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

[Hammy]

I'm not sure to find the ice melt data, but looking at SSTs from July 2013 vs this year there was no solid pattern, and multiple patches of significantly cold areas were present in tropical waters (and a major cold pool along western Europe) which contrasts sharply with this year--was that likely one of the mappable symptoms of the weakened circulation and salinity changes?

[Bocadude85]

Starting to remind me of 2013 here. All the discussion was very similar, just wait until August. Seeing nothing in the models at long range is alarming. Still think we might see a threat or two in September and October but doesn't seem to be an active season coming.

It's July and we have already had 4 named storms, none have been particularly strong but we shouldn't expect them to have been so early in the season. An average hurricane season is 12 named storms, that means we can only have 8 or less named storms from now until November 30th to end up at or below average ...I would say the chances of that happening are relatively slim.

[Hammy]

Starting to remind me of 2013 here. All the discussion was very similar, just wait until August. Seeing nothing in the models at long range is alarming. Still think we might see a threat or two in September and October but doesn't seem to be an active season coming.

It's July and we have already had 4 named storms, none have been particularly storng but we shouldn't expect them to have been so early in the season. An average hurricane season is 12 named storms, that means we can only have 8 or less named storms from now until November 30th to end up at or below average ...I would say the chances of that happening are relatively slim.

We're about even on named storms with 2013. That being said instability was lower, shear was significantly higher, and SSTs were also lower than they are presently. The only reason we're seeing limited activity at the moment is a combination of SAL and as others have pointed out, the suppressive MJO phase.

[SFLcane]

Boy... a threat or two in August maybe September? Guys we are still in " JULY " nothing in the long range models I mean come on every year it's the same season over talk only for things to explode 2-3 week of aug. Nothing looks like 2013 one thing which has concern is all that heat focused in the main development region with cold ssts to the north ( horse shoe config) spells trouble when the real season starts. Abviously plenty other factors to consider but the one I just mentioned is what sticks out for me. Also shear has been below normal across the central and eastern Atlantic for weeks now. Just let things play out before you know it this forum will be lighting up at all hrs.

Can't wait!

[Hurricaneman]

The satellite picture currently on this date looks most similar to 1998 and we all know how that season went, Bonnie in OBX, Georges in Puerto Rico, Hispaniola, and the Gulf Coast, and Mitch in the Caribbean so even if the lid comes off late August we can still have a large number of hurricanes to track and I think we might have more majors then that year

My numbers from here on out is 16/10/6 based on the potential conditions

[Dylan]

At this point, comparing 2013 to this season is just trolling. I am going to end this once and for all right now.

Lets take a look at a major indicator for hurricane activity in the Atlantic Basin since 1995, the MDR, which is relevant since we are in a multi-decadal warm AMO. Since 1995, there have been 9 hurricane seasons where the MDR was above normal (Not including this year because the results are not complete!): 1995, 1998, 2003, 2004, 2005, 2008, 2010, 2012, and 2016. Here is what happened those years:

1995: 19/11/5
1998: 14/10/3
2003: 16/7/3
2004: 15/9/6
2005: 28/15/7
2008: 16/8/5
2010: 19/12/5
2012: 19/10/2
2016: 15/7/4

Comparing warmer than normal MDR years to the 30 Year Average of 11 named storms, 6 hurricanes, and 2 major hurricanes, you get 17.8 named storms, 9.8 hurricanes, and 4.5 major hurricanes in those 9 years. This means that since 1995, if the MDR was warmer than normal, the Atlantic was significantly more active than normal, with the # of major hurricanes being TWICE as high as the 30 year average. In years like 2006 & 2013 that were busts, the MDR had cooled significantly by this point in the hurricane season.

Right now, the Atlantic MDR is running approximately .55C above normal, only behind 2005 and 2010. And with the NAO forecasted to be negative for the foreseeable future, it is likely the MDR will stay anomalously warm, but get warmer too. Since we have established that the OPPOSITE of 2006/2013 is happening, I think it is completely irresponsible & lazy of posters to declare this is a repeat of 2013. The likely outcome is a burst of activity in the coming months, and with a strong Atlantic Ridge established, the threat to land in the Western Hemisphere is increased.

Current MDR Sea Surface Temperature Anomalies:


MDR Sea Surface Temperature Anomalies (1980-2016):

[SFLcane]

Fantastic post Dylan.. Thx for the MDR breakdown.

[Hammy]

Interesting to note that half of the years above also had a lengthy quiet period at some point during the second quarter of the season (the part we're currently in.)

[WeatherEmperor]

https://twitter.com/MJVentrice/status/8 ... 4881945600

https://twitter.com/MJVentrice/status/8 ... 2063600641


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[Ntxw]

We have to be careful not to overhype the CCKW imo. It is a great compliment to background conditions and is definitely a plus but you still have to consider there is still some shear and mid level dry air around the basin also which are more local conditions. The WPAC hasn't yet yielded a STY or has a major occured in the EPAC with this strong CCKW yet like some models have portrayed. Something in the background is not favorable globally. But it does help increase the chance of something forming in the coming days to weeks.

[srainhoutx]

We have to be careful not to overhype the CCKW imo. It is a great compliment to background conditions and is definitely a plus but you still have to consider there is still some shear and mid level dry air around the basin also which are more local conditions. The WPAC hasn't yet yielded a STY or has a major occured in the EPAC with this strong CCKW yet like some models have portrayed. Something in the background is not favorable globally. But it does help increase the chance of something forming in the coming days to weeks.

You are correct that this CCKW is only one of the indicators of many that need to be followed. If we look across the Atlantic Basin, The ECMWF EPS pressure fields are beginning to suggest lower pressure trends particularly across the Southern portion of the MDR at a low latitude into the Southern Caribbean Sea with the lowest pressures in the SW Caribbean and into the Western Gulf over the next 15 days. The Azores / Bermuda Ridge looks to remain very strong. There may be a chance of potential development along the SE and Mid Atlantic Coastal Region as the Eastern trough digs in, but that feature does not appear to be permanent as Upper Ridging builds back into the Eastern US in about 8 to 10 days.

[gatorcane]

To summarize some of the key points discussed in this thread as of late:

1. July is climatologically an unfavorable month for development across the Atlantic so it is really difficult to use this month's indicators to make any prediction for peak hurricane season months. SAL, shear, TUTTs are all usually ubiquitous across the basin this month.

2. The GFS has shown it is much more conservative in the deep Atlantic MDR than the previous GFS - seems more similar to the ECMWF now which was always on the conservative side - this could mean we may not always get as much notice of tropical development as we have gotten in the past. Could be more like less than a week (3-5 days?) than a week or later.

3. Active seasons do not necessarily need to start in July or even early August in fact many active seasons did not start getting going until late August.

4. We are just about ready to start the steep ramp in climatologically favored hurricane activity which peaks Sept 10th so not a surprise thing are still slow now - we would expect conditions to gradually improve from here on out but particularly after Aug 15th.

5. Indicators suggest this season is not comparable to 2013 (much less active than expected) or 2005 (much more active than expected).

[RL3AO]

We have to be careful not to overhype the CCKW imo. It is a great compliment to background conditions and is definitely a plus but you still have to consider there is still some shear and mid level dry air around the basin also which are more local conditions. The WPAC hasn't yet yielded a STY or has a major occured in the EPAC with this strong CCKW yet like some models have portrayed. Something in the background is not favorable globally. But it does help increase the chance of something forming in the coming days to weeks.

This is an interesting "test case" for what a strong CCKW can do. A very strong KW signal vs a somewhat unfavorable background. It'll be a fun few weeks in the tropics (at least for me since this fits right into my research interests).

[Alyono]

One thing starting to bug me is that it appears as if we will have a nor'easter soon. That's more of a late fall-like pattern. Something worth considering and to be monitored over the next couple of weeks

[Hammy]

One thing starting to bug me is that it appears as if we will have a nor'easter soon. That's more of a late fall-like pattern. Something worth considering and to be monitored over the next couple of weeks

Would this indicate the start of 2013-esque troubles, or simply a steering pattern change? I'm noticing models are showing a fairly strong cold (for summer) outbreak as well.

[CyclonicFury]

One thing starting to bug me is that it appears as if we will have a nor'easter soon. That's more of a late fall-like pattern. Something worth considering and to be monitored over the next couple of weeks

Would this indicate the start of 2013-esque troubles, or simply a steering pattern change? I'm noticing models are showing a fairly strong cold (for summer) outbreak as well.

Wasn't a cooler than normal US in August supposed to be a positive for Atlantic development? I thought I remember reading that somewhere in the past, but I know 2013 was cooler than normal in August across much of the Eastern US.

[Hammy]

One thing starting to bug me is that it appears as if we will have a nor'easter soon. That's more of a late fall-like pattern. Something worth considering and to be monitored over the next couple of weeks

Would this indicate the start of 2013-esque troubles, or simply a steering pattern change? I'm noticing models are showing a fairly strong cold (for summer) outbreak as well.

Wasn't a cooler than normal US in August supposed to be a positive for Atlantic development? I thought I remember reading that somewhere in the past, but I know 2013 was cooler than normal in August across much of the Eastern US.

That I'm not particularly sure of, but I remember 2013 being abnormally cool (high of 67 in north Georgia in mid-August!) and we even had the trees changing color a few weeks later, so I know cold outbreaks in August are potential indicators (though I've admittedly done little study of summer temps vs hurricane season--I just know the last several years otherwise have been quite hot.) I'm sticking to "2015 minus El Nino" for now, but if we do start having any sort of 2013-ish issues I'm going to try and see them in real time so I'm not caught off guard so to speak.

While it's not something that's easy to predict, is there anyone here who knows if the real time data can be seen anywhere? I want to have that on hand if possible same as we do with SSTs and shear charts.

[Kingarabian]

One thing starting to bug me is that it appears as if we will have a nor'easter soon. That's more of a late fall-like pattern. Something worth considering and to be monitored over the next couple of weeks

Euro had it stronger a few runs ago. But it's eyebrow raising to see one so early.

[CyclonicFury]

Would this indicate the start of 2013-esque troubles, or simply a steering pattern change? I'm noticing models are showing a fairly strong cold (for summer) outbreak as well.

Wasn't a cooler than normal US in August supposed to be a positive for Atlantic development? I thought I remember reading that somewhere in the past, but I know 2013 was cooler than normal in August across much of the Eastern US.

That I'm not particularly sure of, but I remember 2013 being abnormally cool (high of 67 in north Georgia in mid-August!) and we even had the trees changing color a few weeks later, so I know cold outbreaks in August are potential indicators (though I've admittedly done little study of summer temps vs hurricane season--I just know the last several years otherwise have been quite hot.) I'm sticking to "2015 minus El Nino" for now, but if we do start having any sort of 2013-ish issues I'm going to try and see them in real time so I'm not caught off guard so to speak.

While it's not something that's easy to predict, is there anyone here who knows if the real time data can be seen anywhere? I want to have that on hand if possible same as we do with SSTs and shear charts.

One thing that does seem different from 2013 for sure is the shear is lower. Wind shear has been lower than normal in the MDR, and near normal in the Caribbean.

[TheStormExpert]

Yeah I thought that Nor'easter seemed quite off. This very well could be a bad sign for those (like me) hoping for an active Atlantic hurricane season. If in 2 weeks the models still show zilch 10-16 days out I'm willing to call it season cancel especially if the pattern starts changing to more of a fall/winter type pattern.