textproduct: Reno

KEY MESSAGES

* Near-record high temperatures and dry weather prevails through Sunday afternoon with areas of wildfire smoke today.

* A weak low pressure system brings up to a 5% chance of rain for the Sierra and northeast California on Sunday evening into Monday morning. * Above normal temperatures persist through the middle of next week, with cooldown possible going into next weekend.

DISCUSSION

For today, forecast guidance projects an upper ridge residing over the western CONUS. With this pattern aloft, dry conditions are expected to continue today through at least the first half of Sunday. Above normal high temperatures remain in the forecast today and tomorrow with NE CA and W NV valleys being between the mid-80s to around the 90F mark and Sierra communities being in the mid-70s to mid-80s range. The latest NBM run even shows a ~33% chance today and a ~67% chance tomorrow for the Reno-Tahoe International Airport to tie record values for the Oct. 3rd and Oct. 4th dates (Please see the Climate Section for record temperature data). The NBM also shows good probability (80-90%) of tying record warmest low temperatures this weekend and going into next week at RNO. The latest forecast still has area low temperatures around 10-20 degrees above early October normals with lows in the 50s for the W NV valleys and between 40F and 50F in Sierra communities.

The latest HRRR smoke product has more smoke filtering into the region from the Dome Fire in central CA today along with smoke being produced from the recent Bull Fire near Verdi. While not currently anticipating reductions in visibility outside of the immediate areas of the wildfires, there may be some hazy skies again today due to smoke in the Sierra and the Sierra Front. Those sensitive to reduced air quality should continue to watch conditions through the day on airnow.gov for more information.

The latest forecast guidance then projects a weak upper trough moving across N CA on late Sunday. This feature then will track across the CWA going through Monday. As a result, the latest run of the NBM continues to show up to around a 5% chance for a light rain shower or virga for the Sierra and NE CA Sunday night into early Monday. While these are very low chances, it's worth mentioning that the 06Z run of the RRFS model appears be an outlier as it extends these chances into Monday afternoon while expanding coverage into Washoe County. The trough feature will also allow for a slight increase in winds Sunday night going into Monday with Southern Mono and Mineral Counties having a 50-70% NBM probability of 25+ mph wind gusts and NE CA seeing a 10-30% NBM probability of the same. Daytime highs on Monday may be a few degrees cooler than those experienced over the weekend, but will remain above seasonal normals.

Ensemble guidance then projects the ridge rebuilding in the W CONUS on Tuesday through Thursday. This pattern will allow for more dry weather and above normal temperatures going through the middle of next week. NE CA and W NV valleys will have highs in the mid to upper 80s through the midweek with the Sierra communities being in the lower 70s to lower 80s range. By Friday and going into the weekend, the latest GFS and ECMWF guidance looks to be in better agreement this morning with an upper trough moving into the NW CONUS which signals a cooling trend. Currently, the forecast shows next Saturday's high temperatures closer to normal with the W NV valleys being in the 70s and Sierra communities being in the 60s. Precipitation chances to end next week are still less than 10% at this time, but this could change depending on the evolution of this potential upper trough. -MRC

AVIATION

VFR conditions prevail today with high cloud cover decreasing across the region. Terrain-driven afternoon breezes with gusts up to around 15 kts are expected between 03/20Z-04/03Z. Smoke from the Bull and Dome Fires may lead to slantwise visibility reductions today. -MRC

CLIMATE

Near record high temperatures and near record warmest low temperatures are forecast for both area climate sites (Reno at KRNO and South Lake Tahoe at KTVL) this weekend into next week.

Current record high temperatures for Reno and South Lake Tahoe:

Date Reno NV South Lake Tahoe CA ---- ------------ ------------------- 10/3 91F (2024) 80F (2024) 10/4 89F (1987) 82F (1988) 10/5 89F (1979,1980) 80F (1991) 10/6 88F (1980,1991,1996,2004) 78F (2014) 10/7 87F (1964,1980,1996,2014) 78F (1991,2014)

-------------------------------------------------------

Current record warmest low temperatures for Reno and South Lake Tahoe:

Date Reno NV South Lake Tahoe CA ---- ------------ ------------------- 10/3 56F (2010) 49F (2007) 10/4 54F (2024) 45F (2015) 10/5 52F (1947,1999,2024) 39F (2024) 10/6 57F (2021) 46F (2021) 10/7 52F (2021,2024) 43F (2021)

REV Watches/Warnings/Advisories

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