2021 Indicators: SST's / SAL / MSLP / Shear / Steering / Instability / Sat Images

[AxaltaRacing24]

It was well below normal across the Caribbean and Gulf though, at least based on the climatology period used:
https://i.imgur.com/n3sZD98_d.webp?maxwidth=640&shape=thumb&fidelity=medium

Thus far this month, wind shear has been much greater than average over the Caribbean and Gulf of Mexico.
https://i.imgur.com/cJVJWpj_d.webp?maxwidth=640&shape=thumb&fidelity=medium

This is likely primarily a result of intraseasonal variation and should decrease a bit later in the month. There have also been Octobers (like 2007 and 2019) which had fairly low shear but did not have any significant hurricanes, as well as Octobers with fairly high shear that had significant activity (like 2018). It's important to remember that the October/November we saw last year was very anomalous (5 major hurricanes after October 1, when the previous record was only 2).

October 2020 put September 2020 to shame. 2021 does not look like a repeat IMO.

I agree, last October was crazy. This October looks much more "normal" even if it is quieter than recent years.

2020 October was like 2005 July. It was a sight to behold that might not be repeated for several seasons.

[AlphaToOmega]

This gives me a good chuckle. The GFS shows virtually no tropical cyclone activity from now until the end of October. Could this be the GFS adjusting to an impending CCKW and favorable MJO phase? As they say, the models show nothing until they show something.

[AlphaToOmega]

The CFSv2 is showing rising air cells in the Atlantic as late as mid-November

[Category5Kaiju]

This gives me a good chuckle. The GFS shows virtually no tropical cyclone activity from now until the end of October. Could this be the GFS adjusting to an impending CCKW and favorable MJO phase? As they say, the models show nothing until they show something.

In my honest opinion, I do think this may be the case, as whatever the GFS thinks, it does not seem to show anything substantial form in the WPAC and EPAC after Pamela. In fact, mid to end of the month is where the WPAC is literally shown to be a desert for cyclone activity, with no indicated closed level lows with notable low pressures. The EPAC is also pretty dead too. If I recall, even if it was just a few days ago, the GFS showed no Atlantic activity but copious WPAC and EPAC activity, so maybe it is finally realizing the CCKW/MJO progression eastward will inevitably reach the Atlantic basin?

[psyclone]

The global tropics hazard maps from CPC show a snooze fest for the next 2 weeks. I am amazed at how this season has gone. Imagine for just a moment if a downcaster posted at the end of August a belief that the US was done paying rent with the biggies for the year. They would have been torched...probably accused of trolling...and yet here we are with that scenario more than likely coasting effortlessly to the finish line. It's extraordinary. the tropics amaze in both directions. there are clearly things we don't know but should on this topic. We don't know what we don't know....but i am confident we're missing some critical piece(s) of the tropical puzzle.

[AlphaToOmega]

The global tropics hazard maps from CPC show a snooze fest for the next 2 weeks. I am amazed at how this season has gone. Imagine for just a moment if a downcaster posted at the end of August a belief that the US was done paying rent with the biggies for the year. They would have been torched...probably accused of trolling...and yet here we are with that scenario more than likely coasting effortlessly to the finish line. It's extraordinary. the tropics amaze in both directions. there are clearly things we don't know but should on this topic. We don't know what we don't know....but i am confident we're missing some critical piece(s) of the tropical puzzle.

If the CONUS did not see any more land impacts this season, it would probably be thanks to the negative NAO. Over the past few weeks there has been some general toughing that has weakened the NAO. This might be the one thing that could spare the CONUS from any impacts. However, the Antilles would still be vulnerable.

[Category5Kaiju]

The global tropics hazard maps from CPC show a snooze fest for the next 2 weeks. I am amazed at how this season has gone. Imagine for just a moment if a downcaster posted at the end of August a belief that the US was done paying rent with the biggies for the year. They would have been torched...probably accused of trolling...and yet here we are with that scenario more than likely coasting effortlessly to the finish line. It's extraordinary. the tropics amaze in both directions. there are clearly things we don't know but should on this topic. We don't know what we don't know....but i am confident we're missing some critical piece(s) of the tropical puzzle.

What's for sure though, it only takes one right? And that one CONUS MH landfall this year happened to be near a major city, a high end Cat 4, and the sixth costliest Atlantic TC ever recorded. Getting a CONUS MH landfall is not something you see every year, let alone a phenomenal high end Cat 4 near a large metro region in any given year (especially when looking back to all years since 1851), and that alone I will remember for a while.

[abajan]

Link: https://youtu.be/ATjG3qD55tY

[kevin]

An overview of the most intense hurricane every season since 1960. If it stays like this, 2021 would have the 'weakest' strongest storm since Matthew in 2016. Not that weak is a term I'd ever use as a descriptor for Sam. It would also make 2021 the first year since 2013 where the strongest storm of the season did not result in any significant damage or casualties. Now that is a statistic that I hope will hold for the rest of the season. Another interesting tidbit I noticed when making this list is that 2017-2020 is the longest streak of sub-920mb hurricanes, at least since 1960. No other sequence has 4 subsequent years with sub-920mb hurricanes.

The most intense storms (by pressure) for each decade are bolded.

Year / Name / Pressure (mb) / Winds (mph) / Category

2021 / Sam / 929 / 155 / 4
2020 / Iota / 917 / 155 / 4

2019 / Dorian / 910 / 185 / 5
2018 / Michael / 919 / 160 / 5
2017 / Maria / 908 / 175 / 5
2016 / Matthew / 934 / 165 / 5
2015 / Joaquin / 931 / 155 / 4
2014 / Gonzalo / 940 / 145 / 4
2013 / Humberto / 979 / 90 / 1
2012 / Sandy / 940 / 115 / 3
2011 / Ophelia / 940 / 140 / 4
2010 / Igor / 924 / 155 / 4

2009 / Bill / 943 / 130 / 4
2008 / Ike / 935 / 145 / 4
2007 / Dean / 905 / 175 / 5
2006 / Gordon, Helene / 955 / 120 / 3
2005 / Wilma / 882 / 185 / 5
2004 / Ivan / 910 / 165 / 5
2003 / Isabel / 915 / 165 / 5
2002 / Isidore / 934 / 125 / 3 (Lili was a cat 4, but had a pressure of 938mb)
2001 / Michelle / 933 / 140 / 4
2000 / Keith / 939 / 140/ 4

1999 / Floyd / 921 / 155 / 4
1998 / Mitch / 905 / 180 / 5
1997 / Erika / 946 / 125 / 3
1996 / Edouard / 933 / 145 / 4
1995 / Opal / 916 / 150 / 4
1994 / Florence / 972 / 110 / 2
1993 / Emily / 960 / 115 / 3
1992 / Andrew / 922 / 175 / 5
1991 / Claudette / 944 / 130 / 4
1990 / Gustav / 956 / 120 / 3

1989 / Hugo / 918 / 160 / 5
1988 / Gilbert / 888 / 185 / 5
1987 / Emily / 958 / 125 / 3
1986 / Earl / 979 / 105 / 2
1985 / Gloria / 919 / 145 / 4
1984 / Diana / 949 / 130 / 4
1983 / Alicia / 962 / 115 / 3
1982 / Debby / 950 / 130 / 4
1981 / Harvey / 946 / 130 / 4
1980 / Allen / 899 / 190 / 5

1979 / David / 924 / 175 / 5
1978 / Greta / 947 / 130 / 4
1977 / Anita / 926 / 175 / 5
1976 / Belle / 957 / 120 / 3
1975 / Gladys / 939 / 140 / 4
1974 / Carmen / 928 / 150 / 4
1973 / Ellen / 962 / 115 / 3
1972 / Betty / 976 / 105 / 2
1971 / Edith / 943 / 160 / 5
1970 / Celia / 945 / 125 / 3

1969 / Camille / 900 / 175 / 5
1968 / Gladys / 965 / 85 / 1
1967 / Beulah / 923 / 160 / 5
1966 / Inez / 929 / 150 / 4
1965 / Betsy / 942 / 140 / 4
1964 / Cleo / 938 / 150 / 4
1963 / Flora / 933 / 150 / 4
1962 / Ella / 958 / 110 / 3
1961 / Hattie / 914 / 165 / 5
1960 / Donna / 930 / 145 / 4

[Deshaunrob17]

The global tropics hazard maps from CPC show a snooze fest for the next 2 weeks. I am amazed at how this season has gone. Imagine for just a moment if a downcaster posted at the end of August a belief that the US was done paying rent with the biggies for the year. They would have been torched...probably accused of trolling...and yet here we are with that scenario more than likely coasting effortlessly to the finish line. It's extraordinary. the tropics amaze in both directions. there are clearly things we don't know but should on this topic. We don't know what we don't know....but i am confident we're missing some critical piece(s) of the tropical puzzle.

Facts!!! It would have quickly been labeled as season cancelling post... This season was quite different to what many imagined. We did have the long-tracked hurricanes, but harmlessly missed the Caribbean and US. Those 2004 analogs surely didn't come into fruition (Amen). While there maybe a pick up in activity towards the end of the month, climatology alone will tell you that significant activity( more than 1 major hurricanes ) is unlikely. Last year November was as anomalous as July 2005.

There is still sometime to go don't won't rule out a landfslling US hurricane. However, it is getting harder for that to happen!!!!

[AlphaToOmega]

What I will say is that the next burst of activity (whenever that may be) will probably be more powerful than expected; for the MJO has been very high-amplitude this year, and October is still part of the three-month peak of hurricane season (ASO).

[Ubuntwo]

An overview of the most intense hurricane every season since 1960. If it stays like this, 2021 would have the 'weakest' strongest storm since Matthew in 2016. Not that weak is a term I'd ever use as a descriptor for Sam. It would also make 2021 the first year since 2013 where the strongest storm of the season did not result in any significant damage or casualties. Now that is a statistic that I hope will hold for the rest of the season. Another interesting tidbit I noticed when making this list is that 2017-2020 is the longest streak of sub-920mb hurricanes, at least since 1960. No other sequence has 4 subsequent years with sub-920mb hurricanes.

As an aside, Matthew will (in all likelihood) be downgraded to 130-135kt following SFMR reanalysis. Still a very impressive stretch of high end hurricanes.

[Teban54]

If something gets to the NW Caribbean... YIKES.


For reference, here's last year at virtually the same time. Not suggesting we'll see things as crazy as last year, of course.

[Category5Kaiju]

If something gets to the NW Caribbean... YIKES.
https://i.imgur.com/GxjBmqk.png

For reference, here's last year at virtually the same time. Not suggesting we'll see things as crazy as last year, of course.
https://i.imgur.com/VcEqqmy.png

I'm also quite sure that that absurd UOHC pool in the WCAR will not change by much throughout this month, so if anything with otherwise favorable conditions gets there even by the end of this month, it could really blow up. Also talk about the Gulf being much warmer than average compared to last year!

[Teban54]

If something gets to the NW Caribbean... YIKES.
Also talk about the Gulf being much warmer than average compared to last year!

To be fair, last year's image was taken just after Delta passed through the area.

[aspen]

If something gets to the NW Caribbean... YIKES.
https://i.imgur.com/GxjBmqk.png

For reference, here's last year at virtually the same time. Not suggesting we'll see things as crazy as last year, of course.
https://i.imgur.com/VcEqqmy.png

I made a marked-up version of that SST graphic earlier today, but didn't have time to post it before class. Better late than never I guess.


MPIs for the WCar are sub-900 on CIMSS's MPI map, but since Invest 93L was removed, you can't see them anymore; 8km resolution while focused on Pamela doesn't show the WCar.

[WiscoWx02]

 https://twitter.com/BenNollWeather/status/1448272313066024973




Ben Noll himself saying this isn't a normal La Nina. Figures. One would think despite this though the affects would be the same as from a traditional La Nina or not deviate too far from what is normal right?

[gatorcane]

If something gets to the NW Caribbean... YIKES.
https://i.imgur.com/GxjBmqk.png

For reference, here's last year at virtually the same time. Not suggesting we'll see things as crazy as last year, of course.
https://i.imgur.com/VcEqqmy.png

https://www.ospo.noaa.gov/data/ocean/ohc/images/ohc_naQG3_ddc.gif

I'm also quite sure that that absurd UOHC pool in the WCAR will not change by much throughout this month, so if anything with otherwise favorable conditions gets there even by the end of this month, it could really blow up. Also talk about the Gulf being much warmer than average compared to last year!

Wow we better hope nothing makes it into the NW Caribbean, yikes is right. To see the GFS long-range entertaining this idea is a little concerning, fingers crossed it is another phantom.

[Category5Kaiju]

https://twitter.com/BenNollWeather/status/1448272313066024973/photo/1

Ben Noll himself saying this isn't a normal La Nina. Figures. One would think despite this though the affects would be the same as from a traditional La Nina or not deviate too far from what is normal right?

 https://twitter.com/webberweather/status/1448279107830095873




Honestly individual La Ninas are different, and there will always be a variety of different exact "flavors" per se. However, this year's La Nina does not seem to be that strange given Pamela struggled to achieve even Cat 2 status, so it's not as if this La Nina is an exceptionally weird one that favors the EPAC and hurts the Atlantic like an El Nino.

[WiscoWx02]

https://twitter.com/BenNollWeather/status/1448272313066024973/photo/1

Ben Noll himself saying this isn't a normal La Nina. Figures. One would think despite this though the affects would be the same as from a traditional La Nina or not deviate too far from what is normal right?

https://twitter.com/webberweather/status/1448279107830095873

Honestly individual La Ninas are different, and there will always be a variety of different exact "flavors" per se. However, this year's La Nina does not seem to be that strange given Pamela struggled to achieve even Cat 2 status, so it's not as if this La Nina is an exceptionally weird one that favors the EPAC and hurts the Atlantic like an El Nino.

I was really bullish on Pamela until I saw it being heavily sheared less than a day after it formed and pretty much knew from that La Nina was gonna work its magic. Mexico isn't complaining, but on the Atlantic side.....a La Nina year with no activity in the Caribbean...well, you know the historical anomaly that would be better than I do.

Add on: I just realized something too.....anyone notice that we have not had a monsoonal gyre this October yet? 2017, 2018, 2019, 2020 all had one set up by now....just feels weird. I know we are in the suppressed phase of the MJO and a most -CCKW is parked over the Atlantic but it makes me scratch my head a bit.