aspen wrote:So far the ceiling looks pretty high for Pamela. The GFS has consistently shown a favorable 200mb-level environment and RI on nearly all of its runs, and SSTs of 30-30.5C are capable of supporting a sub-900mb storm. However, this is a -ENSO year, and the GFS has hyped up plenty of EPac systems this year that fell way short of expectations.
Pamela will only become anything significant if:
—It organizes at the pace the GFS has shown it to
—The UL environment is indeed favorable like the GFS says it’ll be
—No pesky mid-level shear pops up
—The precursor disturbance isn’t too broad that it slows development and/or results in a large core that’s hard to tighten up
—The presence of a -ENSO somehow doesn’t impact it
If Pamela somehow overcomes or avoids all of those hurdles, watch out Mexico.
The setup is quite favorable with cold air damping triggering the gap event in the Gulf of Tehuantepec, which will enhance the vorticity over the upcoming days, plus the favorable trough interaction from an unseasonably strong trough off the West Coast. These events have help trigger several powerful hurricanes in this area before in the fall, most notably Patricia and Willa so I’d be a little surprised if the UL modeled by the GFS did not verify. The GFS does have issues in the medium and long range with moving the MJO too quickly across the Pacific and showing an American standing wave like pattern anytime MJO is in the Pacific yes but the GFS has shown this feature for several days now and has moved the timeframe earlier. There’s no CAG involved just a compact wave moving over the dry Atlantic so it’s not likely to be particularly broad. While at times the ECMWF was showing a setup that could invoke mid to upper level shear, it’s been trending away from that for several runs now, and global models in general have gotten better at predicting mid level shear. It’s also not impossible to get a strong recurving hurricane in a -ENSO (I believe October has had 4 -ENSO hurricane landfalls) though climo certainly isn’t on its side, and why I was skeptical of this back on Sunday. Given the impressive consistency and realism of the GFS and the fact that other models have at least been hinting (ICON, ECMWF) at sometimes showing a very similar setup, I’m fairly sure we get something formidable near the Mexican coast. It’s maximum strength will largely depend on how fast it gets going, which the GFS has previously been overdoing prior to yesterday, and to a lesser extent, depends on at what point does recurvature begin.