2017 indicators: SST's / MSLP / SAL / Steering / Instability

[NDG]

With the NAO going negative over the next couple of weeks expect the MDR waters to stay above average if not get even warmer. IMO.

I feel silly asking as long as I've been following weather but what are the general effects of the NAO on Atlantic activity?

A negative NAO usually means a weaker Azores Surface High Pressure, so weaker easterly trade winds across the Atlantic MDR more chance for tropical waves coming out of Africa to organize.

[AtlanticWind]

Wasn't sure what thread to pose this question for our pro mets.

I was just curious if Hurricane forecasts tracks are performed better/worse in other basins.
For example does the NHC do better on tracks in the Eastern Pacific compared to the Atlantic .

Also does the NHC do better/worse than other forecasting agencies around the globe.
And if so is because atmospheric conditions are more difficult to forecast in some basins rather than others?

Thanks

[WeatherEmperor]

https://twitter.com/MJVentrice/status/8 ... 8846874624


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[RL3AO]

Wasn't sure what thread to pose this question for our pro mets.

I was just curious if Hurricane forecasts tracks are performed better/worse in other basins.
For example does the NHC do better on tracks in the Eastern Pacific compared to the Atlantic .

Also does the NHC do better/worse than other forecasting agencies around the globe.
And if so is because atmospheric conditions are more difficult to forecast in some basins rather than others?

Thanks

NHC has a large amount of information available relating to verification.

http://www.nhc.noaa.gov/verification/verify5.shtml

In general, NHC does better in the EPac. This makes sense when you consider most EPac hurricanes generally move in one direction and have little land interaction.

As for other basins, I'm not sure how much verification information is available since JTWC is a military forecast center.

[AutoPenalti]

https://twitter.com/MJVentrice/status/889806388846874624


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Finally! It's the first REAL breakthrough of the season.

[cycloneye]

https://twitter.com/MJVentrice/status/889806388846874624


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The lid will be off very soon.

[Steve]

https://twitter.com/MJVentrice/status/889806388846874624


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The lid will be off very soon.

Have you seen the late July CFSV2 seasonal forecasts yet? I can only get 6/22's for A-S-O. I'm looking to see if there remain anomalies where they had them last month. The June ones had lower precipitation near Latin America (Western Caribbean) and also over the central Gulf. The weekly ones (through July 23) have modified some with more precipitation just west of Florida in Week 3. I want to see if there are any model hints for the late summer and fall. Thanks.

[tolakram]

I just noticed that while the tropical Atlantic vertical instability graph makes it look like years past, but the anomaly image paint's a different picture.





There is a strong area of low instability in the middle of the tropical Atlantic, most likely due to the July dust outbreak, but the remaining parts of the basin are near to above normal. This is a big difference from years past.

I have no idea if it means anything or not, so my prediction is still for a normal season, but I think one has to objectively recognize that conditions that caused issues in past seasons are not present this year.

[Hammy]

The suppressive MJO/Kelvin waves are also likely contributors to the below normal instability at the moment. Most indicators showed the latter part of July (and potentially first week of August) being quite unfavorable for development even before the conditions arrived.

[WeatherEmperor]

https://twitter.com/MJVentrice/status/8 ... 2038463489

The NAO is currently negative and forecast to remain such way for the next 7-10 days. Ventrice tweeted about a big heat wave next week in the western US indicative of a huge high pressure ridge out west and through on the east coast...which matches with the -NAO.

Need to keep an eye on this as we approach the peak of the season as this can have implications on the steering of tropical cyclones as they approach the US coast.


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[TheStormExpert]

 https://twitter.com/bigjoebastardi/status/890057376899969030

[Kingarabian]

https://twitter.com/bigjoebastardi/status/890057376899969030

EPS has been showing higher than normal pressure in the MDR since the spring. It hasn't verified at all.

[Dylan]

Just had a lot of fun reading the Storm2k forums from this time back in 2004. This is just one of the threads in the link below. A lot of the discussion was very similar to what we are talking about 13 years later. Some of the common phrases were " strong Bermuda High", "MJO coming by the beginning of August", "Tropical Atlantic is boiling", "Waves are moving too fast", ect. A lot of the members were comparing 2004 to 1998, like were comparing 2017 to 2004 today. Interesting stuff.

viewtopic.php?f=31&t=34277

[AutoPenalti]

Just had a lot of fun reading the Storm2k forums from this time back in 2004. This is just one of the threads in the link below. A lot of the discussion was very similar to what we are talking about 13 years later. Some of the common phrases were " strong Bermuda High", "MJO coming by the beginning of August", "Tropical Atlantic is boiling", "Waves are moving too fast", ect. A lot of the members were comparing 2004 to 1998, like were comparing 2017 to 2004 today. Interesting stuff.

viewtopic.php?f=31&t=34277

Time has seriously flown by, amazing.

[WeatherEmperor]

https://twitter.com/MJVentrice/status/8 ... 1257956352

2nd Kelvin Wave for the ATL?? That could really help increase development chances in the ATL basin.


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[RL3AO]

https://twitter.com/MJVentrice/status/890149311257956352

2nd Kelvin Wave for the ATL?? That could really help increase development chances in the ATL basin.


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There's the one very strong KW associated with the +MJO that should move through the Atlantic next week.

EDIT: Maybe you were seeing a weaker 2nd wave in mid-August?

[tatertawt24]

Just had a lot of fun reading the Storm2k forums from this time back in 2004. This is just one of the threads in the link below. A lot of the discussion was very similar to what we are talking about 13 years later. Some of the common phrases were " strong Bermuda High", "MJO coming by the beginning of August", "Tropical Atlantic is boiling", "Waves are moving too fast", ect. A lot of the members were comparing 2004 to 1998, like were comparing 2017 to 2004 today. Interesting stuff.

viewtopic.php?f=31&t=34277

Thanks for posting, that was a lot of fun to read. It's kind of eerie reading stuff from that time, knowing what we had coming in that season and the next.

[WeatherEmperor]

https://twitter.com/MJVentrice/status/890149311257956352

2nd Kelvin Wave for the ATL?? That could really help increase development chances in the ATL basin.


Sent from my iPhone 7 using Tapatalk

There's the one very strong KW associated with the +MJO that should move through the Atlantic next week.

EDIT: Maybe you were seeing a weaker 2nd wave in mid-August?

I think I posted something different than what I had intended. Check the below tweet from Ventrice where he talks about this 2nd wave will be like a 1-2 punch.

https://twitter.com/MJVentrice/status/8 ... 8706014210


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[cycloneye]

The experts agree that the next Kelvin Wave will be strong that will turn the Atlantic Active in August.

@webberweather
Monstrous CCKW forecast to enter the Atlantic by next week, wherein KW filtered VP200 anomaly forecasts are exceeding 3.5 sigma. Yikes.

 https://twitter.com/webberweather/status/890034260412956680

[Steve]

LMAO at me fighting with someone whose post must have gotten deleted. They must have called me a Joe B. bootlicker or something. Not a chance. What he says goes in the mix, but it sure wasn't Gospel to me then or now. We all know how 2004 turned out. Many of our friends here and on CFHC were without power for weeks after Frances and Jeanne. Then came Ivan to destroy the Eastern Shore of AL and Pensacola Beach and Pensacola. It turned into a very wild year for the USA. Then came 2005 which I'm just going to ignore for now.

The indicators and dynamics this year would seem to put Florida back in the crosshairs in a few weeks. Bahamas and North may be the main target, but I'd be almost shocked if Florida doesn't take a blow from something.