textproduct: Reno

UPDATE

With latest guidance consistent in keeping gusty winds going through Wednesday, we extended the current Lake Wind Advisory. Even for tonight, breezy to gusty winds will continue with only occasional lulls. Winds should diminish late Wednesday evening or overnight, although another round of increased winds could bring unfavorable lake conditions again Thursday afternoon. MJD

KEY MESSAGES

* Critical fire weather conditions continue today for northeast CA and parts of western NV due to gusty winds and low humidities.

* Cooler and breezy conditions persist through the week, with rain chances to northeast CA and northwest NV Thursday and Friday.

* Uncertainty remains regarding the trajectory of tropical moisture, which could increase shower/thunderstorm chances early next week.

PREVIOUS DISCUSSION

/issued 143 PM PDT Tue Sep 1 2026/

DISCUSSION...

The dry cold frontal passage is well underway across the region this morning, bringing gusty winds and low humidities. Surface observations show southwest to west winds 15-25 mph across western Nevada valleys and Sierra communities, with gusts up to 35-45 mph, especially in the Tahoe Basin and along exposed ridges. Ridgetop gusts could reach 60-70 mph through the afternoon. These winds, combined with relative humidity values dropping into the 10-20% range across much of the forecast area, are leading to critical fire weather conditions. Red Flag Warnings remain in effect for northeast CA and northwest NV, with Lake Wind Advisories for area lakes. Blowing dust is also possible in desert playas and sinks, likely reducing visibilities. Temperatures today will remain well below seasonal averages, generally in the 60s for Sierra communities and 70s to low 80s for western Nevada valleys.

Wednesday will see continued gusty conditions, with afternoon gusts of 25-40 mph still possible, particularly across the Sierra and northern portions of the forecast area. Temperatures will remain cool, 10-15 degrees below normal, with highs in the 50s and 60s for the Sierra and 70s for western Nevada valleys. The main change for Wednesday night into Thursday is the increasing chance for precipitation. A low pressure system tracking inland will begin to bring moisture into northeast CA and northwest NV. Precipitation chances increase to 10-30% Wednesday night, then jumping to 70-80% by Thursday morning. This incoming rain will be showery in nature, with the highest probabilities focused on Lassen County and northern Washoe County. Farther south into the eastern Sierra and western Nevada, precipitation chances remain low (less than 10%) on Thursday.

Friday onward we'll see persistent troughing along the West Coast, keeping temperatures cooler than normal, and introducing increasing uncertainty regarding a potential tropical moisture interaction early next week. Friday and Saturday are expected to be relatively dry for most of the region. NBM guidance generally shows low precipitation probabilities (below 10%) across the region, though some Sierra locations like Mammoth Lakes show isolated higher chances (up to 15% on Saturday). Temperatures will remain cool, with highs in the 60s-70s for the Sierra and 70s-80s for valleys. Breezy afternoons are still possible, but winds are expected to be lighter than earlier in the week.

The main forecast challenge for the latter half of the long term (Sunday into Labor Day) revolves around the potential interaction of remnant moisture from a tropical system (Invest 95E) in the Eastern Pacific. For western NV, NBM guidance for Sunday and Labor Day shows a notable increase in precipitation chances. PoPs jump to 15-30%. This suggests that while a direct hit is unlikely, there is a growing potential for enhanced showers and thunderstorms from this remnant moisture. Given the ongoing uncertainty, confidence in specific precipitation amounts and coverage remains low, but the trend for increased activity is evident in the blend of models. Temperatures will remain cool to mild, generally in the 60s-70s for highs.

-Justin

AVIATION...

VFR conditions persist today with afternoon gusts of 25-30 kts. FL100 winds out of thew SW increase to 40-45 kts this afternoon, bringing LLWS and mountain wave turbulence to all Sierra and Sierra Front sites. Areas of reduced visibility from blowing dust may impact KLOL, KNFL, KHTH as well as aviation operations on the Black Rock desert today.

-Justin

FIRE WEATHER...

Today will pose the highest concern for critical fire weather conditions as humidity values drop to 12-20% and afternoon wind gusts increase up to 40 mph. As such, a Red Flag Warning has been issued for the northern Sierra Front and extending northward into NE CA east of CA-139, northern Washoe county, and the Surprise Valley in Modoc county. Winds will be primarily out of the southwest, shifting westerly/northwesterly after sunset.

Winds will remain elevated Wednesday (30 to 45 mph) but higher humidity values and increasing chances for precipitation will limit fire concerns for most areas. Breezy afternoons continue through Friday, with precip chances and cooler temperatures mitigating the fire threat for the remainder of the week.

-Giralte/Justin

REV Watches/Warnings/Advisories

NV...Red Flag Warning until 11 PM PDT this evening NVZ458.

Red Flag Warning until 11 PM PDT this evening NVZ420.

Lake Wind Advisory until 5 AM PDT Thursday NVZ002>004.

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

Lake Wind Advisory until 5 AM PDT Thursday CAZ071-072.