2024 Indicators: SST's, MSLP, Shear, SAL, Steering, Instability (Day 16+ Climate Models)

[SFLcane]

New NMME for May..

[LarryWx]

New NMME for May..

https://i.postimg.cc/MGLkt0Tv/HKHKHKHHK.png

https://i.postimg.cc/8chq1qb6/JKJKJKJ.png

This NMME run is slightly warmer in the MDR than the prior run and is forecasting near the record high 2023 anomalies fwiw.

[Deshaunrob17]

Nothing is ever a sure thing in weather.

 https://x.com/BenNollWeather/status/1787556232221606095

Does anyone recall examples of the other way round, where ECMWF shows high precipitation anomalies only for the season to turn out much less active? (Other than extreme bust years like 2013, of course)

I did a quick look at the ECMWF's official site which has data up to 2017. The only notable one I could find was 2022, which shows a rather extensive chunk of wet anomalies just north of South America. However, they seem rather localized and suppressed to the south, while 2024's forecast is much more extensive with wet anomalies all over the MDR.

https://i.postimg.cc/3xZJW5tY/image.png
https://i.postimg.cc/CKPhHCy2/image.png

Also, just like 2020, the 2017 ECMWF forecasts were even more of a nothingburger:

https://i.postimg.cc/xT3S3GMP/image.png

In 2017 , the Euro was one model that had us going into El Niño , but that never happened. I remember the days when we were talking about the EURO and it’s warm ENSO bias . Seems like the model got better with this since then

[LarryWx]

The MDR avg anomaly just went back to barely higher than 2010 to being again the warmest on record back to 1982

https://kouya.has.arizona.edu/tropics/MDRsst.png

[cycloneye]

NMME May run: The September one has a split of precipitation, between evading the NE Caribbean islands and more Central/ Western Caribbean precipitation. Also notable is dry air NE of South America.

August and September:

[chaser1]

What I find interesting about the possible steering pattern is no Western Heat Doom-Death Ridge yet and nothing on the models. In the last five years by early May, the Western Death Ridge was already becoming established in the SW. Due to the lack of a mean Western Heat Doom-Death Ridge, the downstream pattern across North America is much more progressive this spring and will likely remain that way for the foreseeable future.

I was looking at that as well, along with the reinforcing May CANSIP summer month 500mb height forecasts for the Atlantic basin also seemingly above average as well. Putting that last thought aside for just a moment and assuming that we do in fact have a more progressive zonal pattern over North America, the overall implication would seem to be less of a "break" for storms to feel that poleward tug toward the westerlies. Now add to the mix that July/August/September could have anomalous mid-level (east/west) ridging between 15N-30N and two thoughts come to mind. A potential outcome could be July/August tropical storm tracks that simply continue to slide westward where Central America and Yucatan would receive the overall brunt of landfalls. The other thought is how crazy low the W. Caribbean SSP's are forecast to be along with the "uber-high" precip anomaly bullseye that is most focused toward the southwest Caribbean throughout most of the season. The May CANSIP precip forecast for October shows a increasingly stark precipitation delineation (or gradient) with the entire GOM, Florida and Bahamas showing "below average" while well above average precipitation remains forecast across the Caribbean (from about 23N southward). Typically speaking, October spells the greatest risk for a Florida landfall yet this long-range Oct forecast would seem to imply against that.

It goes without saying, that all this conjecture is based on 1) broad average CANSIP forecasts 2) at a long range 3) and even if broadly verifying, is not created to identify or forecast meso or short-term forecasts. More than anything, this is just a thought experiment with regard to potential W. Atlantic basin storm track motion and storm tracks that originate from the MDR/lower latitudes. From the CANSIPS and EURO alone, I'd probably guess that a fair degree of other tropical genesis during July, August, and September could well occur anywhere in the near-shore waters of the Greater Antilles, Bahamas, Florida and GOM. Without any significant W. Atlantic or CONUS troughing however, I'd have to guess that motion within a broad region of mid-level ridging would generally be slowly westward.

I've never been much into trying to forecast ACE but here's a thought about that for this season. The many professional and nonprofessional ACE forecasts imply to me that most people are anticipating a fair number of long storm tracks and Cape Verde development. That could well happen; Or the fly in the ointment that we never seem to be able to foretell will be mid-level humidity/dry air (SAL induced or otherwise). Depending on when LaNina conditions truly begin to impact the W. Atlantic basin, mid-level low humidity could potentially spell less long storm tracks and also impact the number of major hurricanes to develop.

[toad strangler]

 https://twitter.com/dylanfedericowx/status/1787886881943814198

[zzzh]

Caribbean SST is now about where it would typically be on Aug. 30
Edit: added a dashed line for comparison

[SFLcane]

[jlauderdal]

 https://twitter.com/dylanfedericowx/status/1787886881943814198

Rather disturbing seasonal forecasts even if 25% too high.

[Category5Kaiju]

https://i.imgur.com/3kZLc7x.png
Caribbean SST is now about where it would typically be on Aug. 30
Edit: added a dashed line for comparison

Wow, that recent jump in warming rate is pretty alarming. If you extrapolate the instantaneous rate of warming, it is basically equivalent to roughly 2.5-3 degrees C per one month.

[NotSparta]

https://i.imgur.com/3kZLc7x.png
Caribbean SST is now about where it would typically be on Aug. 30
Edit: added a dashed line for comparison

Yeah the Caribbean has been going wild lately. Warmth is definitely a little more west based than last year. Feels like it has to come down soon with a look like that

[skyline385]

Latest EPS weekly still showing chances in first week of June in line with the MJO passage

[chaser1]

https://twitter.com/dylanfedericowx/status/1787886881943814198?s=46

That's it! You went ahead and made me do it. Time to issue a Silver Alert for Uncle SAL.

Last seen in Western Africa and looking rather "hazy". Might be a good time to bring SAL home here in the Western Atlantic basin
a bit earlier then normal

[TheWisestofAll]

I know it currently doesn’t seem likely based on this latest Euro, but I’ll reiterate that there’s still good reason to hope that the very active 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. There’s been a pretty clear pattern when they’ve gone very active in April:

-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!

-#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.

-# 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.

-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!

But OTOH even if they were to miss these 4 categories too high by these averages there’d still be 75 NS days, 8 H, 3 MH, and 124 ACE, not a quiet season. Also, it sometimes only takes only a few or even just one to make it a bad season for land impacts. So, a lot of luck will be needed, regardless!

It was discussed here in a while ago, but it's generally recommended to separate CSU's forecasts between two different periods: 1995-2014, and 2014-Persent. Forecast skill has improved so significantly between the two that the first period isn't applicable to today, in which case 2022 is the only season where things didn't really pan out. Every other year either verified or over-verified the April forecast.

[Cat5James]

https://twitter.com/dylanfedericowx/status/1787886881943814198?s=46

That's it! You went ahead and made me do it. Time to issue a Silver Alert for Uncle SAL.

Last seen in Western Africa and looking rather "hazy". Might be a good time to bring SAL home here in the Western Atlantic basin
a bit earlier then normal

A sloppy tropical storm that brings needed rain to west coast FL wouldn’t be the worst thing.

[LarryWx]

I know it currently doesn’t seem likely based on this latest Euro, but I’ll reiterate that there’s still good reason to hope that the very active 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. There’s been a pretty clear pattern when they’ve gone very active in April:

-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!

-#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.

-# 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.

-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!

But OTOH even if they were to miss these 4 categories too high by these averages there’d still be 75 NS days, 8 H, 3 MH, and 124 ACE, not a quiet season. Also, it sometimes only takes only a few or even just one to make it a bad season for land impacts. So, a lot of luck will be needed, regardless!

It was discussed here in a while ago, but it's generally recommended to separate CSU's forecasts between two different periods: 1995-2014, and 2014-Persent. Forecast skill has improved so significantly between the two that the first period isn't applicable to today, in which case 2022 is the only season where things didn't really pan out. Every other year either verified or over-verified the April forecast.

That’s not encouraging. And 2022 still had the beast, Ian.

[skyline385]

I know it currently doesn’t seem likely based on this latest Euro, but I’ll reiterate that there’s still good reason to hope that the very active 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. There’s been a pretty clear pattern when they’ve gone very active in April:

-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!

-#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.

-# 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.

-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!

But OTOH even if they were to miss these 4 categories too high by these averages there’d still be 75 NS days, 8 H, 3 MH, and 124 ACE, not a quiet season. Also, it sometimes only takes only a few or even just one to make it a bad season for land impacts. So, a lot of luck will be needed, regardless!

It was discussed here in a while ago, but it's generally recommended to separate CSU's forecasts between two different periods: 1995-2014, and 2014-Persent. Forecast skill has improved so significantly between the two that the first period isn't applicable to today, in which case 2022 is the only season where things didn't really pan out. Every other year either verified or over-verified the April forecast.

That’s not encouraging. And 2022 still had the beast, Ian.

I mean, the AMO setup right now is just too good to imagine that 23/11/5 will under-verify in my opinion. I have a tendency to remain bearish typically but the setup this year just looks incredible to imagine anything holding the NATL back which is why we have got all our preparations in place already. The NATL just absolutely loves ENSO -ve transitioning years (2020, 2017, 2010, 2005, etc) and with a record warmth +AMO set up, its hard to stay bearish when you look at the numbers from the years I just mentioned and consider that they didnt even have that much warmth compared to what we have right now. 2023 NATL which had almost similar levels of SST managed to shut down the WPAC during September in a strong Nino year which is just an incredible feat to achieve so now as we are moving into a ENSO -ve season which as I mentioned earlier, the NATL absolutely loves and while maintaining the same levels of SSTs & transitioning into a very classic +AMO, its just hard to see how we will under-achieve.

[Category5Kaiju]

It was discussed here in a while ago, but it's generally recommended to separate CSU's forecasts between two different periods: 1995-2014, and 2014-Persent. Forecast skill has improved so significantly between the two that the first period isn't applicable to today, in which case 2022 is the only season where things didn't really pan out. Every other year either verified or over-verified the April forecast.

That’s not encouraging. And 2022 still had the beast, Ian.

I mean, the AMO setup right now is just too good to imagine that 23/11/5 will under-verify in my opinion. I have a tendency to remain bearish typically but the setup this year just looks incredible to imagine anything holding the NATL back which is why we have got all our preparations in place already. The NATL just absolutely loves ENSO -ve transitioning years (2020, 2017, 2010, 2005, etc) and with a record warmth +AMO set up, its hard to stay bearish when you look at the numbers from the years I just mentioned and consider that they didnt even have that much warmth compared to what we have right now. 2023 NATL which had almost similar levels of SST managed to shut down the WPAC during September in a strong Nino year which is just an incredible feat to achieve so now as we are moving into a ENSO -ve season which as I mentioned earlier, the NATL absolutely loves and while maintaining the same levels of SSTs & transitioning into a very classic +AMO, its just hard to see how we will under-achieve.

At this point unless something truly unimaginable happens, I think we're locked in for an active season.

With that being said....I think it's still interesting and fun to discuss the next step, which is HOW IMPACTFUL this season will be? Will it be mainly a nightmare for the Gulf, kind of like 2005 and 2020? Will it have storms fly out to sea and miss land like 2010? Or will it kind of be like hell for a whole bunch of people, including Florida and the Caribbean islands (kind of like 2017 or 1933?)

[jlauderdal]

https://twitter.com/dylanfedericowx/status/1787886881943814198?s=46

That's it! You went ahead and made me do it. Time to issue a Silver Alert for Uncle SAL.

Last seen in Western Africa and looking rather "hazy". Might be a good time to bring SAL home here in the Western Atlantic basin
a bit earlier then normal

A sloppy tropical storm that brings needed rain to west coast FL wouldn’t be the worst thing.

Getting the rainy season underway would be goos, this is a tough time of the year, hot and dry, looks like moisture arriving over the weekend.