Is TS BARRY really a TS or....

[Matt-hurricanewatcher]

Matt:

I have to disagree--and this is part of the reason I want to ask the question elsewhere, so we can really talk about it.

The warm core in warm core sysstem, as I understand it, is a result of compressional warming form subsidence--SINKING air, not lighter or rising air. All that air converging in convection near the center exits at the top and there is compensating subsidence.

Also, I learned that the LLC forms because low pressure forms--driven by convection firing and lowering pressure (indivisual cells organizesand helps to lower surface pressure)...the resulting temperature gradient is a result of the convection organizing and forming a low center-the temperature gradient does not cause the LLC, but is a result of the typical process for tropical development as far as I understnad it.

And a cold core low is formed by a trough aloft (usually a short wave to go with it) causing divergence aloft. As air exits the column aloft due to the vorticity changes aloft, the total column weight (and surface pressure) drops. But this sort of low forms near a baroclinic zone--temperature gradients are present.

The pro mets usually step in and correct my oversimplifications at this point (Steve or Wxman57 HELP!)

Subtropical as I understand it has the characteristics of both tropical and extratropical cyclones (I know you know this, Matt, but for those who haven't read it: http://www.aoml.noaa.gov/hrd/tcfaq/A6.html

and

https://courseware.e-education.psu.edu/ ... lones.html)

WJS3

It is true that convection forms the low pressure, convection=heat into the Atmopshere. Over time a low pressure will form. But once formed the temperature from inside to outside is important in strengthing. The air rises as it heads to the center then moves up into the upper Atmosphere. In which forms into the upper level Anticyclone. As the storm strengthen your right about this one, that the air sinks or compresses near the center. That is why winds are lower in that area. But it is temperature grad by the convection and heat release from it that causes much of its strengthing. Its a heat engine.

[bvigal]

OK, the season started today. Let's not begin it by second-guessing NHC. I'll go with their wealth of advanced knowledge, experience, and sensitivity to public safety. No matter how much I might deem to think I or my weather-enthusiast friends know about tropical systems, the folks at NHC know MORE - gobs more than I will ever learn that I don't know. Let's give these people some backing, they deserve it, and it's probably going to be a long season. RAH-RAH NHC! I'm behind you 100%!!

[wjs3]

It is true that convection forms the low pressure, convection=heat into the Atmopshere. Over time a low pressure will form. But once formed the temperature from inside to outside is important in strengthing. The air rises as it heads to the center then moves up into the upper Atmosphere. In which forms into the upper level Anticyclone. As the storm strengthen your right about this one, that the air sinks or compresses near the center. That is why winds are lower in that area. But it is temperature grad by the convection and heat release from it that causes much of its strengthing. Its a heat engine.

Matt:
I still am not sure I agree with this and hope someone else can jump in and help.

Sorry but I have to drop this for the night...there are a couple of clarifications I'd like to make (and questions I have), but I have to get to bed!

Talk to you!

WJS3

[senorpepr]

While recon data semi-supported a tropical cyclone, I will say this:

Looking at a water vapor loop over the region (not just over the system) clearly shown that "Barry" was an extratropical wave cyclone developing downstream from a large upper-level trough in the western GOM. This system was driven by dynamics and was supported by a jet stream--not thermodynamics like a tropical cyclone.

[Noah]

OK, the season started today. Let's not begin it by second-guessing NHC. I'll go with their wealth of advanced knowledge, experience, and sensitivity to public safety. No matter how much I might deem to think I or my weather-enthusiast friends know about tropical systems, the folks at NHC know MORE - gobs more than I will ever learn that I don't know. Let's give these people some backing, they deserve it, and it's probably going to be a long season. RAH-RAH NHC! I'm behind you 100%!!

IM with bvigal.
Judging NHC? Lets not get carried away here. They are professionals, Why a debate? Keep that for the politcal stuff this is a weather forum.

[senorpepr]

What I'm saying isn't political... just the observation of a dozen or so degreed meteorologists (some with over 40 years in the field). From what I've seen, a majority of the weather community feels that we haven't had a REAL named storm yet. Why debate? Because debate is good when it comes to learning.

With that said, I'd like to know when tropical cyclones started becoming supported by a jet stream. I know extratropical waves are supported, but the rules of tropical meteorology say something different about tropical cyclones.

[wjs3]

...and I'm not questioning here--just trying to learn.

How, meteorologically, does a jet-stream induced low get a warm core that quicky after forming? Can someone make the fact that the storm seems to have been really baroclinic and the fact that it was warm core (which would be a sign of the more typical--I think you called it thermodynamically driven, Senorpepr--tropical development, right?)?

Thanks

WJS3

[Tampa Bay Hurricane]

Well we did have sustained winds just over 40 mph with
gusts to 50+ in the squall at landfall...also fact789
reported similar tropical storm force observations...
It seemed like a warm core given the low
level clouds rising from the waters and moving
rapidly...

[miamicanes177]

I have found the people who have the hardest time accepting Barry are the one's who forecast it to dissipate. When it strengthened with winds over 50mph this caught them off guard and they searched for ways to justify not naming it. Wunderground busted big time on Barry and then Jeff Masters and Margie Kieper each questioned if it was a tropical storm. Margie Kieper posted several blogs just trashing the NHC and attempted to make them sound like little children. I can't blame them as just hours before it was named they said the Atlantic is off to a slow start and the chance of a storm forming in June is below average. Go back and look at the background of the individuals who are so adamant it should not have been named. I think you'll see the whole story then. Regardless of what people say, the only people with power to designate storm names are the forecasters at the NHC. We can debate it all we want to, but at the end of the day what the NHC says will be recorded in the records.

[HURAKAN]

If we accept Alberto, 2006; Arlene, 2005; Grace, 2003; Lee, 2005; Lorenzo, 2001, and many others as tropical storms, then Barry, 2007, was a tropical storm. Furthermore, the HURRICANE HUNTERS found a tropical storm. Case closed.

[senorpepr]

Hurricane Hunters found evidence that supported a tropical storm.

But tropical cyclone are not supported by a jet stream.

It's not a matter of, "Oops... I didn't forecast it, so I'm against it." Actually, I and others forecast the NHC to make it Barry by bending the rules of tropical meteorology. That's just the facts. Yes, Barry officially formed--but only by "twisting" the rules.

[WindRunner]

So I guess you're not buying the "it has too many tropical features to be subtropical, so it must be tropical" line?

I agree that it had extratropical origins, but it seemed tropical enough to me. Didn't look like the most tropical of storms, but I've seen far worse . . .

[curtadams]

Hurricane Hunters found evidence that supported a tropical storm.

But tropical cyclone are not supported by a jet stream.

It's not a matter of, "Oops... I didn't forecast it, so I'm against it." Actually, I and others forecast the NHC to make it Barry by bending the rules of tropical meteorology. That's just the facts. Yes, Barry officially formed--but only by "twisting" the rules.

The jet stream was supporting a huge storm covering almost all of Florida and beyond. Barry was a small warm-core system in the area. Had Barry been driven by the jet stream divergence the storm would have been warm-core from Miami to Talahassee. But actually, much of the time, there was no other convection anywhere near Barry even though all that area within 100 miles was experiencing roughly similar divergence. Barry was a small straight-up sheared hot tower thunderstorm complex (3 degree C difference, pretty substantial) within the large extratropical cyclone. The divergence formed Barry (as usual, a tropical cyclone needed a baroclinic push to get started) but the intermittent sheared columns coming off the LLC were good old tropical thermodynamics.

[Nimbus]

There were fast moving low altitude scud clouds rotating around a low level center at landfall.

scud


The LLC was in the process of breaking up as it came ashore. The winds out of the east, north of the landfall were lighter. Clearwater Beach reported 31 MPH.

[Air Force Met]

Hurricane Hunters found evidence that supported a tropical storm.

But tropical cyclone are not supported by a jet stream.

It's not a matter of, "Oops... I didn't forecast it, so I'm against it." Actually, I and others forecast the NHC to make it Barry by bending the rules of tropical meteorology. That's just the facts. Yes, Barry officially formed--but only by "twisting" the rules.

Howdy all...

Hey Senorpepr...I understand what you are saying...and agree with you. Recon found a little bit of a warm core system...but there is no doubt that this thing was baroclinically enhanced and supported by the jet...especially by the time it made landfall. That is a meteorological fact...not opinion.

Bottom line was the effects were the same...and that is what the NHC has to make warnings for. The average joe doesn't understand that the thing that is giving him 6" of rain and 50 mph winds isn't really a TS. He really doesn't care. So..the NHC names it so average Joe will pay attention and won't wonder out into the rip current.

Unfortunetly...there are times when meteorology gets seperated from the need to warn people...and science is the one that suffers...and rightly so.

[Noah]

By the way, I do respect all the professional mets on here as well and all their input.

[tolakram]

I don't mind people discussing the ifs and whens and whys, but I just don't understand the apparent anger at the NHC. This is especially true of M Keepers blog. It seems way out of place and un-constructive and frankly it makes me wonder if politics has entered into the equation.

[Thunder44]

Hurricane Hunters found evidence that supported a tropical storm.

But tropical cyclone are not supported by a jet stream.

It's not a matter of, "Oops... I didn't forecast it, so I'm against it." Actually, I and others forecast the NHC to make it Barry by bending the rules of tropical meteorology. That's just the facts. Yes, Barry officially formed--but only by "twisting" the rules.

Maybe it was "Barry" itself that twisted rules. We are dealing with a system that seemed to have the characteristics of tropical cyclone, yet it also seemed it was all enhanced by baroclinic processes, as you would expect with an extratropical cyclone. Maybe we still have things to learn about tropical meteorology. Maybe that's why we still suck at intensity forecasting.

[artist]

I remember when Wilma came thru there was a cold front that was on its way down and that cold front was enhanced by Wilma -my question - would that mean that the cold front wasn't really a cold front or that Wilma at that point wasn't really a hurricane at that point? It got sooo cold and windy here is West Palm just a Wilma roared thru, fortunately making being without power not nearly as miserable for those that didn't have back up power. Would this be a similar situation?

[Ptarmigan]

Barry was a tropical storm how I see it. Now, it's an extratropical low.