textproduct: Reno

KEY MESSAGES

* Temperatures heat up further this week with daily afternoon shower and storm chances from Tahoe southward. * By Monday into Wednesday, a heatwave will induce moderate to locally major HeatRisk concerns.

* Later this week a pattern change may bring cooler temperatures, breezy afternoon winds, and increased shower and storm chances.

DISCUSSION

Upper level instability with the overhead troughing paired with afternoon heating and sufficient moisture will result in another day of shower and thunderstorm chances. High resolution simulations continue to highlight showers and storms forming along the Sierra crest from Tahoe southward into Mono county mid to late afternoon. Typical thunderstorm threats exist with any storms that pop off: lightning, locally heavy downpours, small hail, and gusty erratic winds. Ensure you have a way to receive alerts if you are out and about today! As temperatures continue to ratchet up through the week, plan on daily afternoon thunderstorm/shower potential.

High pressure ridge over the eastern Pacific will finally migrate eastward with the ridge axis over the Sierra and western Nevada by Tuesday and Wednesday. This feature will enact significant warming across the region resulting in daytime highs near/in excess of 90F and 100F for Sierra communities and lower NE CA/W NV valleys, respectively, between Monday and Thursday. Plan on widespread moderate HeatRisk with major HeatRisk creeping into W Nevada valleys. A contributor to the higher HeatRisk will be the warmer overnight minimum temperatures as the lows will only fall to the mid/upper 60s. Plan accordingly for the upcoming heat! Beat the heat by staying hydrated, avoiding the outdoors during the hottest parts of the day, and wearing cool, light clothes. The quick heat up will allow for our late day westerly, zephyr winds to return Monday and Tuesday, with some localized stronger wind gusts possible. More details on winds in the fire section.

Don't fret if you're not ready for the triple digit heat! There is relief in sight as simulations continue to highlight the pattern change involving the breakdown of the high pressure ridge later this week. Unfortunately, the introduction of low pressure pushing out the ridge will result in some consequences, including, but not limited to increased breezes, shower/storm chances, and cooler temperatures.

-Edan

AVIATION

Plan on another day of warm temperatures with showers and isolated thunderstorms, especially for the Sierra terminals. For KMMH, there is a 20-30% chance thunderstorm within 10 miles, while chances for KTRK/KTVL will be around 15%. Expect gusty/erratic winds, brief downpours, and occasional lightning with any storm. Otherwise, widespread VFR conditions and typical afternoon breezes prevail.

Above average temperatures Monday through Thursday will result in density altitude concerns. Nevada terminals will be the most vulnerable to the density altitude concerns as temperatures approach the triple digits.

-Edan

FIRE WEATHER

An extended period of very warm/hot and dry conditions is expected through Thursday. The hottest temperatures are forecast for Monday through Wednesday with relative humidity in the teens and single digits. Additionally, overnight temperatures will remain unusually warm resulting in poor overnight humidity recoveries in the valleys and midslope areas through the week. Isolated thunderstorms will be possible from Tahoe southward each afternoon this week, raising localized concerns for lightning ignitions and strong outflow winds.

While winds aren't anticipated to deviate much stronger than our typical afternoon breezes during this hot/dry period, Tuesday stands out as having the strongest breezes from E Lassen County into far western Nevada. A brief 1-3 hour overlap of critical wind/RH may unfold across these areas in the afternoon as a result.

A critical ridge breakdown takes place after Wednesday, increasing the potential for thunderstorms and new lightning ignitions/strong outflow winds, and increased afternoon breezes during the second half of next week. With the hot and very dry weather early this week, vegetation will have had several days to dry out, exacerbating the potential fire threat late this week.

-Salas

REV Watches/Warnings/Advisories

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