textproduct: Reno

KEY MESSAGES

* Near-record high temperatures and dry weather continue through this afternoon, accompanied by localized wildfire smoke today.

* A weak low-pressure system brings isolated light shower chances back to the region tonight into Monday afternoon.

* Above-normal temperatures are expected to persist through midweek, with a potential cooling trend and precipitation chances arriving by next weekend.

DISCUSSION

To begin today, forecast guidance shows the region underneath an upper ridge with a weak low-pressure trough moving toward the CA coast. This pattern will allow for dry conditions and well-above- normal temperatures to persist through this afternoon. Near- record temperatures are in the forecast again with highs between the upper 80s and lower 90s in the lower valleys and between the mid-70s and lower 80s in Sierra communities. The latest NBM run projects a 65-75% chance for the Reno-Tahoe International Airport to tie the October 4th high temperature record today (see Climate Section below for record data). Near-record warmest low temperatures are expected through the first half of the week as well with KRNO having a 70-90% chance of tying those records through Wednesday. The latest HRRR smoke product continues to show some smoke from the Dome Fire moving into the Sierra and Sierra Front today. However, smoke from Bull Fire does not really show up in the product very much as smoke generation appears to have been reduced by the ongoing firefighting efforts. Please continue to consult airnow.gov for the latest air quality updates, especially if you sensitive to poor air quality.

Going into tonight and through Monday, model guidance projects the aforementioned trough moving across N CA and into N NV. This will increase cloud cover today before introducing low shower chances (<10%) to NE CA and the Sierra this evening. But around midnight and going into Monday, isolated shower chances increase up to ~20% and spread into the Sierra Front. The recent runs of both the HRRR and RRFS have been showing some showers popping up around the Reno-Sparks metro area on Monday afternoon. There's a low chance (<10%) that showers on Monday could contain some rumbles of thunder, but not anticipating severe weather. Model forecast soundings project a dry layer at the surface, so light virga showers may occur. But if rain overcomes this dry layer and reaches the ground, QPF values generally look range between a trace to less than 0.1 inch locally. Winds gusting up to 20-30 mph will also accompany the trough passage, with temperatures on Monday cooling a degree or two while staying above normal.

For Tuesday through Thursday, forecast guidance projects an upper ridge rebuilding over the W CONUS as the trough departs to the east- southeast. Dry conditions will resume on these days with daytime high temperatures around 10-15 degrees above season normals. However, the pattern does change on Friday and going into the weekend with increasing model confidence of an upper trough dropping down from the Pac NW. This looks to usher in a cooling trend beginning on Friday as the temperature forecast currently calls for highs closer to normal on Saturday and then 5-10 degrees below normal (forecast highs in the 60s for the lower valleys and in 50s in the Sierra communities) next Sunday. Not only is this system looking to be cooler, but also potentially windier and wetter as the latest GFS run shows increased winds and precipitation chances returning through next weekend. Details still are uncertain this far out, but please continue to watch for forecast updates, especially if you have plans for the upcoming holiday weekend. -MRC

AVIATION

VFR conditions are expected across the region today with cloud cover increasing through the day. Haze caused by smoke from the Bull and Dome Fires may reduce slantwise visibility within the region at times. Afternoon gusts up to around 15 kts are expected for most area TAF sites, with KMMH seeing SE winds gusting up to 25 kts between 04/19Z-05/00Z. A weak low-pressure system moves through the region late tonight into Monday bringing up to around 20% chances for light showers to NE CA, the Sierra, and the Sierra Front. -MRC

CLIMATE

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

Current record high temperatures for Reno and South Lake Tahoe:

Date Reno NV South Lake Tahoe CA ---- ------------ ------------------- 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)

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

Date Reno NV South Lake Tahoe CA ---- ------------ ------------------- 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.