textproduct: Reno

KEY MESSAGES

* Isolated showers are possible today and tomorrow, mainly in Churchill, Lyon, Mineral, Mono, and Pershing Counties.

* Breezy to gusty winds will return today and Thursday, leading to elevated to critical fire weather conditions.

* A weak system will bring increased chances for showers on Friday with milder temperatures through the weekend.

DISCUSSION

The latest forecast guidance continues to show the CWA with a southwesterly upper flow as an upper ridge resides over the SW CONUS. It also shows a PacNW low moving closer to the coast near the Canada-U.S. border today and then making landfall on Thursday. With this pattern aloft, the latest HREF run is showing around a 10-20% chance for diurnal showers in the NV Basin and Range portions of the CWA as well as S. Mono County between 1-8 PM today. The 06Z HRRR convective parameters do not look too impressive (CAPE values <100 J/kg in these areas), so the thunderstorm threat looks to be lower today, but cannot completely rule out a few rumbles of thunder today. Forecast PW values are 0.5-0.8 inches, so a brief bout of heavier rainfall is possible though showers will be moving quickly and short-lasting. Similar shower chances are seen on Thursday generally in the same areas, though the forecast CAPE values currently look to be slightly higher. Low confidence currently on these shower chances as some other models keep these areas dry. The remainder of the CWA though looks to stay on the dry side.

Another concern today and tomorrow will come from breezy to gusty winds in the area. The aforementioned upper air pattern will enhance the upper jet over the region a bit, which in turn will cause surface winds to speed up slightly during the day when mixing occurs. SW winds gusting up to around 25-35 mph are forecast in the afternoon today and tomorrow. With higher end wind gusts expected in NE CA and NW NV, this will allow for elevated to isolated critical fire weather concerns in these areas on both days (See Fire Weather section for more details). Daytime high temperatures for the valley areas will be in the 90s on both days while Sierra communities look to be in the upper 70s to middle 80s range.

On Friday and going through the weekend, model guidance shows the upper low traveling eastward along the Canada/U.S. border, which will allow a potential weak system to move through the region, bringing milder temperatures and increased precipitation chances. Daytime high temperatures are forecast to lower about 5-10 degrees on Friday with the valleys in the 80s and Sierra communities in the upper 60s to middle 70s range. As for precipitation chances, the latest NBM shows around a 40-80% chance for showers with a 5-15% chance for thunderstorms on Friday. This precipitation as well as slightly decreased winds will lower fire weather concerns on Friday. Will be monitoring this system going forward, but currently not anticipating severe thunderstorms out of this based on the forecast convective parameters. While precipitation chances may linger into the first half of Saturday, temperatures look to rebound by a few degrees over the weekend with dry conditions returning going into early next week. -078

AVIATION

VFR conditions will prevail again today and tonight at all area TAF sites. Area winds between 26/20Z-27/03Z generally will gust up to around 20-25 kts with portions closer to the OR border seeing gusts up to around 30 kts. Forecast guidance shows a 10-20% chance for isolated showers in the NV Basin and Range area as well as S. Mono County between 26/20Z-27/04Z. Similar precipitation chances will be seen on Thursday with forecast wind gusts between 20-30 kts. -078

FIRE WEATHER

Elevated to localized critical fire weather conditions are expected today and tomorrow in NE CA and NW NV. SW winds gusting up to 25-35 mph (up to 40 mph possible in wind prone areas) and minimum RH values between 10-20% are in the forecast in the afternoon for these areas. RH recoveries tonight are generally between 25-40% with slightly better recoveries of 30-50% on Thursday night. Increased precipitation chances (~40-80%) are forecast for the region on Friday reducing fire weather concerns with milder temperatures in the forecast through the weekend. -078

REV Watches/Warnings/Advisories

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