DISCUSSION

The latest RAP analysis shows an upper air high off the coast of northern CA that controls a large ridge over the western CONUS.
Current surface observations and satellite imagery continue to report light winds and dry conditions underneath sunny skies for the region this afternoon. Forecast guidance predicts the upper air ridge residing over the western CONUS going through the weekend before moving slightly eastward and tilting in a positive orientation so that the ridge's axis passes over the CWA on Tuesday. Models then have the ridge continuing eastward through the remainder of the work week with an embedded weak upper air trough passing over the CWA on Thursday and Friday though the latest runs of the long term models show some uncertainty in the exact timing. This evolution in the upper air pattern means that the surface will continue to see well above normal temperatures and dry conditions through the weekend and into the next week. But by the tail end of the next work week, the region may see temperatures starting a slow decreasing trend with precipitation chances rising slightly (10-15%) south of US-50 on Friday.

While monitoring of the next week's trend change will continue, the main story continues to be the near record to record high temperatures and warmest low temperatures in the forecast (See Climate Section for some local records) due to the heat expected this weekend and the beginning of next week. Overall, some areas within the CWA expect to see triple digit daytime high temperatures through the weekend and through next week at this time. As the CWA expects moderate to major HeatRisk in the region, the Excessive Heat Warning for western NV and the Heat Advisory for the CA portion of the CWA continues for Saturday through Wednesday. Please see the Excessive Heat Warning and Heat Advisory products for more detailed information on these upcoming heat hazards. It is recommended to take precautions during this time such as limiting outdoor activity, taking breaks in a cool area, staying hydrated, and checking in on neighbors and relatives that may be more susceptible to heat related illness. For more heat safety tips, please visit weather.gov/safety/heat.

While models show the CWA staying dry through the rest of this week, they continue to show single probabilities of precipitation returning next week which are still pretty low. As mentioned earlier in the discussion, the latter half of next week may see a slight increase in precipitation chances. Will continue to monitor to see if better confidence for precipitation seen in future model runs or if there is a chance for some dry lightning that may cause a fire weather concern. Hazy conditions are also possible in the CWA as well with the ongoing CA wildfires, so will be monitoring for potential smoke in the area though for now there may be some slightly hazy skies in some locations for a bit. -078

AVIATION

VFR conditions continue at all REV TAF sites again today and are expected going into the weekend. Typical afternoon breezes are also in the forecast across the region with KMMH again seeing gusts up to around 20 kts between 23Z-03Z. Well above normal temperatures through the weekend and into next week still may produce periods of density altitude concerns across all TAF sites in the Sierra and western NV. -078

FIRE WEATHER

No changes made from the previous fire weather forecast. High confidence for well above normal temperatures, low daytime relative humidity values, and dry conditions persisting through next week.
Winds will remain light with only late afternoon breezes up to 20 mph possible.

As for next week, our more typical afternoon/evening breezes may return with gusts in the 30 mph range as models show the upper air ridge shifting slightly eastward. Fire concerns will remain with the hot temperatures and very dry conditions as well as any remaining holiday weekend activities. There are also some very slight (<5%)
chances for showers and thunderstorms starting on Sunday afternoon and going into the beginning of next week. -078

CLIMATE

Record High and Warm Low Temperatures for July 6th-9th at Reno-Tahoe International Airport (KRNO)
------------------------------------------------------- Date Forecast(High/Low) Record High(Year) Record Warm Low(Year)
------ ----------------- ---------------- -------------------- July 6 105/66 101F (2021+) 71F (2007)

July 7 106/71 102F (2014) 68F (2004++)

July 8 106/70 104F (2017) 71F (2014)

July 9 106/69 104F (2021) 69F (2021)

+ denotes record also seen in 2014

++ denotes record also seen in 2001

Current record for consecutive days of 100F or greater at KRNO is 10 days, set in July 2021 and July 2005. The record for consecutive days of 105 or greater is only 2 days, which has occurred 6 times in climate history, most recently July 2023. Both of these have the potential to be broken with this heatwave.

REV Watches/Warnings/Advisories
NV...Heat Advisory from 10 AM Saturday to 10 AM PDT Wednesday NVZ002.

Excessive Heat Warning from 10 AM Saturday to 10 AM PDT Wednesday NVZ001-003>005.

CA...Heat Advisory from 10 AM Saturday to 10 AM PDT Wednesday CAZ070>073.