ATL: MARIA - Models

[wxmann_91]

I don't get what's in doupt? Jose hangs on long enough to produce enough of a weakness for Maria to head north. Most models as of today in rather good agreement of this outcome. Hoping it continues

Isn't it supposed to be a strong ridge though? How can the remnants of Jose have that much of an affect on it to open an escape route for Maria.

Because it's a high-latitude ridge. Jose and an ULL over the Southeast U.S. will push Maria north. The question is what happens after it gets far enough north. Without Jose, the high-latitude ridge prevents Maria from recurving to the east. With Jose, that route is opened up.

[Dean4Storms]

I don't get what's in doupt? Jose hangs on long enough to produce enough of a weakness for Maria to head north. Most models as of today in rather good agreement of this outcome. Hoping it continues

But to keep the weakness you need convection and between up welling, no oceanic heat content anywhere near 80F and SST's in the 60's to low 70's how does Jose continue to produce thunderstorms from Tuesday to Sunday?

[Alyono]

There is one other BIG thing the models may be missing

They are NOT indicating enough weakening over the DR. This isn't going to spend 12 hours over the DR and still be a cat 3. If this hits the DR, even as a cat 4 or a 5, it is going down to a 1 or a TS, just like David did in 1979

[jlauderdal]

I don't get what's in doupt? Jose hangs on long enough to produce enough of a weakness for Maria to head north. Most models as of today in rather good agreement of this outcome. Hoping it continues

Their solutions in 10 days don't make sense on how they resolve the atmosphere...maybe maria misses but it wont be because it plows through a ridge or mysteriously a ridge vanishes

[Ken711]

I don't get what's in doupt? Jose hangs on long enough to produce enough of a weakness for Maria to head north. Most models as of today in rather good agreement of this outcome. Hoping it continues

10 day ensemble probabilities favor a landfall more than out to sea. But out to sea is most certainly a viable track

Do you have any sense of the intensity of Maria at the time it makes a landfall assuming that happens? Do they expect it to ramp up intensity even if it has land interactions with the islands?

[Aric Dunn]

I don't get why people aren't realizing this more. This is not the subtropical EPAC, Jose will get injected with baroclinic energy that will allow it to maintain a mid-level reflection longer. That's all we need to steer Maria out.

That would only really work if it was moving and transitioning .. it will no be moving very fast over very cold water you can look at the upper synoptics over JOse at the time. not much forcing going on..

for instacne ( though not exactly the right map) you can see all the energy is long gone and well to the north.. nothing to keep it as strong as the models are showing ... unless the models have the water temps all wrong..

[im g]https://www.tropicaltidbits.com/analysis/models/gfs/2017091718/gfs_shear_atl_18.png[/img]

Jose is under the right-entrance region of a 200mb jet, which will help with outflow and ascent near the storm center. This looks more like a recipe for extratropical transition than slow degradation into a remnant low.



I think the GFS is overdone as usual, but it's difficult to discount many runs of the Euro and GFS that indicate Jose will steer Maria. It's still a tossup to what extent, but the idea at least, has merit.

your forgetting that even if it had ideal conditions ITS SITTING OVER 60 degree water ! the models are showing a warm core system and some with a hurricane for days ! not possible.

[Aric Dunn]

There is one other BIG thing the models may be missing

They are NOT indicating enough weakening over the DR. This isn't going to spend 12 hours over the DR and still be a cat 3. If this hits the DR, even as a cat 4 or a 5, it is going down to a 1 or a TS, just like David did in 1979

or Jeanne..

[wxmann_91]

That would only really work if it was moving and transitioning .. it will no be moving very fast over very cold water you can look at the upper synoptics over JOse at the time. not much forcing going on..

for instacne ( though not exactly the right map) you can see all the energy is long gone and well to the north.. nothing to keep it as strong as the models are showing ... unless the models have the water temps all wrong..

[im g]https://www.tropicaltidbits.com/analysis/models/gfs/2017091718/gfs_shear_atl_18.png[/img]

Jose is under the right-entrance region of a 200mb jet, which will help with outflow and ascent near the storm center. This looks more like a recipe for extratropical transition than slow degradation into a remnant low.

[im g]https://i.imgur.com/XKfaCDC.png[/img]

I think the GFS is overdone as usual, but it's difficult to discount many runs of the Euro and GFS that indicate Jose will steer Maria. It's still a tossup to what extent, but the idea at least, has merit.

your forgetting that even if it had ideal conditions ITS SITTING OVER 60 degree water ! the models are showing a warm core system and some with a hurricane for days ! not possible.

I think you're missing my point here. Obviously it's not going to be warm core anymore -- and the GFS is completely wrong in this regard. But there will be a leftover entity that remains in the TC steering layers of the atmosphere. That's what's important. Whether that's tropical, extratropical, hybrid, whatever doesn't matter. What matters is how it perturbs the steering flow to the north of Maria that would otherwise be favorable for a U.S. landfall because of the big blocking high over the Great Lakes.

[Aric Dunn]

Jose is under the right-entrance region of a 200mb jet, which will help with outflow and ascent near the storm center. This looks more like a recipe for extratropical transition than slow degradation into a remnant low.

[im g]https://i.imgur.com/XKfaCDC.png[/img]

I think the GFS is overdone as usual, but it's difficult to discount many runs of the Euro and GFS that indicate Jose will steer Maria. It's still a tossup to what extent, but the idea at least, has merit.

your forgetting that even if it had ideal conditions ITS SITTING OVER 60 degree water ! the models are showing a warm core system and some with a hurricane for days ! not possible.

I think you're missing my point here. Obviously it's not going to be warm core anymore -- and the GFS is completely wrong in this regard. But there will be a leftover entity that remains in the TC steering layers of the atmosphere. That's what's important. Whether that's tropical, extratropical, hybrid, whatever doesn't matter. What matters is how it perturbs the steering flow to the north of Maria that would otherwise be favorable for a U.S. landfall because of the big blocking high over the Great Lakes.

fair enough.... but the models are showing a warm core.. the issue is more of how ? and why ? and not what it is.. it is that "we" are assuming the models are correct. its a warm core.. so warm core.. coold water == ( similar to epac when they hit the cooold water) ... noting but a shallow cloud swirl within 24 to 36 hours.. not sitting for 3 days mainitaing convecion..

[Aric Dunn]

Now if we want to sit here and speculate if it is going to transition well.. looking at jose now... I would lean towards yes.. however even if it does once it is left behind there is little to nothing to support a vertically deep system of any kind..

and that is one of the issues the models are having and everyone looking at them..

[wxmann_91]

your forgetting that even if it had ideal conditions ITS SITTING OVER 60 degree water ! the models are showing a warm core system and some with a hurricane for days ! not possible.

I think you're missing my point here. Obviously it's not going to be warm core anymore -- and the GFS is completely wrong in this regard. But there will be a leftover entity that remains in the TC steering layers of the atmosphere. That's what's important. Whether that's tropical, extratropical, hybrid, whatever doesn't matter. What matters is how it perturbs the steering flow to the north of Maria that would otherwise be favorable for a U.S. landfall because of the big blocking high over the Great Lakes.

fair enough.... but the models are showing a warm core.. the issue is more of how ? and why ? and not what it is.. it is that "we" are assuming the models are correct. its a warm core.. so warm core.. coold water == ( similar to epac when they hit the cooold water) ... noting but a shallow cloud swirl within 24 to 36 hours.. not sitting for 3 days mainitaing convecion..

NWP has gone through numerous iterations of improvement and have years of verification statistics behind them that show how good they are. They're products of thousands upon thousands of man-hours of research and coding. It's by far our "best guess" that our minds by ourselves could not conceivably make. I think it's fair to start with models and, with awareness of their biases and shortcomings, make tweaks to the forecasts. In this case, we are aware the limitations of the parameterizations of warm core processes, but we realize that in general, the layout of how things can unfold makes sense.

[Ken711]

There is one other BIG thing the models may be missing

They are NOT indicating enough weakening over the DR. This isn't going to spend 12 hours over the DR and still be a cat 3. If this hits the DR, even as a cat 4 or a 5, it is going down to a 1 or a TS, just like David did in 1979

It looks like from the NHC track it's expected to track just to the north of DR.

[LarryWx]

Jose is under the right-entrance region of a 200mb jet, which will help with outflow and ascent near the storm center. This looks more like a recipe for extratropical transition than slow degradation into a remnant low.

[im g]https://i.imgur.com/XKfaCDC.png[/img]

I think the GFS is overdone as usual, but it's difficult to discount many runs of the Euro and GFS that indicate Jose will steer Maria. It's still a tossup to what extent, but the idea at least, has merit.

your forgetting that even if it had ideal conditions ITS SITTING OVER 60 degree water ! the models are showing a warm core system and some with a hurricane for days ! not possible.

I think you're missing my point here. Obviously it's not going to be warm core anymore -- and the GFS is completely wrong in this regard. But there will be a leftover entity that remains in the TC steering layers of the atmosphere. That's what's important. Whether that's tropical, extratropical, hybrid, whatever doesn't matter. What matters is how it perturbs the steering flow to the north of Maria that would otherwise be favorable for a U.S. landfall because of the big blocking high over the Great Lakes.

This! Also, just because there's a strong ridge one day doesn't mean that that ridge can't start weakening pretty quickly. Ridges and troughs strengthen and weaken constantly as nothing is even close to remaining stable for long periods. An eroding ridge is nothing extraordinary.

[wxmann_91]

your forgetting that even if it had ideal conditions ITS SITTING OVER 60 degree water ! the models are showing a warm core system and some with a hurricane for days ! not possible.

I think you're missing my point here. Obviously it's not going to be warm core anymore -- and the GFS is completely wrong in this regard. But there will be a leftover entity that remains in the TC steering layers of the atmosphere. That's what's important. Whether that's tropical, extratropical, hybrid, whatever doesn't matter. What matters is how it perturbs the steering flow to the north of Maria that would otherwise be favorable for a U.S. landfall because of the big blocking high over the Great Lakes.

This! Also, just because there's a strong ridge one day doesn't mean that that ridge can't start weakening pretty quickly. Ridges and troughs strengthen and weaken constantly as nothing is even close to remaining stable for long periods. An eroding ridge is nothing extraordinary.

Yeah, I forgot to mention the timing aspect of this -- that Great Lakes ridge will start breaking down in time. Even if Jose doesn't totally turn Maria OTS, it can slow it from steamrolling NW towards the Carolinas for just long enough that by the time Jose dissipates, the ridge is no longer in a position to steer Maria into the CONUS.

[BlowHard]

I had to double check to see if I had accidentally clicked on the JOSE discussion....

[Digital-TC-Chaser]

http://rammb.cira.colostate.edu/product ... 1709171200

A few wobbles in the track and who knows at this point of time the eventual track solution.

[chaser1]

Logically, your post makes sense. But ALL models flubbing this? Seems very unlikely

the strength of jose over that water temp? yes.. all we need to do is look at the eastern pacific when a full on hurricane moves nw hits the cold current and dies down to nothing but a low level swirl with zero convection within 24 two 36 hrs.. the models have jose over cold temps for longer..

But all it takes sometimes is a little weakness in a 500 mb ridge to allow for a TC to move north into it.

That is generally SO true, however i'm beginning to theorize that during those seemingly less common years where the entire long wave set-up is entirely different, that in fact strong ridging becomes a more dominant factor where recent weeks/months have proven such a pattern to reoccur. The dominant CONUS east coast trough seems to be anchored further east of Greenland and while we have seen some impressive sharp troughs drop south from the Central Plains or Great Lakes, their energy just as quickly seem to pull back up and into the progressive Westerlies. The few troughs we've seen inside the U.S. Coastline over the recent months, have seemingly been quite a bit more tilted WSW then most years and often coinciding with substantial W. Atlantic ridging poking into the SE CONUS. Of course we're moving toward late September and Climo conditions will begin toward subtle changes as we approach the beginning of Fall (Sept 22). I am also a big believer that each hurricane season presents a certain pattern(s) that impact points of origin and their overall tracks. I'm not suggesting that there won't be one or more tropical systems that'll simply re-curve out to sea, but I'm inclined to believe that the long wave pattern as such this season will have Maria generally take a path that will be somewhat similar to Irma with Jose another reasonable candidate for a (weaker) U.S. threat as well.

[RL3AO]

This really is a "Bahamas to Florida to Newfoundland to Bermuda should watch" situation. Too much uncertainty with two tropical cyclones, a upper trough over Florida, and two ridges on either side of the trough. The location of Maria in 8 or 9 days cannot be predicted with any skill.

[AutoPenalti]

This really is a "Bahamas to Florida to Newfoundland to Bermuda should watch" situation. Too much uncertainty with two tropical cyclones, a upper trough over Florida, and two ridges on either side of the trough. The location of Maria in 8 or 9 days cannot be predicted with any skill.

Amazing how fluid our weather is, the little things matter the most in scenarios like these.

[gatorcane]

I have a hard time seeing Florida at the moment. The global models are in too good agreement on a recurve well east of Florida and they really haven't been deviating much from this. Jose doesn't seem to be going anywhere anytime soon.

Latest 18Z GFS ensembles. Pretty good agreement here: