We will have a very cold introduction to 2019, as clearing skies and a cold airmass will combine to ring in downtown Reno temperatures down into the 20s with wind chills that could drop into the teens. And the first day of the New Year will start out at sunrise in the tees (without wind chills, topping out in the mid-30s under mostly sunny skies. The first week of the New Year will be mostly dry, with a warming trend into the weekend with the low 50s reachable by the weekend. A weak storm system gives us our first chance of 2019 rain or snow by Sunday.

For those of you keeping score, winter officially began at 2:22 pm local time today (Friday.) And as is not always the case, this time the weather will play along.

A few light mountain showers should dry up for Saturday, before a moderate winter storm makes its way into the region late Sunday into early Christmas morning. Saturday’s high temperature will peak in the upper 40s with light winds, climbing to the low 50s on Sunday. By Sunday afternoon some light to moderate precipitation should start in the mountains, with winds picking up, especially along the ridgetops. A Winter Storm Watch has been posted for the mountains starting Monday morning and going into Christmas morning, with a few inches likely at Lake level, and a foot or more possible in the upper elevations.

As for the valleys, rain showers with gusty winds are likely Monday. As the cold front moves through the snow levels will drop to the valley floors, giving us a chance of a white Christmas, although the airmass should dry up with the passage of the front and accumulations should be limited in the lower valleys.

Three things will occur in our weather picture, all involving increases. First, the clouds will increase overnight tonight, ahead of a storm system that is likely to miss us here in western Nevada. Along with that frontal band, the winds will also increase overnight tonight, which should be enough to keep the temperature inversions from forming, and will keep our overnight low temperatures on the mild side. Finally, with the ejection of the inversions and the rebuilding of a ridge of high pressure, temperatures will also increase to the upper 40s on Wednesday and peaking in the low 50s by Friday. A couple of weak systems bring only a slight chance of rain showers late Friday night, and then a better chance of rain Sunday afternoon into Monday morning.

A Winter Storm Warning is in effect in the mountains from late Wednesday night through early Friday morning, with total accumulation ranging from a few inches at the Lake level to two feet or more up on the crests of the Sierra. After a break on Friday, a colder and slightly drier storm moves through the region bringing more snow, but this time to all elevations. Accumulations in the valley are likely to be light, but the foothills could accumulate enough to cause some travel issues. A Winter Storm Watch is now up for the upper elevations for Late Friday night through Saturday night, with a foot or more possible in the prime locations. Temperatures will drop to the 30s to end the week, with overnight lows likely to fall to the teens.

Wintry weather will settle in for most of the rest of the week, with the mountains, as usual, feeling the strongest impacts. For Wednesday, widely scattered showers (mostly up in aforementioned mountains) will increase in intensity overnight into Thursday. Snow levels will range from near Lake Tahoe level and slowly fall to about the 5,000′ elevation (just above the valley floor) by Friday morning. A Winter Storm Warning is in effect for the mountains from 10 pm Wednesday through early Friday morning. Total snow amounts through the time period could range from trace amounts in the foothills to a few inches at the Lake to amounts measured in feet on the crests of the Sierra.
After a brief break Friday a colder storm moves through which could bring snowfall all the way down to the valley floor, although at this time it’s uncertain if we will get any accumulations.

It is shaping up to be a very active week or two in our area. By late in the day Tuesday, a storm front will move through bringing rainfall with high elevation snow. Precipitation amounts will vary greatly between the mountains (with an inch or more of liquid possible by Wednesday afternoon) to marginal amounts in the Reno area due to the rain shadow. Late Wednesday into Thursday a colder and potentially stronger storm moves in and a mountain Winter Storm Watch is in effect as a result during that time. After a brief break Friday another cold storm moves in with limited precipitation.

Looking further into late next week, the possibility of an Atmospheric River  is starting to look likely enough to bear watching. The specifics are still a little iffy, but I’ll be keeping an eye on it.