textproduct: Reno

KEY MESSAGES

* Isolated shower and thunderstorm chances continue this afternoon over portions of western Nevada, the Sierra and northeast CA.

* Gusty to strong winds return Friday afternoon through Sunday morning, with winds peaking on Saturday bringing impacts to fire weather, aviation, and recreation.

* A significant cooling trend is expected for Friday through early next week, followed by a gradual warm up.

DISCUSSION

We got a few more clouds and rain showers than expected this morning over portions of northeast California and northern Nevada. More showers and isolated thunderstorms are expected this afternoon per the HREF. This activity should remain light and move quickly to the east. Any impacts with these should be minor. The extra cloud cover is also leading to slightly cooler temperatures compared to yesterday.

There are no major changes to the forecast starting tomorrow. Winds will slightly increase from the southwest and west with gusts to 25-35 mph. This will lead to some minor impacts to aviation and recreation. Lake waters will be choppy in several lakes across western Nevada, the Sierra and NE CA. However, more winds are coming on Saturday.

By Saturday, an upper level low pressure system will push into the PacNW. This will lead to an upper level jet setting over northern CA/NV and southern OR, and a tightening of the surface pressure gradient. Furthermore, there is potential for an inversion near the 700 mb level around the Sierra crest level which could potentially lead to strong downslope winds along the Sierra Front on Saturday. The trend has persisted through the week with gusty to strong winds on Saturday. Therefore, we issued Wind Advisories for Saturday across the NV Basin and Range, northern Washoe, NE CA, and the Tahoe Basin. The area where we have the most uncertainty about how strong the winds will be, where we could see those downslope winds, is from the Sierra Front into northern Mono county. However, despite this, we decided to issue a High Wind Watch. We will choose tomorrow if a High Wind Warning or a Wind Advisory is the appropriate product. Regardless, wind prone areas along I-580 and US-395 from Janesville down to Sonora Junction will see gusty winds greater than 45 mph with a 10-40% chance of exceeding 55 mph. Winds will continue into the overnight hours, and will slowly subside by Sunday morning. Areas of blowing dust are also likely before the cold front moves in on Saturday afternoon and early evening across northern Washoe and the NV Basin and Range.

Behind the frontal passage Saturday, temperatures will come down into the 70s for lower valleys, and upper 60s for Sierra communities. Temperatures will start to gradually climb up around mid-week next week with weak ridging developing in our region.

-HC

AVIATION

Mostly VFR conditions continue this afternoon. The main exception will be near showers and thunderstorms, where lower VIS and CIG are possible. There is a 10-30% chance of showers through 03Z this evening across most sites, and through 06Z for KHTH, KNFL and KLOL.

Winds increase on Friday with gusts to 20-25 kts. Winds will further increase on Saturday, when the strongest winds of the week are expected. Saturday gusts could be up to 60 kts. Areas of LLWS and turbulence are expected starting tomorrow morning over the Sierra and Sierra Front.

-HC

FIRE WEATHER

An approaching upper level storm system brings strong winds to most of the region for Friday and Saturday. Elevated to near critical conditions are expected on Friday for portions of northern Washoe, eastern Lassen, Churchill, and northern Lyon counties. The minimum relative humidity of 10-15% will accompany winds gusting to 25-35 mph in the late afternoon and evening. No products are expected as the areas are isolated and the timing is expected to be short, but it will be highlighted in the Fire Planning Forecast.

By Saturday, winds increase significantly with gusts to 35-45 mph and 55-65 mph in wind prone areas. Min RH increases slightly to 10- 20%, however, the strong winds will overcome any increase in RH. Fire Weather Watches have been issued for all zones, except for 271 and 272 which include from western Lassen to eastern Sierra counties and the Tahoe Basin. These areas will experience gusty to strong winds but minimum relative humidity is above 25%. However, elevated to near critical conditions are still likely due to the gusty winds.

Conditions will improve by Sunday morning as the winds very slowly come down on Saturday night.

-HC/HRICH

REV Watches/Warnings/Advisories

NV...Fire Weather Watch from Saturday morning through Saturday evening NVZ458.

Wind Advisory from 11 AM Saturday to 2 AM PDT Sunday NVZ002-004- 005.

Lake Wind Advisory from 2 PM to 8 PM PDT Friday NVZ002>004.

Fire Weather Watch from Saturday morning through Saturday evening NVZ420-421.

High Wind Watch from Saturday morning through late Saturday night NVZ003.

Fire Weather Watch from Saturday morning through Saturday evening NVZ423-429.

CA...Fire Weather Watch from Saturday morning through Saturday evening CAZ270-278.

Wind Advisory from 11 AM Saturday to 2 AM PDT Sunday CAZ070>072.

Lake Wind Advisory from 2 PM to 8 PM PDT Friday CAZ071-072.

High Wind Watch from Saturday morning through late Saturday night CAZ073.

Fire Weather Watch from Saturday morning through Saturday evening CAZ274.