Reno, Nevada

• Periods of mountain snow will create travel disruptions in and across the Sierra through the weekend.
• Rain and a low chance of thunderstorms are expected this weekend, with light snow falling near valley floors by early Sunday morning.
• Warmer and drier weather prevails early next week, with another Pacific storm possible around midweek.

Radar continues to show intermittent light rain and snow showers across the region. This activity will continue through the morning with the approach of the main weather event this weekend.

The upper level system in the Pacific will be merging this afternoon and evening near our region. This is the timing when rain and snow showers will start to increase. Also the time when we may see some isolated thunderstorms, as there is some marginal instability with the merger of the warm and cold airmasses (both moist) leading to MUCAPEs of 100-300 J/kg and LIs of 0-1C, combined with decent synoptic and orographic lift. The higher chances for storms will be in the Sierra at 10-15%, below 10% for all other areas. This also means some thundersnow may be possible, briefly inflating amounts in isolated locations.

Talking about the snow today and tomorrow. Snow levels start at 6-7 kft today with areas above 8000 ft receiving the heaviest snowfall this season so far. Snowfall rates will be at 0.5-1" per hour at the highest Sierra passes, potentially higher for brief periods tonight. There is a 20-80% chance of receiving more than 6 inches of snow above 8000 ft, and 20-50% chance of seeing more than 1 inch of snow above 6000 ft. For more detailed information about snow amounts see our Winter Weather Advisory for the Tahoe Basin and Mono county. For western Nevada and northeast California, most of the event will be rain today, with a rain snow mix overnight until the full transition to snow by Sunday morning to most areas as snow levels drop to 4500-5500 ft. However, snow accumulations in the valleys are expected to be little to none as the system starts to leave the area and showers become more spotty in nature. The foothills in western NV including Virginia City may get up to an inch of snow, but chances are low at 10-30%. Rain amounts will be generally below 0.25 inches in the NV and NE CA valleys through tomorrow morning.

An upper level ridge returns by Sunday evening clearing all the precipitation chances away for a couple of days. Therefore, expect warmer and drier conditions. By late Tuesday into Wednesday, ensemble members are highlighting the approach of the next upper level trough. Currently it looks like a quick passage with light amounts of precipitation. We remain near the edge of the storm track afterwards, which keeps the possibility of another system towards the end of next week and weekend.

-HC

Isolated showers and low clouds continue producing brief periods of MVFR conditions and mountain obscurations through 18-21Z Saturday at Sierra terminals. A few showers may spill into W Nevada terminals, although low clouds and mountain obscuration will be the primary issue.

Showers increase in coverage and likelihood Saturday afternoon between 20-00Z, resulting in more prolonged periods of MVFR for all terminals. Moreover, there is a low 10-15% chance of thunderstorms between 18-03Z Saturday afternoon, which may briefly reduce CIGS/VIS to IFR conditions if storms drift over airfields.

-Salas/HC

NV...Winter Weather Advisory from 8 AM Saturday to 7 AM PDT Sunday NVZ002.

CA...Winter Weather Advisory from 8 AM Saturday to 7 AM PDT Sunday CAZ072-073.