5 p.m. NHC discussion is cause for concern..

JetMaxx · #1 Postby **JetMaxx** » Wed Sep 17, 2003 5:11 pm

Apparently what is going on with Isabel is the top and mid levels of the hurricane are intensifying....why the winds at 10,000' flight level are 130-140 mph -- but the low levels of the storm near the ocean's surface are still only running 100-110 mph, due to the lack of convection in the eyewall.....and this hurricane still has to cross the GULF STREAM :o :o

How many times in the past 25 years have we seen hurricanes cross the gulf stream and suddenly gain 10-15 mph in wind speed? Many....from Andrew in southeast Florida to Hugo in South Carolina to Bertha and Emily in North Carolina. I sat in amazement in 1993 as I watched the convection increase in the eyewall as hurricane Emily passed over the Gulf Stream SE of Cape Hatteras.

With upper level conditions improving over Isabel and expected to become even more favorable as she approaches the Carolina coast...if the hurricane recieves the same shot of convective energy crossing the gulf stream as Andrew, Bertha, and Emily did: watch out Morehead City to Virginia....because the cat-2 will be a strong cat-3...possibly cat-4. :o

I now wonder if hurricane Hazel looked the same way -- and exploded over the gulf stream just before slamming into Myrtle Beach and Wilmington? Without satellite and radar at that time, we may never know (there was recon by the military in 1954, but it was used sparingly. In 1969, only three penetrations of hurricane Camille's eyewall were made in the 48 hours she took to cross the GOM from western Cuba to Mississippi).

This situation with hurricane Isabel is potentially disasterous....and we may not know if, and how much she'll "blow up" in sustained wind speed while crossing the gulf stream UNTIL she's coming ashore -- making it even more imperative for EVERYONE on the Outer Banks and barrier islands southwestward to New Topsail Beach be off those islands as soon as possible.

#2 Postby **JtSmarts** » Wed Sep 17, 2003 5:13 pm

Bad News For NC if it does play out this way.

#3 Postby **wxman57** » Wed Sep 17, 2003 5:20 pm

I think the problem is in the lower levels. The most likely reason why winds aloft are not building to the surface is the layer of cooler air being entrained into the southwest quadrant of the storm. That's why there is no longer any convection near the center this afternoon. See the latest IR imagery:

http://home.houston.rr.com/wx/isabelir.gif

Without convection at the center, it'll be hard for Isabel to intensify. The center is now a 100+ mile wide area of nothing but cirrus and mid-level clouds.

soonertwister · #4 Postby **soonertwister** » Wed Sep 17, 2003 5:21 pm

JetMaxx, that IS alarming. Franklin says it in such a matter of fact way, you almost wonder if he is mentally processing the concept of mid-level spin-down of these more intense winds!

I really think you are onto something there, and I fervently hope that doesn't happen at the same time.

What would people think if the hurricane suddenly arrived on shore with 140 mph winds 150 miles across? Too scary to even imagine.

Anonymous · #5 Postby **Anonymous** » Wed Sep 17, 2003 5:21 pm

I guess I can understand their reluctance to upgrade it to a Cat 3 for now (because the winds are not there at the surface), but I am confused as to why they dropped the wind speed by 5 mph earlier. I think the general population (not the people reading this board) already overestimate the difference between a Cat 3 and a Cat 2 and dropping the wind speed makes people think the storm is weakining -- when in fact it has gained strength -- at least in its upper levels. I hope I am making sense here.

Rainband · #6 Postby **Rainband** » Wed Sep 17, 2003 5:22 pm

wxman57 wrote:I think the problem is in the lower levels. The most likely reason why winds aloft are not building to the surface is the layer of cooler air being entrained into the southwest quadrant of the storm. That's why there is no longer any convection near the center this afternoon. See the latest IR imagery:

http://home.houston.rr.com/wx/isabelir.gif

Without convection at the center, it'll be hard for Isabel to intensify. The center is now a 100+ mile wide area of nothing but cirrus and mid-level clouds.

Looks like a sub-tropical storm.. Is it losing it's tropical characteristics due to the dry cool air??

HuffWx · #7 Postby **HuffWx** » Wed Sep 17, 2003 5:35 pm

Nice post PW...

Such a conundrum this storm is...much confounding data.

If the lower levels pull together...Watch out!

Huff

JCT777 · #8 Postby **JCT777** » Wed Sep 17, 2003 5:58 pm

Perry - that is interesting. Not sure if Isabel will be able to strengthen a lot, but it certainly is possible and worth watching.

southerngale · #9 Postby **southerngale** » Wed Sep 17, 2003 6:10 pm

Wow! Do ya'll really think Isabel could strengthen that much before landfall??? :o

But what about that dry/cooler air that some have mentioned is being entrained into Isabel?

Stormsfury · #10 Postby **Stormsfury** » Wed Sep 17, 2003 6:23 pm

Good post, Perry.

The northern eyewall flank is generating new convection as I type.

SF

PTrackerLA · #11 Postby **PTrackerLA** » Wed Sep 17, 2003 7:55 pm

That new blow up is already fading, it will be interesting to see if we have a big blow up overnight, if so, watch out NC!

Wolfman21 · #12 Postby **Wolfman21** » Wed Sep 17, 2003 8:25 pm

Man, this storm really confuses me. I am a HUGE fan of meteorology and anything that goes along with weather. I am just AMAZED by it. I love seeing you guys talk about it, and you have usually been right on. I hope this thing doesnt increase in strength or move any farther inland NC than it is.... cuz if it does, im in trouble.

huricanwatcher · #13 Postby **huricanwatcher** » Wed Sep 17, 2003 8:26 pm

Wolfman21 wrote:Man, this storm really confuses me. I am a HUGE fan of meteorology and anything that goes along with weather. I am just AMAZED by it. I love seeing you guys talk about it, and you have usually been right on. I hope this thing doesnt increase in strength or move any farther inland NC than it is.... cuz if it does, im in trouble.

more inland the less intense it gets....... let it stay away from the coast and head inland...... deep west before north...... sorry just my opinion.....
and lookin out for that eastern shore.. :wink:

Wolfman21 · #14 Postby **Wolfman21** » Wed Sep 17, 2003 8:28 pm

huricanwatcher wrote:
Wolfman21 wrote:Man, this storm really confuses me. I am a HUGE fan of meteorology and anything that goes along with weather. I am just AMAZED by it. I love seeing you guys talk about it, and you have usually been right on. I hope this thing doesnt increase in strength or move any farther inland NC than it is.... cuz if it does, im in trouble.

more inland the less intense it gets....... let it stay away from the coast and head inland...... deep west before north...... sorry just my opinion.....
and lookin out for that eastern shore..

Understandable..... but im lookin out for my own @$$ too..... :lol:

5 p.m. NHC discussion is cause for concern..

5 p.m. NHC discussion is cause for concern..

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