textproduct: Reno

KEY MESSAGES

* Isolated showers and thunderstorms are possible this afternoon and evening in Northeastern California and Western Nevada.

* Smoke from the Hawk Fire will continue to impact air quality and visibility, especially near the Reno/Sparks metro area today.

* Increased winds will bring elevated to critical fire weather to the region along with potential recreational impacts by midweek.

DISCUSSION

For today, forecast guidance shows the CWA with a generally southwesterly flow aloft being underneath the western portion of an upper air ridge residing over the southwestern CONUS. Models also show a shortwave disturbance traveling through the flow over N CA and then into OR during the afternoon and evening hours. This feature looks to be the driver for precipitation chances today as there is a 15-25% chance for isolated showers and thunderstorms for NE CA and W NV today with the higher end chances expected in areas closer to the OR border. The window for precipitation looks to be between 1-8 PM today according to the latest hi-res guidance though some lingering showers may be possible in eastern portions of Pershing and Churchill Counties before midnight. When looking at the latest convective parameters from CAMs, MUCAPE values appear to go up to around 500 J/kg with DCAPE values exceeding 1000 J/kg. This will allow storms today to be capable of producing wind gusts up to around 45-55 mph once again. Storms also look to have quicker storm motions today, so dry lightning could be possible especially in areas closer to the OR border. Not anticipating a flooding threat with storms today as there is a dry surface layer seen in the model soundings, but brief bouts of heavier rainfall can be possible with PW values up to around 0.7 inches. As for the Tahoe region and the Sierra, dry conditions are to be expected today.

The latest run of the HRRR near-surface smoke product shows that smoke from the Hawk Fire will continue to cause impacts today in W NV particularly within the Reno-Sparks metro area. Lighter winds this morning will allow smoke to settle which can reduce visibility and degrade air quality. Area winds expect pick up in the afternoon with gusts up to around 25-30 mph when smoke concentration increases allowing smoke to have better dispersion. But when winds decrease overnight, smoke will settle again. Those sensitive to poor air quality will want to continue to monitor airnow.gov today for the latest air quality information.

Daytime high temperatures through Thursday are forecast to be in the lower to middle 90s for NE CA and W NV valleys with Sierra communities in the middle 70s to lower 80s range. By Friday and going into the weekend, the forecast shows slightly milder temperatures with the valleys in the upper 80s to lower 90s and the higher Sierra elevations in the 70s. The main concern going through the rest of the week is increased winds Tuesday through possibly Saturday as a PacNW upper low moves into SW Canada. The latest NBM run continues to show around a 50-80% probability for maximum wind gusts over 30 mph on these days within the region. These winds will cause elevated to critical fire weather (see Fire Weather Section for more information) and recreational concerns on area lakes within the region, especially for the second half of the week. Please continue to watch for forecast updates especially if fire or wind products need to be issued. While the remainder of the week looks to be mostly dry, some models are hinting at around 10-20% chances for precipitation in the Sierra and W NV on Friday. -078

AVIATION

VFR conditions will prevail for the area TAF sites today and tonight with winds gusting up to 20-25 kts between 24/19Z-25/03Z. Smoke from the Hawk Fire may continue to reduce visibilities at KRTS and in the vicinity of KRNO through the day, but the latest forecast is not calling for sub-VFR conditions at area terminals. Will continue to monitor this situation and amend TAFs if needed. The increased winds will aid in smoke dispersion this afternoon, but smoke expects to settle in portions of W NV going through the night when winds decrease.

As for precipitation chances today, there looks to be around a 15- 25% chance for isolated showers and thunderstorms in NE CA and W NV beginning around 24/21Z with portions closer to the the OR border seeing the higher end chances. By 25/03-04Z, precipitation chances look to exit out of the region to the east. Otherwise, conditions look to be mostly dry through the middle of the week with afternoon wind gusts increasing to around 30 kts. -078

FIRE WEATHER

Breezy W/SW winds with gusts up to around 25 mph and RH reductions of 20-25% will support elevated fire weather conditions again this afternoon across the Sierra Front and NE CA, including the Hawk Fire. Slightly better overnight RH recoveries are forecast around the 40-50% range near the Hawk Fire.

Another concern today is that there is potential for dry thunderstorms this afternoon with the latest SPC fire weather outlook highlighting areas along the OR border where there is a 15- 25% for showers and thunderstorms generally between 1-8 PM today. The latest HRRR shows CAPE values up to 500 J/kg signaling an unstable environment that can support vertical plume growth with the moist mid-level seen in forecast soundings.

Going through the rest of the week, increased winds with gusts upwards of 35 mph (40 mph in wind prone areas) are expected Tuesday through possibly Saturday, mainly for the Sierra Front and NE CA. The SPC's Fire Weather Outlook for these days also highlights these areas with 40% chance of critical fire weather conditions due to increased winds and low RH. Currently, days with the most widespread critical fire weather conditions in these areas looks to be Wednesday through Friday. Please continue to watch for further updates in case fire products need to be issued. -078/Justin

REV Watches/Warnings/Advisories

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