textproduct: Reno

KEY MESSAGES

* Leftover snow showers and recent heavy snow will produce lingering travel impacts through the remainder of today.

* Another quick moving storm will bring additional snow accumulations and travel impacts mainly for the Sierra, northeast California and far western NV on Thursday. * After a break in storm activity Friday through early Sunday, more storms are likely to return late Sunday and next week.

DISCUSSION

This week's big winter storm is in its final few hours as lighter snow and snow showers have generally pushed south of I-80. Even after this snow ends, we'll continue to have slick roads and travel delays through this morning's commute with temperatures well below freezing. While the majority of today and tonight will offer a small window to dig out from all this snow, isolated snow showers with modest additional accumulations (up to 3") remain in the picture near the Sierra and northeast CA.

One more storm is lining up to bring additional snowfall on what has already fallen. Although this system isn't as strong compared to this current storm, it will be cold enough for snow at all elevations, and aggravate the ongoing travel impacts. There have been some challenges in this storm's track, although latest guidance is favoring a track that brings the best accumulations to the Sierra/northeast CA with new snow of a foot or more near the crest and several inches down to lake level in the Tahoe Basin, western Mono County and northeast CA, starting early Thursday morning and lasting through the evening. Enhanced snow bands from convective activity will still be capable of producing short duration 1+"/hour snowfall rates especially Thursday afternoon. Unlike this recent storm, winds are less likely to be a factor, with Sierra ridge top gusts generally peaking near 55-70 mph and surface wind gusts generally 25 mph or less.

For western NV, snow could arrive soon enough across the Reno- Carson region to produce slick travel for the Thursday AM commute, then snow coverage increases through the remainder of the morning and into the afternoon. With more potential for impacts and 30-60% probabilities for at least 2" for the main cities, confidence is sufficient to introduce a new Winter Weather Advisory. Foothill sites including Virginia City could receive up to 6" of new snow.

The storm appears to take on a "Tonopah Low" character for a few hours Thursday afternoon, with an area of snow wrapping around the US-95 corridor of west central NV. Given the majority of the snow reaching these areas when the sun angle is higher in the afternoon, along with the lower elevations of most communities, accumulations could be harder to occur. Current blended guidance shows the main US-95/US-95A communities (Lovelock, Fallon, Yerington, Hawthorne) having a 20% or less chance of reaching the same 2" threshold Thursday.

As this storm departs and snow ends later Thursday night, temperatures again plunge into the single digits and teens, so plan on slick travel conditions to carry over into the Friday AM commute.

For Friday and Saturday, a larger window to dig out of this week's snow is still opening up. However, temperatures remain below average so it will be a slow process of melting even for valley locations. Sunday brings more notable warming, but another storm is on the horizon later in the day. An active and unsettled weather pattern is shaping up next week, more likely to be milder storms with more rain than snow for lower elevations, and a higher density snow for Sierra communities. The details are quite murky with timing and storm tracks, but as an early heads up, lower elevations especially in northeast CA that received heavy snow could be dealing with accelerated snowmelt runoff, if a band of deeper Pacific moisture persists for a longer time span. MJD

AVIATION

* Sierra terminals (KTVL, KTRK, KMMH): Although snowfall will diminish to scattered snow showers today with short intervals of MVFR/IFR conditions, lingering aviation concerns continue due to this strong storm's large snowfall accumulations. The next storm will bring additional runway accumulations (70+% chance of at least 4") and widespread IFR/LIFR conditions Thursday. Current projections indicate snow arriving around 12Z, peaking between 17-00Z, and ending by 06Z. * Western NV terminals (KRNO, KCXP, KMEV): Lingering -SHSN tapering off by 12Z early this morning and patchy low IFR CIGS until around 16Z. A short window of improved conditions arrives this afternoon and tonight, before the next round of snow brings more widespread MVFR/IFR conditions on Thursday with a 20-40% chance of at least 2" of runway accumulations. Current projections indicate snow arriving around 12Z, peaking between 17-22Z, and ending by 04Z. MJD

AVALANCHE

Our major, multi-day winter storm comes to a close this morning, with lingering showers possible through the remainder of today, though additional amounts will be relatively light (less than 4" of new snow after daybreak). Another storm system arrives by early Thursday morning, continuing through the evening hours.

* Snowfall totals and rates: For the Thursday system, 6-12" with locally up to 18" along the highest peaks in the Tahoe Basin. Snowfall rates up to 1"/hr, but may exceed 1"/hr in the late morning through early afternoon timeframe.

* SLRs and SWE: Low confidence on SLRs with this second system, best guess 13-15:1 ratios due to the origin of the system off the coast of British Columbia. SLRs may drop to 12:1 or stay around 16:1, as seen with this previous storm system. SWE ranges from 0.5-1", though 1" will mostly be seen along the highest peaks of the Tahoe Basin.

* Ridgetop gusts: Southwest winds of 50-60 mph Thursday with localized gusts up to 70 mph.

-Giralte

REV Watches/Warnings/Advisories

NV...Winter Storm Warning until 10 PM PST this evening NVZ002.

Winter Weather Advisory from 4 AM to 10 PM PST Thursday NVZ002- 003.

CA...Winter Storm Warning until 10 PM PST this evening CAZ071>073.

Winter Weather Advisory from 4 AM to 10 PM PST Thursday CAZ071>073.