| typhoon_tip |
| (Meteorologist) |
| Wed Oct 19 2005 07:32 PM |
Re: Wilma Continued
|
Quote:
They use whatever data they have available while maintaining the data density as feasible. It's not radiosonde launches that kill it, it's the satellite obs -- thousands per model run, largely over the poles, that they can't use. Ten radiosonde obs don't make a large difference; much of the other data are used in normal times as well. This comes from discussions with people at NCEP.
The other suggests that the airplane dropsondes were not input into the model, perhaps because there weren't any around/just prior to 12z or perhaps because of a data ingest issue. Not sure on that one, though.
Well, then that's a bit of a change over the years... so it is then..
Anyway, this doesn't really change the significance one way or the other, regarding a "slight" westward shift beyond 72 hours; it is still plausible that trough will be able to pick her up in mind - so I do agree with what you said in your other post... Which, believe it or not, the sonding data was the lesser issue for me.
As to Zack...your notion certainly is within the envelope of possibilities, however, not any more possible than the models prematurealy or erroneously backing off such as they have.. .Met 101 in forecasting is to be very weary of model runs with such drastic discontinuity; this is particularly true when not only have several runs of the same model trended, but also when different camps have come into agreement. The 18z GFS for example is ever so slightly back N again, and together with different data as Clark has mentioned, and or "doing their best to make the data density feasible", makes the 12z guidance disconcerting for accuracies sake.. Does anyone no the formal status of the 18z initialization at this time...??. In addition, the NOGAPs 12z being shifted right is really only about 5 degrees right of the of 00z out around 144 hours; i.e., too close for comfort and of all the guidance, showing the best continuity...
why...i have no idea... personally i'd never really liked the NOGAPs model for it progressivity bias above 30N latitude... which makes it's more meridianal appeal that much more intriguing...