we've had this year, probably several of them would have been missed without satellites.
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based on infrared satalite you could see the trough that could pick hilary up. if she does made landfall in baha, then the intensity will be anywhere from a td to a cat 2
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Product: Air Force Vortex Message (URNT12 KNHC)
Transmitted: 24th day of the month at 18:19Z
Aircraft: Air Force Aircraft (Last 3 digits of the tail number are 303)
Storm Number & Year: 16L in 2011
Storm Name: Ophelia (flight in the North Atlantic basin)
Mission Number: 3
Observation Number: 04
A. Time of Center Fix: 24th day of the month at 17:40:30Z
B. Center Fix Coordinates: 17°07'N 57°23'W (17.1167N 57.3833W)
B. Center Fix Location: 294 miles (474 km) to the ENE (65°) from Roseau, Dominica.
C. Minimum Height at Standard Level: Not Available
D. Estimated (by SFMR or visually) Maximum Surface Wind: 23kts (~ 26.5mph)
E. Location of the Estimated Maximum Surface Wind: 47 nautical miles (54 statute miles) to the NW (312°) of center fix
F. Maximum Flight Level Wind Inbound: From 59° at 25kts (From the ENE at ~ 28.8mph)
G. Location of Maximum Flight Level Wind Inbound: 92 nautical miles (106 statute miles) to the NW (315°) of center fix
H. Minimum Sea Level Pressure: 1013mb (29.91 inHg) - Extrapolated
I. Maximum Flight Level Temp & Pressure Altitude Outside Eye: 23°C (73°F) at a pressure alt. of 396m (1,299ft)
J. Maximum Flight Level Temp & Pressure Altitude Inside Eye: 24°C (75°F) at a pressure alt. of 396m (1,299ft)
K. Dewpoint Temp (collected at same location as temp inside eye): 17°C (63°F)
K. Sea Surface Temp (collected at same location as temp inside eye): Not Available
L. Eye Character: Not Available
M. Eye Shape: Not Available
N. Fix Determined By: Penetration and Wind
N. Fix Level: 1,500 feet
O. Navigation Fix Accuracy: 0.02 nautical miles
O. Meteorological Accuracy: 10 nautical miles
Remarks Section:
Maximum Wind Outbound: 32kts (~ 36.8mph) in the southeast quadrant at 18:05:00Z
Maximum Flight Level Wind: 32kts (~ 36.8mph) in the southeast quadrant at 18:05:00Z
Sea Level Pressure Extrapolation From: Below 1,500 feet
Maximum Flight Level Temp: 25°C (77°F) which was observed 61 nautical miles (70 statute miles) to the NW (316°) from the flight level center
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Quoting Drakoen:
I'm not sure what Stewart is seeing. All I see is a ragged mess on 91L.
acc/ to the rule book 48 hrs so i guess they are hedging the betting line alittle could lead to some heavy rain where it does not need it
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Quoting PcolaDan:


Missiles are actually quite predictable. They are under power and have specific designs to control trajectory. Something falling will be affected by the atmosphere (skipping, friction, etc) and be much harder to predict.
I think he's trying to make a point about detection rather than prediction. The heat signature from that thing falling through the atmosphere must have been in the range of "detection", or so you would think.
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Quoting MiamiHurricanes09:
Dem TV mets are some of the last people you should listen to. Stick to Dr. Masters and your local NWS.

91L is under the meridional flow of the western periphery of the subtropical ridge. There's basically no place for it to go except north into North Carolina.




may need to read that again. to me it sounds like the Mets are saying moisture not the storm will be across south fla
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120. Gorty
Quoting cat5hurricane:

And all going OTS. Next please.

However, this is the perfect opportunity for NHC to use what they have under their sleeves and fudge some numbers to justify yet another seemingly bogus, over-exaggerated 2011 Atlantic Basin outlook.

Time for them to quit with the fantasy football and start doing their jobs. The tax payers will want another tax cut eventually.


I know right? Dang it, they under-done their numbers for named systems...
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Quoting GiovannaDatoli:

SO, NOW do you believe climate change is occurring? 16 named storms is rather remarkable for September 24th. There is simply no other way that that could happen unless humans are belching trillions of tons of C02 into the Earth's atmosphere every year.


If I remember correctly, climate models generally project no significant change in storm frequency and only an increase in intensity.
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I am 59 years old and I listen to my parents talk about not knowing a storm was coming your way until a day or two before it hit. They talk about recorded history, but they should say before satellites. How many fish storms and hurricanes did they missed seeing? So the numbers are not accurate before then.
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Quoting Hurricane1956:
Wondering if we are going to get any rain here in South Florida from 91L?, some local Met said that the moisture from the Bahamas will cross South Florida by tomorrow? it will be a very rainy day here,but Dr.Masters said it will move to NC?,don't understand,can somebody explain?
Dem TV mets are some of the last people you should listen to. Stick to Dr. Masters and your local NWS.

91L is under the meridional flow of the western periphery of the subtropical ridge. There's basically no place for it to go except north into North Carolina.

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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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