Seasonal Indicators (Beyond Day 16): Instability / SST's / MSLP / Steering / Sal

[Ntxw]

One thing we have to think about. In the mid latitudes, warmer than normal SST's often is a sign of stronger ridging. Weaker Azores high years (thus sometimes bigger season) are amongst years with the Atlantic tripole. Cooler waters up there is often indicative of lower pressures. It's not as simple as warmer than normal SST's means more activity. The past two seasons much above SST's anoms have coincided with the stronger Bermuda ridge thus reflecting the higher than normal pressures. It is always warm enough to sustain tropical activity during peak season regardless of SST anoms. But the anoms can give hints to upper air patterns.

[tarheelprogrammer]

One thing we have to think about. In the mid latitudes, warmer than normal SST's often is a sign of stronger ridging. Weaker Azores high years (thus sometimes bigger season) are amongst years with the Atlantic tripole. Cooler waters up there is often indicative of lower pressures. It's not as simple as warmer than normal SST's means more activity. The past two seasons much above SST's anoms have coincided with the stronger Bermuda ridge thus reflecting the higher than normal pressures. It is always warm enough to sustain tropical activity during peak season regardless of SST anoms. But the anoms can give hints to upper air patterns.

Thanks for the input and that really broke down if SSTs are important or not in terms of the hurricane season activity.

[TheStormExpert]

We might have a weaker than normal Azores High but what's the strength of the Bermuda High? That will be key in determining if we see storms recurving out to sea or coming close and or affecting land.

[Ntxw]

We might have a weaker than normal Azores High but what's the strength of the Bermuda High? That will be key in determining if we see storms recurving out to sea or coming close and or affecting land.

The Azores and Bermuda high's are essentially the same thing. One is an extension of the other. They move and intensify or weaken accordingly. The SST's anoms gives you a hint of where it is likely located.

[TheStormExpert]

We might have a weaker than normal Azores High but what's the strength of the Bermuda High? That will be key in determining if we see storms recurving out to sea or coming close and or affecting land.

The Azores and Bermuda high's are essentially the same thing. One is an extension of the other. They move and intensify or weaken accordingly. The SST's anoms gives you a hint of where it is likely located.

How was the 2004 hurricane so active in the MDR with such a strong Azores/Bermuda High? One would think there had to be quite a lack of instability and tons of SAL, but there wasn't.

[gatorcane]

I really don't get the emphasis on colder than normal north Atlantic SSTs. As I pointed out before, 2004 saw such anomalies but we know what happened. Note warmer than normal SSTs in the Western Atlantic around Bermuda and Azores area:

[WPBWeather]

I really don't get the emphasis on colder than normal north Atlantic SSTs. As I pointed out before, 2004 saw such anomalies but we know what happened. Note warmer than normal SSTs in the Western Atlantic around Bermuda and Azores area:

It seems the disagreements are on where to look to measure and even what models are accurate for temp measurements. ProMets here on Storm2K disagree and in the greater climo community there is disagreement also.

[Ntxw]

We might have a weaker than normal Azores High but what's the strength of the Bermuda High? That will be key in determining if we see storms recurving out to sea or coming close and or affecting land.

The Azores and Bermuda high's are essentially the same thing. One is an extension of the other. They move and intensify or weaken accordingly. The SST's anoms gives you a hint of where it is likely located.

How was the 2004 hurricane so active in the MDR with such a strong Azores/Bermuda High? One would think there had to be quite a lack of instability and tons of SAL, but there wasn't.

I did a reanalysis from June-Oct 2004. There was much below normal surface pressures of where the Azores high/Bermuda high should be and it was displaced well west (east of Bahamas and off east coast). It actually looks like much weaker than normal high. But the location that it was displaced to is stronger than it relatively is typically thus probably helped steer everything into Florida.

[NDG]

It looks to me that the Azores Surface High was not strong at all during Jul-Sept 2004, ridging was abnormally high across NE US and eastern Canada & extreme NW Atlantic.

[TheStormExpert]

How does this all compare up to this season?

[NDG]

:uarrow: How does this all compare up to this season?

I will hate to make a comparison because season has not started yet and a pattern has not set yet, most models show a strong Azore's High during the hurricane season thus why many think the Atlantic MDR could be below average this season.

But since you asked this is how pressures have run across the Atlantic in average during the past month. Most of the eastern tropical Atlantic pressures have run above average while the Caribbean and GOM have run near average to below average. Pressures just east of Bermuda are running higher than average.
I think the neutral to negative NAO during the past 6 weeks have kept the Azores High at bay so far, maybe why the Atlantic MDR has not cooled as much as many were thinking it was going to do this month.

[HurricaneFan]

Are the models still predicting the NOA to turn positive soon?Why hasn't it turn positive as predicted yet?

[Hurricaneman]

According to NESDIS it looks like the PDO is becoming quite a bit less positive and the Atlantic Tripole is becoming more neutral if not slightly positive

PS The CDAS SSTA chart is showing the drop in PDO but not agreeing on the tropical Atlantic with the NESDIS charts

The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products

[Hurricaneman]

The GFS seems to be showing a weak to non existent Bermuda\Azores high, that would be good news if you like tracking Cape verde systems, but who knows that Azores high may come back with gusto and kill off the MDR but if we keep a weak Bermuda\Azores high it could mean recurves of Tropical cyclones from the MDR but as always we need to watch all factors

PS A Bermuda high that sets up between 50 and 60W and 35 to 40N could spell trouble for the US from Eastern Atlantic waves
The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products

[hurricanehunter69]

you know we're in for a busy season when " Ninel Conde " is NOT writing season cancel posts! ...just sayin?

[ninel conde]

I predicted 14/8/4 so i dont think it will be slow, but the neg NAO and east coast trof is as strong as ever.

[NDG]

I predicted 14/8/4 so i dont think it will be slow, but the neg NAO and east coast trof is as strong as ever.

But just because the NAO is negative does not mean that there could be a stronger Bermuda ridge which extends into the NE US like it is doing over the next few days from time to time.
Just a reminder that the NAO was negative through most of the summer of 2004, but the Bermuda ridge was stronger.

[CaliforniaResident]

According to NESDIS it looks like the PDO is becoming quite a bit less positive and the Atlantic Tripole is becoming more neutral if not slightly positive

PS The CDAS SSTA chart is showing the drop in PDO but not agreeing on the tropical Atlantic with the NESDIS charts

The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products

I think the PDO will drop like a rock very quickly over the summer and revert a long lasting negative phase for years to come and the climatic patterns that go with the negative PDO will resume course as well.

[Kingarabian]

According to NESDIS it looks like the PDO is becoming quite a bit less positive and the Atlantic Tripole is becoming more neutral if not slightly positive

PS The CDAS SSTA chart is showing the drop in PDO but not agreeing on the tropical Atlantic with the NESDIS charts

The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products

I think the PDO will drop like a rock very quickly over the summer and revert a long lasting negative phase for years to come and the climatic patterns that go with the negative PDO will resume course as well.

No evidence at all that the PDO is going to drop anytime soon.

[Yellow Evan]

I think the PDO will drop like a rock very quickly over the summer and revert a long lasting negative phase for years to come and the climatic patterns that go with the negative PDO will resume course as well.

There is likely no turning back at this point, given the PDO records of the last 2 years and the negative PDO from 1998-2013 makes me think we are in a +PDO era again and will stay that way for another 7-10+ years.