TS Ernesto #9 Sat pics, models,analysis thread

[Air Force Met]

Hey AF, a question for you.

I heard in the past that the GFS tends to erode ridges to quickly therefore recurving tropical cyclones to soon. Is this something you have observed also ? I know that the GFS has been showing this for at least a couple of cycles now, but the NHC while adjusting the track a little right is not anywhere close to the turn the GFS or GFDL are showing.

IT overreactes...especially in the summer when it overdoes trofing....thus it erodes ridges too much.

As far as the NHC...they use more than the GFS to make a forecast. They use all of them and when they don't get a clear cut answer (like now)...they split the difference.

The models are showing a weakness in the ridge...most mets are just having a hard time accepting this (including those at the HPC) because its summer and we know these models. That is why the reluctance to shft the track.

[jpigott]

when is recon scheduled to go back out and investigate the system

[jasons2k]

I'm torn this morning on what to think.

I read this morning from a Pro-Met on another forum:

1) It's hard to trust any of the models b/c none of them have initialized the system well yet

2) He is very concerned about the ridge weakness forecast next week is being overhyped. He said this there is a good possibility the models are lowering heights over the Eastern US too quickly due to the presence of a cyclone on the GOM. In summary, he said expect the models to trend more westward with time.

[cycloneye]

when is recon scheduled to go back out and investigate the system

http://www.storm2k.org/phpbb2/viewtopic ... 86#1435886

[HouTXmetro]

Just an observation, but since last night Ernie has not made much northward progress. The implications are that it may go south of Jamacia if this continues. longterm, who knows?

[Stratosphere747]

Sure would like to see the NOAA flights in the air....

[tailgater]

And just in case anybody is interested, this is what it looks like when a storm is getting "pounded" by shear. Clearly this is not what Ernie looks like.

http://rammb.cira.colostate.edu/researc ... bertx4.gif

I'm sorry but are you like the head of the "Ernesto" fan club?

I couldn't resist.

No. I just want to be sure that everybody understands the difference between a storm that is encountering weak to moderate shear and a storm that is getting the stuffing knocked out of it by shear. It just seems silly to me to suggest that Ernesto is, or is about to, fall apart because of the shear he is encountering. If you've seen "badly sheared" systems before, it's not difficult to tell that Ernie ain't even close to being "badly sheared."

I guess we need to come up with some type of scale.
5-10 knots = low shear
10-20 knots = moderate shear
20-30 knots = strong shear
30-40 knots = very strong shear
40> knots = No chance shear
Pro mets please correct as needed.

[Opal storm]

Just an observation, but since last night Ernie has not made much northward progress. The implications are that it may go south of Jamacia if this continues. longterm, who knows?

I agree, looks like it will go south of Jamacia.I wonder if it will clip the Yucatan before entering the Gulf?

[rnbaida]

the convection looks like it is loosing power.... could it be the shear?

[PTPatrick]

Well, I was hoping not to wake up and see those models pointing back on the NC GOM. My parents REALLY dont need this, having said that, they are survivors and whatever happens, they will deal with.

In the meantime, to chime in on the "weakness". It seems like in recent memory, the models do tend to somewhat overestimate weakness and troughs...but only in the longer ranges like 5 days. SO FOR EXAMPLE: So as a storm approaches the gulf you get this(lets say by way of the Keys), ok its hitting the Big bend, then apalachicola, then panama city, Mobile, Biloxi...until withing 3 days it zeros in on say, The AL/MS line. It will hang on to that area within a 100 miles then in the last 24 hours, the models swing back east.
To make a long story short, I dont like seeing the Katrina ravaged areas to th west of the recurving models right now, because if I had to guess, they will be swinging westward some in the coming days, only to swing back east and bit...there you have it

That is my HIGHLY meteorogically educated discussion. I am no pro-met, but have watched a lot of these suckers come up the NGOM in the past few years and it ALMOST always happens that way.

[rnbaida]

when does the next recon go into ernesto?

[Brent]

when does the next recon go into ernesto?

It takes off at 11:15am EDT.

[Mac]

I guess we need to come up with some type of scale.
5-10 knots = low shear
10-20 knots = moderate shear
20-30 knots = strong shear
30-40 knots = very strong shear
40> knots = No chance shear
Pro mets please correct as needed.

It's not so simple. First of all, it's not merely a matter of how high the shear is but the direction of the shear in relation to the track of the storm. Shear that is moving at 10 knots in the opposite direction of the storm is more destructive than shear moving at 15 knots in the same direction as the storm. Additionally, shear located at the periphery of the storm may actually help to vent the storm...improving its outflow and therefore serving to increase its intensity. And the size and strength of the storm may also factor into the storm's ability to combat the adverse impace of the shear.

So, as you can see...not so cut and dry as coming up with a numerical scale.

[Mac]

the convection looks like it is loosing power.... could it be the shear?

Are you kidding me??? LOL

[Air Force Met]

I'm torn this morning on what to think.

I read this morning from a Pro-Met on another forum:

1) It's hard to trust any of the models b/c none of them have initialized the system well yet

2) He is very concerned about the ridge weakness forecast next week is being overhyped. He said this there is a good possibility the models are lowering heights over the Eastern US too quickly due to the presence of a cyclone on the GOM. In summary, he said expect the models to trend more westward with time.

I agree with that. THe other thing I am wonder is if it is moving on a 285 right now as far away from the ridge as it is....why will it move on a 300 as it near the ridge axis located over Florida....in 72-96 hours?

Seems to me that a better track would be bending back to the left as if approaches the ridge axis (which is a lot stronger in 72 hours than what it is feeling now) and then turning more NW later into a weakness. This would mean the storm moves a little faster in the 60-96 hour points too.

[skysummit]

the convection looks like it is loosing power.... could it be the shear?

Are you kidding me??? LOL

I know...it's getting old.

[hurricanesfans27]

cat 3 storm is coming soon to a coast near you. just keep it away from my house.

[Extremeweatherguy]

one thing that might make those in N.O. and MS/AL feel safer:

The models are usually very incorrect at 5 days out. The chance that this set of exact runs verifies is slim to none. I've noticed that early on, it is usually the outlier models that end up being the best.

I just hope the folks devastated last year don't have to go through that again!

[Brent]

the convection looks like it is loosing power.... could it be the shear?

Not anymore that it has been for the last 12 hours.

[PTPatrick]

Well, I'll bite, then why if the western side look like earning slammed on breaks and smashed againts his windshield....it just i funnny shape of a funny storm, and not really shear?