textproduct: Reno

KEY MESSAGES

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

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

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

DISCUSSION

The synoptic pattern across the Western U.S. remains dominated by an upper-level ridge centered over the Southwest US, with an upper trough moving eastward across the Pacific NW. This setup maintains a southwesterly upper flow over western NV. Continued monsoonal moisture transport around the western periphery of this ridge will support daily thunderstorm activity across portions of the Basin & Range.

For today, expect mostly sunny to partly cloudy skies. Daytime high temperatures will remain warm, generally in the low to mid 90s for western Nevada valleys and 70s to low 80s in the Sierra. Isolated diurnal showers are still possible (15%), primarily across the Nevada Basin and Range such as Mineral County, with a <10% chance of thunder. Breezy to gusty southwesterly winds will be a notable concern, with gusts generally reaching 25-30 mph, and up to 35 mph possible in wind-prone areas of northeast CA and northern Washoe County. These winds, combined with low afternoon relative humidity, will lead to elevated fire weather conditions.

Thursday will see a similar pattern, with continued warm temperatures and gusty southwesterly winds. Gusts up to 30-35 mph are again expected across exposed areas. Isolated shower chances (20%) in the evening, mainly in the eastern Sierra, Mineral, Churchill, and Pershing counties. The precipitation looks fairly stratiform in nature, however, there's a 15% chance of a few stronger storms that produce occasional lightning strikes.

A more significant change is expected for Friday as the weak system associated with the Pac NW trough moves closer to the region. This will usher in cooler temperatures and increased chances for widespread showers. NBM guidance has 50-80% PoPs across a majority of the CWA for Friday. The precipitation could start as early as late Thursday night/early Friday morning for some areas. High temperatures will drop noticeably, generally into the upper 70s to mid-80s for the valleys and upper 60s to mid-70s for the Sierra. Isolated thunderstorms are possible (15-20%), particularly along the Sierra crest in Mono County. Winds will generally be lighter than previous days, though ridge gusts up to 50 mph are still possible in the Greater Lake Tahoe Area.

The weak system impacting the region on Friday is expected to gradually exit to the east, with lingering shower chances possible during the first half of Saturday, particularly across the eastern Sierra and far eastern Nevada portions of the CWA. By Sunday and into early next week, high pressure is forecast to rebuild across the region, leading to a return of dry and mostly clear conditions. Temperatures will begin a gradual warming trend through the weekend, reaching near-normal to slightly above- normal values by Monday and Tuesday. Valley highs will generally be in the low to mid 80s, with Sierra communities in the upper 60s to upper 70s.

-Justin

AVIATION

VFR conditions will prevail again today and tonight at all area TAF sites. Area winds between 20Z-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 20Z-04Z tonight. Similar precipitation chances will be seen on Thursday with forecast wind gusts between 20-30 kts.

-078/Justin

FIRE WEATHER

Elevated to areas of critical fire weather conditions expected today and tomorrow in far NE CA and far NW NV. SW winds gusting up to 25-35 mph (isolated pockets of up to 40 mph possible in wind prone areas) and minimum RH values between 8-20% are in the forecast in the afternoon for these areas. RH recoveries tonight are generally between 20-40% with slightly better recoveries of 35- 50% on Thursday night. Increased precipitation chances (~20-60%) are forecast for the region on Friday reducing fire weather concerns with milder temperatures in the forecast through the weekend. -078/HRICH

REV Watches/Warnings/Advisories

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