The Intersection

A Troubling Hurricane Humberto Record

From forecaster James Franklin:

BASED ON OPERATIONAL ESTIMATES…HUMBERTO STRENGTHENED FROM A 30 KT DEPRESSION AT 15Z YESTERDAY TO A 75 KT HURRICANE AT 09Z THIS
MORNING…AN INCREASE OF 45 KT IN 18 HOURS. TO PUT THIS DEVELOPMENT IN PERSPECTIVE…NO TROPICAL CYCLONE IN THE HISTORICAL RECORD HAS EVER REACHED THIS INTENSITY AT A FASTER RATE NEAR LANDFALL. IT WOULD BE NICE TO KNOW…SOMEDAY…WHY THIS HAPPENED.

Well, that’s blunt enough, no? I’m not entirely clear on what Franklin means, though–the record hinges on “near landfall”, I guess. Obviously there has been more rapid strengthening over the open ocean.

Perhaps he’s saying that what we’ve observed with Humberto is particularly scary because it suggests that more rapid intensifications may occur just before a storm strikes land than previously thought possible.

Comments

  1. #1 bigTom
    September 13, 2007

    Regardless if it has anything to do with climate change it is scary for a forcaster. It a case like this one, they could not issue needed warnings because they didn’t think the storm would be very strong, and then get blindsided.

  2. #2 Steve Bloom
    September 13, 2007

    Well, he can ask Chris Landsea, but perhaps the Gang of Five has a better grasp on the problem.

    Wasn’t Humberto moving somewhat parallel to the coast during that time? If so those near-shore ocean temps must have been warm pretty far down, maybe all the way to the bottom since IIRC it’s fairly shallow there.

    Anyway, now we add this event to the very rare cat 5 landfall recorded earlier in the season.

  3. #3 llewelly
    September 13, 2007

    If memory serves, total NHC budget – of which research is only a part – is about $6 million. It might be that finding out why Humberto intensified so quickly so close to land might be cheaper than war in Iraq.

  4. #4 bigTom
    September 14, 2007

    steve, I’m not a meterologist, but have a pretty good feel for a lot of scientific stuff. My gut feeling would be that the rate of intensification is a function of water surface temperature (and other atmospheric conditions). The amount of excess heat consumed by the storm is probably related to the energy dissapation of the storm. The later is a rapidly rising function of intesity. So the depth of warm water to support a major hurricane is substantial, for a storm undergoing a tropical strom to cat 1 intensification, probably not that much energy is needed.

    If any experts are reading. Is Ingrid doing some good, i.e. consuming a significant amount of the latent heat available to generate hurricanes, in it’s apparentlt futile attempt to become a hurricane? Or does a weak storm like this simply consume too little of the excess heat to matter?

  5. #5 llewelly
    September 14, 2007

    Hurricanes do not consume heat per se – they move it from the lower atmosphere to the upper troposphere or to the tropopause. (Strong hurricanes also move heat from upper ocean waters to deeper ocean waters.)

  6. #6 Jim Ramsey
    September 14, 2007

    Chris,

    I got to this discussion a little late.

    When I followed your link in the posting, I didn’t find the quote you excerpted.

    Did the NOAA political officer sanitize this?

  7. #7 philip H
    September 14, 2007

    1) NOAA doesn’t have political officers thank you very much. If they did, they’d be tarred an feathered by the mostly liberal staff.
    2) Following the link at present will send you to the latest advisory. If you go out a couple of pages, you will find the advisory archives, and I believe the quote you are looking for is in advisory 6 at 2100 UTC.
    3) Ingrid is still a Tropical storm, so its attempt to become a hurricane may no longer be futile.

  8. #8 Emily
    September 14, 2007

    Chris,
    It looks like your birthday may not be ruined after all. Humberto appears to be bring much needed rain inland – and becoming less of a threat to party plans at the same time?

  9. #9 Jim Ramsey
    September 14, 2007

    philip H,

    Thanks for the correction.

  10. #10 Chris C. Mooney
    September 15, 2007

    Thanks for the comments all. Yes, Emily, I’m here in NOLA and not a drop of rain!!!

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