textproduct: Reno

KEY MESSAGES

* Gusty southwest winds through this evening bring periods of critical fire weather conditions and lake recreation impacts to parts of northeast CA, northwest and far western NV.

* Showers and isolated thunderstorms across parts of the eastern Sierra and western NV through this evening, with decreasing chances Sunday and Monday.

* Seasonal temperatures, overall dry conditions and afternoon breezes prevail for much of next week.

DISCUSSION

Narrow shower bands moved across far western and west central NV this morning, producing sparse rainfall (trace amounts up to 0.02") and a couple lightning strikes in Lyon County. As instability increases this afternoon, another round of showers and isolated thunderstorms (20-40% chance) is expected this afternoon and evening mainly from Mono County northward across Lyon, Mineral, Churchill and Pershing counties. A few showers or storms may form a bit farther west across eastern portions of Douglas, Carson City and Storey counties (10-20% chances) this afternoon before the main activity shifts eastward to west central NV. The main concerns with stronger storms will be gusty outflow winds up to 45 mph, several lightning strikes, brief heavy rainfall and small hail. Meanwhile, breezy-gusty winds across northeast CA, northwest and far western NV this afternoon and evening continue to produce lake recreation and fire weather concerns--see the Fire Weather section below for more details.

By Sunday, winds and chances for thunderstorms decrease as the upper trough responsible for today's wind and storm activity departs to the northeast. Southwest to west winds return to more typical levels (gusts to near 25 mph). For west central NV, lingering moisture and instability leads to a few showers and storms, with best chances (15-25%) shifting to areas near and east of US-95 by late afternoon before diminishing in the evening.

For Monday, another weak upper disturbance moving across northern CA/NV may bring isolated afternoon showers to parts of far northeast CA and western NV mainly north of I-80. Instability is more limited, with a reduced (10-15%) chance of lightning with these showers.

Otherwise for next week, a dry pattern sets up with southwest flow aloft over the Sierra and western NV, which remains between a persistent high pressure over the southwest US and low pressure off the Pacific NW coast. Typical southwest-west breezes are expected each afternoon, although winds could edge upward a bit around midweek as the offshore low moves inland to southwest Canada. Another similar wind enhancement could occur toward the start of next weekend, but confidence is lower due to a more varied track of the next shortwave trough in the medium range guidance. Temperatures through the upcoming week remain near late August averages, with highs mainly 90-95 degrees for lower elevations and lower 80s for Sierra communities. MJD

AVIATION

* VFR conditions continue with areas of mid to high level clouds becoming more widespread again Sunday into Monday. Shower chances remain low at the main terminals with a 10-15% chance of affecting KRNO/KCXP/KMEV/KMMH between 21-00Z this afternoon, but less than 10% chance of lightning. Storm chances increase across west central NV this afternoon with about 10-20% chance of lightning affecting KHTH/KNFL/KLOL between 21-03Z. Otherwise, dry conditions prevail through Monday at the main terminals.

* SW-W wind gusts 25-30 kt at the main terminals this afternoon, except a bit less at KTVL, with winds diminishing between 02-04Z this evening. Expect areas of turbulence and minor LLWS which could linger through 08Z tonight. Lighter winds expected Sunday- Monday afternoons with gusts near 20 kt. MJD

FIRE WEATHER

* Fire weather concerns continue through the evening, as wind gusts range from 30-40 mph across northeast CA, northwest NV, and the Northern Sierra Front. While humidity values aren't exceedingly low (minimums 12-18%), most of these areas did not receive much rainfall last week, resulting in a greater extent of dry vegetation where fire could spread more quickly when the winds pick up. Therefore, a Red Flag Warning remains in effect for these areas. So, be extra cautious and fire safe, avoid outdoor recreation or work activities that could spark any fires.

* Farther east across west central NV, isolated thunderstorms bring the potential for a few lightning fire starts this afternoon. Lightning becomes more sparse Sunday-Monday across isolated portions of west central and northwest NV, although a few dry strikes can't be ruled out. * Otherwise from Sunday through next week, afternoon breezes continue but at lower speeds compared to today. The next period to watch is next Wednesday-Thursday, when winds potentially trend upward, while afternoon humidity decreases as a dry air mass settles in. MJD

REV Watches/Warnings/Advisories

NV...Red Flag Warning until 11 PM PDT this evening NVZ420-458.

Lake Wind Advisory until 11 PM PDT this evening NVZ003.

CA...Red Flag Warning until 11 PM PDT this evening CAZ270-278.

Lake Wind Advisory until 11 PM PDT this evening CAZ071.