textproduct: Reno

KEY MESSAGES

* Very warm days prevail through Tuesday with temperatures near record highs.

* Dry conditions are expected through early this week with typical afternoon west breezes. A few stronger gusts may occur Tuesday afternoon in western Nevada with isolated thunderstorms.

* Some cooling returns by mid-late week with isolated shower chances and periods of breezy winds.

DISCUSSION

The latest RAP upper air analysis shows a high pressure ridge still over the W CONUS this morning. Model guidance projects this feature hanging around today and going into the tomorrow. By Tuesday afternoon, the ridge begins to move east as a closed low makes its way towards the west coast. With this pattern aloft, near record to record daytime high temperatures across the region will continue today and tomorrow with temperatures climbing to around 15-20 degrees above seasonal normals (please see the Climate section for a list of the current temperature records at our two climate sites: Reno, NV and South Lake Tahoe, CA). Generally, the temperature forecast for the next three days shows highs in the upper 80s to middle 90s range in NE CA and W NV valleys while the Sierra communities will range between the upper 70s and the lower 80s. The latest NWS HeatRisk forecast continues to display an areawide minor category of HeatRisk with the warmer valley portions of W NV being in the moderate category today and tomorrow. Please remember to stay hydrated and limit exposure to the sun during the warmest parts of the day, especially if you have outdoor plans and are sensitive to heat. Also, please use extra caution near rivers and resist the urge to enter them to cool off as area rivers still remain cold and could be flowing fast, presenting a risk of hypothermia.

The ridge pattern will also allow for generally dry conditions to prevail today and tomorrow. However, increased daytime heating could allow for brief pop-up showers though chances look to be less than 10%. The latest runs of the CAMs do still show some isolated showers possible in Mineral and Southern Lyon Counties between 4-8 PM today. But in the late afternoon and evening on Tuesday, the latest runs of the RRFS and the HRRR both showing shower and thunderstorm potential in western Nevada as well as Mono County when the ridge has moved east. Model forecast soundings are showing an "Inverted-V" shape around that time along with DCAPE values over 1000 J/kg. This kind of environment signals that strong wind gusts (50+ mph) could be possible with this high based convection. There still is some low confidence on forecast details like exact locations that would see this threat, but please watch for forecast updates as they become available. Otherwise, winds look to gust up to around 25-35 mph on Tuesday afternoon with the Sierra ridges gusting up to around 45 mph. For Wednesday and Thursday, models show a potential cold front passage for the CWA as the Pacific low opens into a trough and passes over the region. This will cause the W NV valley high temperatures to cool down to the 70s and 80s on Wednesday and then drop a bit more to between the lower and upper 70s on Thursday. Sierra communities are forecast in the middle 60s and lower 70s on both days. Wednesday also looks to be the windiest day of the week for the region with westerly winds gusting up to around 40 mph in the after (up to 60 mph in the Sierra ridges). These winds may cause some potential hazardous maritime conditions on area lakes, so please be prepared for this. Precipitation chances (15-25%) are forecast on Wednesday and Thursday with portions of the CWA closer to the OR border seeing chances up to around 40% on Wednesday.

On Friday and going into the weekend, forecast guidance shows a zonal flow over the region after the trough moves out. This pattern will allow for daytime high temperatures to rebound a bit with dry conditions returning to the region. -078

AVIATION

VFR conditions are expected at the main terminals through Tuesday, with potential density altitude concerns for western NV terminals due to very warm temperatures each afternoon. Southwest to west wind gusts of 20-25 kt are expected each afternoon today and Tuesday mainly between 20Z-03Z. There is a potential for isolated showers and thunderstorms in western NV on Tuesday afternoon that could produce strong wind gusts (45+ kts). MJD/078

CLIMATE

Both climate sites set new record high temperatures yesterday for the May 10th date. The Reno-Tahoe International Airport in Reno, NV recorded a high of 92F breaking the old record of 88F set in 1934. South Lake Tahoe, CA recorded a high of 79F breaking the old record of 75F set in 2025.

Current record high temperatures for Reno, NV that have potential to be broken or tied (Today & Tuesday):

May 11: 90F, set in 2001 and 2013.

May 12: 89F, set in 1959 and 2013.

Current record high temperatures for South Lake Tahoe, CA that have potential to be broken or tied (Today & Tuesday):

May 11: 78F, set in 2013.

May 12: 79F, set in 1988 and 1996.

REV Watches/Warnings/Advisories

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