textproduct: Reno

KEY MESSAGES

* Dry and cold conditions will prevail across the region today.

* Another storm will bring valley rain and mountain snow to the Sierra and western Nevada late tonight through Friday morning.

* Looking ahead to the week of Thanksgiving, the weather for traveling looks good the early part of the week. Simulations are then pointing toward a potential colder storm during the weekend after the holiday.

DISCUSSION

Quite calm conditions out there today as the fog and low stratus continue to erode. Main theme today will be sunny skies and light winds. This is all thanks to an upper level ridge that's getting compressed as it passes over today. A trough off the PacNW coast is throwing this ridge out east and quickly moving onshore.

This next system will arrive in NE CA late tonight, with the leading edge of the precip working its way south to Tahoe, then to Mono County by Thursday morning. We're seeing a bit of spillover into western NV in the CAMs Thursday morning as well. Spillover will shift from mostly north of I-80, to south of I-80 by Thursday afternoon. Snow levels will start off around 5500-6500ft at the start of the precip, then drop slightly to 5000-6000ft Thursday night. Current snow probabilities have an 80% chance up to 2 inches along the higher peaks above 6500ft in NE CA and western NV (20% chance of 2+ inches), a 50-60% chance of 4+ inches along the crest surrounding Lake Tahoe above 7000ft, and a 40-80% chance of 4+ inches along the crest in Mono and the Wassuk Range above 7000ft. Lower valleys are expected to get 0.05-0.20" of rain, with the higher amounts south of US-50. To add a little complexity to the forecast, a north/northeast flow aloft and at the surface Thursday afternoon-evening will trap cooler air against the eastern slopes of the Sierra. This cooler air combined with the band of precip that will form south of US-50 may act to lower snow levels slightly, giving lower valleys like Yerington, Hawthorne, and Smith Valley chances for a rain/snow mix by Thursday evening. A Winter Weather Advisory has been issued above 6000 feet in Mono, southern Lyon and Mineral counties Thursday morning to Friday morning due to this latest development.

The storm finally moves out Friday morning with lingering snow showers in southern Mono County. Friday through next week we'll warm up slightly and dry out. High pressure attempts to build in, but models are showing a trough sneaking by to our north on Monday, squishing the ridge a bit. We may see some precip chances Monday afternoon near the OR border, though the probabilities remain low (10-15%).

-Justin

AVIATION

Dry conditions, light winds, and decreased cloud cover are forecast through the afternoon allowing for VFR conditions. Looking ahead to tonight, an approaching weather system will cause cloud cover to increase within the region. This system will bring snow chances to the Sierra and NE CA while ridgetop winds gusting up to around 30-35 kts are in the forecast through Thursday morning. These precipitation chances spread across the rest of the region going through the night allowing for rain and snow that could lower flight rules. The precipitation coverage looks to begin to taper off from north to south beginning Thursday evening before vanishing completely by midday Friday.

-Justin/078

REV Watches/Warnings/Advisories

NV...Winter Weather Advisory from 7 AM Thursday to 7 AM PST Friday NVZ001.

CA...Winter Weather Advisory from 7 AM Thursday to 7 AM PST Friday CAZ073.