2024 Atlantic Hurricane Season

[Stormchaserchuck1]

Another thing to note is, since October, the Hadley Cell has been expanded north, all around the globe. 

In the Summer, those mid-latitude cells lift north. The past doesn't necessarily predict the future, but lack of deep troughs digging, coupled with normal La Nina pattern could potentially create a more favorable pattern for US hits. 

All this while SLP has been below normal:

https://ibb.co/KhfXCNz

Earth's precipitable water has been record highest, a whole 120% #2 analog 2015-16, for the Sept-Apr period (records go back to 1948).

https://ibb.co/cbLGHQV

[purduewx80]

17 hours ago, Stormchaserchuck1 said:

Another thing to note is, since October, the Hadley Cell has been expanded north, all around the globe. 

In the Summer, those mid-latitude cells lift north. The past doesn't necessarily predict the future, but lack of deep troughs digging, coupled with normal La Nina pattern could potentially create a more favorable pattern for US hits. 

Been thinking about this a lot, mostly in terms of whether it leads to subsidence and stability issues in the MDR.

[GaWx]

On 4/4/2024 at 12:46 PM, MJO812 said:

Very active season 

There is good reason to hope that this April CSU forecast is going to end up too high based on past very active April CSU predictions. They’ve been making April predictions since 1995. I see a pretty clear pattern when they’ve gone very active in April:

1. # NS: They’re predicting 23. Prior to this the highest they predicted in April was 17-19 (five times). Four of those five progs ended up too high. For those 5, they averaged 2.8 too high.

2. NS days: They’re predicting 115. Prior to this the highest they predicted in April was 85-95 (four times). All four of those progs ended up too high. The highest actual of these four was only 58 and they averaged a whopping 40.5 too high!

3. # H: They’re predicting 11. The prior highest predicted in April was 9 (six times). All of those 6 progs ended up too high by an average of 3.

4. H days: They’re predicting 45. The prior highest progs in April were 40-45 (five times). Of these five, four progs came in too high. The five averaged a whopping 19 too high!

5. # MH: They’re predicting 5, which they’ve predicted three other times in April. All three of those progs came in too high by an average of 2.33.

6. MH days: They’re predicting 13, which is tied for the highest ever predicted in April. They’ve progged 10-13 five times. Of those five, three progs were too high. The five averaged 3.25 too high.

7. ACE: They’re predicting 210. The prior highest April progs were 160-183 (five times). Of these five, all progs ended up too high with even the closest being 34 too high! The five averaged a whopping 85.8 too high!

Conclusion: If I were a betting man, I’d short CSU’s April ‘24’s forecast overall, especially NS Days, # H, and ACE.

[Rhino16]

9 hours ago, GaWx said:

There is good reason to hope that this April CSU forecast is going to end up too high based on past very active April CSU predictions. They’ve been making April predictions since 1995. I see a pretty clear pattern when they’ve gone very active in April:

1. # NS: They’re predicting 23. Prior to this the highest they predicted in April was 17-19 (five times). Four of those five progs ended up too high. For those 5, they averaged 2.8 too high.

2. NS days: They’re predicting 115. Prior to this the highest they predicted in April was 85-95 (four times). All four of those progs ended up too high. The highest actual of these four was only 58 and they averaged a whopping 40.5 too high!

3. # H: They’re predicting 11. The prior highest predicted in April was 9 (six times). All of those 6 progs ended up too high by an average of 3.

4. H days: They’re predicting 45. The prior highest progs in April were 40-45 (five times). Of these five, four progs came in too high. The five averaged a whopping 19 too high!

5. # MH: They’re predicting 5, which they’ve predicted three other times in April. All three of those progs came in too high by an average of 2.33.

6. MH days: They’re predicting 13, which is tied for the highest ever predicted in April. They’ve progged 10-13 five times. Of those five, three progs were too high. The five averaged 3.25 too high.

7. ACE: They’re predicting 210. The prior highest April progs were 160-183 (five times). Of these five, all progs ended up too high with even the closest being 34 too high! The five averaged a whopping 85.8 too high!

Conclusion: If I were a betting man, I’d short CSU’s April ‘24’s forecast overall, especially NS Days, # H, and ACE.

Just to be sure, in the bold, you’re referring to the previous 5 (or other number) highest times?

Are they the same years?

[GaWx]

36 minutes ago, Rhino16 said:

Just to be sure, in the bold, you’re referring to the previous 5 (or other number) highest times?

Are they the same years?

 In bold for seven categories I’m referring to where the respective seasons ended up on average vs the 3-6 seasons’ most active CSU April forecasts for each category. There’s lots of overlap from category to category, which is intuitive, though they’re not necessarily all the same years from category to category.

 To clarify in case anyone is wondering, I do not think CSU is trying to sensationalize as I respect them for their objectivity, knowledge, analytical abilities, and clear communication showing how they get their numbers. I still think the season will be very active even if this April CSU forecast ends up being a bit too bullish.

[Rhino16]

29 minutes ago, GaWx said:

 In bold for seven categories I’m referring to where the respective seasons ended up on average vs the 3-6 seasons’ most active CSU April forecasts for each category. There’s lots of overlap from category to category, which is intuitive, though they’re not necessarily all the same years from category to category.

 To clarify in case anyone is wondering, I do not think CSU is trying to sensationalize as I respect them for their objectivity, knowledge, analytical abilities, and clear communication showing how they get their numbers. I still think the season will be very active even if this April CSU forecast ends up being a bit too bullish.

Thanks. Interested to see updated numbers as the year continues.

[GaWx]

45 minutes ago, Rhino16 said:

Thanks. Interested to see updated numbers as the year continues.

 You’re welcome.
 I’d like to make one more clarification. I wasn’t trying to say they’ve ended up too bullish on average with their April forecasts overall as they, indeed, have actually averaged too bearish with them overall. It is only when they’ve been their most bullish in April that they’ve averaged too bullish.

 For example, I’ll look at their 29 April # of NS forecasts. Although their five most bullish April forecasts ended up 2.8 too high on average, the 29 April forecasts (which include those five very bullish forecasts) actually ended up 2.7 too low on average! Interesting dichotomy of sorts.

[Ed, snow and hurricane fan]

3 hours ago, GaWx said:

 You’re welcome.
 I’d like to make one more clarification. I wasn’t trying to say they’ve ended up too bullish on average with their April forecasts overall as they, indeed, have actually averaged too bearish with them overall. It is only when they’ve been their most bullish in April that they’ve averaged too bullish.

 For example, I’ll look at their 29 April # of NS forecasts. Although their five most bullish April forecasts ended up 2.8 too high on average, the 29 April forecasts (which include those five very bullish forecasts) actually ended up 2.7 too low on average! Interesting dichotomy of sorts.

I haven't compared as you have, but Dr. Klotzbach mentioned in his 2024 prediction recent April forecasts have improved.  Hadley Cell talk makes me wonder, they don't (usually) have time to become extreme, but pieces of mid-level disturbances that break off and come back W as inverted troughs sometimes spin up.  Locally (NW Gulf), Edouard and Humberto come to mine, Lee was badly sheared, making landfall in Louisiana with no rain of the W side in 2011, but it blew down the powerlines that started the Bastrop fire E of Austin.  Rural country, but 1700 structures destroyed in 7 weeks, two dead.    Even if the MDR is a bit suppressed, US threat is not zero.  Alicia, last major to landfall inside NWS HGX CWA over 40 years ago, was of non-tropical origin.  

First day of fire, I didn't think trees that green would burn.  But rainless tropical storm and no rain all summer.  Below video from day fire started, between Bastrop and La Grange.

 

 

[Eskimo Joe]

Aren't La Nina summers historically a higher risk for landfall along the east coast of the United States?

[GaWx]

On 4/7/2024 at 8:25 PM, Eskimo Joe said:

Aren't La Nina summers historically a higher risk for landfall along the east coast of the United States?

Interesting dichotomy when looking at # of TCs producing H force winds summer/fall somewhere VA north broken down by ENSO :

1956-2023:

La Nina: 0 storms out of 23 seasons

Neutral: 4

El Nino: 3

 

1851-1955:

La Nina: 12 storms during 24 seasons/9 seasons of the 24 (3 during 1954 and 2 during 1869)

Neutral: 5

El Nino: 2

 

1851-2023:

La Nina: 12 storms during 47 seasons/9 seasons of the 24

Neutral: 9

El Nino: 5

 

 So, for the period 1851-1955, somewhere VA north had H winds on average once every other La Nina/during 38% of them but have had none the last 23 La Nina seasons! Also, whereas a portion of VA north during 1851-1955 had H winds on avg once every 5.5 years, that has dropped to only once every 9.5 years 1956-2023. Could climate change be playing a role or are these changes mainly due to other factors including randomness?

[MJO812]

[Windspeed]

Fantastic thread about long-range MDR and an equatorial Atlantic Nino vs ENSO Nina event; furthermore, any implications on the upcoming Atlantic Hurricane season.

[WxWatcher007]

I’m solidly on the hyperactive train for this season, but we’ll need to see what happens in the eastern Atlantic with stability. I doubt SAL is a big inhibitor this season but we’ll see. A number of the big dog seasons have meaningful activity in spite of the SAL peak mid-summer. 

[GaWx]

  Based on a recent analysis I did, the threat for CONUS landfalls appears to have been the highest when the ASO ONI was 0.0 to -1.0 with closer to just an average threat for sub -1.0. The April dynamic model avg is only down to weak La Nina (-0.7) for ASO. If that were to verify, even with a adjustment further down for RONI, that might be kind of scary as far as CONUS landfall history suggests depending on how RONI lines up with ONI. Hopefully, ASO ONI will come in lower than -0.7. Some of the individual models like UKMET (a very good model) give hope for that.

Of the more followed dynamic models for ASO:
- UKMET is the implied coldest for ASO but it doesn't go that far. It is -1.3 for JAS, which implies a bit colder than that for ASO. It did very well last year and thus I like seeing it this strong.
- CFS had by far been the coldest for ASO at -1.9, but it has since warmed considerably to -1.3. It tended to be too cold last year.
- Next is the CMC, which is -1.1 in ASO.
- JMA is -0.7 in ASO, right at the average. In general, the JMA has averaged only a small bias and thus has been a pretty good model. That's concerning to me for the CONUS risk.
- Then comes MeteoFrance's -0.4 as of ASO, but it was way too warm for last year.
- Next is the Euro's -0.2, which is considerably warmer than last month's run. It also has a warm bias though it wasn't nearly as off as MeteoFrance was last year.
- Bringing up the rear is Australia's Access's +0.1 though it like MeteoFrance was way too warm last year.

[Rtd208]

https://www.foxweather.com/weather-news/saharan-air-layer-tropical-cyclone-impact

[WxWatcher007]

Definitely something to watch. We’ll see what happens. In the meantime, I wonder if we’ll pick back up in the preseason TC genesis department this year. 

[WxWatcher007]

First lemon

[AU74]

From the Washington Post: 

Forecast group predicts busiest hurricane season on record with 33 storms

University of Pennsylvania climate scientist Michael Mann cites record ocean warmth as key factor in unprecedented Atlantic forecast

A research team led by University of Pennsylvania climate scientist Michael Mann is predicting the upcoming Atlantic hurricane season will produce the most named storms on record, fueled by exceptionally warm ocean waters and an expected shift from El Niño to La Niña. The new forecast, issued Wednesday, calls for a range of 27 to 39 named storms, with a best guess of 33. The most on record was 30 named storms in 2020.

Gift link: https://wapo.st/3JBWmIZ

 

[Normandy]

Part of me thinks it would be hilarious if after all this hype the season busted (meaning ends up just average or slightly below average).  The parameters suggest, however, that this season will be a painful blow.  Just have to hope for a bit of luck with tracks and intensity timing of each storm

[GaWx]

1 hour ago, Normandy said:

Part of me thinks it would be hilarious if after all this hype the season busted (meaning ends up just average or slightly below average).  The parameters suggest, however, that this season will be a painful blow.  Just have to hope for a bit of luck with tracks and intensity timing of each storm

 As a near coastal resident, 100% of me would love for that to happen even though I’m certainly not betting on it as the odds aren’t good. Regardless, one of the top analogs cited by at least two well-known forecasters in April is 2010 because the MDR in March of 2010 was the 2nd warmest since at least 1981 and only barely behind March of 2024 (gray line just below blue line):

 In addition and similar to what’s forecasted for 2024, 2010 was La Niña that followed strong El Niño. So, there’s a decent amount of hope for the CONUS to luck out with 2024 tracks ending up similar to 2010. I say “hope” because in 2010 the CONUS had no H hits and only 2 TS that had direct effects (with one only a minimal TS). This was despite it being a very active season with a whopping 12 H and 5 MH, similar to where 2024 seems to be heading as of now.

 In 2010 (see image below), there were a whopping 8 NS that formed E of 42W. Even when looking at the aggregate of non-El Nino seasons, a large majority of those still don’t make it to the US even though a higher % do vs those during El Niño seasons. Fortunately for the US none made it past 75W, not shocking based on history.
 There were 7 that formed W of 70W. Not surprisingly, all affected land. Belize and MX were particularly hard hit from this group. The two TS that affected the US were from this group.

 

 Though not noted as an analog, 1995 (see image below) was another very active season with 11 H and 5 MH and with somewhat similar tracks. It also was La Niña that followed El Niño. Out of 12 NS that formed E of 72W, none hit the CONUS. But from the 7 that formed W of 73W, unfortunately 5 hit the US including 2 H (one H hit twice)(1 MH), very different from 2010.

[Ed, snow and hurricane fan]

I've been wondering about your ONI/US landfall correlation in prior cold ENSO seasons.  Far above normal NS but below normal US impacts, something most people would like.  I'm sensing another strong STR for Texas, and an early season TS/Cat 1 with some decent rain before the oven kicks on wouldn't bother me. 

42 minutes ago, GaWx said:

 As a near coastal resident, 100% of me would love for that to happen even though I’m certainly not betting on it as the odds aren’t good. Regardless, one of the top analogs cited by at least two well-known forecasters in April is 2010 because the MDR in March of 2010 was the 2nd warmest since at least 1981 and only barely behind March of 2024 (gray line just below blue line):

 In addition and similar to what’s forecasted for 2024, 2010 was La Niña that followed strong El Niño. So, there’s a decent amount of hope for the CONUS to luck out with 2024 tracks ending up similar to 2010. I say “hope” because in 2010 the CONUS had no H hits and only 2 TS that had direct effects (with one only a minimal TS). This was despite it being a very active season with a whopping 12 H and 5 MH, similar to where 2024 seems to be heading as of now.

 In 2010 (see image below), there were a whopping 8 NS that formed E of 42W. Even when looking at the aggregate of non-El Nino seasons, a large majority of those still don’t make it to the US even though a higher % do vs those during El Niño seasons. Fortunately for the US none made it past 75W, not shocking based on history.
 There were 7 that formed W of 70W. Not surprisingly, all affected land. Belize and MX were particularly hard hit from this group. The two TS that affected the US were from this group.

 

 Though not noted as an analog, 1995 (see image below) was another very active season with 11 H and 5 MH and with somewhat similar tracks. It also was La Niña that followed El Niño. Out of 12 NS that formed E of 72W, none hit the CONUS. But from the 7 that formed W of 73W, unfortunately 5 hit the US including 2 H (one H hit twice)(1 MH), very different from 2010.

 

[GaWx]

14 hours ago, Ed, snow and hurricane fan said:

I've been wondering about your ONI/US landfall correlation in prior cold ENSO seasons.  Far above normal NS but below normal US impacts, something most people would like.  I'm sensing another strong STR for Texas, and an early season TS/Cat 1 with some decent rain before the oven kicks on wouldn't bother me. 

 

 To clarify: What I actually found for the aggregate of moderate to strong La Niña ONI already by ASO was an AVG of NN H hits rather than BN H US impacts. Of course that’s just an avg as there were still some mod to strong Niña years by ASO that were bad for the US. But the avg for weak Niña or cold neutral ONI in ASO was worse with AN H hits on US. No matter what, there’s still a lot of variability/randomness of course.