Status: 9FEB07 (Friday - midday)
IOP-5 began at 20 UTC on 8FEB and continues to monitor a big, warm storm, which is expected to last another two days. NWS issued a winter storm warning, but no flood problems are anticipated, thanks to a month of dry weather preceeding this week. The IOP-5 storm's precipitation accumulations (liq. equiv.) already exceed 2.5 inches at Blue Canyon, and are approaching 2 inches at Colfax and Foresthill. Snow levels have been 6-7 kft. Cazadero in the Coast Range has already been drenched by 5 inches of rain.
Forecasts call for quite a lot more precipitation (QPF values of 3-4 inches additional) before the storm moves out of the ARB on Monday morning. More than 3 feet of snow may be still ahead for the very highest altitudes. No prolonged breaks in the precipitation are predicted by the models. The back-end cold frontal passage is predicted to arrive around 18 UTC on 11FEB (10 am Sunday) and precipitation should end 12-18 hours later.
Soundings at Sloughhouse and Reno have been mostly good, and will continue at 4 hour intervals. Currently we expect these launches to continue through 20 UTC on 11FEB (noon Sunday). The SMART-R radar has been having trouble with its antenna controller, causing occassional 15-30 minute data outages. The SMART-R crew will continue operations, as best they can, and should expect to be on duty through Sunday night. Rainwater chemistry sampling is in progress by USGS at Alta, Bodega Bay and Cazadero, but the equipment electronics at Cazadero got swamped and its continuing health is uncertain. ESRL's high-resoltion model ensembles failed to be produced this morning.
Botttom line: This is the biggest storm of the winter so far and IOP-5 will continue to cover it, in spite of some mostly minor problems.