Jump to content

  • Member Statistics

    17,587
    Total Members
    7,904
    Most Online
    LopezElliana
    Newest Member
    LopezElliana
    Joined

NE Tropical Thread

free_man

By free_man,
in New England

Recommended Posts

  • Replies 1.6k
  • Created
  • Last Reply
Ed Lizard

Ed Lizard

Posted
Posted

I think I posted a link to it, a study for ChinaCanes, regression, Poisson stuff or whatever (some pople think fish, I guess it is some kind of regression analysis method, but I'll always think of the Greek letter nu and mechanical properties of rocks), and OHC is more important than skin SST temps. For typhoons.

But I was always suspected, a storm moving with sufficient alacrity, that it didn't spend much time over the cooler water upwelled, would be less affected by shallow warm water than a slower storm. A hurricane like Mitch, a slow moving Cat 4 or 5, would never happen in the Gulf. Yet the Gulf does see Cat 4 storms, and even an occasional Cat 5 storm.

The 26º one meter temps at the Islip buoy may be paper thin, but a storm moving quickly won't have too much time to experience colder upwelled water. And even if OHC is the be all and end all, a fast moving storm still won't spend much time over water beyond the Gulf Stream. And that 26º at Islip may not be paper thing (see below).

And I'll leave it up to the degreed experts to tell us how the introduction of baroclinic forcing can initially compensate for decreasing ocean energy beneath a storm.

2012228atd26.png

Link to comment
Share on other sites
ORH_wxman

ORH_wxman

Posted
Posted

Baroclinic forcing will often expand the higher winds outward but I don't think it would help the core...when a storm starts taking on baroclinic processes, it is going from warm core to cold core and extra tropical.

But yeah, it can really enhance some of the winds outside of the core initially if it goes right.

Link to comment
Share on other sites
CT Rain

CT Rain

Posted
Posted

I posted the SST anomalies more in regard to the expansive +1.5-+3 and even higher across the Maritimes.

It is impressive.

SSTs I think in general really aren't important up here. I think they're much more important between HSE and the Bahamas. Getting a storm strong enough near HSE (cat 4, preferably) followed by a very strong baroclinic assist with a digging/super anomalous cut off low with strong downstream ridging is key to getting a hurricane north.

However, there are cases where anomalous SSTs could be important. A Bob or Edouard kind of storm has the potential to be stronger when the baroclinic assist is rather meh and the storm isn't rocketing north.

Link to comment
Share on other sites
Typhoon Tip

Typhoon Tip

Posted
Posted

This should be appreciated.. TC and zygote TC moving around the periphery of semi-permanent subtropical ridge axis.

post-904-0-71835100-1345313886_thumb.jpg

Currently the NAO is negative, which initially is favorable for transporting TCs generally westward where, what is likely to soon be designated an Invest (if not direct to depression) is currently located; near 14N/12W, moving west. Broad cyclonic motion in on-going convection is noted. This wave had some apparent closed cyclonic structure already as it was leaving the African continent. A -NAO would promote a general westward motion until approximately 55W, where -NAO teleconnects to a polarward shift in steering should likely induce an early re-curvature over the open Atlantic. However, the prognostic from CPC indicates that the NAO is at present in a nadir, and will abruptly begin rising toward neutral during the next week. That conceptually supplies some argument that the position of the subtropical ridge currently dictating the west motion will reposition westward through the 55W longitude; and that appears in most operational guidance to collocate spatial-temporally with the positions(s) of the impulse.

In short hand that relay suggests a Cape Verdi system with perhaps enhanced probability of succeeding 55W before moving N of 30N.

There may be longer terms statistical applications that argue for support and not given this gyre's initial position. This is the current teleconnector layout peering out across the next 7 to 10 days.

There is another reason this is an interesting system to track. Currently the 200mb velocity anomalies have basin wide entered positive, which generally submits a better genesis regime. There are other tools; the Roundy Probabilities, on the other hand, are indicating that for the next 2 to 3 weeks the Basin is generally passing through a slight negative anomaly in overall TC production probability. I am not sure honestly how that product derives its probability field(s); since it is oft referenced by HPC longer term guidance, it would appear pragmatic to mention it here. So perhaps some conflict there. However, a negative bias in probability is not 0, either, so it may be less important. I think the real-time observation, combined with both the 200mb anomalies being favorable, as well as the general agreement in most operational guidance for this system to develop, may be more telling overall. The Euro is less developed.

Link to comment
Share on other sites
Typhoon Tip

Typhoon Tip

Posted
Posted

The 06z GFS almost deserves to be hung on the wall. Phil is blown out to sea, and then we all have a Labor Day Weekend frost.

This is not the place for this but I'm toying with cooler than normal autumn and early winter - well, cooler mid level heights than normal; whether that materializes at the thermometer houses, we'll see.

Link to comment
Share on other sites

Archived

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

Go to topic listing

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...