textproduct: Reno

KEY MESSAGES

* A weather system will bring showers, thunderstorms, and cooler temperatures this weekend. Be prepared for recreation and travel impacts due to gusty winds, rain, hail, and mountain snow.

* Cool, showery weather continues Monday to Wednesday. Snow may impact travel over mountain passes above 8000 feet Monday.

* Warm weather returns late next week.

DISCUSSION

A few more days of temperatures 5-10 degrees above average (mid-70s for NV valleys) are in store today and Sunday. Martis Valley and Truckee could see fog again this morning for a couple hours (30% chance). Winds today will be out of the southwest with gusts 15-20 mph. Fairly light winds generally out of the west continue into early next week. Temperatures take a hit on Monday to a few degrees below average (mid-60s in NV valleys), then bounce right back up into the low 80s across western NV by Wednesday.

The highlight of forecast over the next 5 days will be afternoon showers and thunderstorms. A closed low is approaching our area and moving onshore over central CA, creating an area of upper level diffluence over our CWA this weekend.

Stronger showers and thunderstorms are expected today and Sunday due to increased forcing aloft and more available moisture to tap into. PWATs today and Sunday are forecast to be around 0.5-0.7" which is right around the sweet spot for our area. Current precip chances are 30-40% today (20% chance t-storms) and 50-80% Sunday (30% chance t-storms), with the higher end being along the Sierra crest around the Greater Lake Tahoe area. Latest CAM guidance is showing MUCAPE values of 500-800 J/kg this afternoon and Sunday, which is enough to potentially get a couple severe storms. Storm motions look to be fast around 20-30kt today and Sunday as well, so there is potential for dry lightning. Model soundings show DCAPE values around 400-700 J/kg today and Sunday, which theoretically puts estimated wind gusts near thunderstorms around 30-35 mph. Overall, main concerns with these storms will be brief heavy rainfall, occasional-frequent lightning, small hail (<1" in diameter) and ice pellets, and brief gusty winds from outflows.

The storms look to continue after Sunday, with Monday possibly being another strong thunderstorm day. Longer range models such as the GFS and RRFS are showing MUCAPE values upwards of 600-900 J/kg on Monday, which could also promote strong thunderstorms. Snow levels also drop on Monday to around 8000 feet, which may lead to the highest peaks in Mono County receiving a couple inches of snow. Later this week, the forecast becomes more uncertain. Models are now showing high pressure settling in by mid-week, though that could very well change again tomorrow. At the very least, temperatures will warm up nicely into the mid-80s across western NV valleys and low-70s in Sierra valleys.

-Justin

AVIATION

VFR conditions with light winds tonight. KTRK has a 30% chance to see FZFG tonight through sunrise.

An incoming system on Saturday will increase winds out of the south and southwest 20kts in the afternoon. Shower chances jump up to 30-40% on Saturday and 50-80% on Sunday, each with a 15% and 30% chance of lightning, respectively. Mountain tops may become obscured as cloud heights lower through the weekend.

-Justin

REV Watches/Warnings/Advisories

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