2015 indicators: Instability / SST's / MSLP / Steering / Sal

[gatorcane]

Following up from my previous post, here is a current vis sat image of Africa where I circled three distinct waves, with the two on the left showing distinct spin. That wave in the middle is especially impressive. You got to think with these types of waves, that MDR is going to gradually moisten over the next few weeks:

[Alyono]

JB is not considering that the Atlantic conditions are less favorable than 1997. It does not matter at all what the steering flow is if there is nothing that will form

[Hurricaneman]

Low humidity in the MDR usually leads to less storms and EL Nino usually causes dry conditions in the MDR and shear is a major issue in the Caribbean which can lead from 3 to 10 storms depending on the shear and the instability in the MDR

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[Hammy]

I have very strong doubts that any of those waves over Africa will do anything to moisten the atmosphere. We've been seeing all season strong wave after strong wave come off, and the GFS developing them, only to poof into nothing after coming off. It's not simply SAL this time--the atmosphere ahead of the waves will have to change first.

[NDG]

JB is not considering that the Atlantic conditions are less favorable than 1997. It does not matter at all what the steering flow is if there is nothing that will form

Yeap, that's what I said a few weeks ago, who cares what the steering pattern is when the waves will not survive the passage across the bone dry Atlantic, like you said conditions are worst than 1997 and even worst than 2002.

[xcool22]

two more storm ding all over,,

[LarryWx]

I still am educatedly guessing that one named storm will form in August, whether within the MDR or not and despite the slightly unfavorable for August "within circle" MJO. Looking at the 17 strong El Nino's since 1877, only 1997, 1905, and 1902 had no genesis within August. Regarding 1997, it had a whopping four TC's form in July. Due to the cyclical nature of active periods, perhaps the very active July was sort of at the expense of activity in August. Besides, a storm did form just after the end of August (on Sep. 3). Regarding 1905 and 1902, it is entirely possible that an August storm did form in either or both due to some storms that remained at sea being missed then. Even if that was not the case, that would mean only 3 of 17 strong Nino's had no August genesis.

As we get to Sept.: if the MJO were to remain within the circle, that actually becomes favorable per hard stats compiled for 1995-2012. Regardless, as far as CONUS threats are concerned, I wouldn't let a quiet August lead one to believe that Sept-Oct. will likely have no H threats based on the prior 2nd year very strong Nino seasons. Though I'm not predicting this since it isn't predictable, two CONUS H hits in Sep.-Oct. (especially mid-Sep. through mid Oct.) wouldn't at all be surprising to me based on history of similar ENSO. If so, my educated guess is that they wouldn't be storms that form east of 50W.

[Ntxw]

As we get to Sept.: if the MJO were to remain within the circle, that actually becomes favorable per hard stats compiled for 1995-2012. Regardless, as far as CONUS threats are concerned, I wouldn't let a quiet August lead one to believe that Sept-Oct. will likely have no H threats based on the prior 2nd year very strong Nino seasons. Though I'm not predicting this since it isn't predictable, two CONUS H hits in Sep.-Oct. (especially mid-Sep. through mid Oct.) wouldn't at all be surprising to me based on history of similar ENSO. If so, my educated guess is that they wouldn't be storms that form east of 50W.

Larry, per your MJO statistics for activity does it regard only El Nino's as a guide or include all years?

[floridasun78]

this EL Nino very strong doing job on atlantic hurr season it been long i not seen tropical wave at time of season we by now see strong troical in tropical

[LarryWx]

As we get to Sept.: if the MJO were to remain within the circle, that actually becomes favorable per hard stats compiled for 1995-2012. Regardless, as far as CONUS threats are concerned, I wouldn't let a quiet August lead one to believe that Sept-Oct. will likely have no H threats based on the prior 2nd year very strong Nino seasons. Though I'm not predicting this since it isn't predictable, two CONUS H hits in Sep.-Oct. (especially mid-Sep. through mid Oct.) wouldn't at all be surprising to me based on history of similar ENSO. If so, my educated guess is that they wouldn't be storms that form east of 50W.

Larry, per your MJO statistics for activity does it regard only El Nino's as a guide or include all years?

Ntxw,
All years 1995-2012. However, as a result of your Q, I decided to do an analysis this evening for just El Nino 1976-2014 (13 El Ninos).

1. For just the four Ninos since 1976 that were +1.0+ in Sep. (1982, 1987, 1997, and 2002...near where we are now), a whopping 14 of the 15 Sep TC geneses (for those that later became TS+ strength) were when the MJO was within the circle:

1982: Chris, Debby, Ernesto
1987: Cindy, Dennis (but not Emily)
1997: Erika
2002: Edouard, Fay, Gustav, Hanna, Isidore, Josephine, Kyle, Lili

- There were 78 days within the circle during those 120 days...so, one Sep genesis every 6 days when within the circle for these four strongest Nino Sep.'s.
- There were 42 days outside the circle during those 120 days..so only the one genesis during those 42 days (Emily during phase 2) for these four strongest Nino Sep.'s.

2. For the nine Ninos in Sep. that were cooler than +1.0 (1976, 1977, 1986, 1991, 1994, 2004, 2006, 2009, & 2014), only 3 of the 25 Sep TC geneses (for those that later became TS+ strength) were when the MJO was within the circle:

2006: Florence
2014: Dolly, Edouard

- There were only 58 days within the circle during those 270 days. Still, it was a genesis only every 19 days when within the circle for the 9 weaker Nino Sep.'s.
- There were 212 days outside the circle during those 270 days. There were 22 geneses during those 212 days when outside the circle for the 9 weaker Nino Sep.'s or one every 10 days

Conclusion for El Nino: the most favorable conditions for genesis during Sep. may very well be when within the circle and when Nino 3.4's anomaly is +1.0C or warmer. The hard stats since 1976 at least suggest that. So, if/when the MJO is within the circle this Sep. being that Sep will be >+1.0, that may be the time for the best shot for genesis. Interestingly, the four strongest Nino's in Sep. had 3 of the most days within the circle during Sep. So, just having very warm in 3.4 may tend to increase the chances for more days within the circle during Sep.

[Alyono]

also, the 16 day GFS is showing more troughing off of the east Coast. Not buying the idea of a large ridge steering any non existent systems into the coast.

[Hammy]

Tropical Tidbits updated the map quality and the 850mb wind maps are now quite detailed streamlines vs the old spread out arrows. This should make it easier to determine if a closed low or sharp wave is being forecast on some of the faster moving systems (should any occur)

[TheStormExpert]

Maybe a sign of conditions trying to improve somewhat?

@TropicalTidbits: Both CMC and GFS ensembles really getting rid of the shear in the west-central Atlantic as we head toward September: http://t.co/CxB6hBmACq

[CrazyC83]

Maybe a sign of conditions trying to improve somewhat?

@TropicalTidbits: Both CMC and GFS ensembles really getting rid of the shear in the west-central Atlantic as we head toward September: http://t.co/CxB6hBmACq

That would be short-lived I would think? But a storm like Erika 1997 or Bill 2009 might be possible in that hole.

[SFLcane]

Were did the cold sst's go?

Improvement...

[TheStormExpert]

@TropicalTidbits: Interesting agreement on low heights south of big New England ridge in 7-10 days. Can cause tropical trouble if sits. http://t.co/maS5Drz80E

[Alyono]

won't see an Erika or a Bill given that in the unlikely event that something does form, it will recurve at 45W. Maybe a Fred from 2009 is possible though in September

[galaxy401]

Were did the cold sst's go?

Improvement...

The lack of storms is heating up the water.

[Hurricaneman]

The Euro also seems to have this feature but stronger so its something to keep an eye on as systems like Bob in 1991 came from something similar so I'm not writing this one off especially if it trends stronger in later runs and am also not expecting a Bob like system either

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

[Hybridstorm_November2001]

I'm not surprised by the potential development off the East Coast. If any storm is going to be a huge deal this year I suspect it will be either a Bob 1991 or Halloween Storm 1991 type scenario.

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