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

[tarheelprogrammer]

An East Coast trough will usually take something in the open Atlantic and turn it out to sea. An east coast trough will also take a Caribbean storm and turn it into the GOM.

The Caribbean has been really quiet lately. If theres a major hurricane in there, an east coast trough will not be good for the US.

Exactly my thoughts as well. It may be good for the East Coast but bad for the Gulf of Mexico residents.

[srainhoutx]

The steering pattern at the moment is very similar to that of most of 2010/2011 with an persistent East Coast trough which would recurve anything that tries to strike the U.S. from the East or Southeast. Then there is the Texas Death Ridge(which started their bad drought from a few years ago) which would shove anything that tries to sneak in from the Western Caribbean into Central America or Mexico.

There is no 'Death Ridge' anchored over Texas this year. The main Upper Ridge is well West of Texas. We have had repeated rounds of showers and thunderstorm complexes dropping SE in the NW flow aloft along the Eastern periphery of the Western Ridge. The latest Day 8+ and Day 11+ Analogs suggest the Upper Ridge will remain anchored over the Great Basin with an occasional weakness as the Eastern trough sharpens up.

[tarheelprogrammer]

Nice graphic that was posted by Phil Klotzbach on twitter that corresponds with the up and coming MJO phase in the Atlantic.

https://twitter.com/philklotzbach/statu ... 1491710976

[RL3AO]

Should be a favorable MJO in the Atlantic sometime during the first two weeks of July.

[TheStormExpert]

Should be a favorable MJO in the Atlantic sometime during the first two weeks of July.

Wouldn't it be favorable at the same time as it is for the Eastern Pacific?

[cycloneye]

Michael Ventrice ‏@MJVentrice · 16m16 minutes ago

Seeing indications for -AO/-NAO development in July.

[RL3AO]

Should be a favorable MJO in the Atlantic sometime during the first two weeks of July.

Wouldn't it be favorable at the same time as it is for the Eastern Pacific?

Generally. Obviously I'm not a waves expert, but I don't follow some on Twitter!

[tarheelprogrammer]

Michael Ventrice ‏@MJVentrice · 16m16 minutes ago

Seeing indications for -AO/-NAO development in July.

That would be a negative for development correct? If so good.

[TheStormExpert]

Michael Ventrice ‏@MJVentrice · 16m16 minutes ago

Seeing indications for -AO/-NAO development in July.

And the -NAO/-AO goes negative for the 2nd or 3rd time in the past month or two.

[BigA]

Michael Ventrice ‏@MJVentrice · 16m16 minutes ago

Seeing indications for -AO/-NAO development in July.

A negative NAO (throughout the hurricane season) tends to be associated with weaker trade winds over the MDR, which is favorable for development. However, a negative NAO also tends to be associated with a weaker (and less westward- extending Bermuda high), thus making recurvature more likely.

Obviously this is only one of the many factors that affects Atlantic TCs (and if anything here is wrong, please say so).

[SFLcane]

Um.....

[1900hurricane]

CDAS analysis via Levi Cowan still supports a negative AMO look.

[TropicalAnalystwx13]

CDAS analysis via Levi Cowan still supports a negative AMO look.

When central/eastern Atlantic ocean temperatures are average while the rest of the globe is anomalously warm, yes it's going to give the appearance of a negative AMO. Actual anomalies have cooled recently under a substantial +NAO regime this past week, but they should warm again as we head more Neutral. There are signs of a -NAO for July.

The AMO has been positive all this year; May's value was the 3rd highest on record. I don't see any reason why that would change.

[1900hurricane]

CDAS analysis via Levi Cowan still supports a negative AMO look.

When central/eastern Atlantic ocean temperatures are average while the rest of the globe is anomalously warm, yes it's going to give the appearance of a negative AMO. Actual anomalies have cooled recently under a substantial +NAO regime this past week, but they should warm again as we head more Neutral. There are signs of a -NAO for July.

The AMO has been positive all this year; May's value was the 3rd highest on record. I don't see any reason why that would change.

I'll take your word on it, but I'm surprised at how something like an NAO change can have such drastic effects on the anomaly configuration. Then again, despite it being my home basin, I'm not as familiar with this basin as I am the Pacific basins, where the more interesting storms in recent years have driven my attention for personal study.

[weathaguyry]

Why does NOAA map state warmer than average MDR in Atlantic, and CDAS shows lots of colder water around Atlantic MDR?

[Yellow Evan]

Why does NOAA map state warmer than average MDR in Atlantic, and CDAS shows lots of colder water around Atlantic MDR?

NOAA uses a 30 year average while CDAS is the difference between the 30 year average SSTA's and the global SSTA''s to better account for climate change.

[Fego]

Hi all.
If I'm interesting in following up the SST to verify Dr Klotzbach "cold blob" theory, Which SST map is the best?

[NDG]

IMO, another thing about the difference between the CDAS sst map and the NOAA map is that CDAS's are daily averages while the NOAA map are weekly averages.
That's why I dismiss the CDAS map many times, it could be bipolar in a very short period of time, lol. It also looks to do not so good closer to the poles and when the Atlantic basin is full of African dust, like in the Caribbean right now, it shows incorrectly that the SSTs are "cooler", IMO.

[SFLcane]

Why does NOAA map state warmer than average MDR in Atlantic, and CDAS shows lots of colder water around Atlantic MDR?

Um yes it's been the story last few weeks. Depends who you talk to some say anomalies are cool others say there warm. I for one will side with NOAA.

[tolakram]

So if the overall oceans are warming but the anomalies in the Atlantic are lower than this 'new warm normal' they will show up as cool? All we really want to know is if the temps are above the 30 year average, or really if the temps are warm enough to support a TS or Hurricane. I'll take the simple 30 year average approach.