Jump to content
  • Member Statistics

    17,502
    Total Members
    7,904
    Most Online
    Weathernoob335
    Newest Member
    Weathernoob335
    Joined

Major Hurricane Irma


NJwx85

Recommended Posts

  • Replies 7.2k
  • Created
  • Last Reply
cdas-sflux_sst_watl_1.png&key=4487b354278ecd88101e2b6faef09f3beeb8e10df7ce479167d485ff84a7cebe

 

I mean they are well into the 80s until Cape Hatteras, a storm won't spin down that significantly the last 75 miles if verbatim this run were correct. At the speed it would be moving it would have maybe 6 hours not over 82 degree water. Not saying it is probable or likely or anything along that line, but I wouldn't completely rule it out at all especially if it is a strong cat 5 which there is a chance coming out of the Bahamas.

 

I'm not even focusing on the SSTs. I realize fast moving systems take time to wind down. But in this case, you would still have rapid pressure rise in an eyewall that is being undercut by a larger mid-latitudinal low/trough mid-level flow at that latitude. Perhaps Irma isn't going through baroclinic processes, but a sub 920 mb low making landfall into the Del/Penn/NJ is just pure fantasy. The same mechanics in the atmosphere to get the vortex at that position in the first place are also going to be significantly weakening it. Perhaps the surface pressure remains below 940 mb, but the intensity of an eyewall is disrupted to the extent that 155+ mph winds will not be sustained at sea level. That's why I think the GFS showing that intensity 850mb level down is garbage.

 

Link to comment
Share on other sites

2 minutes ago, Hoosier said:

Ok, is it like a 0.2% chance?  Sure, if we have a 175 mph storm right off the coast of North Carolina, then maybe it could hold on long enough as it headed north.  

Now even though it is unlikely and never been recorded, I would be less dismissive of a category 5 being able to occur in the Carolinas.  In theory...

Dismissive of a cat 5 in the carolinas? We've had 5's and 4's it isn't historically abnormal.

Link to comment
Share on other sites

21 minutes ago, Derecho! said:

It has nothing to do with the dust. It's the low humidity of the air that carries the dust. Dumping dust into humid air would do jack diddly.

So you need a plan to dehumidify millions of cubic miles of air. Good luck with that. 

lol I see it gets really "entertaining" here late at night, people arguing over space bars and rainfall amounts and how far north Cat 5s can "go".....but since we're talking "experimental" stuff, how much energy would be required to generate enough wind shear to simulate how nature often weakens one of these storms?

*edit after reading what he said and what you said again, wouldn't dumping particulate matter into humid air just help to create condensation and thus cause more rain to fall ?

 

Link to comment
Share on other sites

12 minutes ago, Stebo said:

Honestly I would agree under normal circumstances, but seeing so many records fall all over the world over the last 15 years, gives me pause.

Same here, but a lot of those are precip records, which could be due to increased blocking (we see increased precip totals with winter events now too.)  To get  Cat 5 at that latitude requires more than just warm SST, you need an ideal no-shear environment, which is hard to do at these latitudes.  Heck, it's even hard to do in the tropics.  We haven't had many Cat 5s even in the near 90 bathwater of the GOM, Caribbean, etc.

Link to comment
Share on other sites

Just now, thewxmann said:

Man reading some of these comments I'd think that Cat 5's happened all the time in the Atlantic. Never mind that we went 9 years without one, much less one at 35N.

That's basically what I was saying.  You get very few of them even in the near 90 degree bathwater where they are "supposed" to happen.

Link to comment
Share on other sites

13 minutes ago, Windspeed said:

I'm not even focusing on the SSTs. I realize fast moving systems take time to wind down. But in this case, you would still have rapid pressure rise in an eyewall that is being undercut by a larger mid-latitudinal low/trough mid-level flow at that latitude. Perhaps Irma isn't going through baroclinic processes, but a sub 920 mb low making landfall into the Del/Penn/NJ is just pure fantasy. The same mechanics in the atmosphere to get the vortex at that position in the first place are also going to be significantly weakening it. Perhaps the surface pressure remains below 940 mb, but the intensity of an eyewall is disrupted to the extent that 155+ mph winds will not be sustained at sea level. That's why I think the GFS showing that intensity 850mb level down is garbage.

 

Yeah, I mean even when Sandy was a hurricane near the south NJ coast at 938 mb or so, it never even got to Cat 2.  In that position, its sustained winds were like 90 mph.

Link to comment
Share on other sites

Looking at the ocean temperature map it would seem as though the limit for a Category 5 would be at Virginia Beach fresh off the gulf stream weakening rapidly under perfect conditions. I would draw the line in the sand there, anything past that up the Delmarva or through the Chesapeake Bay just seems ridiculous. That has always been a question of mine just how high in latitude can a Category 5 major Hurricane get? Who knows, in the end the chances of Irma hitting as a Category 5 anywhere seems like a push. Let alone making land fall at all. I'm sure I along with many others sound like a broken record, and I lack the knowledge to make very insightful posts in terms of meteorology but I do know when a topic has been de-railed by a debate on the intensity 7-10 days out. I'm here to stay informed, offer my two cents, laugh a little, and learn. No one knows exactly what lies ahead, but I want to be one of the first who do know. ;)

Link to comment
Share on other sites

6 minutes ago, tim123 said:

But the wind field was huge. That's the reason. Low pressure but spread out hundreds of miles around it

 

6 minutes ago, tim123 said:

But the wind field was huge. That's the reason. Low pressure but spread out hundreds of miles around it

Yeah these things typically expand at our latitudes.  Conservation of momentum means the highest wind speeds are lower, but spread out over a larger area.

Surge can still be much higher though, as that is accumulated when the storm was stronger.

 

Link to comment
Share on other sites

1 hour ago, TriPol said:

I think new laws of physics apply because of the new climate we're living in. It's now possible to get a storm of that magnitude all the way up here and for Houston to get 50"of rain in one week. Scary.

Warning: This post is offered as an honest effort to mitigate some of the hyperbole, I've been reading, associated with "Irma" and the most recent long range model runs:   

I totally understand the excitement derived from these recent model runs suggestive of a prospective category-five hurricane on the East coast, N of Florida.  That said, I believe the probabilities of such an occurrence is closer to 0% than any other numerical figure.  Not only is there a significant decrease in OHC as one goes N of 30N, but the synoptics in the subtropics and mid-latitudes are much more hostile to TC's of major hurricane intensity (much less a category 4/5 deep H).   

Moreover, the increased size of a typical H above 30N requires a much deeper BP to sustain a pressure gradient tight enough to support category-five intensity.  As such, these extreme long range model runs, showing central pressures typical of a category 4/5, would more likely correspond to at least a full category, if not two, below that magnitude. Currently, "Hugo" is the most intense H (934 mb/120 kt/140 mph) to hit the US above 30N.  I most definitely believe the atmospheric/oceanic conditions can support a category-four intensity H up to 35N, in the right circumstances, but I highly doubt there is any reasonable atmospheric scenario whereby we will be witnessing a category-five landfall above 33 N.  And, probabilities aren't too great for such an eventuality above 31N, for that matter.  

As for the record-setting extreme rainfall produced by Harvey, one much recognize that the largest contributor to those 50" totals was the extended duration of the event: directly attributable to the agonizingly slow and erratic movement of the tropical system.  Such incredible rainfall rates aren't  as uncommon as they may otherwise appear.  For example, H "Camille" of 1969 went on to deliver an astounding 27.35" of rainfall in a single 8 hour period, as a tropical depression in central Virginia.  Amazingly,  officials believed that totals of 40" were a more accurate figure given that many rain gauges in the area were unable to handle such dramatic amounts,. while others, were simply washed away with the great floods they created.  

Regardless, it will be quite interesting to see if "Irma" can achieve an intensity remotely close to those 900 mb extremes over the open Atlantic, and whether or not, it ultimately makes a direct landfall on some portion of the US coastline.  Right now, it is still far too early for anyone to reasonably suggest, categorically, that there will be a MH landfall on the US East Coast.  Even 5 days out, from the presumed trajectory Irma will be traveling, it could just as easily recurve and miss the USA, altogether.  To clarify, I'm not suggesting that a MH landfall won't occur, but simply, that it's still too early to make any definitive conclusions.   Anyway, time will tell! 

 

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

Guest
This topic is now closed to further replies.
  • Recently Browsing   0 members

    • No registered users viewing this page.

×
×
  • Create New...