textproduct: Reno

KEY MESSAGES

* Isolated showers and thunderstorms are possible today across western NV, with chances spreading into northeast CA on Monday.

* Smoke from the Hawk Fire will continue to impact air quality and visibility, especially near the Reno/Sparks metro area today.

* Seasonably warm temperatures are expected through the week, with increasing afternoon winds Tuesday through Thursday.

DISCUSSION

The synoptic pattern for the short term features a persistent upper ridge anchored over the Southwest US, with western NV remaining on the northern periphery of this ridge. Embedded shortwave disturbances within the prevailing southwesterly flow aloft will be the primary drivers for any convective activity.

A significant concern for today, particularly in Reno/Sparks and adjacent areas, is smoke from the Hawk Fire. The latest HRRR smoke model continues to show patchy smoke this morning, with an increase in near-surface smoke concentration this afternoon and evening. This may lead to reduced visibilities and degraded air quality (higher AQI). Patchy smoke is also possible in portions of the Nevada Basin and Range through tonight.

Also today, a slight shortwave disturbance is progged to move through central Nevada, allowing for isolated shower and thunderstorm chances primarily over Mineral, Lyon, and Churchill Counties between 2 PM and 10 PM PDT. Hi-res model soundings show MUCAPE around 400-700 J/kg and DCAPE around 1400-1700 J/kg, indicating any storms that form may see outflow winds of 45-55 mph. Storm motions will be leaning towards the faster side too, so we can't rule out new lightning starts. Current PoPs over the aforementioned areas are around 15-30%.

On Monday, another disturbance is forecast to track closer to the Oregon border, shifting the 15-25% chance for showers and thunderstorms northward into Lassen, Modoc, and Northern Washoe Counties. Forecast PW values are expected to range from 0.5-0.7 inches, raising the potential for isolated dry thunderstorms. The SPC Day 2 Fire Weather Outlook showcases an area of isolated dry thunderstorms for the far northern portions of our CWA, specifically northern Washoe County and Surprise Valley.

By Tuesday, drier conditions are anticipated across the CWA through the rest of the week, as the monsoonal moisture shifts east over eastern NV. Afternoon winds will generally be light to moderate, typically gusting up to 20-25 mph today and Monday, however, NBM guidance suggests an increase in afternoon winds on Tuesday. Gusts could potentially reach 30-35 mph in some areas across northeast California and northwest Nevada.

A notable feature for the mid-week period, particularly Wednesday through Thursday, will be an increase in afternoon winds. This is attributed to a Pacific Northwest upper low moving towards British Columbia, which will enhance the pressure gradient across our region. NBM probabilities show a 50-80% chance for maximum wind gusts exceeding 30 mph on these days across parts of northeast California and northwest Nevada. While widespread critical fire weather conditions are not currently anticipated, these elevated winds combined with dry conditions will lead to elevated to locally critical fire weather concerns. Winds are expected to gradually subside by the upcoming weekend.

-Justin

AVIATION

VFR conditions will continue for most terminals today, although KRNO will likely see reductions to visibility from smoke from the Hawk Fire. Timing of the smoke settling into Reno will coincide with the winds dying off, around 04-05Z tonight. It will disperse again Monday morning around 19Z.

Otherwise, mostly dry conditions are expected today across the region with typical afternoon zephyr breezes. Mineral, Lyon, and Churchill Counties see a ~10-25% chance for isolated showers with a 10-15% chance for an isolated thunderstorm between 23/21Z-24/06Z. Outside ~15-30% chances for showers in NE CA and far NW NV on Monday, dry conditions look to prevail through at least the first half of the week.

-Justin/078

FIRE WEATHER

Breezy west winds with gusts up to 25 mph and RH reductions of 20-25% will support elevated fire weather conditions this afternoon across the Sierra Front and northeast CA, including the Hawk Fire. Overnight recoveries remain around the 35-45% range near the Hawk Fire, potentially extending burn periods into the overnight hours.

We will have an unstable airmass overhead again today, with thunderstorms chances of 20-30% over Mineral/Lyon/Churchill counties. There are two main concerns with this: potential dry thunderstorms due to faster storm motions, and deeper vertical plume growth due to increased instability.

Looking ahead to this upcoming week, increased winds with gusts upwards of 35 mph (40 mph in wind prone areas) are expected Tue- Thu, mainly for the Sierra Front and northeast CA. The SPC's Fire Weather Outlook for Tue-Thu also outlined those areas under a 40% chance of critical fire weather conditions due to wind and low RH.

-Justin

REV Watches/Warnings/Advisories

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