91L no concern; more postcards from the AMS hurricane conference

By: Dr. Jeff Masters , 1:12 PM GMT on April 18, 2012

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I'm in Ponte Vedra Beach, Florida this week, where the world's hurricane experts are gathered to attend the 30th Conference on Hurricanes and Tropical Meteorology of the American Meteorological Society. Most of the Hurricane Specialists from the National Hurricane Center are here, and they are keeping an eye on the waters a few hundred miles east of Bermuda, where an extratropical storm has cut off from the jet stream and is slowly acquiring tropical characteristics. This system was designated Invest 91L last night by NHC. Ocean temperatures are around 20°C (68°F) in the region, which is well below the 26°C usually needed for a tropical storm to form. Wind shear is a high 20 - 30 knots. Nevertheless, 91L has managed to develop a small amount of heavy thunderstorm activity near its center, and may continue to show more organization as it moves slowly southeastward over the next day or two. I give 91L a close to 0% chance of becoming a named storm in the next two days, and NHC seems to have stopped issuing new products for the system. By the end of the week, 91L should get picked up by a trough of low pressure and move off to the northeast. The storm is not a threat to any land areas.


Figure 1. Morning satellite image of Invest 91L. The island of Bermuda is seen at the left side of the image.

Global tropical cyclones and climate: current signal
Now, I'll summarize a few of the excellent talks given at this week's AMS hurricane conference. Dr. Greg Holland of the National Center for Atmospheric Research talked about the impact of global warming on hurricane intensities. Using data beginning in 1975, the beginning of the satellite era, he showed that while the total number of hurricanes globally has decreased in recent years, the proportion of hurricanes that are of Category 4 - 5 intensity has increased by 40%. He showed that this change could be related to a 0.8°C increase in global temperature during the period. He concluded that when hurricanes form, they are finding that it is easier for them to reach higher intensities.

Sensitivity of the strongest hurricanes to ocean surface warmth
Dr. Jim Elsner of Florida State University showed that observations indicate a sensitivity of hurricane winds of 8.2 m/s +/- 1.19 per degree Centigrade of ocean warmth, using data in the Atlantic from 1981 - 2010 (for oceans areas warmer than 25°C.) Using a high resolution model (HiRAM) with 50 km resolution, a sensitivity of only 1.5 +/- .6 m/s was found, calling into question the usefulness of current models for assessing future hurricane activity.

How will climate change affect hurricane tracks?
Angela Colbert of the University of Miami used 17 global climate models, the BAM hurricane tracking model, and the Atlantic historical HURDAT data base to see how hurricane tracks might change in the future. She classified storms as either straight moving (which tend to hit the Caribbean or U.S. Gulf Coast), recurving landfalling (U.S. East Coast impacts), or recurving ocean storms that miss landfall. She projected a 6% increase in recurving ocean storms and an 8% decrease in straight-moving storms by the end of the century, due to climate change. A decrease of 1- 2 storms per decade is predicted for the Caribbean and Gulf of Mexico, and an increase of 1 - 2 storms per decade in the waters of the mid-Atlantic, and along the East Coast of Florida. This occurs primarily because of an increase in westerly winds over the Central Atlantic, and to a lesser degree, an eastward change in genesis location closer to the coast of Africa. Both of these factors would tend to increase the number of recurving storms.

Jeff Masters

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Quoting bluheelrtx:
Even in the northwest part of Harris County, we haven't seen more than a trace since the 2nd.
In Tomball, we have only picked up about 0.25" on Monday... and that was the only rain since the 2nd.
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Quoting MississippiWx:


And that makes you a high quality person. Stick to marijuana, it's more natural...

...Totally kidding.

Back to the weather before Dr. Masters thinks I'm turning his blog into a haven for druggies.

I think the last 40-something posts have shown that the majority of us either have partaken of illicit substances, or we are acting like we are currently partaking.
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Quoting RitaEvac:
On serious note: I'm near 4.5" for month of April, but that's in SE TX near the coast. Folks in central TX like Austin,San Antonio, are not doing as good.
Even in the northwest part of Harris County, we haven't seen more than a trace since the 2nd.
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All the howling tells me everything I need to know.

It is time that I shake the dust off my feet from this blog.

I bid adieu, and God bless.
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Quoting kwgirl:
I grew up in the 60's in Key West. Really, I wouldn't touch the stuff. But heard a lot about it.


And that makes you a high quality person. Stick to marijuana, it's more natural...

...Totally kidding.

Back to the weather before Dr. Masters thinks I'm turning his blog into a haven for druggies.
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Quoting hydrus:
Must be ungodly powerful. I,ll just stick to beer.

I agree wholeheartedly. May the gods of malt and hops smile upon you.
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Quoting Minnemike:
i think i get what's trying to be communicated... perhaps this is reference to lensing effects notable on certain satellite imagery, most notably water vapor loops. these will appear as concentric circles reminiscent of the gravity waves protruding from the overshooting tops Hydrus posted. i've observed this myself, and pray that's what's being referenced... otherwise i haven't a clue. attempts to substantiate claims appear to involve superimposing the (supposed) regions of imagery swath's used in image composites.
if i'm anywhere close to the poster's intention, i assert now that the relationship of such rendering artifacts has nothing to do with weather... and definitely nothing to do with the observations Hydrus had posted.
I will post more about the gravity waves when I can find the time, for it is a complex subject requiring a lot of typing. In short form, a collapsing thunderstorm has a lot of potential energy as it falls to Earth, when it hits the surface, its like a rock dropping into the calm pond, and you see circular waves emanating from the point of contact. When rapidly forming thunderstorms crash into the tropopause and stratosphere, it too causes this ripple effect in the atmosphere, just way up high, and a somewhat different way.
Member Since: September 27, 2007 Posts: 1 Comments: 22643
Quoting MississippiWx:


You say this too confidently. Do we have an experienced partaker? :-)
I grew up in the 60's in Key West. Really, I wouldn't touch the stuff. But heard a lot about it.
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Fastest ever recorded: 484±32 km/h (301±20 mph) 3-second gust; Observed by a DOW (Doppler On Wheels) radar unit in a tornado near Oklahoma City, Oklahoma on May 3, 1999.[113]
Fastest recorded with an anemometer: 113.2 m/s or 407 km/h (253 mph) 3-second gust; one of five extreme gusts during a series of 5-min time periods; Barrow Island (Western Australia), 10 April 1996, during Cyclone Olivia.[114]
Fastest recorded with an anemometer outside of a tropical cyclone: 372 km/h (231 mph) sustained 1-minute average; Mount Washington, New Hampshire, April 12, 1934.[115]
Fastest daily average: 174 km/h (108 mph); Port Martin (Adélie Land), Antarctica, 24-hour period from March 21, 1951 to March 22, 1951.[71]


List of Weather Records
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Quoting caneswatch:


WPTV and WPEC are showing it as well.




nice temps
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Quoting Levi32:


I was greatly looking forward to the initialization improvements from ESRL's experiments making it into the GFS. That should be very useful this season.


Been waiting on that magical day for the GFS too long. I'll have to keep my allegiances with the foreigners (Euros) until I see reason to bow to the GFS.
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Quoting Birthmark:

Did you correct for quantum effects?

Good catch, Birthmark!

If you don't correct for quantum effects, then the phase variant could be shifted 2 picometers to the left, which would then negate the chronotropic resonance that is inherent outside of quasi-pyramidal facets of the continuum.
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Quoting MississippiWx:


Dude, I started trippin' out just trying to read what that guy was saying. I'll have what he's having.
Must be ungodly powerful. I,ll just stick to beer.
Member Since: September 27, 2007 Posts: 1 Comments: 22643
Quoting kwgirl:
I'll only have some if it is Orange Sunshine:)


You say this too confidently. Do we have an experienced partaker? :-)
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Quoting jeffs713:

Must not forget the circle... Missing the circle eliminates the positive euclidian correlation between the synergistic nature of the angular momentum within the external structures of the atmospheric strata.

The circle is in the dark!
Everybody forms a circle on the floor, sitting in lotus positions around a candle, chanting OM and listening to the Moody Blues, In Search of The lost Chord.
The entire entropic geometric significance of wind blown spaghetti reveals itself.
Images and sequences are no longer random as the human element of visualization fails to identify what on Earth comes next!
Oh the gift the gifty give us to see the charts of Octobers NOAA!
Member Since: January 21, 2011 Posts: 0 Comments: 2180
Presslord,

It's either acid or the man got a hold of Grothar's medication.
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Quoting MississippiWx:


Dude, I started trippin' out just trying to read what that guy was saying. I'll have what he's having.
I'll only have some if it is Orange Sunshine:)
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i think i get what's trying to be communicated... perhaps this is reference to lensing effects notable on certain satellite imagery, most notably water vapor loops. these will appear as concentric circles reminiscent of the gravity waves protruding from the overshooting tops Hydrus posted. i've observed this myself, and pray that's what's being referenced... otherwise i haven't a clue. attempts to substantiate claims appear to involve superimposing the (supposed) regions of imagery swath's used in image composites.
if i'm anywhere close to the poster's intention, i assert now that the relationship of such rendering artifacts has nothing to do with weather... and definitely nothing to do with the observations Hydrus had posted.
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Quoting jeffs713:

Must not forget the circle... Missing the circle eliminates the positive euclidian correlation between the synergistic nature of the angular momentum within the external structures of the atmospheric strata.
Yes, yes, and lets not forget the sphere, the universal sphere whose center is everywhere and circumference nowhere, and in each of us, whoever and where ever we may be- is then, in fact, the center. Within he or she , whether they know it or not, is that the mind at large, and the laws of which are the laws not only of the minds, but of all space as well. For we are children of the Universe and this beautiful planet..sniffle, cry
Member Since: September 27, 2007 Posts: 1 Comments: 22643
Quoting presslord:
acid must be making a comeback...


Dude, I started trippin' out just trying to read what that guy was saying. I'll have what he's having.
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Quoting GeoffreyWPB:
Miami NWS Discussion - 2:30 p.m.

POSSIBLE STRONG TO SEVERE STORMS SATURDAY NIGHT THROUGH SUNDAY


WPTV and WPEC are showing it as well.



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Quoting jeffs713:

Must not forget the circle... Missing the circle eliminates the positive euclidian correlation between the synergistic nature of the angular momentum within the external structures of the atmospheric strata.

Did you correct for quantum effects?
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Quoting nrtiwlnvragn:


Same timeframe for the introduction of the new GFS (EnKF init).


I was greatly looking forward to the initialization improvements from ESRL's experiments making it into the GFS. That should be very useful this season.
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Miami NWS Discussion - 2:30 p.m.

POSSIBLE STRONG TO SEVERE STORMS SATURDAY NIGHT THROUGH SUNDAY
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Quoting nrtiwlnvragn:


Global Weather & Climate Extremes

Thanks as well nrtiwlnvragn
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Quoting jeffs713:

Must not forget the circle... Missing the circle eliminates the positive euclidian correlation between the synergistic nature of the angular momentum within the external structures of the atmospheric strata.


Precisely my point!!!!
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Quoting Levi32:


No, I said the GFS has been showing that area becoming the most favorable for any possible May mischief. In my opinion it is probably just working out some early quirks. We will likely have to wait until after May 15th as always, unless we get a cutoff upper low in the tropics before then.


Same timeframe for the introduction of the new GFS (EnKF init).
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Quoting presslord:
Nea: the street I live on runs exactly parallel to the Atlantic Ocean...and several streets run parallel to my street...at almost equi-distant points, other streets cross mine (as well as the others running parallel in the same direction) at almost perfect right angles...and this phenomenon runs in this manner for several miles...How can you not clearly see what this illustrates?!?!?!!?! Oh yea...there's a traffic circle...I forgot to mention the traffic circle...

Must not forget the circle... Missing the circle eliminates the positive euclidian correlation between the synergistic nature of the angular momentum within the external structures of the atmospheric strata.
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I see Hurricane Katrina in there somewhere

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Quoting Patrap:
..hmmmmmmmmmmmmmmmm?



See?!?!?!?!?!?!?!
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Quoting JNCali:
Does anybody really know what time it is?
Its 2:08 P.M. here, which means its really 2:08 P.M. everywhere...muhahaha..
Member Since: September 27, 2007 Posts: 1 Comments: 22643
Member Since: July 3, 2005 Posts: 428 Comments: 129848
Quoting Levi32:


Hey Nigel. As far as I know, in 2010 the WMO made the 253mph gust from TC Olivia on Barrow Island, Australia in 1996 official, making it the highest official gust over the previous record-holder of 231mph at Mount Washington in 1931.


Thanks Levi...that's what I posted yesterday, but it was being disputed by fellow bloggers
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Quoting presslord:
...and there are thousands of little universes coexisting at the tip of my left ring finger...
There at least a few more thousand in the pack of 1.5,s I have stashed under the coffee table...
Member Since: September 27, 2007 Posts: 1 Comments: 22643
Nea: the street I live on runs exactly parallel to the Atlantic Ocean...and several streets run parallel to my street...at almost equi-distant points, other streets cross mine (as well as the others running parallel in the same direction) at almost perfect right angles...and this phenomenon runs in this manner for several miles...How can you not clearly see what this illustrates?!?!?!!?! Oh yea...there's a traffic circle...I forgot to mention the traffic circle...
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Quoting Tropicsweatherpr:
Hi Levi, I saw your post on another Dr Masters blog two days ago where you mentioned the CentralEast Caribbean as a favored area for early development this upcomming season. What factors you see as favor for that area?


No, I said the GFS has been showing that area becoming the most favorable for any possible May mischief. In my opinion it is probably just working out some early quirks. We will likely have to wait until after May 15th as always, unless we get a cutoff upper low in the tropics before then.
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http://www.abarim-publications.com/MostDeceitfulT hing.html


Mankind's amazing ability to see patterns is often as helpful as it is confusing. Man's primary sense is vision and when our eyes tell us that there's a pattern our other senses are often discarded. Hence we make ourselves believe that we see ......., or recognizable features in a foggy stain. Recognizing patterns allows us to process large quantities of information at once. It allows us to plot our position in the world around us, to enjoy music, art, fellow humans since all behavior and all objects are in fact patterns caused by huge amounts of little particles or impulses.

Patterns are good. Patterns are our friend. Except when you see a pattern that no one else sees. In that case you are either brilliant and apt for volleys of wrongful derision or completely nuts like Mell Gibson in Conspiracy Theory and in for a sea of trouble against which no arms can be raised. Anyway, history as well as literature suggest that the seers of the unconfirmed are often also speakers of the unconfirmed, usually lonesome souls blabbering on about the end of the world, howling at the moon, or hugging curls of caustic fires set to end their diatribes. If you don't fit in to that good old pattern called proper human behavior there's always some xenophobic volunteer to light the stake.

Nuts or nostos

But the question is: when is a pattern really there and when do we only think it is? A face in the clouds isn't really there. Deriving our reality model from that face in the clouds will throw our world in disarray as soon as the cloud dissipates. And sure, old Mell was right in the movie but many conspiracy theories are houses of cards; mountains of data woven together upon imaginary spines. It's not a valid argument to believe that a pattern is there. Everybody who sees a pattern somewhere is convinced that the pattern is really there, and all additional observations are interpreted in such a way as to confirm that belief.

A pattern in the clouds is always something we know and we see it in the clouds because we project that which we know upon that which we observe. Even when no one else sees that pattern. And the fact that everybody sees a certain pattern is also not a valid argument for the pattern's factuality. There was a time that all observations about the earth confirmed the consensual belief that the earth was flat. And that turned out to be a face in the clouds as well.

Hold that thought:

Our beliefs are not valid instruments to analyze either reality in general or any specific pattern.
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Quoting wxmojo:


That's why the tutorial was written. It describes the process of identification and systematic construction of the grids. If that doesn't click for you, then I am at a loss of how to further point it out to you.
Does anybody really know what time it is?
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Quoting Neapolitan:
If there is, I'd appreciate you pointing it out to us...


That's why the tutorial was written. It describes the process of identification and systematic construction of the grids. If that doesn't click for you, then I am at a loss of how to further point it out to you.
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MESOSCALE DISCUSSION 0565
NWS STORM PREDICTION CENTER NORMAN OK
0148 PM CDT WED APR 18 2012

AREAS AFFECTED...PARTS OF CENTRAL AND ERN SC/ADJACENT PART OF SERN
NC

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY

VALID 181848Z - 182015Z

ISOLATED STRONG TO SEVERE STORMS WILL BE POSSIBLE THIS AFTERNOON
ACROSS THE ERN HALF OF SC INTO ADJACENT COUNTIES INTO SERN NC.

18Z MESOSCALE ANALYSIS SHOWED AN AREA OF WEAK LOW PRESSURE CENTERED
OVER NRN-NERN SC /INVOF CHESTERFIELD COUNTY/ WITH A TROUGH /ALSO
DEPICTED AS A DIFFERENTIAL HEATING BOUNDARY PER VIS IMAGERY/
EXTENDING SSWWD THROUGH SRN SC TO SERN-SRN GA. SURFACE HEATING
WITHIN THE AIR MASS ALONG AND EAST OF THE TROUGH WILL ALLOW FOR
ADDITIONAL DESTABILIZATION WITH CURRENT MLCAPE AROUND 500 J/KG.
REGIONAL RADAR IMAGERY SHOWED A BROKEN BAND OF TSTMS EXTENDING SWD
FROM NEAR THE LOW INTO COLLETON COUNTY SC. THIS ACTIVITY WAS
LOCATED ALONG THE LEADING EDGE OF STRONGER FORCING FOR ASCENT/DPVA
SPREADING ACROSS THIS REGION AS A SHORTWAVE TROUGH LIFTS NEWD.

ALTHOUGH LOW LEVEL WINDS ARE FAIRLY WEAK...35-40 KT SWLY MIDLEVEL
WINDS ARE SUPPORTING BULK SHEAR SUFFICIENT FOR STORM ORGANIZATION.
A FEW SUSTAINED STORMS WILL BE POSSIBLE WITH HAIL AND STRONG WIND
GUSTS THE PRIMARY THREATS...BUT LIMITED COVERAGE DUE TO THE WEAK
INSTABILITY WILL RESULT IN A LOW THREAT FOR SEVERE STORMS.

..PETERS.. 04/18/2012

Member Since: February 11, 2012 Posts: 84 Comments: 8040
On serious note: I'm near 4.5" for month of April, but that's in SE TX near the coast. Folks in central TX like Austin,San Antonio, are not doing as good.
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Hi Levi, I saw your post on another Dr Masters blog two days ago where you mentioned the CentralEast Caribbean as a favored area for early development this upcomming season. What factors you see as favored for that area?
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Quoting nigel20:

Whats up Levi...i've been getting varying answers to what the highest wind gust on earth.. What is the highest official wind gust on earth?


Global Weather & Climate Extremes
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..Science..!
Member Since: July 3, 2005 Posts: 428 Comments: 129848
It's poetry in motion
She turned her tender eyes to me
As deep as any ocean
As sweet as any harmony
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Quoting ncstorm:
So let me see if understand the blog...when you dont understand someone's concept, you insult them?
No, we ask them--repeatedly and patiently--to explain their concept. But then when they repeatedly fail to provide an explanation and instead disrespect the forum's members by saying anyone who can't see what they're seeing clearly lacks even minimal observation skills, then we insult them.
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Quoting ncstorm:


I feel sorry for you..


Chill out, it's just a blog
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Quoting nigel20:

Whats up Levi...i've been getting varying answers to what the highest wind gust on earth.. What is the highest official wind gust on earth?


Hey Nigel. As far as I know, in 2010 the WMO made the 253mph gust from TC Olivia on Barrow Island, Australia in 1996 official, making it the highest official gust over the previous record-holder of 231mph at Mount Washington in 1931.

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Quoting nigel20:

Whats up Levi...i've been getting varying answers to what the highest wind gust on earth.. What is the highest official wind gust on earth?


Let me fill in fer Patrap here...

uh, er, try using google search, might help ya out.
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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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