textproduct: Reno

KEY MESSAGES

* Gusty southwest winds are expected today, with widespread valley gusts of 30-40 mph and Sierra ridgetop gusts potentially reaching 70-80 mph.

* Isolated light rain and mountain snow showers are possible across far northeast California today. Most other areas will remain dry through Wednesday.

* Increasing chances for unsettled weather, cooler temperatures, and widespread precipitation are expected late week into the weekend.

DISCUSSION

An upper-level trough currently moving onshore across the Pacific Northwest will clip northern California and western Nevada today. This system will be the primary driver for gusty southwest winds across the region. Sierra ridgetop winds are forecast to increase significantly overnight, reaching 70-80 mph by early morning, and potentially up to 90 mph along the highest peaks. Valley locations will experience southwest gusts up to 30-40 mph, with wind prone areas along US-395 from Susanville down through Mono County reaching 45-55 mph. These winds will create hazardous boating conditions on area lakes, prompting Lake Wind Advisories through this afternoon. Winds will gradually diminish this evening as the trough moves eastward.

Precipitation chances associated with this system will be very limited and confined to the Warner Mountains, Surprise Valley, and far northern Washoe County. The chance of light rain and snow today is around 25-35%. Along the northern half of the Warners in eastern Modoc County, there's around a 50-60% chance of 1" or more of snow. Elsewhere along that range, there's only a trace of snow expected. Otherwise, conditions are expected to remain dry across western Nevada and northeast California.

By Tuesday and Wednesday, a transient upper-level ridge will build over the Great Basin, leading to a return of dry and mild conditions. Skies will be mostly sunny, and winds will be light. Temperatures will be near to slightly above seasonal averages, with highs in the 50s and 60s for most areas. Overnight lows will remain cool, generally in the 20s and 30s for the Sierra and colder valleys, and 30s to low 40s elsewhere.

By Friday, active weather will pop back into the forecast with a deep Pacific NW low churning off the coast of Washington. Precipitation chances will increase, particularly for the Sierra and northeast California, with slight chances (15-30%) for rain and mountain snow showers. Confidence increases further for more widespread precipitation Saturday and Sunday. Long range models start to diverge in the exact evolution of the western trough (consolidated upper low vs. elongated trough), which will impact the finer details of QPF and timing. However, the overall trend points to a series of low pressure systems moving through the region into early next week. This will bring additional chances for valley rain and mountain snow showers to most of the forecast area, with snow levels likely dropping. Extended outlooks continue to lean wetter and cooler than average conditions into the first week of November.

-Justin

AVIATION

VFR conditions continue today, however, an incoming low pressure system will bring mountain wave turbulence, LLWS, and lenticular clouds to the Sierra and east of the Sierra, starting this morning through this evening. Southwest gusts across the Sierra and Sierra Front will range from 25-35 kt mainly between 18Z-03Z this afternoon. Winds will taper off late tonight, becoming light.

-Justin

REV Watches/Warnings/Advisories

NV...Lake Wind Advisory from 10 AM to 6 PM PDT Monday NVZ003-004.

Lake Wind Advisory from 4 AM to 6 PM PDT Monday NVZ002.

CA...Lake Wind Advisory from 10 AM to 6 PM PDT Monday CAZ071-073.

Lake Wind Advisory from 4 AM to 6 PM PDT Monday CAZ072.