Pressure Up!

[ConvergenceZone]

good call to those who predicted no weakening with this update. Latest update just issued shows winds still at 160 mph... I think I'll just have a small plate of crow this time around.

[The Big Dog]

n/m

[mtm4319]

good call to those who predicted no weakening with this update. Latest update just issued shows winds still at 160 mph... I think I'll just have a small plate of crow this time around.

I don't think recon had made it all the way through the storm yet.

[djtil]

recon has been through both the nw and ne ......winds are definitely down but no way are they going to drop a category considering the media ramifications until they are sure..especially with the pressure....if the pressure continues to tick up and the winds stay where they are during the next recon they will drop at 5am..imo.

[ConvergenceZone]

You could be right. My reasoning as to why I thought it would be a bit weaker with this update is because the west side of the storm is getting a bit flattened by the trough. That is evident on the Satellite loop. I figured that was good for a 5 mph or 10 mph drop, but perhaps the reason it wasn't dropped is because of what you mentioned regarding lack of recon data. It still looks very healthy, just a bit flat on the western side as if the side of it is being impacted by the impending trough.

[btangy]

Satellite (0430Z - GOES-10) showing some pretty significant deteoration on the W side of the storm. Also, recent recon pass provides evidence that Katrina may have weakened to a Cat 4. The long range radar out of New Orleans hasn't been updating, but the eye looks like it's going to come into short range soon.

[joe_koehle]

the hurricane hunter on geraldo just said they found 907 mb and 145 kts at 5,000 feet

[jpigott]

i'm just an weather enthusiast, most definetly not an expert, but from everything i've ever read the wind/pressure ratios seem to be significantly off in Katrina given some of the most recent wind readings from recon. Any opinions from the professional mets

[mtm4319]

Satellite (0430Z - GOES-10) showing some pretty significant deteoration on the W side of the storm. Also, recent recon pass provides evidence that Katrina may have weakened to a Cat 4. The long range radar out of New Orleans hasn't been updating, but the eye looks like it's going to come into short range soon.

Both observations good news for NOLA.

Edit: 20 minutes of NE eyewall observations weren't included... interesting. Might explain why no winds of even cat-4 intensity were sent back.

[ConvergenceZone]

Now on the CNN Satellite they just showed, I don't see quite the west erosion that I saw with the weather.com Satellite. So perhaps Cnn's isn't quite current, not sure.


Most of the enjoyment I get out of hurricanes is trying to predict weakening/strengthening phases. Yes it makes you pull your hair out and I'm wrong alot, but it's fun and I learn alot : )

[btangy]

Now on the CNN Satellite they just showed, I don't see quite the west erosion that I saw with the weather.com Satellite. So perhaps Cnn's isn't quite current, not sure.

That's because they're using the GOES-12 satellite, which has an eclipse period after 4Z. The GOES-10 looks out over the E Pacific, but still captures the Gulf of Mexico. You can find updated IR satellite snapshots of Katrina here:

http://www.nrlmry.navy.mil/tc_pages/tc_home.html

[Windy]

910mb now, according to recon. (Check the recon thread)

[btangy]

134 knots max flight level wind... so 120 knots/ 140 mph max surface wind. Yet pressure has only come up slightly to 910mb, which is a rather low pressure for a Cat 4, but I guess it's in one of these not so well understood ERC phases right now. Lets just hope the outer wind max doesn't contract within the next few hours.

[ConvergenceZone]

Pressure FINALLY starting to raise a bit more 910 now. I knew my eyes wearn't playing tricks on me

[ConvergenceZone]

134 knots max flight level wind... so 120 knots/ 140 mph max surface wind. Yet pressure has only come up slightly to 910mb, which is a rather low pressure for a Cat 4, but I guess it's in one of these not so well understood ERC phases right now. Lets just hope the outer wind max doesn't contract within the next few hours.

wow, that's the max flight level winds? I actually thought they would have been higher then that. Hmmm, perhaps we will see a reduction to 145 then on the next update, interesting. Still a strong storm though.

[wlfpack81]

910mb is still very low but nice to see the pressure indeed rise some. However, still want to pound it into peoples head that Katrina at 140mph or even down to 130-135mph just east of NO will be a problem for the lake levees. If I remember correctly I remeber seeing a graphic somewhere where they would be fine in Cat 3 winds but once to Cat 4 you'd have overspill into NO. And even if the surge amounts (20-25ft, possible 30-35ft in some parts of the city) are 50% over done, 12-15ft of water is still a bad problem.

I know the media and mets (and myself included) have been talking mainly in terms of Cat 5 making landfall today but even at a Cat 4 (131mph +) NO can still receiving a lot of flood damage. Don't want people in NO or anywhere in SE LA / MS / AL to let they're guard down. Cat 1 Katrina killed 7 in FL so imagine what Cat 4 Katrina could do if people still aren't prepared correctly.

[vbhoutex]

I think Katrina is in the midst of an ERC and if she is then she could be strengthening as she comes ashore. That and the warm eddy off the mouth of the MS river still lead me to believe she will be a solid CAT 5 at landfall.

[djtil]

the western erosion correlated to the radar at 5z....since then..based on radar the dry slot has been replaced by convection thrown from the north to the north west/west........lets see if the 5:30 and 6z sat pics show this.

[Derek Ortt]

its well passed the eddy now.

definite EWRC occurring. can see really strangwind readings during these processes, such as Floyds 929mb 105KT cat 3

[ConvergenceZone]

I hope you are wrong vbhoutex. I have a couple of questions


#1 They keep on talking about land fall in New Orleans, but New Orleans is well inland. I always thought the term "landfall" was only used if the city was on the coast??


#2 Also, they talk about New Orleans dealing with Cat5 or strong Cat4 winds, but won't the storm have weakened someone by the time it reaches New Orleans, I don't mean alot, but it should weaken somewhat, right?