Long-range forecast models see 92L developing into a powerful hurricane (Katia) next week

Post by Dr. Ryan N. Maue

Update:  August 29 — Tropical Depression 12 has formed out of the strong African easterly wave near 30W.  It will generally move Westward over the next 5-days gaining strength steadily, likely becoming a major hurricane by the end of the week.  Colorado State satellite imagery — here.

Update:  the wave that had 0-10% chance of developing near Bermuda was given the name Jose.  Actually, the Canadian Met Model predicted this genesis a week ago, kudos to them.  It is a “baby-whirl” and will last 12-24 hours and be one of the shortest-lived and weakest storms in history.

As hurricane season ramps up, eyes turn towards the African coast as “easterly waves” emerge over the warm waters of the North Atlantic.  Invests or areas of concern are “named” by simply numbering them starting with 90 and lettered according to basin:  Atlantic = L, Eastern Pacific = E, and Western North Pacific = W.  So, 92L has just come off the African coast and already has a 30% chance of developing into a tropical cyclone during the next 48-hours according to the latest National Hurricane Center Tropical Weather Outlook.  The next named storm will be Katia.

Current forecast model animation links follow:

The king of global weather forecast models ECMWF sees a very strong Category 4+ hurricane NE of the Lesser Antilles in 6 to 7 days, with the GFS showing proto-Jose Katia recurving North much sooner.  At this point, we can sit and watch things develop, but keep an eye to the “tropical update” — too bad John Hope isn’t around to make us love meteorology again.

ECMWF 10-day Forecast (click to animate) — updated twice-daily …

ECMWF 10-day Forecast for North Atlantic Tropics

NCEP GFS 16-day forecast — updated 4-times daily

NCEP GFS 16-day Forecast for North Atlantic tropics

A quick way to visualize the “tracks” of the storms is to look at a “wind swath” map:

ECMWF 10-day Maximum wind speed swath map

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34 thoughts on “Long-range forecast models see 92L developing into a powerful hurricane (Katia) next week

  1. No fair! don’t distract me with next week’s wipe out while I’m busy being blown away. Umm, okay, it won’t be that windy. Washed away? Umm, okay both house and yurt are on hillsides and I have rain gauges that hold 10″ that I don’t expect will overflow.

  2. “Long-range forecast models see 92L developing into a powerful hurricane (Jose) next week”

    This is funny because the picture above shows a Jose on it. Jose became yet another storm that would never have been given a name 10 years ago.

  3. Too late. Jose has already been named, and it looks like it barely last the day.

    The strong will be Katia (unless another one sneaks in there).

    Good luck to New England. We felt the edges of Irene last night, and wind gusts of 50 MPH were enough for me.

  4. Looks like Jose popped up out of nowhere by Bermuda. Guess that tropical wave will get named Katia, unless another quickie fish storm appears.

  5. I think something is mangled in the headline here. Jose has been named and is on a northward track off of Bermuda per the graphic. The wave coming off Africa will be called Katia if it develops.

  6. “The king of global weather forecast models ECMWF sees”
    =======================================================
    Is that the same model that had Irene going into the Gulf….
    …and last Sunday had Irene going straight up the middle of Florida as a Cat4

  7. Looks like the little one south of Bermuda has done enough to take the name of Jose (not that it looks like doing much), so the Cape Verde system would take the name subbed in for Katrina, Katia.

    As someone said on another thread about Irene being a warmup for the next one on September 10th, they might not be far off in the timing. Keep ‘em peeled…

  8. The name “Jose” already designates a little storm east of Irene and due to spin off north. Katia will probably be the designation of the storm now forming off the African coast. While it appears Katia will be powerful, it hopefully will exert its power well off-shore in the open ocean.

  9. Satellite loops of 91L (upstart Jose) show the outflow from Irene obliterating it already:

    http://www.ssd.noaa.gov/goes/east/eaus/flash-avn.html

    It’s trying to maintain a good level of convection, but the shear is much too great. No chance of the lower-level circulation staying coupled with the convection aloft.

    Probably worth a littlr amendment at the top of this story to make it clear which system is the potential beast the ECMWF is forecasting.

  10. > I think something is mangled in the headline here.

    Come on guys, think. The NHC named Jose in their 1200 UTC announcement:

    TROPICAL STORM JOSE SPECIAL DISCUSSION NUMBER 1
    NWS NATIONAL HURRICANE CENTER MIAMI FL AL112011
    800 AM AST SUN AUG 28 2011

    THE AREA OF LOW PRESSURE SOUTH OF BERMUDA HAS MAINTAINED ENOUGH
    ORGANIZED DEEP CONVECTION TO BE CONSIDERED AS A TROPICAL CYCLONE.

    This post was made about four hours earlier than the announcement. This is hardly a “Dewey Wins!” moment….

  11. Let Jose go to Texas they need RAIN we had enough and we are trying to recover here from Irene and Good Night Irene……………..Give us a Break here!

  12. Katia, looks to be on a Isabel path, which was really bad news for VA last time. Irene took the more typical land in NC, slow the western edge winds down to a nice tropical storm and move on up the coast. Isabel just plowed into us and kept going inland. Hopefully the Katie to be will recurve before land fall.

  13. “too bad John Hope isn’t around to make us love meteorology again.”

    I’ll second that, he was great and now sorely missed. He was objective and honest and always delivered forecasts and analysis that let the information tell the story plain and simple. His kind of integrity is practically impossible to find in the MSM these days.

  14. Interesting animations above.

    So GFS shows a weaker ridge of high pressure extending from the Azores, partially eroded by another small low by this time next week, giving 92L room to recurve with what might be TS Lee behind it and slam into Ireland and Scotland.

    ECMWF appears to be building enough ridging between the small low and 92L to keep it on a WNW heading for longer. This would appear to be the key variable in determining where 92L eventually heads, be it recurving in plenty of time to avoid land on the left side of the Atlantic or, in the other extreme, a stronger ridge forcing it towards Florida or even further west.

    Irene looks like a dress rehearsal…

  15. Due to the fact the media over-hyped this storm, CWS will set in. (CWS = Crying Wolf Syndome.)

    The next one is the REAL “Big One.” However everyone will go “Ho hum” and focus on whether the Red Sox are better than the Yankees, as their house lifts off and floats away.

  16. Have you noticed, ever since, and even before, that Women’s Lib stuff, guys just don’t seem to amount to anything anymore. Guys! It’s time to put our foot down! (Just be really careful where you step. Land mines, ya know;-/)

  17. Dr. Maue

    That’s what happens when you put a piece like this out as hurricane season is peaking … within hours, everything changes and a quick rewrite is called for … and not just Jose … as 92L went from 30% to 40% and is now at 70%. At this rate it may even get named tomorrow.

    And what happens if Katia turns into a real monster and no one listens after the hype of Irene?

    As for today’s on air personalities … honesty and integrity are sorely missed attributes these days.

    [RyanMaue: agree totally. but if Katia threatens even an uninhabited atoll at this point, the media will be like vultures swooping in to link it to climate change]

  18. What does Piers Corbin of WeatherAction say about Katia?

    After all, he predicted Irene 85 days ago.

    REPLY: We don’t know that he in fact successfully predicted Irene 85 days ago. I’ve asked him to provide his original proof of forecast, so far no response. I find it pretty hard to read Piers’s claims, they are too full of self aggrandizing for my tastes. If he really has a valid method, he’d do a lot better if started presenting them in a verifiable way. Right now I don’t see his claims as verifiable. – Anthony

  19. Dr. Maue

    Maybe you can answer this here or write up a separate post.

    While trying to wrap my mind around the confusion engendered by Irene, I tried to work through the issue of sustained winds. It was then that I discovered that while the WMO standard is the average speed for 10 minutes at a height of 10 m, the Saffir-Simpson scale only uses a 1 minute average. I also found that there are different standards employed in India & Australia.

    My question is, how do you reconcile the different standards when working up your numbers for ACE? Or do you take the values from each method at face value as long as they remain consistent over time, and treat them as being the same?

    [RyanM: ACE is one-minute sustained winds, the maximum intensity estimate from each 6-hour synoptic advisory. You can use the WMO standard which is 10-minute and apply a 1.14 multiplication factor to normalize. JMA uses 10-min vs. JWTC which is 1-minute ... this has caused confusion for sure]

  20. Ryan,

    Do you think this has a chance to be on the same track as 1938 or 1893? Looks like if a high builds over Bermuda that it could be on one of those tracks?

    Jim Arndt

  21. Hi Ryan,

    Starting indeed to look like Katia will only be a threat to Bermuda. However, that system in the Gulf is looking interesting. ECMWF has it bringing some much-needed rain to Texas, but GFS shows it looping away from the Texico coast and making a bolt for New Orleans with near-100kt winds.

    Have you any view yet on which of these scenarios, if either, is more likely? Seems a larger-than-usual discrepancy between models, and one with greater-than-usual potential impacts.

  22. I looked at the 38 and although they are somewhat similar the 96 120 start to seperate them pretty far and the 38 dug into a southerly route before recurving to an almost straight N on the 73. With this storm being almost ten degrees farther east when it passes the 24 I dont see it having a chance of following a similar path. It seems to me its only chance of landfall would be between NC and Delaware, if the westerlies drift far North. More likely it will be ripped back out to sea by the gulf stream due to its more NE placement and also slow forward speed later in the forecast.

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