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June 2013

Tropical Depression #2 Forms and Moves into Belize – and a Look at the Rest of the Season

   Posted by Levi at 1:25am on June 18, 2013




  • derayka says:

    I always learning something from your dissertations. I’m interested to see what happens in the first ten days of July. We shall see what happens.

  • Mech 70002 says:

    Thanks for the information.

    On your last video I posted a question about the MJO. Could it influence not just the formation but the strength / intensification rate of existing storms. Specifically: Is there any data available on 2005, and whether or not the MJO could have influenced Katrina’s unexpected intensification?

    Another poster replied intensification could be influenced by ‘kelvin’ waves. As TC strength has always been difficult to forecast; are there any efforts to use data from MJO & Kelvin waves to help refine and improve the strength forecasting methods & models?

    • Levi says:

      The MJO is less important in the peak of the season, and even less important for mature hurricanes, which run on their own processes, and their intensity is a function of their immediate environment. The MJO is a large-scale modifier of the environment, so it is useful for forecasting TC genesis, but not as much for the intensity of mature TCs. The Katrina case actually follows this rule, as the MJO came out into phase 1 and may have helped Katrina form, but the MJO was no longer amplified by the time Katrina began her rapid intensification period.

  • Anonymous says:

    Do you think the a storm could hit around Texas,Louisiana,and Mississippi this year?

    • Levi says:

      A storm could hit any of the coastal states during any year. It is impossible to declare any states “safe” from being hit. Just be prepared for it every year.

  • Eric Webb says:

    Great video Levi, they are always very informative and full of so much very useful information. I do have a concern here though, I don’t know if you’ve seen this, but I looked at the AMJ MJO in 1996 and was very surprised to see just how amazingly close this year’s behavior of the MJO is following to it, in that there are very persistent pushes of the MJO into the Indian Ocean, with very little in the way of MJO action over towards the western Pacific. I know this is one of your analog years you had way back in the early stages of March for this upcoming season, has to really grab your attention though to see a phenomena even as complex as the MJO closely following 1996.

    1996 JFM MJO
    1996 AMJ MJO
    MJO last 90 days

    Interestingly, like many of the current forecasts, in 1996, there was a large push of the MJO into the favorable octants 8-3 towards the end of June and beginning of July.

    Given the similarities in the winter pattern this past year with 1996 (cold start, warm in the middle, cold ending lasting into spring), the cold spring pattern, Atlantic Tripole, sunspot cycle extremity, 400 millibar, etc.. I definitely think it is safe to say we are closely following 1996. Also seeing the MJO closely approach the western Pacific and seeing many of the computer models predicting a modiki el nino has me aware that we may see a major equatorial Kelvin Wave propagate eastward across the Pacific and even into the Atlantic in the relatively near future. I’ve also come across in some scientific readings that Kelvin Waves are possibly a factor to enhance convection associated with African easterly waves over the African continent. Taking into account how 92L almost became designated in the early stages of June and how the conditions appear to be favoring an active Cape Verde season, this information implies that we may in fact see the Cape Verde hurricane season come to life much sooner than normal, perhaps as soon as when this next upward MJO pulse enters the Atlantic. That would put the formation of any long track system in the very late stages of June or early July, about the time Hurricane Bertha formed in July 1996.
    I was intrigued to see the latest CFS hint at a potential long-track Cape Verde hurricane in the early stages of July that seems to further support this notion for the first long track tropical cyclone of the hurricane season to come potentially in July.

    Also, I couldn’t help but notice how closely the track of Tropical Storm Josephine in 1996 seemed to resemble the recent Tropical Storm Andrea.
    Josephine (1996)
    Andrea (2013)

    • Eric Webb says:

      I want to add to the comment above, in that looking further into the MJO behavior and years with some similarities, I also noticed 2008 was another year that had some reminiscence to this year. Notice the large MJO push into late May and early June (much like what just happened with the MJO) in 2008 that helped to trigger Tropical Storm Arthur, and then look at how by the end of June, after the MJO almost went into the western Pacific, how it dives towards phase 1 & 2. The overall behavior of the MJO is similar as well, with what seems to be very consistent bombardment into the Indian Ocean, with very little activity for the western Pacific.
      MJO 2008 AMJ
      Looks very similar to some of the current MJO forecasts remember that year in July 2008, we also saw a long track Cape Verde hurricane in the month of July, also named Bertha. Given how 92L almost became designated in early June and the pattern you have described in your videos & posts, I think it is safe to say that we may have our first long track Cape Verde hurricane in July.
      Any thoughts on this?

      • Levi says:

        Cape Verde storms in July are so rare that correlating one formation with one MJO cycle in one year is not going to make it “safe” to say anything. However, if it happens, it will likely need the support of the MJO, which is why it is useful as a forecast tool.

        • Eric Webb says:

          Ok, thanks Levi, but let me add
          The CFSv2 surface pressure spreads, interestingly showing some type of system
          (Tuesday’s run)

          (Monday’s run)

          (Sunday’s run)

          (Saturday’s run)

          (Fridays run)
          (About the exact same time frame, as in the other runs it hints at a long track tropical system, this time a very large tropical wave emerging off Africa, at least by this model’s standards.)

          Whatever tries to develop is certainly going to have quite a bit of support from the MJO, at least according to the ECMWF and ECMWF monthly
          Now, what from I’ve read in some scientific papers on tropical cyclone genesis in relation to the MJO, especially for systems associated with African easterly waves over western Africa and the eastern Atlantic is that there is on average, a 5 day lag between when the MJO pulse arrives over this region of the globe and tropical cyclone formation. That seems to jive with general timing being given by the CFS around the 15-20th or so, which corresponds to the ECMF and the EMON’s timing of the MJO into octant 2 & 3 as we get towards the end of the first week of July or around the 10th or so.
          Now, I’ve done even more digging into this pattern, and here’s the storms (tropical storm or hurricanes) that have actually were long track Cape Verde storms, we’ll just say east of the Lesser Antilles because I realize that the Berthas of 1996 & 2008 were anomalies, and even formation that far east is quite an accomplishment this early in the season.
          Hurricane Bertha (2008), TS Chris (barely in July), (2006) Hurricane Emily (2005), TS Alex (1998), Hurricane Bertha (1996), TS Arthur (1990), TS Cesar (1990), TS Barry (1989), Hurricane Dean (once again, barely in July) (1989), TS Claudette (1979), TS Anna (1969), TS Ella (1966), Hurricane Arlene (1963), Hurricane Anna (1961), (did form east of the Antilles, but quite anomalous in that it became a major hurricane during July), Hurricane Abby (1960), TS Two (1944), TS Three (1933), Hurricane Five (1933), Nassau Hurricane (1926), Hurricane Two (1926), TS One (1917), Hurricane Three (1916), Velasco Hurricane (1909), TS Two (1901), Hurricane Three (1901) Carrabelle Hurricane (1899), (The storm was initially detected as already a category 1 hurricane over the eastern Caribbean. Given the intuition that this region of the tropical Atlantic is naturally a dead zone because of higher trade winds enforced between the Columbia Low & Bermuda High that get squeezed in between South America & the Greater Antilles, promotes surface divergence and has a tendency to disrupt surface circulations, thus I suspect the actual formation of this storm was much farther to the east, likely east of the Lesser Antilles)

          What I found intriguing about these storm formations is that many of them seem to coincide with flips in the PDO & AMO oceanic cycles.
          AMO flip to its cold mode near 1900 coincides with Carabelle Hurricane of 1899, TS Two of 1901 and Hurricane Three of 1901. By 1915, there was a very brief AMO spike into its warm cycle, the PDO turned cold, this correlates to TS One (1917) & Hurricane Three (1916). Around 1925, the AMO & PDO both flipped into their warm cycles, not surprisingly we observed The Nassau Hurricane in 1926 and Hurricane Two in 1926. Just before 1935, the PDO briefly went into its cold cycle, corresponds to TS in 1933 and Hurricane Five in the same season. Then, just before 1945, the PDO went into its cold cycle which lasted through the late 1970s, in 1944 near the PDO flip we had TS Two. In the late 1950s, near 1960, the PDO briefly flipped into its warm cycle, corresponds to Hurricane Abby & Anna in 1960 and 1961 respectively. In 1964, the AMO went into its cold cycle that lasted until 1995, but the AMO was rather slow to enter its cold phase in the mid-late 1960s, and as a result 3 storms ocurred in this period, Hurricane Arlene (1963), TS Ella (1966), TS Anna (1969). Then, the PDO flipped into its warm cycle in the late 1970s also known as the “Great Climate Shift”, during this period in 1979 TS Claudette occurred. Around 1990, there was a rather sudden, but relatively brief flip in the AMO into its warm cycle (more than likely the reason for the landfalls of Hurricanes Hugo (1989) & Bob (1991) during this time period), this led to several July Cape Verde storms in 1989 & 1990. Then, the AMO finally flipped completely into its warm cycle in 1995, around this time, Hurricane Bertha (1996) formed. After the “super el nino” of 1998, the Pacific went through several years of la nina, that led to a period of cold PDO in the very late 90s and into 2000, TS Alex occurred during this general time period in 1998. The PDO continued in its overall warm state through the mid 2000s, then flipped fully into its cold cycle around 2007. Around this flip was Hurricane Bertha (2008), TS Chris (2006), and Hurricane Emily (2005).

          Given that the AMO appears to closely follow the solar cycles
          And that the current solar cycle is anomalously low, I suspect that the AMO should soon tank into its cold cycle, thus, if this is indeed the case and a flip in the oceanic cycle flip is in order, then it makes a little more sense given other evidence and how favorable the conditions are at hand this year, to see a long track Cape Verde storm this July.

  • jrrp says:

    normal pressure in the MDR
    the higher pressure is north of 20n
    acording to the Euro model

  • Stephanie says:

    Thanks very much for the sea surface temp analysis. This video was very informative! (I must say, I don’t like the 2004 comparisons that keep popping up this year. I got hit dead on twice within 3 weeks of each other that year!)

  • Justin says:

    Just out of curiosity, are you viewing the BRAMS datasets through GrADS or are there visual displays of the data somewhere online?

  • Jason Scott says:

    Very well done…. Thanks

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