Is this like Debbie does Dallas? Just wondering...
10:39 central 8/22/06The initial motion estimate is 295/16. Although the global modelsare in reasonable agreement and tightly clustered through 48-72h...the model consensus has shifted well to the west or left of theprevious track...due in part to the continued westward shift ofthe GFS...GFS ensemble...and GFDL models. The BAM models have beenatrocious at best with a large right-of-track bias over the past 36hours...so they were not even considered in the forecast process.The GFS and GFDL models appear to have been overdeveloping a weakmid- to upper-level low located about 550 nmi northwest of Debby.This feature is so indistinct and much smaller than the circulationenvelope of Debby that it is hard to locate in water vapor imagery.In contrast...the NOGAPS and UKMET models have been downplaying theupper-low and dissipate it completely by 48 hours. Given that theupper-low at best is moving westward at the same speed as Debby...any northward influence by this system on Debby should be less thandepicted by the GFS and GFDL models. The official forecast trackwas shifted westward...but not as far west as the GUNA...GUNS...andCONU consensus models. As mentioned in last night's discussion...if Debby doesn't reach 20-25n latitude in 72-96 hours...then ashortwave trough and forecast weakness in the subtropical ridgewill bypass the cyclone...as alluded to by the 18z UKMET model run.
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