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

[WPBWeather]

the east coast trof has dominated since 2005 and thats just a fact. I suppose at some point the bermuda high will return but there is zero sign of that this season. California better hope the pattern reverses because this winter rainfall there will be far below normal.

Again, there are always "zero sign" of the trough lifting out in early July.

http://i.imgur.com/MNsfBKX.png 1998
http://i.imgur.com/ENreIZW.png 2004
http://i.imgur.com/J9mK2mA.png 2005
http://i.imgur.com/HKnOAdZ.png 2008
http://i.imgur.com/b3lpEde.png 2016

Interestingly 2008's pattern looks almost identical to the current one.

Thanks Hammy. You always seem to find the data in the end.

[ninel conde]

1998, 2004 and 2005 were all before the permanent trof set it and it simply can not be denied it has dominated since 2005 thus the hurricane landfall drought. and yes, dan leonard is right, the 11 year pattern is once again set.



As we can see here on july 11 the trof is in full force and effect with the low still firmly locked and loaded over se canada. california will be bone dry again this winter. Oh, and those maps showing how shear has been so much less this season compared to last year an be thrown out now. With the east pac firing up in response the the digging west atlantic trof expect ripping shear to flood the atlantic basin. One final thing is the position of the atlantic high is pluperfect to flood the atlantic with choking saharan dust. There is zero, nada, nothing right now pointing to an active landfall season or much of a cape verde season.

The reason the shear was lower in june this season was simply due to nonexistent east pac activity. last season in june there were 2 cat4,s and a cat 1 thus causing ripping atlantic basin shear. Now that the east pac has fired up the shear will return like a bull in a china shop. Move everything 500 miles wnw in the atlantic on that map and you could expect an epic atlantic season.

[AJC3]

August 1 - September 30, mean 500MB height anomalies over the eastern CONUS/western Atlantic, 2004-2015, broken down by year...

[AJC3]

One last image set...Out of those 12 years for AUG - SEP, I took the three with the (1) Strongest positive (2005), (2) Most neutral-looking (2009), and (3) Strongest negative (2011) 500MB height anomalies, then reconstructed mean 500MB height maps for those periods. What stands out, for those that may not realize it, is that climatologically speaking, there tends to be a weak mean trough along the east coast of the U.S. in the late summer, which owes more to the strength of the Atlantic ridge to its east.

[tarheelprogrammer]

I am officially lowering my numbers for the 2016 hurricane season. I am now going with 10/3/1. Seems shear (our life saver) is returning to Caribbean and high pressure is going to dominate the Atlantic ocean. Also, trofs should take most of the threats to land from the MDR storms that do form out to sea. Basically a repeat of last season minus a major hurricane, a hurricane, and a named storm.

[BigA]

August 1 - September 30, mean 500MB height anomalies over the eastern CONUS/western Atlantic, 2004-2015, broken down by year...

Excellent maps. I think the lesson here is that the talk of a "Permanent East Coast Trough" during the last 11 years is highly exaggerated, and is something of a simplistic excuse for explaining the lack of major US hurricane landfalls. In fact, in some of the years with substantially lower heights along the East Coast (2008, 2011, 2012), there were substantial landfalls in the United States. In other years (e.g.,2014 and 2015), there was no major East Coast trough, but there were no or few storms that threatened the East Coast.

It's not always as simple as a trough versus a ridge. A negatively-tilted trough steered Sandy into the East Coast. A ridge pushed Joaquin southward so that it did not get caught in a steering flow that would have caused it to make landfall.

[Yellow Evan]

There's a big difference between the 2004/05/07 graphs (years with Caribbean Cruisers) and the others with some extent of a recurving pattern though.

[NDG]

Great job AJC3, I love it when somebody puts up the evidence versus no evidence.
So in another words, since 2005 the only years with a big trough pattern across the eastern US during the heart of the hurricane season was 2006, 2010, 2011, 2012 & 2013.
Interesting that lower heights across the SE US was analyzed during 2008 when the US was struck by 3 hurricanes, almost a fourth hurricane had it not been for land interaction TS Fay had to deal with. I guess the higher heights over SE Canada play a bigger role on the tracks of hurricanes.
And as mentioned before by myself and others, last year had it not been for the record breaking windshear over the Caribbean last year, the pattern was set most of the hurricane season for SE US strikes due to a stronger Bermuda ridge.

[NDG]

:uarrow: There's a big difference between the 2004/05/07 graphs (years with Caribbean Cruisers) and the others with some extent of a recurving pattern though.

Most Caribbean Cruisers don't strike the eastern US, only threat is to FL and or the Gulf Coast. When a strong ridge is present over the southern US like 2007 they become a threat to C.A. and MX.

[WPBWeather]

1998, 2004 and 2005 were all before the permanent trof set it and it simply can not be denied it has dominated since 2005 thus the hurricane landfall drought. and yes, dan leonard is right, the 11 year pattern is once again set.

No I think you are misreading him, but this argument made each year gets us nowhere. Perhaps it needs a special forum where we can throw verbal pies at each other when bored>

[Macrocane]

I am officially lowering my numbers for the 2016 hurricane season. I am now going with 10/3/1. Seems shear (our life saver) is returning to Caribbean and high pressure is going to dominate the Atlantic ocean. Also, trofs should take most of the threats to land from the MDR storms that do form out to sea. Basically a repeat of last season minus a major hurricane, a hurricane, and a named storm.

Well, wind shear in the Caribbean is always stronger in July than in June but most of the forecasts indicate lower shear than in 2014 and 2015, those 2 years we had a severe drought in Central America, hopefully we won't experience that again.

[tarheelprogrammer]

I am officially lowering my numbers for the 2016 hurricane season. I am now going with 10/3/1. Seems shear (our life saver) is returning to Caribbean and high pressure is going to dominate the Atlantic ocean. Also, trofs should take most of the threats to land from the MDR storms that do form out to sea. Basically a repeat of last season minus a major hurricane, a hurricane, and a named storm.

Well, wind shear in the Caribbean is always stronger in July than in June but most of the forecasts indicate lower shear than in 2014 and 2015, those 2 years we had a severe drought in Central America, hopefully we won't experience that again.

Yeah I hope so for you guys sake but the Atlantic coastal communities can deal without hurricanes we prefer it that way. I am leaning toward the Atlantic being dead again for the most part. Becoming an oddly common theme.

[SFLcane]

So....... what's the suggestion here to skip hurricane season?

[WPBWeather]

I am officially lowering my numbers for the 2016 hurricane season. I am now going with 10/3/1. Seems shear (our life saver) is returning to Caribbean and high pressure is going to dominate the Atlantic ocean. Also, trofs should take most of the threats to land from the MDR storms that do form out to sea. Basically a repeat of last season minus a major hurricane, a hurricane, and a named storm.

Well, wind shear in the Caribbean is always stronger in July than in June but most of the forecasts indicate lower shear than in 2014 and 2015, those 2 years we had a severe drought in Central America, hopefully we won't experience that again.

Yeah I hope so for you guys sake but the Atlantic coastal communities can deal without hurricanes we prefer it that way. I am leaning toward the Atlantic being dead again for the most part. Becoming an oddly common theme.

Sorry, but you are off base about this. Don't fall for the permanent trough or death ridge nonsense,

[NDG]

1998's hurricane season didn't really get going until late August, conditions over the Caribbean and most of the Atlantic basin were hostile during June & July. If conditions right now would had been during late August then I would say most of you calling for a dead Atlantic Hurricane season would give you the benefit of doubt.

[TheStormExpert]

TWC may want to revise their numbers if the next few named storms don't become hurricanes at the very least.

Seems they are leaning towards a 1998 repeat which is still very possible but conditions would need to improve a good deal come August or September for that to verify.

EDIT: Didn't realize TWC updated their forecast today, leaning more towards CSU regardless with weaker short-lived named storms until I see something change in the Atlantic in terms of favorable conditions.

[gatorcane]

Ninel conde, here is an example of where basically no Bermuda High and strong EC troughing is no guarantee for no landfalling U.S. hurricanes.

8 Hurricane-4 18-26 SEP 115 940 CAT 4
9 Hurricane-3 3-16 OCT 110 971 CAT 3



Also all it takes is one window of opportunity for a system to get under a ridge and get driven into the U.S. even with lots of troughing most of the time, as we have seen in years past.

4 Hurricane-4 4 4-21 SEP 125 938 CAT 4

[TheStormExpert]

Excluding Hurricane Alex so far this season we've had three short-lived weak Tropical Storms. I'm going to guess we are currently in our lull for the season before the real season kicks in at the very earliest later this month into early August.

 https://twitter.com/nhc_atlantic/status/748977463515082752

[psyclone]

What a spicy conversation. It seems we're always too quick to write the obit on the season. It's worth remembering that July is often no man's land in the Atlantic basin. It is the core of the wide moat that often separates early season junk from the real season...dominated by shear, SAL and just a general non conducive environment. I really wake up around August 10. At that point things are often starting to percolate on a sustained basis. That is still 40 days away! We're likely to have some good storms to track later this season but we've still got awhile to wait. Enjoy the downtime and don't worry about those walking out midway through the first quarter:)

[Hammy]

TWC may want to revise their numbers if the next few named storms don't become hurricanes at the very least.

Seems they are leaning towards a 1998 repeat which is still very possible but conditions would need to improve a good deal come August or September for that to verify.

EDIT: Didn't realize TWC updated their forecast today, leaning more towards CSU regardless with weaker short-lived named storms until I see something change in the Atlantic in terms of favorable conditions.

As 1998 is brought up often, it serves as a good reason not to make assumptions about the season based on June/July--we didn't have so much as a depression until July 27 (and 2004 nothing until July 31 for that matter) and I can imagine how the season cancel people would be flipping out calling for 4-5 storms total if such a thing occurred again with the forums being much busier than those years.

Well, wind shear in the Caribbean is always stronger in July than in June

A bit off topic but would this explain why there are so many years with June but no July activity than there are with July but no June activity?

I'll add as far as the models showing little to nothing--the high pressure is perhaps too far west and south, as the troughs are pretty linear east-west and not dipping below Tennessee for the most part, meanwhile the waves are all going into the Pacific.