textproduct: Reno

KEY MESSAGES

* An ongoing winter storm is currently bringing valley rain and mountain snow, mainly above 5000 feet, through this evening. Expect hazardous travel conditions through the Thursday evening commute.

* A cold, dry pattern will establish itself over the weekend, bringing widespread chill morning low temperatures. A 10% chance of precipitation is possible along the Oregon border Monday.

* Weather looks good leading into Thanksgiving, but simulations point toward a potential colder storm during the weekend after Thanksgiving.

DISCUSSION

* This Afternoon and Friday: The upper low currently digging south along the California coast continues to generate precipitation across the Sierra and western Nevada. Observed snow levels have consistently been lower than the previous forecast package, bottoming out in the 5000-5500 foot range this afternoon. This confirmed the need for the Winter Weather Advisory expansion to include the Greater Lake Tahoe Area and the Greater Reno-Carson City-Minden Area above 5000 feet. The advisory elevation for southern Lyon/Mineral counties was accordingly lowered to 5000 feet, and the duration for Mono County and S. Lyon/Mineral counties advisory has been extended through 8 AM PST Friday. High-resolution models show precipitation chances peaking this afternoon and evening, with the heaviest snowfall confined to the Sierra and Carson Range as of this writing. By 4-6 PM, the bulk of shower activity begins to taper and shift south of the Reno-Tahoe corridor. The remaining moisture will become increasingly confined to Mono/Mineral counties after 8 PM. Showers across the entire region finally exit and diminish by 8 AM Friday, initiating a drier post-frontal pattern.

* The Weekend: An upper ridge remains forecast to build and dominate the pattern over the area on Saturday and Sunday. This synoptic setup will promote dry conditions and light winds across the region. However, the ridge will foster excellent radiational cooling, allowing for widespread chilly mornings, with most of the region seeing temperatures fall into the 20s and lower 30s.

* Thanksgiving Week: The ridge pattern is expected to persist through most of the holiday week, permitting generally dry conditions for the early part of the week. The only exception is seen on Monday along the OR border, where a weak, northern- stream shortwave trough passes by, generating a low probability (10%) for light precipitation along Surprise Valley and N. Washoe Co. For the weekend following Thanksgiving, extended ensemble guidance continues to show very good agreement for a colder weather system to affect the region, although specific details regarding track and QPF remain to be determined.

-Johnston

AVIATION

Winter weather conditions are currently impacting Sierra terminals with all terminals currently IFR with -SN/SN. Western Nevada terminals are generally seeing MVFR CIGs and VIS due to -RA this afternoon. Precipitation is expected to begin tapering off from north to south this evening, with improving flight conditions overnight, though KMMH will see reduced visibility from SN into early Friday morning. Precipitation should exit the eastern Sierra round 14-16Z Friday. A dry pattern initiates into the weekend with light winds.

-Johnston

REV Watches/Warnings/Advisories

NV...Winter Weather Advisory until 10 PM PST this evening NVZ002-003.

Winter Weather Advisory until 8 AM PST Friday NVZ001.

CA...Winter Weather Advisory until 10 PM PST this evening CAZ072.

Winter Weather Advisory until 8 AM PST Friday CAZ073.