teh hayley

If you came here from Cyclocane, you are reading my blog. I am Hayley, the creator of Cyclocane. The purpose of this article is to give you some background information on what happens when the NHC stops covering Hurricane Sandy and what I'm hoping to do with Cyclocane so that coverage of Hurricane Sandy will continue without interruption.

tl;dr - the NHC is going to stop covering Hurricane Sandy

When NHC determines that Sandy has become post-tropical, NHC advisory products will cease.
-- NHC press release

The "too long; didn't read" is that the National Hurricane Center is going to stop covering Hurricane Sandy the moment the system turns post-tropical. At that point, advisory information will come from the local National Weather Service offices, the Hydrometeorological Prediction Center, and possibly the Ocean Prediction Center.

Hurricane Sandy will be no less dangerous at the point that she turns post-tropical. She just will no longer fall under the jurisdiction of the NHC.

Confused yet? If so, based on comments on the NHC facebook page following the transition announcement, you're not the only one.

Though a similar situation happened with Hurricane Isaac (the hand-off from the NHC to the HPC), Isaac had already been affecting land for quite some time and was already weakening. Based on the current forecast for Sandy, the hand-off is going to occur while Sandy is still out at sea, and has yet to do the worst damage.

I understand the reasoning, but I still think this is a bad idea. There's already been confusion over whether the storm will weaken prior to landfall (it won't; its "power source" will just change to something non-tropical). "High Wind Warnings" just don't tend to conjure up the same images as a "Hurricane Warning".

The threats with this storm (whether post-tropical or not) are damaging winds, storm surges, inland flooding, and possibly tornadoes.

where to get information once the NHC "goes dark"

my plans for Cyclocane

Right now, Cyclocane's coverage of Sandy is completely based off of data provided through the NHC. If I were to do nothing, this means that Cyclocane's coverage would effectively end when the NHC's coverage ends.

Of course, I don't want that to be the case, so here are the data sources I'm looking into.

the HPC tropical advisories

Here's an example HPC advisory from Hurricane Isaac. These advisories are fairly similar to the NHC's public advisories (though different enough to make supporting them a non-trivial task), but I believe I should be able to build a data parser in time for the transition from the NHC to the HPC.

local watches/warnings/alerts

You may have noticed that the tropical related warnings and Hurricane Local Statements on Cyclocane only go as far as North Carolina. That is because everything else is being handled under the more ambiguous "High Wind Warning", since the storm is expected to be post-tropical at the point that it will be affecting regions north of North Carolina.

Here is an image of the current watches/warnings/hazards in effect for the Northeast US:

I would love to be able to parse the NWS alerts so that Cyclocane could display the relevant wind and flood warnings for Sandy, but I'm guessing this is not going to be something that can be accomplished in a short time, so most likely I would be including the above warning image in some fashion with a link to more information.

Some of the problems with the graphic above are that it doesn't include a map legend, so unless you happen to have memorized the NWS map colors, you won't know at a glance what any of that means. Second, is the fact that the graphics don't indicate that there are multiple warnings in effect for one area as it only ever shows one color per area.

These are reasons why it would be nice to be parsing the raw data as well.

local headlines

Even less likely to happen is that I'll be able to build an NWS WFO news headline parser.

Going back to the New York example, they currently have the following headlines relevant to Sandy:

I think it would be invaluable to be able to include all of the headlines from all of the NWS offices for this storm, but unfortunately, it appears that there's no common format for the NWS offices to display their headlines (visually, they're all fairly similar... headlines at the top in a bulleted list... but in the actual source there is little to no common ground).

Canadian Hurricane Centre

From what I've read, unlike the US weather offices, there is no hand-off in Canada when a storm goes post-tropical. If there is still a land threat, the CHC continues to cover it.

Here is the CHC's current public advisory for Hurricane Sandy. And here is their technical discussion.

I would love to be able to parse the CHC data as well, but unfortunately, I don't see this as something I'll have time to complete either.

wrap up

At the very least, here's what I'd like you to take away from reading this article:

This storm will be no less serious, just because the National Hurricane Center has decided to stop covering it.

Return to the Sandy Tracker on Cyclocane

teh hayley