Jump to content
  • Member Statistics

    17,586
    Total Members
    7,904
    Most Online
    LopezElliana
    Newest Member
    LopezElliana
    Joined

Tropical Storm Leslie - Discussion, Images, Forecasts


Recommended Posts

  • Replies 348
  • Created
  • Last Reply

If the euro stays the same or comes west at 0z, you should raise those odds to 1 in 100, 1 in 25 for Canada.

I honestly meant to put "Evening" odds!!! Didn't realize I put morning till now. Screwed up because it is always "morning line" or "morning favorite" But I agree, if the Euro holds serve then the odds will increase significantly.

Link to comment
Share on other sites

Before automatically dismissing movement back Eastward, looking at both vis imagery through sunset and false color IR imagery, there is a definite circulation in the convection SE of the LLC, and a center reformation to the East and Southeast seems a definite possibility.

Wouldn't get it back to 60ºW, but could get it close.

Link to comment
Share on other sites

^^

Not sure I can agree with that yet.

In my opinion, the center is still on the NW end of the convection due to heavy shearing.

swir-animated.gif

The LLC was located Northwest of the deep convection at sun down. Probably still is. But the convection is quite vigorous, and has suggestion of its own circulation. What I was saying, I don't think it is impossible the LLC visible at sundown doesn't die overnight as a new LLC forms downshear under the storms.

Link to comment
Share on other sites

Euro salmost always overdoes storms at this lattitude. It probably goes into a positive feedback loop when the outflow meetsup with the Jetstreak. In reality the Jetstresak may help the storm, but it will create some shear and displace the anticyclone so the intensity will be a lot weaker.

Link to comment
Share on other sites

From the shortwave IR, it looks the LLC may have drifted slightly east over the past 6 hours or so...but the convection is still located on it's SE flank. SHIPS has increased shear in the short term on the 00z cycle but intensification begins at 18 hours as shear relaxes. It now tops out at 91 kt at 108 hours.

Link to comment
Share on other sites

GFS came in more west than previous runs. Leslie stays offshore though. Seems like there was more ridging on this run.

The GFS now cuts off a part of the upper level trough over the Southeast United States with the entire height field over the Northeast US subsequently displaced farther north and west. To a less extreme extent than the 12z Euro from 9/3, but the idea is there. This allows Leslie to move more northwest as the Atlantic Ridge builds slightly farther north and west over the top of her.

You can see the differences between the 18z/3 and the 00z/4 GFS very clearly when comparing the two here:

http://www.meteo.psu.edu/~gadomski/AVN_0z/f144.gif

http://www.meteo.psu.edu/~gadomski/AVN_18z/f150.gif

Link to comment
Share on other sites

That cut-off has to go big negative for Leslie to even sniff the northeast. This pattern would cut it if it were in the Bahamas...but it's so far northeast.

Yeah...her position at the time of the cutoff gives her very little chance to landfall on the East Coast. I would think, if the most anomalous solution happens...that she would be a threat to Eastern Canada.

Link to comment
Share on other sites

The key player in this track evolution is not the impeding trough in the long range, but actually the mid level ridge in the 48-96 hour period. This again is the period where the GFS has had difficulty forecasting enough mid level ridging. We saw this with Isaac in the absence of an upper level trough and we are seeing it again with Leslie. While I still believe Leslie has a very low chance of affecting the US other than high surf... The threat for the Canadian maritimes and Bermuda has increased substancially.

I do think that both the GFS and ECMWF are over forecasting intensity. Upwelling has got to be occurring in such a low OHC environment over the next 72 hours and that's something none of the global models will have a good handle on.

Link to comment
Share on other sites

The key player in this track evolution is not the impeding trough in the long range, but actually the mid level ridge in the 48-96 hour period. This again is the period where the GFS has had difficulty forecasting enough mid level ridging. We saw this with Isaac in the absence of an upper level trough and we are seeing it again with Leslie. While I still believe Leslie has a very low chance of affecting the US other than high surf... The threat for the Canadian marigolds and Bermuda has increased substancially.

I do think that both the GFS and ECMWF are over forecasting intensity. Upwelling has got to be occurring in such a low OHC environment over the next 72 hours and that's something none of the global models will have a good handle on.

How about the Canadian pines?

Link to comment
Share on other sites

Archived

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

  • Recently Browsing   0 members

    • No registered users viewing this page.

×
×
  • Create New...