CAT 5 Hurricane Dean - Archived threads

[mempho]

I am taling about the convection tail which is currently following Dean

I don't consider that abnormal. Katrina and Rita were more annular in nature and that is rare.

[tallywx]

I think a more pressing question would be whether that convective tail/feeder band, with its huge blowup of thunderstorms, would serve to cut off some of the inflow into Dean's center from the juicy SE quadrant - similar to how MCSs and thunderstorms along the Gulf Coast very often kill off convective activity over the Carolinas with frontal passages. I've rarely seen a distant convective feeder band as vibrant as this one associated with a powerful hurricane.

[wxmann_91]

Globs of convection don't break off storms and form their own TC's. For one the outflow from the parent storm, and the "stealing" of inflow from the inner core convection, makes these globs relatively short-lived. The longer lived ones can't do anything but orbit the storm due to the strength of the circulation center of the storm which acts sorta like a black hole. Note this only applies to strong storms which completely control the environment around them.

[rjgator]

The eye is the shape of a cross



Shot at 2007-08-17

[srainhoutx]

Interesting thought...THe 5 AM track will feature a landfall point, possibly on the US/MX or even more north. That will REALLY put the media hounds on it...are we ready to hear "Dean eye's texas for the next 5 days''. On a serious note...the 5 am will be the most important advisory yet for the US gulf coast. I imagine the NHC will be thinking long and hard about where to put that dot.

I can only imagine how heavy their hearts where when they had to finally put that Katrina dot on New Orleans.

You can only imagine the implications from OEM perspective.

[KBBOCA]

all, a reminder, we've got a lot of newbies on the board with this kind of developing storm. Try to define lingo, particularly when answering questions.

Annular hurricanes tend to be very round, donut-like. They don't have the trailing bands like most hurricanes. It was unusual to see so many in 2004 - 2005.

[MWatkins]

NOGAPS...through 72 hours...is slightly further north and lagging the ULL just a little...

https://www.fnmoc.navy.mil/CGI/PUBLIC/w ... 00&tau=072

versus same VT at 12Z

https://www.fnmoc.navy.mil/CGI/PUBLIC/w ... 00&tau=084

MW

[Matt-hurricanewatcher]

The eye is the shape of a cross



Shot at 2007-08-17

Interesting that it also shows "blues" between the inner eye forming. Which is the innerring. In a broad outter eye. Maybe a EWRC? I'm thinking so because of the decrease in the overall convection intensity. But once its over a new larger eye will form and it will tighten for a another bombing?

[mempho]

The eye is the shape of a cross

Thank you so much for the image. I'm going to save it...that is very unique!!!

[fasterdisaster]

Yeah like I said I expect an ERC in the next couple hours, could be Category 5 sometime tomorrow after it finishes if that happens.

[CrazyC83]

046
URNT15 KNHC 180450
AF302 0504A DEAN HDOB 42 20070818
044030 1405N 06713W 6968 03133 0034 +087 +077 325031 031 037 000 00
044100 1406N 06712W 6968 03133 0036 +086 +077 327032 032 039 000 00
044130 1408N 06711W 6968 03129 0030 +090 +076 327032 033 038 000 00
044200 1409N 06710W 6967 03129 0026 +090 +081 326035 036 037 000 00
044230 1410N 06709W 6969 03124 0024 +089 +088 325035 036 038 000 00
044300 1411N 06707W 6967 03126 0024 +086 +086 324036 036 037 001 00
044330 1413N 06706W 6967 03123 0022 +087 +087 324036 037 039 000 00
044400 1414N 06705W 6968 03119 0023 +084 +084 325036 036 038 001 00
044430 1415N 06704W 6965 03120 0021 +084 +084 325034 035 037 002 00
044500 1416N 06702W 6967 03115 0011 +088 +085 322036 037 041 000 00
044530 1417N 06701W 6967 03113 0005 +092 +084 319039 040 041 000 00
044600 1419N 06700W 6967 03109 0006 +089 +087 317038 039 043 000 00
044630 1420N 06659W 6961 03116 0013 +080 +080 322040 041 043 001 00
044700 1421N 06657W 6967 03105 9997 +089 +089 319038 039 044 000 00
044730 1422N 06656W 6964 03104 9985 +094 +089 315042 043 046 000 00
044800 1424N 06655W 6964 03096 9989 +086 +086 310043 045 049 038 03
044830 1425N 06654W 6977 03076 0008 +067 +067 316041 047 049 023 03
044900 1426N 06652W 6967 03083 9995 +073 +073 317045 046 046 005 00
044930 1427N 06651W 6967 03081 9964 +094 +094 313047 048 046 003 00
045000 1429N 06650W 6967 03078 9966 +089 +089 313043 044 047 005 00
$$

Looks like another shot at the center now...

[Chris_in_Tampa]

Storms like this wobble, as indicated by this tool:
http://cimss.ssec.wisc.edu/tropic/real- ... npage.html

Does not update much, but showed an earlier wobble south of west.

[Air Force Met]

I can see it now. All the little players wanted to take on the big boy. The GFDL came to play. It's not going to be made a fool of on perhaps the biggest storm of 2007. You stick with your bread and butter. If the GFDL is an outlier, then so be it. You go with your ace when the game is on the line. This is game 7 and I want the ball in the GFDL's hand.

Hey...stick a sock in that kind of talk. The GFDL takes it right into my favorite fishing hole as a Cat 5.

Do you realize how that is going to mess up the flounder run?

Yeah and it also kills my place.

Where I grew up to...Sweeny...just down the road from you.

[mgpetre]

I guess in that vein of my question I was just saying that at the point that solar flares matter then we have definately gotten the models down to a science. I appreciate the very verbose and informative answer. Are you saying that a certain amount of storm history is put into the model on initialization? I think that would definately be a key to an accurate forecast. What about the question of how far-reaching are the parameters? I see a global model outperforming a localized one for obvious reasons. Again, thank you Wthrman13.

Ah, good questions. To answer the first one, if I understand you correctly, yes, a certain amount of atmospheric history is inherent in the initialization, since the "first guess" field comes from a prior prediction from the same model. For example, in the case of the 0Z GFS (it's actually a bit more complicated than this, but this will suffice by way of illustration), the first guess field is a 6 hour prediction from the previous GFS run (18Z, in this case). The real-world data that is valid at or near 0Z is then blended with this first guess state, to produce the 0Z initial fields. The model is then stepped forward in time from this initialization, and so on. There are other, even more sophisticated techniques out there to initialize models, but this is the basic idea.

To answer your second question, limited area models, such as the NAM, generally are "nested" within a global model, so that the boundaries are continually forced from outside by the solution of the global model. In the case of the NAM, the GFS provides the boundary conditions, but the interior model prediction is entirely the NAM. Typically, the local, or regional model will be designed to run at a higher resolution (more detail) than the global model, so it typically will perform better than the global in that particular region, but not always. Otherwise, there would be little point to running regional or local models.

I will wait till Dean is done for further questions, but thank you a million times over for such a succinct and informative answer.

[kozzieman]

My local TV MET was trying to explain something tonight; something about a low pressure system currently located off the east coast of Florida and it was moving to the west. If and when Dean makes it into the GOM with that low pressure coming from Florida already in place the low could have an influence on Dean and pull Dean northward but if the timing is not right; if Dean were to miss the low then the influence of a ridge of high pressure would keep Dean on a westward track. Does any of that make any sense and does anyone know how fast that low is moving from the east if Dean is moving west at 18mph right now?

[Wthrman13]

I will wait till Dean is done for further questions, but thank you a million times over for such a succinct and informative answer.

Any time

[fasterdisaster]

Storms like this wobble, as indicated by this tool:
http://cimss.ssec.wisc.edu/tropic/real- ... npage.html

Does not update much, but showed an earlier wobble south of west.

WOW, I hope you know how much that link helped! I hope this clarifies that it is indeed heading WNW in general, and the due west movement we were seeing was just a wobble.

[PTPatrick]

Was Gilbert blocked by a similar high or was it much more far reaching across the gulf?

[artist]

last I heard the low was moving at 10mph and Dean was at 18 or 19 mph - that was a couple of hours ago.

[Air Force Met]

NOGAPS...through 72 hours...is slightly further north and lagging the ULL just a little...

https://www.fnmoc.navy.mil/CGI/PUBLIC/w ... 00&tau=072

versus same VT at 12Z

https://www.fnmoc.navy.mil/CGI/PUBLIC/w ... 00&tau=084

MW

Well...looking at the 18Z run of the GFDL more...and the HWRF...the GFS is now doing what they WERE already doing with the upper low: moving it more westward towards the lower Texas coast and SW TX instead of rotating it around the high.

Gives some credence here to the shift.