NOW: Hurricane Rita

[Anonymous]

The pressure of 898 mb means that Rita is beginning to approach the upper limits of her MPI...which I think Kerry Emmanuel's calculations are in the 880-890mb range...

http://wxmaps.org/pix/hurpot.html

Only a few hurricanes have exceeded their MPI...Hurricane Lili was one of them, and she wasn't far from Rita's current location I don't believe.

 

[Chad Ringley]

Originally posted by Chad Ringley
The pressure of 898 mb means that Rita is beginning to approach the upper limits of her MPI...which I think Kerry Emmanuel's calculations are in the 880-890mb range...

http://wxmaps.org/pix/hurpot.html

Only a few hurricanes have exceeded their MPI...Hurricane Lili was one of them, and she wasn't far from Rita's current location I don't believe.

I did the same thing...rats. Sorry guys. The previous message was me.

 

[Anonymous]

This is fascinating to watch. I'm at work, and I just overlayed lightning plot. What I find astonishing is that the CG activity in the immediate inner eyewall has shot up dramatically from 23-00z. Interesting to note that inner-core eyewall CG activity also spiked around 15z earlier today... and we see what happened afterward with continued incredible deepening. My question is this: Are we maxed out yet.. considering more inner-core CG activity? What's the general thinking about CG activity and subsequent deepening in the 3-6hr time range? There was almost no CG activity from 16z thru this afternoon... then this sudden burst again at 23z.

Mike U

 

[HAltschule]

I would be almost certain that the significant lightning as you're describing is consistent with continued deepening. Given such a RAPID strengthening process, I don't see why Rita would stop immediately. That said, Rita is still strengthening IMO.

Further: The Northwest movement resumes based on IR Satellite loops over Rita in the past 15 minutes. This turn seems to be about 8-12 hours earlier than NHC thought in its advisory. Hence, my Houston landfall prog. I'll be VERY interested to see what the 11pm and especially 5am adviosory says regarding this. 00Z models should be interesting to watch come in.

HOUSTON, WE HAVE A PROBLEM!!

 

[Justin Walker]

Mike U...did you forget to log in? Where did you see that infomation from? I would like to look at it.

 

[B Ozanne]

I'm perfectly content with this thing maxing out...as long as we accurately measure the lowest pressure of the storm. I don't want to miss anything.

 

[Robert Dewey]

Originally posted by Anonymous
This is fascinating to watch. I'm at work, and I just overlayed lightning plot. What I find astonishing is that the CG activity in the immediate inner eyewall has shot up dramatically from 23-00z. Interesting to note that inner-core eyewall CG activity also spiked around 15z earlier today... and we see what happened afterward with continued incredible deepening. My question is this: Are we maxed out yet.. considering more inner-core CG activity? What's the general thinking about CG activity and subsequent deepening in the 3-6hr time range? There was almost no CG activity from 16z thru this afternoon... then this sudden burst again at 23z.

Mike U

I would generally think that the lightning occurs after the strengthening phase. This would make some sense, since general convection often the most intense lightning during its peak strength/mature phase. I would assume hurricanes would follow a similar rule. But, that's not to say that this thing won't enter another cycle in a few more hours (lightning dropping off, then peaking again). Looking at the heat content of the ocean, if this thing stays on a WNW course, it will generally have plenty of ocean heat to work with (the northwestward extending band of higher heat content). I don't think we have seen the last of the strengthening...

The IR image is beyond impressive, it's had some very cold cloud tops for a solid 12 hours or so...

 

[Robert Dewey]

Originally posted by Justin Walker
Mike U...did you forget to log in? Where did you see that infomation from? I would like to look at it.

It's only available to us AWIPS and N-AWIPS users

 

[Jeff Snyder]

Originally posted by B Ozanne
as long as we accurately measure the lowest pressure of the storm. I don't want to miss anything.

LOL Me too, though this wording doesn't make me comfortable:

THE DROPSONDE INSTRUMENT MEASURED 32 KT/35 MPH WINDS AT THE SURFACE...WHICH MEANS IT LIKELY DID NOT RECORD THE LOWEST PRESSURE IN THE EYE OF RITA. THE CENTRAL PRESSURE IS PROBABLY AT LEAST AS LOW AS 898 MB...AND PERHAPS EVEN LOWER. FOR OFFICIAL PURPOSES... A PRESSURE OF 898 MB IS ASSUMED...

-- > http://kamala.cod.edu/offs/KNHC/0509212351.wtnt63.html

That doesn't really scream "accurate" or reliable! I understand the issues involved, so I'm not disssing NHC or anything!

 

[HAltschule]

Hey Mike U:

I think I read that you are at the NWS in KS, correct? If so, can the NLDN zoom into Rita to see the actual count of CG strikes within the storm over the past hour? I'd be curious to see what it is. We used to be able to do that when NLDN was at SUNY Albany. Thanks.

 

[Jeff Snyder]

It would seem that lightning would precede strengthening a bit... Lightning would be a product of abnormally intense upward vertical motion. Such activity should then result in a further drop in central pressure. I'm no expert on lightning in tropical activity, but that would seem to me to be the order of events.

 

[Mike Umscheid]

Originally posted by Justin Walker
Mike U...did you forget to log in? Where did you see that infomation from? I would like to look at it.

Yeah, I forgot to log in... monitoring on AWIPS at the office, so able to overlay 15-minute lightning data on top of IR imagery...

As far as motion goes... using the center of the eye as a guide... from center at 1845z to center at 0045z.. distance/bearing tool shows 294 heading at 53 statute miles.

Mike U

 

[Tim Vasquez]

898 mb... wow... for the laypeople, that means we're 11% of the way down to a vacuum. Rest assured you won't need to go buy oxygen tanks... 12% is the record.

Tim

 

[Mike Umscheid]

Originally posted by HAltschule
Hey Mike U:

I think I read that you are at the NWS in KS, correct? If so, can the NLDN zoom into Rita to see the actual count of CG strikes within the storm over the past hour? I'd be curious to see what it is. We used to be able to do that when NLDN was at SUNY Albany. Thanks.

here are some interesting 15-minute NLDN stats around the eye since 2115.

Time Z - positive CG - negative CG - total CG

2115 - 1 - 0 - 1
2130 - 3 - 0 - 3
2145 - 0 - 4 - 4
2200 - 0 - 4 - 4
2215 - 0 - 4 - 4
2230 - 0 - 4 - 4
2245 - 0 - 4 - 4
2300 - 0 - 12 - 12
2315 - 1 - 14 - 15
2330 - 0 - 6 - 6
2345 - 0 - 19 - 19
0000 - 0 - 8 - 8
0015 - 0 - 4 - 4
0030 - 0 - 0 - 0
0045 - 0 - 1 - 1
0100 - 1 - 1 - 2

Mike U

 

[HAltschule]

Wow!! Very interesting to see how the intense deepening this afternoon and evening correlates with the negative CG strikes. For those that don't know, negative CG strikes are typically associated with strengthening and steady state thunderstorms. When the strikes are positive, it is usually a sign of weakening (except in the Plainfield, IL F5 tornado and an F5 in Texas...that's a whole different animal).

So, it's interesting to see that these are mostly all negative strikes thus far. Given the dropoff in strikes, one can assume that the deepening may be leveling off. I think we will still see a slightly stronger and deeper hurricane at 11pm, but probably not as rapidly strengthening as before.

Might the CG lightning here be used as a possible forecast tool? This analysis and forecast might come true but it certainly will need a whole bunch of research in the future. We'll See.

Thanks Mike.