Hurricane Earl

[WxWatcher007]

This evening the NHC designated the broad area of low pressure in the central Atlantic Invest 91L.

This began as a complex interaction between the most vigorous African wave of the season thus far (top), and a feature in the monsoon trough (bottom).

There was growing consensus in development in the ensembles, and that is slowly being realized as the two features in the August 25th image above began to interact and form the broad low we see this evening. 

 

There is strong consensus on the guidance that this becomes a tropical cyclone in the next five days, with the Euro operational model and ensembles showing tropical cyclone genesis in the next 48-72 hours. The other guidance also shows development, increasing confidence that despite the omnipresent dry air that has dominated the Atlantic, this area has the best odds yet to overcome and develop. 

The ensemble guidance and operational models, once again led by the Euro, show a potentially favorable environment as the low reaches the SW Atlantic. It is early to discuss track guidance as we do not have a well-defined low yet, but for now at least, long range guidance suggests ridging in the Pacific Northwest that may allow for troughing to keep this one away from the US coast.

Again, very early and not worth much discussion yet IMO. 

The first step is development, and we will see if this gradual organization over the course of the day and evening convective activity allows for us to break the named storm drought. 

 

[Windspeed]

Humble beginnings aren't unusual in this region of the MDR. Despite the anemic appearance, the envelope of the wave is quite large due to folding out of the eroded monsoonal trough / interaction with the AEW. The disturbance also has a nice buffer from subtropical arid airmass. These factors should allow it to at least maintain into more favorable environmental conditions further west if not continued slow organization. I think the ECMWF and its enemble suites are going to beat out the GFS on not only genesis but ultimately downstream intensity due to the latter's mishandling of synoptic forcing from a Caribbean system that doesn't appear to be evolving.

[Ed, snow and hurricane fan]

SHIPS isn't impressed, although it uses data from a model that doesn't think much of it.  https://ftp.nhc.noaa.gov/atcf/stext/22082800AL9122_ships.txt

[WxWatcher007]

Just updated the OP to provide a little more context. 

[NorthHillsWx]

Overall guidance has trended downward in regards to intensity with 91L. There are still some strong solutions but the interaction with the TUTT seems to be trending towards a less favorable look, even in the EPS guidance which had a very favorable environment east of the Bahamas yesterday. My best guess is the low that had been shown to form north of the system along the trough is no longer present allowing the TUTT to extended further south that previously shown. Other observations from morning guidance definitely has trended further west with weaker solutions, with stronger solutions trending towards a recurve. Low level steering is generally east-west but the trough that previously had shown LP development to the north of 91L, with HP rebuilding west behind it, is now just a trough. This would be the escape path out to sea with a stronger/deeper system. It also shows shear as low level steering and mid level flows are at odds. Long story short, 91L has a questionable future for intensity and track, but I am very confident it will become a NS around 60W. Beyond that, I think guidance has trended weaker overall and future path options will hinge on intensity, LP development to the north along the trough, and where a LP center eventually forms for 91L.

[Ed, snow and hurricane fan]

Looking at vis satellite, it doesn't look that far from being a TC.

[Superstorm93]

ASCAT pass was certainly more impressive than I would have guessed. Not too far from becoming a depression, but dry air may prolong this process for at least 48 hours. 

 

[Ed, snow and hurricane fan]

 

 

[GaWx]

 12Z UKMET:

 TROPICAL DEPRESSION 91L        ANALYSED POSITION : 13.9N  44.3W

     ATCF IDENTIFIER : AL912022

                        LEAD                 CENTRAL     MAXIMUM WIND
      VERIFYING TIME    TIME   POSITION   PRESSURE (MB)  SPEED (KNOTS)
      --------------    ----   --------   -------------  -------------
    1200UTC 28.08.2022    0  13.9N  44.3W     1009            35
    0000UTC 29.08.2022   12  14.1N  45.0W     1010            30
    1200UTC 29.08.2022   24  14.0N  46.9W     1010            27
    0000UTC 30.08.2022   36  14.0N  47.6W     1009            27
    1200UTC 30.08.2022   48  14.6N  48.3W     1008            26
    0000UTC 31.08.2022   60  14.7N  49.2W     1008            25
    1200UTC 31.08.2022   72  15.5N  50.6W     1008            26
    0000UTC 01.09.2022   84  16.1N  52.1W     1007            27
    1200UTC 01.09.2022   96  17.0N  54.1W     1007            28
    0000UTC 02.09.2022  108  17.8N  55.9W     1005            27
    1200UTC 02.09.2022  120  18.6N  58.4W     1005            29
    0000UTC 03.09.2022  132  19.6N  60.7W     1004            36
    1200UTC 03.09.2022  144  20.3N  62.9W     1003            36

[Superstorm93]

Best case for this one is very slow development over the next five days. Environment north of the Greater Antilles looks pretty favorable, if it survives. 

[NorthHillsWx]

ASCAT revealed that this system has successfully, though slowly, been organizing. However, visible, water vapor and IR imagery shows what the system is up against. On visible, numerous outflow boundaries can be seen from collapsed storms, indicating dry air. Further, on IR, it’s beginning to have “popcorn” storms on the NW side. A telltale sign of dry air in the formative circulation. Water vapor confirms the dry air it is moving into. Looking at IR, while you can’t see the formative surface circulation as you can on visible, you can see several areas of mid level rotation along the wave axis. This shows the system is still quite disorganized. Lastly, 91L for days has been able to generate constant deep convection as it was still associated with the monsoon trough and in a moist envelope. We’re just now seeing what life outside the monsoon trough will be like for the system, and it’s a similar story as everything else that’s traversed this part of the Atlantic, dry and sheared. This is taking a huge toll on the convective envelope of the system right now.

91L has a couple things working for it previous waves didn’t:

1) it’s the furthest west a wave has made it in a very long time without being obliterated 

2) north of the islands looks, to different degrees, favorable for development 

3) it has a formulative center, and being able to keep some of this organization will help it take advantage of a more favorable environment in a few days, if it can

I think the system’s initial development has been capped as of this morning when it entered the hostile conditions currently affecting it. These hostile conditions should stop any continued organization for at least the next 2 days. Beyond that, this will be a named storm, finally

[ldub23]

Hopefully this  will be the  1 storm of the season. Can it survive the  next  5 days?

[cptcatz]

Very interesting last frame of the Euro model... intensifies from 986 to 973 while moving southwest. 

[marsman]

7 minutes ago, cptcatz said:

Very interesting last frame of the Euro model... intensifies from 986 to 973 while moving southwest. 

 

Andrew-esque

[Kevin Reilly]

9 minutes ago, marsman said:

Andrew-esque

Katrina did the same thing over the everglades moved southwest then resumed a west then northwest turn. 

[hawkeye_wx]

20 minutes ago, cptcatz said:

Very interesting last frame of the Euro model... intensifies from 986 to 973 while moving southwest. 

The steering current collapses as the storm reaches the sw Atlantic, so it is just slowly meandering at this point.

[WxWatcher007]

23 minutes ago, hawkeye_wx said:

The steering current collapses as the storm reaches the sw Atlantic, so it is just slowly meandering at this point.

I know it’s still extremely early, but it just seems to me if the steering pattern collapses this one goes OTS. 

[wxeyeNH]

1 hour ago, WxWatcher007 said:

I know it’s still extremely early, but it just seems to me if the steering pattern collapses this one goes OTS. 

Dorian kind of did the same thing.  Came to a crawl over the Bahamas before it turned NE and weakened.  If that storm had made it a bit further west it would have destroyed the Gold Coast of Florida.  Hopefully we never see that situation happen.

[bigtenfan]

2 hours ago, cptcatz said:

Very interesting last frame of the Euro model... intensifies from 986 to 973 while moving southwest. 

Interesting solution. It does not appear to have any other model support even from it's own ensembles. Keep in mind that this was the same model that yesterday at this time had this doing a virtual 90 degree right turn to the NE.

[GaWx]

2 hours ago, WxWatcher007 said:

I know it’s still extremely early, but it just seems to me if the steering pattern collapses this one goes OTS. 

Based on many of the EPS members also slowing down nearby at 240 hours with similar H5 and then mainly recurving safely offshore the US once resuming movement after 240, I agree with you that the storm would very likely have done what you said (safely OTS) had the 12Z Euro gone past 240 hours. You can also kind of tell by looking over N America at H5/sfc at 240.

 But this is merely speculation on what's already very speculative, the 240 hour position on an operational run. Things will surely change quite a bit over the next few days even though as of this moment staying OTS has a slight advantage imho.

[Ed, snow and hurricane fan]

18Z GFS still has fantasy TC developing which might change steering, but seems like more data is helping.

[Floydbuster]

 

Getting out to sea vibes, but I've also seen invest models like this wind up in Veracruz.

[cptcatz]

38 minutes ago, Floydbuster said:

 

Getting out to sea vibes, but I've also seen invest models like this wind up in Veracruz.

Hurricane Grace just last year. Big miss by the early models. 

[WxWatcher007]

10 minutes ago, cptcatz said:

Hurricane Grace just last year. Big miss by the early models. 

Oh yeah, Grace was one that was supposed to have a high ceiling on the guidance and come more north early on in the but it muddled along right up to the western Caribbean and plowed straight west as the track there shows. 

[LongBeachSurfFreak]

The steering current collapses as the storm reaches the sw Atlantic, so it is just slowly meandering at this point.

That would be a dream scenario for east coast surfers. Prolific swell producer with no landfall worries. One thing is for sure, plenty of untouched warm waters to feed off of


.

[SnowenOutThere]

Currently is looking a little rough on IR view. 

[GaWx]

3 hours ago, SnowenOutThere said:

Currently is looking a little rough on IR view. 

Convection popping back some as we approach DMAX.

[GaWx]

1. 0Z GFS no phantom H and yet this still recurves OTS from US.

2. Only ~10% of members from last 3 GEFS runs hit FL with a TC.

3. 0Z UKMET:

  TROPICAL DEPRESSION 91L        ANALYSED POSITION : 14.1N  45.7W

     ATCF IDENTIFIER : AL912022

                        LEAD                 CENTRAL     MAXIMUM WIND
      VERIFYING TIME    TIME   POSITION   PRESSURE (MB)  SPEED (KNOTS)
      --------------    ----   --------   -------------  -------------
    0000UTC 29.08.2022    0  14.1N  45.7W     1010            28
    1200UTC 29.08.2022   12  13.9N  47.4W     1010            26
    0000UTC 30.08.2022   24  14.2N  49.1W     1010            24
    1200UTC 30.08.2022   36  13.7N  50.0W     1010            24
    0000UTC 31.08.2022   48  14.2N  50.2W     1008            23
    1200UTC 31.08.2022   60  15.2N  50.9W     1009            25
    0000UTC 01.09.2022   72  15.8N  52.5W     1008            25
    1200UTC 01.09.2022   84  16.9N  54.4W     1007            28
    0000UTC 02.09.2022   96  17.6N  56.5W     1007            26
    1200UTC 02.09.2022  108  18.9N  58.5W     1006            29
    0000UTC 03.09.2022  120  19.3N  60.9W     1006            35
    1200UTC 03.09.2022  132  20.0N  62.8W     1007            36
    0000UTC 04.09.2022  144  20.8N  64.3W     1006            38

[StormchaserChuck!]

90% for 4 days, and 88%day3

[Windspeed]

91L is an elongated mess right now with competing clusters of storms. There no longer appears to be any minimally organized surface vorticity with either cluster and just an overall broad SWrly to NErly stretched surface low. Until some deeper convection can concentrate along the axis somewhere and spawn a tighter vortmax, all we've got are the globals that simulate genesis. But these may be far off from where the actual point/location of TCG occurs IRL, if at all. So it might be best to consider and remind of the great uncertainty with any track guidance, as a 200 mile difference from TCG in the NE region of the wave is going to be modeled substantially different than TCG occurring in the SW most region of the wave, with varying degrees of resolved guidance.