The 2017 Atlantic Hurricane Season Thread

[Superstorm93]

5 minutes ago, WxWatcher007 said:

Question: where do you find that info?

ftp://ftp.nhc.noaa.gov/atcf/btk/bal112017.dat 

[SomeguyfromTakomaPark]

Euro ensembles posted in the main thread, looks to be a good number of members turn it North before Florida with several heading up towards GA/SC/NC.

[Superstorm93]

https://twitter.com/Weathernerds/status/903345038356307968 

[MN Transplant]

NCAR's MPAS is GFS-like

 

[SomeguyfromTakomaPark]

4 minutes ago, Superstorm93 said:

https://twitter.com/Weathernerds/status/903345038356307968 

Seems like a pretty safe bet it's going to landfall somewhere in the U.S.  Only a few recurve.  

[SomeguyfromTakomaPark]

3 minutes ago, WxWatcher007 said:

Far from a safe bet IMO. If that ridge isn't as strong and that trough comes in at the right time or is stronger, this recurves. Matthew (though it did devastate NC), Joaquin, the list goes on and on. We're a ways out from being able to say with even moderate confidence that this is a real threat. 

If I had to place the percentages currently of a US landfall, I'd be at like 30%. Which is high, but not that high. 

Yeah you're right I guess it's still pretty far out into the future.  I might go a little higher with the odds though just because I usually don't lose if I go with the EPS over GEFS, maybe I'd go something like 40% or 45%.  

[ErinInTheSky]

Dunno if I missed this but...

 

 

[BTRWx]

41 minutes ago, DCTeacherman said:

Seems like a pretty safe bet it's going to landfall somewhere in the U.S.  Only a few recurve.  

Not necessarily

[WinterWxLuvr]

1 hour ago, DCTeacherman said:

Seems like a pretty safe bet it's going to landfall somewhere in the U.S.  Only a few recurve.  

[WinterWxLuvr]

59 minutes ago, WxWatcher007 said:

Far from a safe bet IMO. If that ridge isn't as strong and that trough comes in at the right time or is stronger, this recurves. Matthew (though it did devastate NC), Joaquin, the list goes on and on. We're a ways out from being able to say with even moderate confidence that this is a real threat. 

If I had to place the percentages currently of a US landfall, I'd be at like 30%. Which is high, but not that high. 

I'd go at 10% east coast, much higher of course should it make it past Fla to the south.

Let me edit that, 10% of east coast landfall below the Va/NC border.

[SomeguyfromTakomaPark]

Hahaha alright y'all!  I get it!  Let me re phrase.  The EPS has a lot of members that would landfall somewhere in the continental US but at this lead time there is still a good chance it doesn't. 

[nw baltimore wx]

6 minutes ago, DCTeacherman said:

Hahaha alright y'all!  I get it!  Let me re phrase.  The EPS has a lot of members that would landfall somewhere in the continental US but at this lead time there is still a good chance it doesn't. 

Yeah, if this was football, your last post would have given a few peeps a 15 yard penalty for piling on.

 Should be a fun storm to track.

[WinterWxLuvr]

Hurricanes sure are an awesome spectacle of nature.  It's a shame they create so much destruction and heartache.

[Amped]

Is there a fastforward button to day 9?  I can't watch another 10 days worth of model runs.

[eurojosh]

31 minutes ago, Amped said:

Is there a fastforward button to day 9?  I can't watch another 10 days worth of model runs.

You're going to love winter.

[Subtropics]

1 hour ago, WinterWxLuvr said:

I'd go at 10% east coast, much higher of course should it make it past Fla to the south.

Let me edit that, 10% of east coast landfall below the Va/NC border.

Far too bearish. This is a coin flip 50% chance in my eyes. And odds are rising.

[smokeybandit]

34 minutes ago, WxWatcher007 said:

Even if it's wrong (and we better hope to God it is) what the globals are doing with Irma's intensity is incredible.

 

His followup tweet

 

"Note: There is a bias correction applied to this forecast data. It could very well be overcooking the model's forecast intensity."

[Amped]

Anyone remember this? Similar looking monster from 2010.

[MillvilleWx]

18 minutes ago, MillvilleWx said:

This! The hurricane is being modeled fairly well IMO from now through at least once its near 55N longitude. After that, the models diverge and a lot of that has to do with the ridge positioning and strength in the Atlantic and the evolution of the trough pattern over NA. If you look at the difference between the Euro and GFS, you'll see the difference once you get out to Monday/Tuesday with regards to ridge over Atlantic. GFS leaves door open for ridge extension further to the north compared to the Euro as the Euro has a low placement off the UK by Tuesday. The end result is a further south shift in the ridge position, keeping the storm from working back north once beyond 55N longitude. GFS also exacerbates the differences with a stronger system that can bully the ridge a bit, helping to gain more latitude. 

 

 

Now check out the Euro up by the UK with the positioning of low pressure

 

 

 

As we extend beyond that, the GFS with the handling of the trough over the CONUS has been waffling back and forth with the depth and progression which would cause significant  impacts down the line with its current evolution. The closed upper features would allow for a better chance at capturing the system due to a neutral to negative orientation at H5, bringing the system, once north of 30N, closer to coast or slamming straight into the Northeast or Mid Atlantic. If the trough remains at a positive tilt, the storm would ultimately be kicked and hooked away from the East Coast, but could be captured late and slam into Canadian Maritimes. Euro with its southern track keeps the system on the southern flank of the ridge and deepening trough over the CONUS pumps the heights out over the Western Atlantic and storm will have to continue working on a west-northwest trajectory into the Northern Caribbean. The Euro is historically better at handling H5 patterns beyond 72 hours, but runs into its own problems beyond day 5/6, so worth noting that despite the "steadiness" of the Euro with the system, it can still make significant adjustments in the long term that would ultimately have major implications on the east coast impact. 

Posted this in the main tropical page, but thought I'd re-post here. Just something I found while looking through the GFS and Euro and identifying the main differences. One of my sites in Puerto Rico is starring at the barrel of Irma next week, so been following very closely.

[Subtropics]

1 minute ago, losetoa6 said:

Latest MREFS ..many hits

Some of those would be a storm of a lifetime for DC

[TheJMan]

 sheesh...been watching from NJ

[Bob Chill]

28 minutes ago, losetoa6 said:

 

Pretty cool graphic based off the Eps.

A bullish 40%

 

Cool graphic! I just now had a chance to check out the 12z euro/eps and 18z gfs/gefs. Nothing to add. Good disco already.

 @MillvilleWx great post earlier. I agree 100%. One thing that crossed my mind driving home tonight was what could happen with a capture or phase scenario. Or a partial phase. Forward speed would accelerate quickly so if Irma is as strong as being advertised as it approaches the US, even a far south landfall could have very significant inland impacts over a very large area. Not that I think that's what's going to happen or anything. But if it did...

We're still probably 5 days away from having any kind of idea what's going to happen. One thing I'm sure of, there are going to be op runs that scare the S out of a lot of people coming up. 

[MillvilleWx]

2 minutes ago, Bob Chill said:

Cool graphic! I just now had a chance to check out the 12z euro/eps and 18z gfs/gefs. Nothing to add. Good disco already.

 @MillvilleWx great post earlier. I agree 100%. One thing that crossed my mind driving home tonight was what could happen with a capture or phase scenario. Or a partial phase. Forward speed would accelerate quickly so if Irma is as strong as being advertised as it approaches the US, even a far south landfall could have very significant inland impacts over a very large area. Not that I think that's what's going to happen or anything. But if it did...

We're still probably 5 days away from having any kind of idea what's going to happen. One thing I'm sure of, there are going to be op runs that scare the S out of a lot of people coming up. 

Thanks Bob! Completely agree with with the impact sentiment if the system were to be fully or partially phased. I mentioned to @WxWatcher007 earlier that the models are going to under forecast the size of the wind field if there was any interaction at H5. This would be Sandy with a stronger wind core and pretty large scope of coverage in tropical storm force gusts away from the center. It's still too far out to discuss specifics, but if the system were to make it to our latitude, that's what we'd be looking at for sure. Going to be a loooong 10-12 days.

[Bob Chill]

1 minute ago, MillvilleWx said:

Thanks Bob! Completely agree with with the impact sentiment if the system were to be fully or partially phased. I mentioned to @WxWatcher007 earlier that the models are going to under forecast the size of the wind field if there was any interaction at H5. This would be Sandy with a stronger wind core and pretty large scope of coverage in tropical storm force gusts away from the center. It's still too far out to discuss specifics, but if the system were to make it to our latitude, that's what we'd be looking at for sure. Going to be a loooong 10-12 days.

This is one of the most intriguing storms in quite a while. No doubt about that. If you just play the odds from analogs then a goal post track would be the most likely outcome. This one is different. Euro isn't wavering with the atl ridge at all. Run over run its very strong and showing no signs of opening the door for the easy escape. And that ridge placement and strength is in the mid range. Euro is pretty damn good with that stuff. The approaching trough in the east is pretty locked in with getting out of the way in time. Still doesn't mean an offshore track isn't very much in the cards. 

I'm just rooting for the center to pass to our west. Don't care if landfall were to happen in the Gulf. I just want to be on the fun side. Moral police can arrest me for rooting for that too. Idgaf

[ErinInTheSky]

1 minute ago, Bob Chill said:

This is one of the most intriguing storms in quite a while. No doubt about that. If you just play the odds from analogs then a goal post track would be the most likely outcome. This one is different. Euro isn't wavering with the atl ridge at all. Run over run its very strong and showing no signs of opening the door for the easy escape. And that ridge placement and strength is in the mid range. Euro is pretty damn good with that stuff. The approaching trough in the east is pretty locked in with getting out of the way in time. Still doesn't mean an offshore track isn't very much in the cards. 

I'm just rooting for the center to pass to our west. Don't care if landfall were to happen in the Gulf. I just want to be on the fun side. Moral police can arrest me for rooting for that too. Idgaf

If it were forecast as a cat 1-2 or something, I'm all for it. I don't find the front right quadrant "fun" though for a cat 4-5 :-/

[MillvilleWx]

1 minute ago, Bob Chill said:

This is one of the most intriguing storms in quite a while. No doubt about that. If you just play the odds from analogs then a goal post track would be the most likely outcome. This one is different. Euro isn't wavering with the atl ridge at all. Run over run its very strong and showing no signs of opening the door for the easy escape. And that ridge placement and strength is in the mid range. Euro is pretty damn good with that stuff. The approaching trough in the east is pretty locked in with getting out of the way in time. Still doesn't mean an offshore track isn't very much in the cards. 

I'm just rooting for the center to pass to our west. Don't care if landfall were to happen in the Gulf. I just want to be on the fun side. Moral police can arrest me for rooting for that too. Idgaf

To me, have to watch the GFS and Euro with the handling of that low near the UK. If GFS catches on, I can almost guarantee it'll stay further south instead of hooking once between 55-60N. That's another thing, the anomalous WSW trajectory starting this weekend has been in lock step on all guidance. That's pretty amazing job by guidance picking up on the ridge strength being strong enough to do that, but the differences after 72 hours start to become more evident and man oh man is that huge. As for impact, I'm all about go big or go home too. I mean, can't control the damn thing, so might as well watch history be made. Not wishing death on anyone either as no one ever does, but being able to say I saw something like that would be amazing. If it misses the FL Keys though, I'll be down there starting the 13th, so if I miss it, I'll watch it from afar with sunglasses and few cold drinks  

[cae]

2 hours ago, MillvilleWx said:

Posted this in the main tropical page, but thought I'd re-post here. Just something I found while looking through the GFS and Euro and identifying the main differences. One of my sites in Puerto Rico is starring at the barrel of Irma next week, so been following very closely.

Nice analysis.  The low near the UK is interesting, but I think it only explains part of what we're seeing with the GFS.  If you look at last night's 00z GFS run for 12z Tuesday, the low is there, and H5 overall looks fairly similar to today's 12z Euro run.  But Irma still comes north.  A notable difference is the strength of the storm.  The GFS generally has been predicting a deeper low than the Euro.  Others more knowledgable than myself have commented that the current GFS has a known problem in that it spins up tropical systems too much, which could also be why it is consistently on the northen end of guidance.

One other thing that caught my eye is that although H5 on the GFS over the North Atlantic has been flopping all over the place, the GEFS have been (not surprisingly) more consistent.  At this range, the ensemble might be a more useful tool for predicting what H5 will look like.

[Bob Chill]

31 minutes ago, supernovasky said:

If it were forecast as a cat 1-2 or something, I'm all for it. I don't find the front right quadrant "fun" though for a cat 4-5 :-/

We don't have to worry much about being in the rfq of a cat 4-5 around here. Or even a 2 or 3 for that matter. Sustained cat 1 winds from I95 west is extremely rare here. I mean sure, it's possible but so unlikely. A storm would have to beeline here from the east. 

[ErinInTheSky]

I mean don't get me wrong, of any year, it would be the year I move to the area that we get a tropical system!

1 minute ago, Bob Chill said:

We don't have to worry much about being in the rfq of a cat 4-5 around here. Or even a 2 or 3 for that matter. Sustained cat 1 winds from I95 west is extremely rare here. I mean sure, it's possible but so unlikely. A storm would have to beeline here from the east. 

 

[MillvilleWx]

2 minutes ago, cae said:

Nice analysis.  The low near the UK is interesting, but I think it only explains part of what we're seeing with the GFS.  If you look at last night's 00z GFS run for 12z Tuesday, the low is there, and H5 overall looks fairly similar to today's 12z Euro run.  But Irma still comes north.  A notable difference is the strength of the storm.  The GFS generally has been predicting a deeper low than the Euro.  Others more knowledgable than myself have commented that the current GFS has a known problem in that it spins up tropical systems too much, which could also be why it is consistently on the northen end of guidance.

One other thing that caught my eye is that although H5 on the GFS over the North Atlantic has been flopping all over the place, the GEFS have been (not surprisingly) more consistent.  At this range, the ensemble might be a more useful tool for predicting what H5 will look like.

Ensembles are definitely the way to go at this juncture for the long range. This pattern screams more westward progression of the cyclone than a hook with how everything is evolving. Not saying a hook is out of the realm of possibility, but it would have to play some meteorological dodge ball with the ridge in the Atlantic and the incoming trough. That trough is going to be so important in my eyes and we have DAYS to figure that out. A deeper, cutoff H5 trough over NA would provide a greater chance for height rises in the Western Atlantic and building the ridge over the top. Would be really hard for the system to escape out to sea and forced toward the west. That would ultimately help the system get fully or partially captured if it were to curve north toward the Bahamas and position between 22-30N on its way toward the CONUS. Obviously, if the Euro is more correct, than the system would likely slide toward the Bahamas, then the trough question comes into play at a lower latitude. End result would be more into the SE from FL to NC and then hooking back north. I think an escape further into the  Central Gulf is a lower probability given ensembles, but a hook into the Eastern Gulf has been advertised by the Euro and some ensemble guidance, so just another option on an already full table.