textproduct: Reno

KEY MESSAGES

* Storm coverage decreases today, mainly favoring Mono and Mineral Counties and areas along the Oregon border in the afternoon before shifting into the Nevada Basin and Range in the late evening. * Monsoonal moisture shifts east late this week, bringing drier weather into early next week with typical late July warmth.

* Increasing winds bring elevated fire weather concerns going into the weekend across northeast California and northwestern Nevada.

DISCUSSION

From the latest radar returns, showers continue this morning in Pershing County with the latest run of the HRRR showing rain chances tapering off by 7 AM PDT. Forecast guidance for today shows the CWA under a high pressure ridge centered over N TX with a Pacific low off to the west through the day. The bulk of the monsoonal moisture will shift east with this pattern though models do project PW values of ~0.7-1.0 inches in W NV (higher end amounts in the NV Basin and Range) and 0.5-0.8 inches in NE CA and the Sierra. However, precipitation chances today are forecast to be lower compared to the previous few days. The latest CAMs are showing generally two areas in the afternoon with 15-25% chances for showers and isolated thunderstorms: Mono and Mineral Counties and areas near the OR border. Elsewhere, chances look to be around 10% or less today. The latest REFS run shows precipitation starting to pop up around 1 PM PDT in both of these areas and lasting into the evening. Going into the night, the REFS also highlights some portions of Pershing County with a 15% chance of isolated showers and thunderstorms. While thunderstorms that occur today may be capable of producing brief periods of heavy rainfall, the flood threat will be lower today due to quicker storm motions and reduced moisture. Model MUCAPE values are between ~500-1000 J/kg today, so thunderstorms could potentially produce some erratic and gusty outflow winds. But with the GFS showing drier air moving in between the 700-300mb levels, not anticipating storms to grow tall enough or last long enough to become severe today.

On Thursday through the weekend, models show PW values dropping quite a bit as the flow of monsoonal moisture is continuing to away from the CWA. Drier conditions look to be on tap the remainder of the week and going into next week with the CWA still underneath the upper ridge. Currently, the only precipitation chances in the forecast are 15% chances of an isolated afternoon shower or two in Mineral County on Thursday and Friday. The forecast through early next week also shows near or slightly above normal high temperatures generally between the upper 90s and lower 100s in W NV valleys and in the 80s for Sierra communities. The latest HeatRisk Outlook projects areas of Moderate HeatRisk in W NV during this time (with isolated high HeatRisk on Friday for the NV Basin and Range). Please remember to stay cool during these very warm to hot summer days!

Forecast models are also projecting winds increasing going into the weekend with afternoon/evening gusts up to around 25-35 mph. With conditions becoming drier, there does look to be an elevated fire weather concern currently in NE CA and NW NV particularly on Friday and Saturday. The latest SPC fire weather outlook shows a marginal (40%) chance for potential critical fire weather conditions in these areas. Will continue to monitor this going forward in case the models trend towards dangerous fire weather conditions, especially in these areas that already have ongoing wildfires. -078

AVIATION

After early fog lowering visibilities near KTRK clears up later this morning, VFR conditions are expected at all area TAF sites today. Generally westerly (southerly at KTVL) afternoon winds gusting up to 18-23 kts are in the forecast. Drier conditions compared to the previous few days are to be expected with ~25% chances for isolated showers in Mono and Mineral Counties as well as areas along the OR border beginning around 22/22-23Z and ending around 23/03Z. Portions of the NV Basin and Range may also see 15% shower chances later between 23/02-07Z. Not anticipating precipitation to move over TAF terminals and lower flight rules today, but will monitor conditions and amend the forecast if this changes. High temperatures around seasonal normals for July are also in the forecast which may allow for density altitude concerns going through this weekend. -078

REV Watches/Warnings/Advisories

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