2021 Indicators: SST's / SAL / MSLP / Shear / Steering / Instability / Sat Images
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- cycloneye
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Re: Expert forecasts for 2021 North Atlantic Hurricane Season
The Caribbean Sea so far this year is less warm than in 2020. Hopefully, we dont have to deal with monster hurricanes in the Islands because for example, in Puerto Rico there are still homes with blue tarps and the electric grid is still not great after the double hits from Irma and Maria.
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Re: Expert forecasts for 2021 North Atlantic Hurricane Season: Crownweather Services is up
wxman57 wrote:aspen wrote:Shell Mound wrote:By “significant,” I assume you mean major hurricanes. If so, then you are definitely correct, as 2018–20 has only seen MH Lorenzo (2019) in the MDR south of 18°N.
Teddy was pretty close, though. It was around the Cat 2/3 border less than a degree north of 18N. We can attribute 2020’s MDR struggles to the state of the ITCZ: rather far north and pumping out huge waves that took a while to consolidate.
Teddy, too, formed in the MDR and quickly moved north and strengthened. It didn't track westward to the Caribbean. If such hostile conditions continue east of the Caribbean, then the eastern islands may get another break this season.
Taking a look at SST anomalies, the eastern Atlantic has a cool anomaly near Africa vs. a warm anomaly last year. Generally, the MDR is cooler so far this year.
http://wxman57.com/images/AtlSSTs.JPG
That’s quite the difference...but didn’t 2020 also have a pre-season stretch with a cooler than normal MDR?
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- Iceresistance
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Re: Expert forecasts for 2021 North Atlantic Hurricane Season: Crownweather Services is up
wxman57 wrote:aspen wrote:Shell Mound wrote:By “significant,” I assume you mean major hurricanes. If so, then you are definitely correct, as 2018–20 has only seen MH Lorenzo (2019) in the MDR south of 18°N.
Teddy was pretty close, though. It was around the Cat 2/3 border less than a degree north of 18N. We can attribute 2020’s MDR struggles to the state of the ITCZ: rather far north and pumping out huge waves that took a while to consolidate.
Teddy, too, formed in the MDR and quickly moved north and strengthened. It didn't track westward to the Caribbean. If such hostile conditions continue east of the Caribbean, then the eastern islands may get another break this season.
Taking a look at SST anomalies, the eastern Atlantic has a cool anomaly near Africa vs. a warm anomaly last year. Generally, the MDR is cooler so far this year.
http://wxman57.com/images/AtlSSTs.JPG
Also, I noticed the GOM is WARMER compared to last year, could we have a Rita-like Hurricane there?
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Bill 2015 & Beta 2020
Winter 2020-2021
All observations are in Tecumseh, OK unless otherwise noted.
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Winter 2020-2021

All observations are in Tecumseh, OK unless otherwise noted.
Winter posts are focused mainly for Oklahoma & Texas.
Take any of my forecasts with a grain of salt, refer to the NWS, SPC, and NHC for official information
Never say Never with weather! Because ANYTHING is possible!
Re: 2021 Indicators: SST's / SAL / MSLP / Shear / Steering / Instability / Sat Images
Apologies if my previous post here was lengthy, but I really wanted to have discussion about the above-average SST’s in the Gulf Loop and the East Coast.
Having both of those being super high leads me to believe a higher chance of significant GoM AND NE US Coast impacts in the same season even though it is extremely rare or even unheard of.
Climate changing means “times a changin” to me.
If the MDR is average or same as last year, minus the ITCZ being weird, I would think 2004/2017 type long-trackers are possible, but they don’t become incredibly strong until close to land.....sadly.
Having both of those being super high leads me to believe a higher chance of significant GoM AND NE US Coast impacts in the same season even though it is extremely rare or even unheard of.
Climate changing means “times a changin” to me.
If the MDR is average or same as last year, minus the ITCZ being weird, I would think 2004/2017 type long-trackers are possible, but they don’t become incredibly strong until close to land.....sadly.
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- Iceresistance
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Re: 2021 Indicators: SST's / SAL / MSLP / Shear / Steering / Instability / Sat Images
ClarCari wrote:Apologies if my previous post here was lengthy, but I really wanted to have discussion about the above-average SST’s in the Gulf Loop and the East Coast.
Having both of those being super high leads me to believe a higher chance of significant GoM AND NE US Coast impacts in the same season even though it is extremely rare or even unheard of.
Climate changing means “times a changin” to me.
If the MDR is average or same as last year, minus the ITCZ being weird, I would think 2004/2017 type long-trackers are possible, but they don’t become incredibly strong until close to land.....sadly.
A Hurricane becoming very strong near land is the Last Thing anyone what's to see & hear . . .
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Bill 2015 & Beta 2020
Winter 2020-2021
All observations are in Tecumseh, OK unless otherwise noted.
Winter posts are focused mainly for Oklahoma & Texas.
Take any of my forecasts with a grain of salt, refer to the NWS, SPC, and NHC for official information
Never say Never with weather! Because ANYTHING is possible!
Winter 2020-2021

All observations are in Tecumseh, OK unless otherwise noted.
Winter posts are focused mainly for Oklahoma & Texas.
Take any of my forecasts with a grain of salt, refer to the NWS, SPC, and NHC for official information
Never say Never with weather! Because ANYTHING is possible!
- DestinHurricane
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Re: Expert forecasts for 2021 North Atlantic Hurricane Season: Crownweather Services is up
Iceresistance wrote:wxman57 wrote:aspen wrote:Teddy was pretty close, though. It was around the Cat 2/3 border less than a degree north of 18N. We can attribute 2020’s MDR struggles to the state of the ITCZ: rather far north and pumping out huge waves that took a while to consolidate.
Teddy, too, formed in the MDR and quickly moved north and strengthened. It didn't track westward to the Caribbean. If such hostile conditions continue east of the Caribbean, then the eastern islands may get another break this season.
Taking a look at SST anomalies, the eastern Atlantic has a cool anomaly near Africa vs. a warm anomaly last year. Generally, the MDR is cooler so far this year.
http://wxman57.com/images/AtlSSTs.JPG
Also, I noticed the GOM is WARMER compared to last year, could we have a Rita-like Hurricane there?
Why specifically a Rita like hurricane? The higher SST near land could suggest a storm that strengthens up to landfall like Michael. If I remember correctly, Rita weakened before landfall.
Many experts are predicting more of a year like 2011 or 2010 with a lot of storms forming in the MDR recurving, that wouldn't really be like Rita.
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Michael 2018
- SFLcane
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Re: Expert forecasts for 2021 North Atlantic Hurricane Season
wxman57 wrote:aspen wrote:Shell Mound wrote:By “significant,” I assume you mean major hurricanes. If so, then you are definitely correct, as 2018–20 has only seen MH Lorenzo (2019) in the MDR south of 18°N.
Teddy was pretty close, though. It was around the Cat 2/3 border less than a degree north of 18N. We can attribute 2020’s MDR struggles to the state of the ITCZ: rather far north and pumping out huge waves that took a while to consolidate.
Teddy, too, formed in the MDR and quickly moved north and strengthened. It didn't track westward to the Caribbean. If such hostile conditions continue east of the Caribbean, then the eastern islands may get another break this season.
Taking a look at SST anomalies, the eastern Atlantic has a cool anomaly near Africa vs. a warm anomaly last year. Generally, the MDR is cooler so far this year.
http://wxman57.com/images/AtlSSTs.JPG
They are cooler thats great but it’s early March. Things quickly turn around with 4-5 months still go before we even look out near the main development region. Unfortunately most of the climate models are focusing the upward motion over Africa during ASO.
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- weeniepatrol
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- Kingarabian
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Re: 2021 Indicators: SST's / SAL / MSLP / Shear / Steering / Instability / Sat Images
weeniepatrol wrote:[url]https://twitter.com/BenNollWeather/status/1371455642410618880[url]
Looks pretty decent for the EPAC too.
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Re: 2021 Indicators: SST's / SAL / MSLP / Shear / Steering / Instability / Sat Images
El Nino or not, I can't remember in recent years that the Atlantic SSTs were actually completely unfavorable for development. Regardless of their state during the spring, unlike the EPAC, I think SST's across the Atlantic will always be sufficient enough to aid hurricane development. The key inhibitors have usually been the strength and positioning of dry air and shear. And those two variables are hard to figure out preseason.
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Re: 2021 Indicators: SST's / SAL / MSLP / Shear / Steering / Instability / Sat Images
It's many years since the last time I saw this classic -PDO show up on a SST anomalies map.


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- SFLcane
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Re: 2021 Indicators: SST's / SAL / MSLP / Shear / Steering / Instability / Sat Images
NDG wrote:It's many years since the last time I saw this classic -PDO show up on a SST anomalies map.
https://i.imgur.com/V2uTatC.png
Yeah it's the first since 2010-2011 or so I think.
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- DorkyMcDorkface
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Re: 2021 Indicators: SST's / SAL / MSLP / Shear / Steering / Instability / Sat Images
NDG wrote:It's many years since the last time I saw this classic -PDO show up on a SST anomalies map.
https://i.imgur.com/V2uTatC.png
Also -NPMM.
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Please note the thougths expressed by this account are solely those of the user and are from a hobbyist perspective. For more comprehensive analysis, consult an actual professional meteorologist or meteorology agency.
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Re: 2021 Indicators: SST's / SAL / MSLP / Shear / Steering / Instability / Sat Images
DorkyMcDorkface wrote:NDG wrote:It's many years since the last time I saw this classic -PDO show up on a SST anomalies map.
https://i.imgur.com/V2uTatC.png
Also -NPMM.
What are -PDO and -NPMM, and how will they impact this season if they hold?
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I am only a meteorology enthusiast who knows a decent amount about tropical cyclones. Look to the professional mets, the NHC, or your local weather office for the best information.
I am only a meteorology enthusiast who knows a decent amount about tropical cyclones. Look to the professional mets, the NHC, or your local weather office for the best information.
Re: 2021 Indicators: SST's / SAL / MSLP / Shear / Steering / Instability / Sat Images
aspen wrote:DorkyMcDorkface wrote:NDG wrote:It's many years since the last time I saw this classic -PDO show up on a SST anomalies map.
https://i.imgur.com/V2uTatC.png
Also -NPMM.
What are -PDO and -NPMM, and how will they impact this season if they hold?
It usually means a quiter EPAC season and a more active N Atlantic season.
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- DorkyMcDorkface
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Re: 2021 Indicators: SST's / SAL / MSLP / Shear / Steering / Instability / Sat Images
aspen wrote:DorkyMcDorkface wrote:NDG wrote:It's many years since the last time I saw this classic -PDO show up on a SST anomalies map.
https://i.imgur.com/V2uTatC.png
Also -NPMM.
What are -PDO and -NPMM, and how will they impact this season if they hold?
PDO is Pacific Decadal Oscillation, PMM is Pacific Meridional Mode (or in this case, NPMM is North Pacific Meridional Mode). They do have an (indirect) influence on the Atlantic as they typically correspond to the ENSO state, and also influence EPAC activity as a result. I'll use the two most recent strong ENSO events on the opposite side of the spectrum as an example: 2010-11's Niña and 2015-16's El Niño. I picked Sep. 10th for these charts as it is the peak of the Atlantic season.
For 2010-11 we had a strong -PDO and -NPMM signature which corresponds with the Niña that was in progress at the time:

Regarding the aforementioned influence on the EPAC, this is obviously a very unfavorable look for that basin. Given that high EPAC activity tends to provide strong shear to the Western Atlantic, the lack of said activity thanks to the coolness (relative to average) of the Northeastern Pacific that year helped open the door for a hyperactive Atlantic season (although the record levels of warmth in the Atlantic MDR certainly helped as well).
Likewise, 2015-16's El Niño event had a well-defined positive PDO/NPMM signature. EPAC/CPAC were extremely active that year, so I'm sure you can connect the dots:

As you can probably tell by now both of these can basically serve to reinforce whatever ENSO state is present, although there are times where they can contrast (+PDO/PMM with -ENSO and -PDO/PMM with -ENSO) but these tandems are relatively rare. Since we have -ENSO combined with a -NPMM/PDO signal, signs are pointing towards -ENSO persisting as the state of the NE Pacific will likely help reinforce the current ENSO background state, which will definitely help the Atlantic in that regard.
(apologies if I deviated into ENSO chatter outside of the actual ENSO thread, in this case it's relevant)
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- SFLcane
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Re: 2021 Indicators: SST's / SAL / MSLP / Shear / Steering / Instability / Sat Images
NDG wrote:aspen wrote:DorkyMcDorkface wrote:Also -NPMM.
What are -PDO and -NPMM, and how will they impact this season if they hold?
It usually means a quiter EPAC season and a more active N Atlantic season.
Yeah Pacific looks fine for now. Atlantic SSTs will determine if it's a busy-ish or extremely busy season probably.
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- cycloneye
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Re: 2021 Indicators: SST's / SAL / MSLP / Shear / Steering / Instability / Sat Images
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Visit the Caribbean-Central America Weather Thread where you can find at first post web cams,radars
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Re: 2021 Indicators: SST's / SAL / MSLP / Shear / Steering / Instability / Sat Images
1999 is the top analog year on Tropical Tidbits for the current SST anomalies. 2010 and 2011 currently remain strong analogues based on the NNME forecasts.
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- wxman57
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Re: 2021 Indicators: SST's / SAL / MSLP / Shear / Steering / Instability / Sat Images
Just saw this video on YouTube. Hypothetical 2021 Atlantic hurricane season. I counted about 44 named storms. Used the entire supplementary list. Two Cat 5s into SE Florida and one Cat 3 into SW Florida peninsula. Uh oh!
https://www.youtube.com/watch?v=Udh_Jn7nZZs&t=339s
https://www.youtube.com/watch?v=Udh_Jn7nZZs&t=339s
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