textproduct: Reno

KEY MESSAGES

* Isolated showers and thunderstorms are possible today, mainly in Churchill, Mineral, and Mono Counties.

* Breezy to gusty winds will return Wednesday through Saturday, leading to elevated fire weather conditions.

* A weak system will bring increased chances for showers to the Sierra and western Nevada on Friday.

DISCUSSION

The upper-level pattern today features a strong ridge over the Southwest US, with western NV on its western periphery, experiencing southwesterly flow aloft. A PacNW low is gradually approaching the Washington coast. This setup continues to funnel monsoonal moisture northward along the western flank of the ridge, interacting with embedded shortwave energy.

Isolated showers and thunderstorms are expected today over Churchill, Mineral, and S. Mono Counties, with 15-25% chances between 2-8 PM. DCAPE values over 1300 J/kg indicate that any storms that do develop could produce strong outflow gusts (40-45 mph). Breezy SW winds with gusts up to 25-30 mph are expected, contributing to elevated fire weather conditions. Smoke from the Hawk Fire may persist, particularly in the Reno-Sparks area, but improved ventilation is anticipated. Patchy smoke may also creep into NE CA from the Timber Fire.

Wednesday and Thursday, the Pac NW low continues its eastward progression, strengthening the upper jet over the region. This will translate to increasing surface winds, with NBM guidance showing gusts up to 25-35 mph across the region, particularly in wind-prone areas of the Sierra and northern Nevada. These elevated winds, combined with low relative humidity, will lead to elevated to critical fire weather conditions. Temperatures will remain above seasonal averages on Wednesday, with NBM highs for western NV valleys in the mid 90s, and Sierra communities in the low 80s.

Precipitation chances remain very low (10%) for most of the CWA on Wednesday. However, NBM guidance shows a slight uptick in shower chances for Wednesday evening into Thursday morning, particularly for western Nevada. This appears to be a localized signal and confidence in widespread precip remains low. By Thursday, conditions are expected to be mostly sunny and dry across the CWA, with continued breezy winds, although some models are showing the potential for rain showers Thursday evening south of US-50.

Friday onward, the upper ridge will flatten late in the week as troughing strengthens over the Northwest. This pattern shift will bring a weak system through the CWA on Friday. NBM guidance shows a notable increase in precipitation chances for Friday (40-60%). Showers are possible across the Sierra and western Nevada, with a slight chance lingering into Saturday afternoon. Temperatures will see a slight cooling trend on Friday, with valley highs dropping into the upper 70s to upper 80s, and Sierra highs in the upper 60s to upper 70s. Winds will remain breezy on Friday, gradually diminishing through the weekend. Beyond Saturday, the NBM and GFS guidance point to a return of dry and mostly clear conditions for Sunday and Monday, with temperatures rebounding slightly but remaining generally near or slightly above seasonal averages. The overall synoptic pattern suggests a more stable, drier regime settling in for the start of next week.

-Justin

AVIATION

VFR conditions are expected at all area TAF sites today and tonight. Surface winds in the region gusting up to between 20-25 kts are forecast between through 03Z tonight. The latest HRRR smoke product does not show much impact from Hawk Fire smoke today compared to the previous days. Not anticipating flight rules to be reduced at this time due to smoke at KRNO, but will continue to monitor in case this changes.

There's a 15-25% chance for isolated showers and thunderstorms in Churchill, Mineral, and S. Mono Counties this afternoon between 25/21Z-26/04Z. Lesser precipitation chances are seen in the NV Basin and Range on Wednesday afternoon.

-078/Justin

FIRE WEATHER

Breezy SW winds with gusts up to around 25-30 mph and RH reductions of 15-25% will support elevated to isolated critical fire weather conditions this afternoon across the Sierra Front and NE CA, including the Hawk Fire. Tuesday night RH recoveries in these areas are forecast to be between 35-50%.

Wednesday through Saturday, increased winds with gusts upwards of 35 mph (40 mph in wind prone areas) are expected mainly for the Sierra Front and NE CA. Currently, the day with the most widespread critical fire weather conditions in these areas looks to be Thursday. Please continue to watch for further updates in case fire products need to be issued.

-078/Justin

REV Watches/Warnings/Advisories

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