textproduct: Reno

KEY MESSAGES

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

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

* Warm and dry weather returns mid-week.

DISCUSSION

Yesterday's storms were about right on par for this time of year, with reports coming in of pea size hail and gusts up to 45 mph. Looking ahead to today, storms will be a little bit stronger. Models are showing a band of upper level vorticity pivoting right over Lake Tahoe, extending from northeast CA all the way across to central Nevada. This coincides with a shortwave trough some models are suggesting is sneaking around the low that's sitting off the CA coast. All of this along with other ingredients will create an atmosphere primed for thunderstorms. One factor that we're not too concerned about but may hinder the strength of the storms a bit is the cloud cover this morning. We currently have some light showers ongoing from Lake Tahoe northward, which will dissipate before sunrise, but the cloud cover will stay. But again, judging by what the CAMs are showing, this shouldn't be a huge issue.

So let's dive into it. Showers and thunderstorms will initiate around 12 PM over the Sierra crest near the Greater Tahoe area. They will then spread north and east throughout the afternoon, with storms pushing into the Sierra Front, western NV, and Sierra/Plumas/Lassen counties. Current PoPs are 40-60% across western NV and northeast CA, and 70-80% along the Sierra crest from Mono County up into Plumas County. Chances for thunder and lightning are around 20-30%. Our available moisture will be less than yesterday, with PWAT values around 0.45-0.6". MUCAPE peaks at 900-1200 J/kg over the Greater Tahoe area this afternoon, while DCAPE is highest over western NV and northeast CA at 900-1100 J/kg. Potential wind gusts around thunderstorms may reach up to 55-60 mph, so be aware of that if you have anything outside that can blow away. Estimated hail size out of these storms is generally less than 1" in diameter, although a stray severe thunderstorm can't be ruled out. If you plan to recreate outdoors today, you will likely be impacted by these storms. Do not get caught out in these storms if you don't have to. Stay up to date on the current conditions, and as always: when thunder roars, go indoors!

Storms will start to taper off in the late evening after 8 PM, with another wave a showers and thunderstorms possible overnight around 2- 6 AM over western NV pushing into the Sierra from I-80 southward. The active pattern looks to continue Monday and Tuesday with chances for showers and thunderstorms each afternoon. Snow levels also drop off Monday to 7500-8000 feet, so there is a 70% chance the highest peaks in Mono County get 2+ inches of snow. Most likely range is 2-5" through Monday night. For now, just be aware that we'll still have daily chances for storms through Tuesday night.

Wednesday through this weekend, high pressure will set in and we'll warm up to the mid 80s in western NV valleys and mid 70s in Sierra valleys.

-Justin

AVIATION

Showers and thunderstorms are once again expected this afternoon for all terminals. Probabilities are higher in the Sierra (70-80%) and lower into western NV (40-60%). Chances for lightning will be 20-30% this afternoon as well. With these storms, frequent lightning, brief heavy rainfall, gusty outflow winds (50-60 mph), and small hail (less than 1"). Lower cloud heights are expected today, which may cause mountaintop obscurations. More storms are in the forecast Monday and Tuesday, though chances for lightning decrease slightly.

-Justin

REV Watches/Warnings/Advisories

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