Greg Newman

One of five power poles downed Friday along the Mt Rose Highway, causing power outages in south Reno. Photo courtesy of Greg Newman

It is shaping up to be a very active weather weekend. As colder air moves in overnight Friday into Saturday, snow levels will drop to near the valley floor by Saturday morning and then should fall all the way to the floor by Saturday afternoon. As the colder air comes in, the heaviest moisture should move out of the region, but there could still be scattered snow in Reno through the afternoon.

The wild card in the weather story comes in on Sunday. A colder winter storm comes on the coast, and depending on its track, could result in nominal to significant snow in the Reno area. Heaviest snow should be south of Reno, but as the low passes by south of us, we might be able to get some wrap around snow reminiscent of a Tonopah Low. Because of this, a Winter Storm Watch has been posted for the Reno area for Sunday. Stay tuned.

 

Six years ago (January 14, 2010) we set an all-time record for the lowest barometric pressure here in Reno of 28.92”. Interestingly enough, it wasn’t accompanied by super-strong winds like we’ve had lately (although it was quite windy a day or two prior to the record being set.) The low pressure was caused by a very deep and strong low pressure center which raised havoc in the west (although we missed out on some of the best precipitation here in Reno.)

High winds aren’t necessarily connected to low pressure per se, but rather to areas in which there is a strong change (gradient) in pressure. When we were at the bottom of the barometer reading, we were close to the center of the surface low, and there’s not that much gradient in the center. Our strongest winds generally occur when the rate of change in pressure is the highest.

If you recall, the stronger winds came before the pressure bottomed out. You can relate it to a hurricane. The lowest pressure is in the eye, but the winds are almost non-existent there. They are much stronger away from the center where the pressure gradient is the greatest.

High winds can also be associated with high pressure, but as is the case mentioned earlier, they are strongest when the pressure is climbing fast, not when it has reached its peak.

 

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