my contention that this thing is really alma.. is because the mid-level vorticity center from the storm which did cross central america.. emerged off the north shore of honduras yesterday. there was a surface spin up present in the area, and a sort of trough axis extending northeast and tangled with that advancing tropical wave. yeah, maybe the surface low did sort of wash out against the base of the low-trough fixture to the northeast, but that mid-level center was clearly present during the entire crossing, and is what 'arthur' just developed underneath during the last 24 hours.
i get it, this is fuzzy territory. if a tropical cyclone center decays at the surface, and redevelops in the same general area (i.e. erin 2001).. is it a different storm? the mitch and ivan examples for a storm that pretty much washes out over land but has it's mid-level vorticity induce another system. remember td 10 and katrina? the gate has swung both ways, but the katrina example was from a several-days dead system.. not something that developed 24 hours later along the vorticity track of a previous system. as far as basin-crossing storms.. since the new rules about name retention were established earlier this decade, they haven't held up with systems like iris and its pacific version, or with our most recent example alma. it does sort of load the numbers a bit when a system that is directly attributable to a weakened storm crosses basins and causes another 'storm', when it isn't clear that it isn't just a reintensified version of the same parent system.
interesting that the same sort of controversy exists around tornado counts. if a parent mesocyclone drops four tornadoes in quick succession... is it the same tornado lifting and touching, or are they four discrete tornadoes to tally? how can you tell if a tornado jumped six times if there were no spotter reports and a bunch of straight line wind damage mixed in, if you're trying to count every touchdown as a discrete tornado? i've been paying attention to this due to all the severe weather we've had recently (and the crazy tornado numbers caused by storms in 2004)... and seen obvious differences from one nws reporting area to another. tornado reporting is way up in recent years, and it's hard to nail down long term statistics for either tornadoes or tropical cyclones with that kind of observation difference built into the tallies over recent decades.
anyhow, lots of stuff to grumble about. lots of conflicting voices and opinions.
HF 1909z31may