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.

While we won’t see the kinds of storms that we saw last week which resulted in several feet of snow cumulatively in some areas, we do have a chance to see some more rain and/or snow in the days to come. A moderate-strength low pressure center will start to move onshore Tuesday, bringing a chance of scattered snow showers Tuesday and Wednesday, even though the bulk of the low itself will slide down to the south of us. With this pattern, we will probably see a little less shadowing here in the Truckee Meadows since the flow will wrap around and come up from the south.
Showers will wrap up by early Thursday morning and the rest of the week should stay dry and cool with variable clouds.

More mountain snow and low valley rain will come through the region Thursday night, with a break in the action coming during the day Friday. A new storm moves across the region late Friday night into Saturday, bringing even colder temperatures and the snow level down to the valley floor. Accumulation amounts will range from trace amounts in the valley to another 1-2 feet in the upper elevations. High temperatures will top out at 45 degrees Friday and then fall to the upper 30s for the rest of the weekend.
After a chilly but dry start to the week, another chance of snow comes back on Tuesday and Wednesday.

Lillian Mendes sent in a very cool shot of a “Hole Punch Cloud” from Palomino Valley. These are created when a jet flies through a thick cirrus layer of clouds, usually when taking off (likely this particular jet took off from the Reno/Tahoe Airport). As it “punches through,” particulates from the jet’s exhaust cause some of the supersaturated moisture in the cirrus layer to condense and drop out as light precipitation up there, only to evaporate within a couple of thousand feet on the way down. It leaves behind this eerie, almost otherworldly looking cloud formation. It’s very cool!

Temperatures will continue to rise into the weekend as a ridge of high pressure builds into the region. Friday’s high in the upper 70s will be followed by a real shot at 80 degrees on Saturday with sunny skies both days. A trough of low pressure approaches the coast by the end of the weekend which will spell the end of the autumn heat, dropping Sunday back into the 70s, Monday into the 60s and bottoming out in the upper 50s on Tuesday. Apart from the cooler temperatures (and variable amounts of cloudiness), the trough will also bring some dusty winds Late Sunday into Monday, which will increase the fire danger. A Fire Weather Watch goes into effect Sunday afternoon and evening as a result.

The first widespread killing freeze of the season will occur Monday morning after a cool northerly flow left a cold airmass across western Nevada. Skies will remain sunny across the region for the next week, with a slow but steady warming trend occurring for the rest of the work week. Low temperatures will range from the upper 20s at the Reno airport to as low as the upper teens in some of the coldest outlying microclimates. High temperatures will start in the low 60s Monday and will warm into the low 70s by the latter half of the week.

The question that is always asked at this time is should I shut off my sprinklers. It really depends on how “freeze-proof” your irrigation system is. Most modern systems can withstand a few sub-freezing nights without any damage (I’ll leave it up to you to decide how freeze resistant your system is.) And with an extended forecast that looks very dry, if yours can survive a few nights in the 20s, I’d keep it active. But is certainly is time to cut back on the amount of water you are using, and do remember to disconnect your hoses from the bibs so that the faucets drain completely.

As our skies clear off, look for some areas to get down into the “hard freeze” territory over the next several days. Morning lows at the airport will likely dip into the upper 30s through Sunday morning (with low 30s and even upper 20s in the colder outlying valleys), while daytime highs will warm into the upper 60s Friday and then to the mid-70s on Saturday. The flow turns back to the north on Sunday, dropping our highs back into the 60s, and dropping Monday morning’s lows to below the freezing mark across the entire region, with several places likely to fall into the mid and even lower 20s. A Freeze Watch has been posted for Sunday night through Monday morning for the entire region as a result. Temperatures will gradually rebound to the low 70s by the middle of next week.