Weather Status: Storm on track for a combination of events: First, an IPW plume is moving down the coast. Observational evidence shows this to be a well defined feature. Models bringing this into the ARB region after 18GMT Sunday, yet forecast no precipitation of any consequence. Second, trough and front with an intense period of warm advection rain begins Monday. Third, cold frontal passage looks to be late Monday/early Tuesday. Total precip amounts look to be in the 2-3 inch category with well defined warm advection precipitation. Thus we are calling an IOP for this event begining at 16GMT Sunday with sonde releases an hour earlier at both Slough House and Reno, and then continuing every four hours. By starting sondes early we can document the establishment of the moist plume, moistening of the PBL, and try to determine if the plume is actually stronger than predicted, and assess why models are not creating any rain in the warm advection on Sunday. Sonde schedules will be adjusted as necesssary at tomorrow's call.
System Status: for planning, sondes at Reno and Slough House centered on Sunday 16, 20; Monday 00, 04, 08 12 16 20; Tuesday 00, 04, 08GMT. Local time releases at Sunday 8am, 12pm, 4pm, 8pm; Monday 12am, 4am, 8am, 12pm 4pm, 8pm; Tuesday 12am....last one.
Rainfall sampling will be done during this event.
John McGinley, GSD