10/3 FCST: OTIS/AZ

[Joe Zemek]

GFS shows plentiful moisture streaming into AZ from Otis, starting Sunday evening into Monday. Best upper dynamics remain somewhat north of the real juice and so pops will likely be limited. The potential for an embedded shortwave in the 300mb jet, though, makes me hopeful for some p.m. convection in the south-central AZ deserts. As noted in the NWS PHX forecast discussion: IT IS DIFFICULT TO HANG ONES HAT ON SUBSYNOPTIC FEATURES LIKE THIS AS THEY OFTEN TURN OUT TO BE SPURIOUS.

 

[David Wolfson]

Not so much upper forcing IMO as whether enough of the low level circulation remains (when the mid/upper circulation is stripped off) to push GoC moisture up and over the modest but not insignificant topography along the Arizona border with Mexico and itself not spin out over the norther GoC. If it can do that then I'd say there's likely enough instability and shear for a few of Arizona's patented fall mini-supercells.

I'm not seeing the kind of GoC WV surge yet I like to see. Subject to change with the 00Z data and Truth, I see at as 70/30 for a bust from Otis for all but the extreme southeast corner of AZ, which should get a glop of rain.

 

[Joe Zemek]

Today's NHC discussion seems more optimistic, if temporally extended:

48HR VT 03/1200Z 27.0N 113.3W 65 KT...INLAND BAJA PENINSULA
72HR VT 04/1200Z 31.0N 113.0W 40 KT...INLAND N MEXICO
96HR VT 05/1200Z 34.0N 112.5W 25 KT...INLAND ARIZONA
120HR VT 06/1200Z...DISSIPATED

Perhaps the ETA will get a better handle on Tues/Wed. Even 15 KT would be good. The appearance of *some* upper support is nice after the monsoon upper doldrums.