TS Ernesto #8 Sat pics, models, analysis thread

[wjs3]

I have a dumb question. When does the diurnal maximum generally occur during the night? I would have thought that it would occur shortly after sunset, but from the comments here that doesn't seem to be the case.

Not dumb. The diurnal maximum over water happens in the wee hours of the night, often just before dawn. I've never seen a verified scientific explanation but my idea is that as the night goes on cloudtops cool by radiation while water maintains its temp by convection with deeper water. Hence more of a temp difference and more convection.

Pretty right on. You destabilize the atmosphere by cooling the upper levels while keeping lower levels warm. That steepens the lapse rates.


edit--water doesn't keep its temp by convection with deeper water (not sure how that would work...) in this case....as far as I know...the real driver is that the lower atmosphere stays relatively warm (influenced by warm water) while the upper atmosphere cools.

[Furious George]

From the NHC website regarding the 5 day cone:

The historical data indicate the entire 5-day path of the center of the tropical cyclone will remain within the outer uncertainty area about 60-70% of the time

This means am avg storm would have about a 15%-20% chance of going on either side of the cone.

Something to consider for Floridians.

[mtm4319]

[img=http://img183.imageshack.us/img183/6933/intensity1ox7.th.png]

Let me help you out with that:

[img]http://img183.imageshack.us/img183/6933/intensity1ox7.png][/img]

All models now predict intensification into a hurricane, with about half saying major. Earlier (today?), some of them had no further strengthening at all.

:lol:

... flood control caught me. Usually I would have fixed that before anyone seeing.

[Typhoon]

Thanks, wjs3 and curtadams. I guess I was forgetting that there isn't much diurnal temperature fluctuation over the ocean, therefore the overnight cooling of the cloudtops by radiation would do far more to create instability than any heating near the surface.

[6SpeedTA95]

I have a dumb question. When does the diurnal maximum generally occur during the night? I would have thought that it would occur shortly after sunset, but from the comments here that doesn't seem to be the case.

Not dumb. The diurnal maximum over water happens in the wee hours of the night, often just before dawn. I've never seen a verified scientific explanation but my idea is that as the night goes on cloudtops cool by radiation while water maintains its temp by convection with deeper water. Hence more of a temp difference and more convection.

Pretty right on. You destabilize the atmosphere by cooling the upper levels while keeping lower levels warm. That steepens the lapse rates.

Thats correct...

Ever seen a skewT? It puts it in a nice graph so you can see temp differences at various altitudes and as mentioned earlier that means instability.

[HouTXmetro]

Anyone have a link to the latest models? need to know if they are trending one way or another.

[linkerweather]

Keep in mind the cone is NOT A FORECAST. It is a representation of Historical Error. So, for arguments sake, if there was 100% certainty of a day 4 solution, the cone at day 4 would still be 450 miles across. Likewise if there was so much uncertainty with the day 2 forecast, the cone would only be 200 miles across.

A better image to look at is something the NHC began publically last year. That is the graphic with the wind speed probability polygons. For example, this storms tropical storm force wind probability out through day 5.


http://www.nhc.noaa.gov/refresh/graphic ... ?tswind120

[skysummit]

Anyone have a link to the latest models? need to know if they are trending one way or another.

No trending yet....more like bouncing! Once they get in the gulf, they split from Mexico to Florida.

[Extremeweatherguy]

I think one important thing to remember is what one of the pros poster earlier...MOST models and forecast tracks in the GOM err too far to the Right...that is the storms ALMOST always end up to the right side of the cone. Many a storm has taken a hard right hook at the last minute into the N GOM coast...Lilli, Katrina, Ivan, Dennis, Rita, Charley( know, not N GOM)...all ended up right of their forecast "black bold line" 3 days out. Keep this in Mind when it starts to look like another another Houston Landfall...Rita ended up In Cameron.

yes, that is true. Either way though, a Houston, a N.O., a Biloxi, a Mobile or even a Pensacola hit are all equally bad.

[BUD]

Thanks,
Some News reports are coming in that gas prices are going up this weekend.

I guess this is slightly off-topic, but oil companies do not set oil or gasoline prices. That's done at the NY Merc exchange by private holders of those seats and whatever the market dictates.

We dread hurricane season. It knocks our production offline, subjects us massive media criticism, and costs us millions and even billions of dollars. We haven't even finished repairs from last year.

So the notion that we're hoping hurricane season will hurt us is an emotional but not rational thought.

We're watching Ernesto primarily because we will have to safely evacuate platform personnel, shut down the facility, and stop all current drilling activity in the Gulf. That's INCREDIBLY costly.

The fact that the company has now extended that kind of preparation to its land based offices only increases the cost to the bottom line.

I'm all in favor of safety and preventing any environmental damage. They may be taking it too far by ordering me out of the office on Tuesday, but I'm the not the CEO.

I know about that on gas prices.Its the news people.But stay safe and those people on thoses rigs.

[whereverwx]

Ernesto seems to be trying to establish an upper level anticyclone. I hope I have the terminology correct, but his outflow does appear to be improving.

[wjs3]

Thats correct...

Ever seen a skewT? It puts it in a nice graph so you can see temp differences at various altitudes and as mentioned earlier that means instability.

Yup..so think of a Skew T--cloud top cooling would move the temp trace to the left--cooler--in the upper atmpsphere--and more unstable.

Wow...thermodynamics on storm 2K--who would have thought!

[wxman57]

A better image to look at is something the NHC began publically last year. That is the graphic with the wind speed probability polygons. For example, this storms tropical storm force wind probability out through day 5.


http://www.nhc.noaa.gov/refresh/graphic ... ?tswind120

From what the NHC said at their conference last year, the probability maps are comprised of historical averages as well. They run thousands of track, intensity, radii possibilities and come up with those graphics. Forecaster confidence does not play any role in their preparation. The NHC may not have a clue where a storm is heading but the probabilities would be the same as if they're 100% sure.

[Jim Cantore]

The following post is NOT an official forecast and should not be used as such. It is just the opinion of the poster and may or may not be backed by sound meteorological data. It is NOT endorsed by any professional institution including storm2k.org For Official Information please refer to the NHC and NWS products.

Although I'm having an LBAR like year making forecasts, I'll try anyways, I got nothing better to do tonight. Mind you I made it this morning.


I had a good year in 2004, an ok year in 2005, and I'm having an awful year this year. I've made one correct prediction and that was TS at 5pm... just this afternoon. So don't even hold me to this, I beg you.

[fci]

I've always had a lot of faith in Derek and the other mets here on the board. But I think the shear is going to let up some in the next 12 to 24 hours and I do believe that we will have a minimal hurricane on our hands at this time tomorrow.

You have faith "but".
Isn't your opinion pretty much what Derek and the others had been saying?
IF Ernesto gets past the current shear he should intensify.

I mean we're not getting down to specific times of day but the general forecast he and the other Pro Mets have been posting is, thus far; true to form.

[El Nino]

Ernesto seems to be trying to establish an upper level anticyclone. I hope I have the terminology correct, but his outflow does appear to be improving.

This thing is getting bigger and bigger, and better organised. I wouldn't be surprised if tomorrow I wake me up something evenbigger and better. Hurricane before 2 days IMO.

Except the legendary uncertainty in tropical meteorology, I don't see anything to prevent Ernesto to be a dangerous keyplayer in the next days.

Have a nice night all.

[all_we_know_is_FALLING]

The following post is NOT an official forecast and should not be used as such. It is just the opinion of the poster and may or may not be backed by sound meteorological data. It is NOT endorsed by any professional institution including storm2k.org For Official Information please refer to the NHC and NWS products.

Although I'm having an LBAR like year making forecasts, I'll try anyways, I got nothing better to do tonight. Mind you I made it this morning.


I had a good year in 2004, an ok year in 2005, and I'm having an awful year this year. I've made one correct prediction and that was TS at 5pm... just this afternoon. So don't even hold me to this, I beg you.

I like your forecast. It isn't over the top and is reasonable.
I wouldn't be shocked to see a Cat 3 though.

[JTD]

Ernesto seems to be trying to establish an upper level anticyclone. I hope I have the terminology correct, but his outflow does appear to be improving.

Any comments on this statement would be appreciated.

[Portastorm]

No offense Hurricane Floyd ... but I hope you're DEAD WRONG with that track as it would be terrible for those who suffered last year at the hands of Rita.

Can't you bend that track about 500 miles to the southwest?

[whereverwx]

Nice forecast, Floyd, but yikes... that wouldn't be good for Texas!