textproduct: Reno

KEY MESSAGES

* Strong and potentially damaging winds today and tonight will bring widespread impacts to fire weather, aviation, travel, and recreation.

* A notable cooling trend later this weekend through early next week, will be followed by a gradual warm up with dry conditions and lighter winds.

DISCUSSION

A storm off the Pacific NW coast accompanied by an unusually strong upper level jet streak (120-140 kt at 300 mb) for September will move inland tonight. While the strongest winds with this storm will remain north of the OR border, we'll still have plenty of wind pushing over the Sierra and into eastern CA-western NV from later this morning through the overnight hours into early Sunday. Wind Advisories remain in place for nearly all of the region, and brief high wind gusts (60+ mph) can't be ruled out especially in wind prone areas near US-395/I-580 and foothills from eastern Lassen County southward across Reno-Carson Valley and into Mono County. See our latest Wind Advisory statement at weather.gov/reno for more details on expected gusts, impacts and preparedness actions to take, and also the Fire Weather discussion segment below for fire-related impacts from this wind event. Given the timing of the peak 700 mb winds (45-55 kt) reaching the northern Sierra/Tahoe region during this evening with the cold front passage, gusty winds will persist into early Sunday morning. While Mineral/southern Lyon counties are not included in the advisory, a short period of 40+ mph gusts could occur tonight as the front brushes across western NV.

For Sunday, gusty winds will linger especially on ridges through the morning, then diminish as the day progresses. For lower elevations, gusts of 25-30 mph are expected through the day behind the early morning cold front passage, with winds shifting to the northwest and eventually to the north by Sunday evening.

After one more day of warmer than average temperatures (highs 90+ degrees for the US-95 corridor of west central NV today), highs on Sunday will drop by 10-15 degrees across most of the region. Sunday night's lows will be more fall-like, with 40s for most lower elevations and 30s near the Sierra.

Next week will start off cool with highs mainly in the 70s Monday, then rebound to near mid-September averages in the 80s for most lower elevations and 70s near the Sierra through the remainder of the week. The weather pattern will be quiet overall with dry conditions prevailing and lighter winds most days, although a weaker low pressure may brush across northern NV and kick up the winds a bit around midweek. MJD

AVIATION

Rough wind conditions for aviation will prevail later this morning through tonight at all main terminals, with 30-40 kt gusts ramping up between 17-19Z and continuing through 03-05Z. Even when surface winds subside later tonight, FL100/ridge top winds will persist with peak gusts to 80 kt from the Tahoe basin northward, and 50-60 kt for Mono County, resulting in continued widespread turbulence and LLWS into Sunday morning.

For the remainder of Sunday, winds will be less impactful although the main terminals can still expect gusts to 25 kt until until early evening. Lighter winds are then expected for the bulk of next week, along with VFR conditions prevailing. MJD

FIRE WEATHER

Fire weather concerns peak today and tonight, with Red Flag Warnings in effect for far northeastern CA and western NV through 2 AM Sunday, so be extra vigilant in avoiding activities that could spark fires. Given the strength of the winds (peak gusts 45+ mph with 55-65 mph for wind prone areas along US-395), the humidity is less of a factor, with the winds capable of rapidly spreading fire even in areas such as northeast CA/northwest NV where humidity is less likely to drop below 15% this afternoon. Farther east and south across western NV and Mono County, humidity is projected to bottom out in the 10-15% range this afternoon, with parts of the Lahontan basin southward to the Chalfant Valley in southern Mono County dipping into the single digits.

Gusty winds will continue through late tonight, finally decreasing Sunday morning. Conditions will improve by Sunday afternoon, with winds dropping back to more typical gusts of 20-30 mph. The upcoming week will remain dry with limited humidity recovery especially for midslopes/thermal belts in western NV, but winds will be lighter. MJD

REV Watches/Warnings/Advisories

NV...Red Flag Warning from 11 AM this morning to 2 AM PDT Sunday NVZ458.

Wind Advisory from 11 AM this morning to 2 AM PDT Sunday NVZ002>005.

Red Flag Warning from 11 AM this morning to 2 AM PDT Sunday NVZ420-421.

Red Flag Warning from 11 AM this morning to 2 AM PDT Sunday NVZ423-429.

CA...Red Flag Warning from 11 AM this morning to 2 AM PDT Sunday CAZ270-278.

Wind Advisory from 11 AM this morning to 2 AM PDT Sunday CAZ070>073.

Red Flag Warning from 11 AM this morning to 2 AM PDT Sunday CAZ274.