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

[TheStormExpert]

One problem is that we may not have any hurricanes in the MDR.

Was about ready to say the same thing.

The MDR looks to be a EXTREMELY HOSTILE DESERT! IMO this El Niño though COULD pave the way and possibly help bring back life once again to the what seems like forever dead MDR. If I were to guess we very well could see a hurricane finally form in the MDR come next season or 2017 IF conditions greatly improve in the MDR by then.

[gatorcane]

Don't forget, it is only June. We expect much of the Atlantic to be a hostile desert at this point.

[Ntxw]

In fact check out the GFS 700MB flow pattern. We see some signs the ridging in the Western Atlantic is connecting with ridging over the Eastern Atlantic which certainly would be a blocking pattern for hurricanes that form in the MDR.

http://i.imgur.com/ujufqYW.png

That looks signature +NAO. Does the stronger ridging also signal higher than normal pressures in the Atlantic?

[WPBWeather]

Again, its really silly to say "no more MDR storms" or other similar nonsense.

Some of these absolutist posts are not worthy of either amateurs or even those that call themselves Pro Mets.

[Yellow Evan]

Well, conditions in the MDR are more hostile than normal, so if the ATL wants to produce MDR hurricanes, it has a LOT of work to do.

[MiamiensisWx]

The presence of strong Eastern North America ridging continues into June. This is one big difference from years past at this time where we have generally seen a semi-permanent trough hanging along the Eastern Seaboard of the United States that continues through the summer and into the peak of the hurricane season allowing storm after storm to recurve out in the open Atlantic. Along with this trough, we have seen a "Texas death ridge" the past several years causing record heat along with very dry conditions and blocking any systems from moving into Texas from the Gulf. Not so this year. Is this an early indicator?
http://i.imgur.com/ujufqYW.png

I have seen many people here, including some otherwise reputable contributors/meteorologists, talking about a persistent "East Coast trough" over the past several seasons (since 2010) that has caused storms to curve out to sea. Unfortunately, a look at the archival data shows that it just isn't true, or at least represents a gross oversimplification (in my view). I utilized data from this source at ESRL to examine the mean 500-mb heights in August-September (period: 1 Aug-30 Sept) from 2010 to 2014. The results show rather conclusively that, although there was a trough in the Atlantic, it was far out in the central Atlantic, not along/just off the East Coast/Eastern Seaboard as is often claimed. In 2010 and 2011, the last seasons in which we had decent MDR development, storms that developed early encountered a southward-displaced weakness/trough axis in the central Atlantic and thus curved out to sea. However, had they remained weaker, the storms would have encountered a strong blocking ridge over SE Canada that would have pushed them toward the Southeast coast. In fact, we did have some notable Southeast hits during this time frame, such as Irene 2011 and Isaac 2012, thanks in large part to the blocking ridge over SE Canada that prevented a full turn out to sea. The fact that such a strong + anomaly/ridge shows up as the mean pattern for almost a full month indicates not only a ridge, but also a persistent one that would have allowed many opportunities for U.S. landfalls.



Really, the main reason as to why the U.S. hasn't had a major hit over the past several seasons is not a lack of opportunity. The real reason is the lack of hurricane activity in the deep tropics, thanks to reduced instability, above-average shear (not just in the MDR, but also in the Caribbean/Gulf), and most recently below-average SSTs in the MDR. Had we continued to perform at a 2008- or 2010-type level since 2010, we would assuredly have seen not only more U.S. hurricanes, but also, most likely, multiple or several major hurricane strikes, probably including at least one in FL. Isaac probably would have been a major hurricane if not for the high shear and reduced instability in its path. The chart that I posted above tells the story. If we had so many ample opportunities for hits that fizzled, don't expect the results to be any different in a year with even less activity due to El Niño. As I have said before, if Gray and Klotzbach--along with other specialists--want to save their original expectations for the current +AMO (which may well have already ended prematurely, quite possibly, in part, due to climate change), they really need to wish for a return to 2008- or 2010-type activity beginning, at the very latest, next year. They also need to hope for a significant increase in U.S. landfalls, starting either now or next season, with at least one major landfall occurring in that time frame.

Having these facts in mind, I will point out that recent seasons have shown a strong correlation between the May-early June pattern and subsequent steering in August-September. Red (blue) circles indicate where ridging (troughs) set up in August-September. Arrows indicate main storm paths. This year's May-June pattern thus far would seem to correlate with threats to S FL and the Gulf by peak season, especially since the Plains drought (ridge) has eased, with a mean trough setting up over that area. However, nothing will come to pass without storms out in the Atlantic.



As for instability, people have been expecting El Niño to cause an increase in vertical instability over the deep tropics. A look at the actual data shows that El Niño has done absolutely nothing to change instability, which is exactly where it was at this time over the past several seasons:

http://www.ssd.noaa.gov/PS/TROP/TCFP/data/current/ts_al_tat_THDV.gif

[ninel conde]

LC continues to say this will be a surprising cane season despite el nino.

[tolakram]

LC continues to say this will be a surprising cane season despite el nino.

Does he offer any reasoning that makes sound sense?

[WPBWeather]

LC continues to say this will be a surprising cane season despite el nino.

Does he offer any reasoning that makes sound sense?

If this LC is Larry Cosgrove, he does offer some interesting ideas on his Google group.

[Cyclenall]

As for instability, people have been expecting El Niño to cause an increase in vertical instability over the deep tropics. A look at the actual data shows that El Niño has done absolutely nothing to change instability, which is exactly where it was at this time over the past several seasons:

They're talking more about next season and 2017 than this current one. If nothing changes over the next few years even with a strong El Nino, I wonder what will be said in its place .

LC continues to say this will be a surprising cane season despite el nino.

That's why I went with surprisingly high numbers for the Atlantic, to balance out all the negative points I agree with.

[Ntxw]

LC continues to say this will be a surprising cane season despite el nino.

Does he offer any reasoning that makes sound sense?

He mentions it in his long term WeatherAmerica blogs. He doesn't specifically state why he believes it will be more active than anticipated but previous he did say he believes the El Nino will head to neutral to cold neutral by fall. His latest blog his idea of that has changed a bit to a weak El Nino vs neutral but that a more active Atlantic season than others think.

[Andrew92]

The following post is NOT an official forecast and should not be used as such. It is just the opinion of the poster and may or may not be backed by sound meteorological data. It is NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products.

Regarding the prior post, yes, the increase of vertical instability caused from El Nino probably will not take place this year, but after the El Nino is gone. I am somewhat worried about 2016, and a lot worried about 2017, if El Nino dissipates before this time next year.

But the season I am most worried about right now is 2015. The tropical Atlantic appears as though it will have a lot of stability, and not much opportunity for development of anything big. On top of that, El Nino should create above average shear that would, even with instability, make things unfavorable anyway. One storm in the MDR wouldn't surprise me near the peak, but it will need to recurve in order to intensify, I think.

That being said, I still believe the Gulf of Mexico is a key place to watch. It's partly just because of lack of activity in recent years, with the most recent major taking place in 2010, and no hurricanes occurring there last year. This kind of inactivity for a long period in the GOM is very rare, and in fact is the longest period without a major hurricane since the satellite was invented. This is even going by a pressure of less than 965 mb, the ideal pressure for a major hurricane. Isaac was close to that pressure in 2012, hitting 965 right on the nose, but going no lower. Although even then, three straight seasons without a pressure that low in the Gulf is also uncommon.

Since 1960, the only other periods of at least three years without a hurricane with a pressure below 965 mb in the Gulf of Mexico were 1971-73 and 1989-91. 1998 almost created a third such period, until Georges hit a pressure that low in late September, as there were no storms like that in the Gulf in either 1996 or 1997.

If 2015 goes without a major, it will be the fifth straight year without such a storm. Already, the last time we went four straight seasons without a storm with a pressure that low was 1937-1940. And if a hurricane that reached the Panhandle in 1936 hadn't had a pressure of 964 mb (and this was a Category 2 by wind), that would have been the last time there were five seasons without such a powerful storm in the Gulf. But as it stands, the most recent period without a hurricane with pressure below 965 mb is 1901-1905. A pretty rare event indeed.

If you're thinking, but this is El Nino, things should be quiet in the Gulf, well maybe you're correct. Only 1957, 1965, 1977, and 2002 had majors in the Gulf (1983 also acted like El Nino, even though it wasn't). But 2002 came on the heels of a period of two straight years without a major in there, and 1977 came after a year with no Gulf hurricanes (2001 was such a year too), both of which are like this year. 1965 was also only a couple years after the rare event of two potentially back-to-back years with no hurricanes at all in the Gulf, if Cindy from 1963 gets downgraded (there is speculation that it could). From a historical standpoint, the Gulf really needs to pay attention in 2015, El Nino or not.

-Andrew92

[WPBWeather]

You make excellent and reasoned points IMO.

It's refreshing to see them here.

The following post is NOT an official forecast and
should not be used as such. It is just the opinion of the poster and may or may not be backed by sound meteorological data. It is NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products.

Regarding the prior post, yes, the increase of vertical instability caused from El Nino probably will not take place this year, but after the El Nino is gone. I am somewhat worried about 2016, and a lot worried about 2017, if El Nino dissipates before this time next year.

But the season I am most worried about right now is 2015. The tropical Atlantic appears as though it will have a lot of stability, and not much opportunity for development of anything big. On top of that, El Nino should create above average shear that would, even with instability, make things unfavorable anyway. One storm in the MDR wouldn't surprise me near the peak, but it will need to recurve in order to intensify, I think.

That being said, I still believe the Gulf of Mexico is a key place to watch. It's partly just because of lack of activity in recent years, with the most recent major taking place in 2010, and no hurricanes occurring there last year. This kind of inactivity for a long period in the GOM is very rare, and in fact is the longest period without a major hurricane since the satellite was invented. This is even going by a pressure of less than 965 mb, the ideal pressure for a major hurricane. Isaac was close to that pressure in 2012, hitting 965 right on the nose, but going no lower. Although even then, three straight seasons without a pressure that low in the Gulf is also uncommon.

Since 1960, the only other periods of at least three years without a hurricane with a pressure below 965 mb in the Gulf of Mexico were 1971-73 and 1989-91. 1998 almost created a third such period, until Georges hit a pressure that low in late September, as there were no storms like that in the Gulf in either 1996 or 1997.

If 2015 goes without a major, it will be the fifth straight year without such a storm. Already, the last time we went four straight seasons without a storm with a pressure that low was 1937-1940. And if a hurricane that reached the Panhandle in 1936 hadn't had a pressure of 964 mb (and this was a Category 2 by wind), that would have been the last time there were five seasons without such a powerful storm in the Gulf. But as it stands, the most recent period without a hurricane with pressure below 965 mb is 1901-1905. A pretty rare event indeed.

If you're thinking, but this is El Nino, things should be quiet in the Gulf, well maybe you're correct. Only 1957, 1965, 1977, and 2002 had majors in the Gulf (1983 also acted like El Nino, even though it wasn't). But 2002 came on the heels of a period of two straight years without a major in there, and 1977 came after a year with no Gulf hurricanes (2001 was such a year too), both of which are like this year. 1965 was also only a couple years after the rare event of two potentially back-to-back years with no hurricanes at all in the Gulf, if Cindy from 1963 gets downgraded (there is speculation that it could). From a historical standpoint, the Gulf really needs to pay attention in 2015, El Nino or not.

-Andrew92

[cycloneye]

The ECMWF June update of Precipitation and MLSP looks grim for MDR and Caribbean.

[chaser1]

While I'd have to admit the ECMWF seasonal surface pressure & precip forecast ( ) for August, Sept., and Oct. look grim for Atlantic MDR and Caribbean tropical development, thus far we're "above average" for Atlantic cyclone development this season. I'd suppose that if Vegas odds even existed for an Atlantic hurricane to develop within the next 30 days, they'd be pretty long odds (10-1 against ?).

[gatorcane]

While we are around 2 months away from the Cape Verde season, this type of steering pattern the ECMWF is showing by day 10 would be one to watch as far as steering as it shows the Bermuda High bridging with the Azores High in the far eastern Atlantic. This would provide a blocking pattern preventing recurvature.

The east wind pattern so far the past couple of months has been dominant around South Florida with ridging to our north, afternoon storms each day along the West Coast of Florida, with no end in sight. The last time I recall such a dominant pattern is 2004.

[HURRICANELONNY]

I agree. Definitly unusual June. No rain each day. Not even sound of thunder out west. Starting to remind me of 92.

[WeatherEmperor]

The only thing is that this is a strong el nino year so having a big ridge in place may not mean anything if there are no storms out there to get trapped under it. All the data currently shows below normal instability in the MDR and doesnt the Euro forecast also show higher than normal sea level pressures? In any case just like 1992 it can only take one little storm to get caught under the ridge and cause chaos. Imagine we had seen this ridge in 2010 when we had a super active cape verde season. The similarity to 1992 is scary though.

[HURRICANELONNY]

I really don't remember if we were in a deficit or surplus of rain in june 92. Just a guess.

[Andrew92]

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.

Bill is inland and will weaken. This is the second storm to strike the United States this year, and this is quite something given this is a true El Nino year. Only two other true El Nino events since 1950 have seen two landfalling tropical storms before July 1: 1957 and 1968...though 1972 did not only see Agnes but also a subtropical storm reach the coast (does that count? If so, make it three). There is even speculation that a very weak storm in May 1957 may have also been a tropical storm in Louisiana, according to Sandy Delgado/HURAKAN's Master's thesis.

One should be careful about labeling this early activity of a harbinger of things to come, though. Even after calamitous storms like Audrey in 1957 and Agnes in 1972, there were very really big threats the rest of the way, if any. Bertha in 1957 was closest to being a hurricane when it hit Louisiana of a few others that occurred after Audrey, and Dawn was a hurricane briefly off the East Coast before fizzling out.

Or maybe Candy in 1968 is a good analog. That storm developed very quickly in the Gulf of Mexico and quickly went into Texas, much like what Bill has done. Bill's forecast track is similar to what Candy did inland. Candy also came after another storm, Abby, hit Florida nearly as a hurricane. However, only Gladys was any major threat from there on out.

As for that ridge mentioned previously, I don't know if it's worth the worry, simply because the area where storms could form to take that kind of track might be too unfavorable for development this year. I'd have to look again though to see what other years had this kind of setup. If someone is mentioning 2004, is it fair to bring up maybe 2002 as a potential analog? It would seem hard to believe that a storm forming where Isidore or Lili did would reasonably survive in the Caribbean, but those two storms did occur slightly past the peak, so maybe things could be a little different around then in that region. The thing to note though is all of the Gulf activity. There were Bertha, Fay, and Hanna, along with the aforementioned two major hurricanes. With last year no hurricanes taking place, and 2001 being likewise...that is another big similarity. It's just so rare to go two years without a hurricane in the Gulf of Mexico...which of course counters my point above. And when you put both arguments together, you come up with only one thing: It only takes one, and it could be one that makes this year.

2002 did also see one long-tracker in the subtropics make it to the East Coast, albeit as a shadow of what it was for a couple days in the Atlantic: Kyle. I could see that kind storm easily taking shape sometime this year as well. I just hope it doesn't take on the role of the "annoying" storm that is just there but not really doing anything other than causing advisories and discussion. I would also think this setup might favor some frontal low activity off the East Coast in July or early August, ala Arthur or Cristobal. That is another signature sometimes seen in other El Nino years, including three July storms in 1997.

Just a hunch, but something tells me early or mid-July is when we see Claudette, and it forms off the East Coast off a frontal low and quickly heads out to sea. Such a storm probably lasts a couple days, little more than that. But I will definitely want to research how this year's setup compares so far with 2002.

-Andrew92