2020 Global Model Runs Discussion (Out thru day 16)

[TheStormExpert]

Not sure if this is where to post this but it may have an affect on future models. 45 people have drowned in SW Niger, near the city of Niamey where the Niger River has overflowed due to excessive rains. This is slightly north of the African tropical belt but may be getting influenced by these heavy rains.

The wetter than average Saharan Desert is likely contributing to the ongoing impressive SAL surges along with mid-level dry air which has been plaguing the Atlantic since the season began. This probably explains why the MDR has been struggling to produce anything significant and the season hasn’t gone complete gang busters!

[chaser1]

Something is just off about this season.

Yeah, on modeling.

Exactly. There's just no way to ignore the number of storms that have developed so far this season. The level to which models have been broadly able to anticipate most of them beyond 2-4 days has been pretty poor. Most of us micro-analyze every aspect of tropical storm development and their future track but the extent of anticipation or expectation for most storms this (and recent years) to even develop have been shortened leaving many to become increasingly skeptical that favorable conditions actually exist. In spite of this, "BOOM" and yet another storm develops anyway.
The only part of this season seeming anything less then busy, is a clear result of the poor model accuracy to forecast genesis.

What else is different about this year?? Most every disturbance seems to have a penchant to try and spin up, SST's are broadly warm to above average, average sea-level pressures across the W. Atlantic have continued to remain low, no ripping upper level westerlies VERSES ARC clouds and sputtering convection from SAL and dry mid-levels. The former won't likely change much. The latter will probably slowly wane. I think the combination of the two will likely result in future storm genesis over a slightly broader area, a higher percentage of stronger storms, and even a small increase in model forecast compared to earlier this season.

[toad strangler]

Note that the GFS Parallel has also been consistently far more reliable than the GFS itself thus far in 2020. Besides the upcoming synoptic pattern, I would also argue that the “clustering” of tracks strongly supports potential TC threats to the Carolinas, Mid-Atlantic, and/or New England sometime in mid-September. For example, besides the numerous impacts in TX and LA (northwestern Gulf Coast), principally Cristobal, Hanna, Laura, and Marco, we have already seen three or more TS+ impacts from SC to NY, including Bertha, Fay, and Isaias. A strong, negatively tilted trough centred over the Great Lakes with equally strong blocking just off the Eastern Seaboard—namely, centred near the Canadian Maritimes—would definitely support the notion of additional threats to the aforementioned region(s). The western Gulf and the Carolinas/Mid-Atlantic/New England definitely seem to be the preferred “hotspots” for U.S. impacts in 2020.

I agree, the troughs that have come have been negatively positioned still giving the US a threat because ridging across the Atlantic has stayed present more often than not.
So just because a strong trough may come down the US in about 10 days it does not mean many if any OTS tracks setting up. The only ones that I may see going OTS are the ones that may develop strong sooner just off of the CV Islands, eventually once the SAL outbreaks settle down and they track through a break in the ridge in the middle or eastern Atlantic.

I have to agree with NDG and Shell that given the primary pattern we are in, it makes sense to assume that additional storm tracks will likely push very close to or track over the US Eastern Seaboard from the Carolina's northward potentially to New York or as far north as Maine.

12z Euro is interesting at 240 hours with a messy bundle of vorticity moving into the LA's but I'm just not inclined to believe anything the models show past four days or so.

Also, I disagree vigorously that the Eastern Seaboard N of Hatteras to NYC is a region that will see multiple real threats say... like a Sandy. It's just take a big time anomalous set up to landfall in that region. No matter how much Bastardi hints at it. Also, not to slight Shell Mound, but he did just forecast that Laura would re-curve away from the CONUS east of the Fl peninsula That said, Long Island through Cape Cod is a different story. I could see that relatively small corridor catching a couple storms that Hatteras misses.

[Frank2]

The lack of PIREPS is having its effect on the models. Personally, I'm glad for a few things, first, so far we've had one major hurricane (the other two hurricanes being low-end Cat 1's, and as we know that's comparng an F1 to an F4 tornado). Laura caused extensive wind damage, but the feared SLOSH model surge forecast did not happen, because the eye moved a bit east - something not expected - a bit (!) of a miracle, considering what almost all experts thought would happen.

And, the GFS is showing a very active and fast-moving west-east trough pattern next month (which can slow the wave progression to a crawl), so perhaps sign of an early Fall - I've seen it happen more than once.

P.S. Don't get nervous over JB's predictions - in the summer he predicts hurricanes and in the winter it's blizzards. He's always been that way...

[SFLcane]

Ace could crank during the next 2 weeks on the EPS fish parade.

[chaser1]

I agree, the troughs that have come have been negatively positioned still giving the US a threat because ridging across the Atlantic has stayed present more often than not.
So just because a strong trough may come down the US in about 10 days it does not mean many if any OTS tracks setting up. The only ones that I may see going OTS are the ones that may develop strong sooner just off of the CV Islands, eventually once the SAL outbreaks settle down and they track through a break in the ridge in the middle or eastern Atlantic.

I have to agree with NDG and Shell that given the primary pattern we are in, it makes sense to assume that additional storm tracks will likely push very close to or track over the US Eastern Seaboard from the Carolina's northward potentially to New York or as far north as Maine.

12z Euro is interesting at 240 hours with a messy bundle of vorticity moving into the LA's but I'm just not inclined to believe anything the models show past four days or so.

Also, I disagree vigorously that the Eastern Seaboard N of Hatteras to NYC is a region that will see multiple real threats say... like a Sandy. It's just take a big time anomalous set up to landfall in that region. No matter how much Bastardi hints at it. Also, not to slight Shell Mound, but he did just forecast that Laura would re-curve away from the CONUS east of the Fl peninsula That said, Long Island through Cape Cod is a different story. I could see that relatively small corridor catching a couple storms that Hatteras misses.

I generally flog myself with a leather belt whenever discovering that my own view of tracks or forecast come even close to Bastardi's Hurricane-thrashcasts. That said, if anomalously strong heights continue to extend west to the mid Atlantic coastline, then I see this as a most imposing set-up for storm tracks to threaten the mid and northeast US coastline. Contour of US mid Atlantic coastline notwithstanding, the overall steering pattern simply implies a heightened risk for the entire E. Coast as a whole. While landfall occurrences may be traditionally less common from Chesapeake to N.Y., far be it for myself to suggest "no worries, time to plan for Winter.

[SFLcane]

It’s almost as models are struggling with the monsoon trough breakdown.

[Nuno]

It’s almost as models are struggling with the monsoon trough breakdown.

Not the first time this season.

[Hammy]

It’s almost as models are struggling with the monsoon trough breakdown.

Would that explain the lack of model development from waves despite what we've seen?

[TheStormExpert]

The lack of PIREPS is having its effect on the models. Personally, I'm glad for a few things, first, so far we've had one major hurricane (the other two hurricanes being low-end Cat 1's, and as we know that's comparng an F1 to an F4 tornado). Laura caused extensive wind damage, but the feared SLOSH model surge forecast did not happen, because the eye moved a bit east - something not expected - a bit (!) of a miracle, considering what almost all experts thought would happen.

And, the GFS is showing a very active and fast-moving west-east trough pattern next month (which can slow the wave progression to a crawl), so perhaps sign of an early Fall - I've seen it happen more than once.

P.S. Don't get nervous over JB's predictions - in the summer he predicts hurricanes and in the winter it's blizzards. He's always been that way...

We still have 75% of activity to go this season. Don’t sound the all clear just yet!

Besides Joe Bastardi and his high land impact forecasting has been verifying very well so far.

[Emmett_Brown]

The lack of PIREPS is having its effect on the models. Personally, I'm glad for a few things, first, so far we've had one major hurricane (the other two hurricanes being low-end Cat 1's, and as we know that's comparng an F1 to an F4 tornado). Laura caused extensive wind damage, but the feared SLOSH model surge forecast did not happen, because the eye moved a bit east - something not expected - a bit (!) of a miracle, considering what almost all experts thought would happen.

And, the GFS is showing a very active and fast-moving west-east trough pattern next month (which can slow the wave progression to a crawl), so perhaps sign of an early Fall - I've seen it happen more than once.

P.S. Don't get nervous over JB's predictions - in the summer he predicts hurricanes and in the winter it's blizzards. He's always been that way...

We still have 75% of activity to go this season. Don’t sound the all clear just yet!

Besides Joe Bastardi and his high land impact forecasting has been verifying very well so far.

Yep. 2020 is the first season to have 7 tropical cyclones landfall in the CONUS before the end of August. So regardless of how 2020 ends, this season has already been unprecedented.

[Frank2]

Don’t sound the all clear just yet!

"l never said that....l don't even recall thinking that." - Terence Mann, Field of Dreams

[Steve]

Something is just off about this season.

In the MDR yes, but we just had a 150mph Cat.4 slam into SW Louisiana a few days ago. 2005 didn’t really produce much of anything in the Tropical Atlantic and look how it turned out! This is definitely no 2005 repeat in terms of ACE but number of storms-wise it may be.

I agree about the similarities in the tropical Atlantic. I like to bring back the 2005 storm tracks map every year or two to remind people you don't need much development down there to have a record/historic season. What I do wonder about is whether the ACE really matters this year. Long term, I suppose it does. But say we make it up to only 125 or 150, but we get hit by 3 more hurricanes that formed a day or two out. In that case, we'd have had 10 US landfalls (5 of them hurricanes). That says something on its own.

[Steve]

The lack of PIREPS is having its effect on the models. Personally, I'm glad for a few things, first, so far we've had one major hurricane (the other two hurricanes being low-end Cat 1's, and as we know that's comparng an F1 to an F4 tornado). Laura caused extensive wind damage, but the feared SLOSH model surge forecast did not happen, because the eye moved a bit east - something not expected - a bit (!) of a miracle, considering what almost all experts thought would happen.

And, the GFS is showing a very active and fast-moving west-east trough pattern next month (which can slow the wave progression to a crawl), so perhaps sign of an early Fall - I've seen it happen more than once.

P.S. Don't get nervous over JB's predictions - in the summer he predicts hurricanes and in the winter it's blizzards. He's always been that way...

We still have 75% of activity to go this season. Don’t sound the all clear just yet!

Besides Joe Bastardi and his high land impact forecasting has been verifying very well so far.

Yep. 2020 is the first season to have 7 tropical cyclones landfall in the CONUS before the end of August. So regardless of how 2020 ends, this season has already been unprecedented.

What is the most named storm landfalls in a year on the US?

[Kat5]

Ace could crank during the next 2 weeks on the EPS fish parade.

https://cdn1.bbcode0.com/uploads/2020/8/29/cb10e4cadf587f3a1d1a654654f71e57-full.png

Fishes!

[Ryxn]

We still have 75% of activity to go this season. Don’t sound the all clear just yet!

Besides Joe Bastardi and his high land impact forecasting has been verifying very well so far.

Yep. 2020 is the first season to have 7 tropical cyclones landfall in the CONUS before the end of August. So regardless of how 2020 ends, this season has already been unprecedented.

What is the most named storm landfalls in a year on the US?

9 in 1916 https://en.m.wikipedia.org/wiki/1916_At ... ane_season

2020 is looking likely to break this record at the pace it's going. 2005 had 3 (or 4 if you want to count Ophelia) US landfalling storms after August 31 and 4 storms before September.

[Steve]

Thanks. I tried searching that the other day and couldn’t find it. 9 is a lot of hits, and it looks like that was a tough year for Pensacola. We are definitely getting hit by 2 more named storms, so at worst it will be a tie. We could beat that record up by a couple or more.

[TheStormExpert]

Ace could crank during the next 2 weeks on the EPS fish parade.

https://cdn1.bbcode0.com/uploads/2020/8/29/cb10e4cadf587f3a1d1a654654f71e57-full.png

Fishes!

Yeah if you believe a model two weeks out!

[toad strangler]

Central America action

 http://twitter.com/pppapin/status/1299850524703981568

[SconnieCane]

Not sure if this is where to post this but it may have an affect on future models. 45 people have drowned in SW Niger, near the city of Niamey where the Niger River has overflowed due to excessive rains. This is slightly north of the African tropical belt but may be getting influenced by these heavy rains.

The wetter than average Saharan Desert is likely contributing to the ongoing impressive SAL surges along with mid-level dry air which has been plaguing the Atlantic since the season began. This probably explains why the MDR has been struggling to produce anything significant and the season hasn’t gone complete gang busters!

I would have thought that would reduce the SAL by tamping the dust down some?