Expert forecasts for 2021 North Atlantic Hurricane Season

[cycloneye]

Thread title says 11:00 AM but NOAA website says 12:30 ET

Yes, that is right.

[SFLcane]

NOAA: Another busy one as expected!

13 to 20 named storms, 6 to 10 hurricanes and 3 to 5 major hurricanes.

[weeniepatrol]

yikes.

[kevin]

Very similar to last year's forecast in terms of numbers. Last year they had 13-19/6-10/3-6. Only difference this time is that they have 3-5 for MH's and 13-20 instead of 13-19.

[kevin]

For reference, here's an overview of all of NOAA's May forecasts since 2010. The only higher forecast in terms of number of named storms was 2010 so it seems NOAA is going all-in for a busy season. However, also note how the 2nd highest forecast (besides 2010 and 2021) was 2013, which eventually turned out to be a well below average season. So yes the forecasts are generally accurate and now seem to indicate an above average season, but as long as the storms haven't formed yet it remains a forecast.

Year / Named storms / Hurricanes / Major hurricanes
2010 / 14-23 / 8-14 / 3-7
2011 / 12-18 / 6-10 / 3-6
2012 / 9-15 / 4-8 / 1-3
2013 / 13-20 / 7-11 / 3-6
2014 / 8-13 / 3-6 / 1-2
2015 / 6-11 / 3-6 / 0-2
2016 / 10-16 / 4-8 / 1-4
2017 / 11-17 / 5-9 / 2-4
2018 / 10-16 / 5-9 / 1-4
2019 / 9-15 / 4-8 / 2-4
2020 / 13-19 / 6-10 / 3-6
2021 / 13-20 / 6-10 / 3-5

[toad strangler]

Rick Knabb on Weather Geeks

https://podcasts.apple.com/us/podcast/weather-geeks/id1373312240

[cycloneye]

TSR is up and raise their numbers from 17/8/3 in April to the May one of 18/9/4.

[Shell Mound]

Past TSR forecasts:
2010: 16 / 8 / 4 (actual: 19 / 12 / 5)
2011: 14 / 8 / 4 (actual: 19 / 7 / 4)
2012: 13 / 6 / 3 (actual: 19 / 10 / 2)
2013: 15 / 8 / 3 (actual: 14 / 2 / 0)
2014: 12 / 5 / 2 (actual: 8 / 6 / 2)
2015: 11 / 5 / 2 (actual: 11 / 4 / 2)
2016: 17 / 9 / 4 (actual: 15 / 7 / 4)
2017: 14 / 6 / 3 (actual: 17 / 10 / 6)
2018: 9 / 4 / 1 (actual: 15 / 8 / 2)
2019: 12 / 6 / 2 (actual: 18 / 6 / 3)
2020: 17 / 8 / 3 (actual: 30 / 14 / 7)
2021: 18 / 9 / 4 (actual: ? / ? / ?)

Since 2010, the TSR underestimated (M)H totals on eleven occasions and overestimated them on six others. This year’s forecast, besides 2016’s, is the only one since 2010 to call for at least nine hurricanes. Note that in the same timeframe TSR has never called for more than four MH. In addition to this year, TSR also called for four MH in 2010, 2011, and 2016.

[jconsor]

Salient Predictions, which has achieved success in forecasts of temperatures and precipitations several months in advance, has developed a model for forecasting ACE based on a neural-network analysis of atmospheric and oceanic conditions. They are forecasting well above average ACE this year.

See https://www.salientpredictions.com/post ... e-forecast

[tolakram]

Salient Predictions, which has achieved success in forecasts of temperatures and precipitations several months in advance, has developed a model for forecasting ACE based on a neural-network analysis of atmospheric and oceanic conditions. They are forecasting well above average ACE this year.

See https://www.salientpredictions.com/post ... e-forecast

Here's their ACE prediction and how it performed when backdating the algorithm to past years.

[HurricaneEnzo]

Salient Predictions, which has achieved success in forecasts of temperatures and precipitations several months in advance, has developed a model for forecasting ACE based on a neural-network analysis of atmospheric and oceanic conditions. They are forecasting well above average ACE this year.

See https://www.salientpredictions.com/post ... e-forecast

Here's there ACE prediction and how it performed when backdating the algorithm to past years.

https://i.imgur.com/U8EwwMN.png

Obviously not a huge sample size but looks to have done a pretty decent job. With the exception of 2012 looks like they were right in the ballpark.

[Blown Away]

Tracks based on the analog years selected by CSU.

[cycloneye]

Tomorrow is the release of the new Phil Klotzbach CSU forecast so stay tuned. He had 17/8/4 on the April one.

 https://twitter.com/philklotzbach/status/1400135787212120071

[aspen]

Tomorrow is the release of the new Phil Klotzbach CSU forecast so stay tuned. He had 17/8/4 on the April one.

I wonder if CSU will keep their original numbers or even slightly lower them, if the models suggesting MDR suppression and a not-that-great SST pattern turn out to be true.

[TorSkk]

 https://twitter.com/philklotzbach/status/1400468463756484610

[toad strangler]

CSU Klotzbach holds serve

[Steve]

Bastardi said Weatherbell’s new forecast would slightly lessen the above normal (red shade = 6x) from Brownsville to New Orleans which would still be above normal. But he was increasing the East Coast threat which was from Charleston to Outer Banks all the way up the seaboard. He said he feels like this is looking like a year that will have a lot of OTS and east coast threats.

[Shell Mound]

Bastardi said Weatherbell’s new forecast would slightly lessen the above normal (red shade = 6x) from Brownsville to New Orleans which would still be above normal. But he was increasing the East Coast threat which was from Charleston to Outer Banks all the way up the seaboard. He said he feels like this is looking like a year that will have a lot of OTS and east coast threats.

Hasn’t he previously highlighted New England during a number of seasons? Putting the highest-risk zone in the Northeast often fails to verify.

[Steve]

Bastardi said Weatherbell’s new forecast would slightly lessen the above normal (red shade = 6x) from Brownsville to New Orleans which would still be above normal. But he was increasing the East Coast threat which was from Charleston to Outer Banks all the way up the seaboard. He said he feels like this is looking like a year that will have a lot of OTS and east coast threats.

Hasn’t he previously highlighted New England during a number of seasons? Putting the highest-risk zone in the Northeast often fails to verify.

Year after year . But he did mention 1954 - not so much as an analog but I think he said the benchmark. For 2021, he had it in yellow for the spring forecast. His paid clients probably have the new map, but they'll probably release it soon otherwise. Here is the original forecast (I know red = 6x normal, not 100% on yellow - 3x?).

[cycloneye]

 https://twitter.com/philklotzbach/status/1412902437975990273