textproduct: Reno

KEY MESSAGES

* A quick-moving low pressure system will bring gusty winds and increased chances for light rain/mountain snow showers on Tuesday.

* Dry and mild weather prevails after Tuesday with temperatures trending warmer through the week.

DISCUSSION

Today, an upper-level ridge is building over the region, sandwiched between two troughs. This pattern will lead to dry conditions and warmer daytime high temperatures. Nevada valleys and Sierra communities are expected to see highs in the mid 50s, roughly 5-10 degrees warmer than yesterday. Winds will remain light for most areas this afternoon and evening. Cloud coverage is already starting to increase this afternoon across the region, which will help moderate overnight cooling. Overnight lows will be 5-10 degrees warmer in the Sierra and western Nevada compared to the previous night, generally in the mid 20s for the Sierra and mid 30s for western Nevada valleys.

Tomorrow, a low pressure system will move across northern California and into northern Nevada by tomorrow night. This system will usher in gusty winds and a chance for light rain and mountain snow showers. Latest model guidance such as the NAM (in it's last full day of operation today) shows Sierra ridgetop winds increasing significantly, gusting 60-80 mph out of the south- southwest. These strong winds may mix down into eastern Sierra valleys and along the Sierra Front, with surface gusts up to 25-35 mph, potentially reaching 50 mph in wind-prone areas.

Precipitation chances will increase through the day on Tuesday. Light showers will move into the Sierra and NE California around 11 AM-12 PM PST, reaching the Sierra Front by 3-4 PM, and the Nevada Basin and Range by 5 PM, before exiting the region by 8-9 PM. PoP values range from 60-80% in NE California and the Tahoe region, with lower chances (~20% or less) elsewhere. Accumulations are expected to be light, generally a trace to 0.15 inches, with higher amounts at the Sierra crest. The NBM shows a 50-60% chance of 1+ inch of new snow at the Sierra crest from Tahoe southward through Mono County, which could lead to minor travel impacts along Sierra passes. Snow levels will generally be around 6000-7500 feet, increasing to the higher end in the afternoon.

Wednesday, the upper low will depart, and a flattened upper ridge will begin to build over the region. This will result in a return to dry conditions across the entire forecast area. Temperatures will remain mild, with a slight warming trend beginning. Highs are forecast to be in the low 50s in the Sierra and upper 50s in western Nevada, warming to the low 60s in the Sierra and upper 60s in western Nevada valleys by Saturday. These dry conditions and mild temperatures will continue through this weekend, with light winds.

-Justin

AVIATION

VFR conditions are expected for most area TAF sites today. Relatively light winds are expected with high cloud coverage increasing through the day. This cloud cover, along with the potential for stronger winds aloft mixing down to the surface overnight, may inhibit fog reformation near KTRK later tonight.

Increased winds and rain/mountain snow shower chances are expected in the region on Tuesday, with Sierra ridgetops gusting up to around 60-70 kts causing potential mountain wave turbulence and LLWS along and east of the Sierra. Timing of the precipitation will be from 22Z-03Z tomorrow afternoon. Snow levels will be around 6000-7500 ft tomorrow, so snow accumulation for Sierra terminals is unlikely.

-078/Justin

REV Watches/Warnings/Advisories

NV...None. CA...None.