textproduct: Reno

KEY MESSAGES

* Gusty winds will bring elevated fire concerns, and impacts to holiday travel and recreation Sunday afternoon.

* A cold front will increase shower and thunderstorm chances near the Oregon border on Sunday.

* Mild temperatures and breezy afternoons prevail next week with increasing shower and thunderstorm chances around midweek.

DISCUSSION

An upper low and cold front will move through the region on Sunday. This will produce likely (50-60%) rain showers and isolated thunderstorms (25%) in northern Washoe and Lassen counties, as well as the Surprise Valley. For thunderstorms, models show meager CAPE values of only 100-300 J/kg, but decent 0-6km shear values up to 50 kts. These storms will have the capability of outflow gusts of up to 40 mph and infrequent lightning. Precipitation amounts with these showers are light, with general amounts of a trace up to 0.10 inches, with locally up to 0.25 inches. Elsewhere across the district, west to southwest winds will increase by the late morning into the evening. Winds will commonly gust upwards of 25-35 mph for most locations, and 50-60 mph along the ridges. For that reason, a Lake Wind Advisory has been issued for area lakes. Further south in Mono, Mineral, and S. Lyon counties, we will keep the strong winds, but humidity is much lower producing fire weather concerns (more details in the fire weather section below).

The setup for the first half of the upcoming week features an upper low in the eastern Pacific with high pressure strengthening over the southwest US. This gives a robust southerly flow aloft, which will allow for subtropical moisture to stream into area starting late Tuesday. The potential for precipitation increases by Tuesday through Thursday, with the best chances in the Sierra from Tahoe Basin southward into Mono County. By Thursday into next weekend, the uncertainty in the upper air pattern is still high. The unknowns are the position of the upper high over the southwest US, the position of the upper low in the east Pacific, and a possible upper trough moving south into the area. For now, temperatures next week will trend warmer with light winds. -McKellar

AVIATION

VFR conditions prevail. Winds this afternoon will be S/SW with gusts of 20-25 kts before shifting to more W/SW in the late afternoon.

Winds aloft and at the surface increase on Sunday, renewing LLWS and mountain wave turbulence potential for all main terminals. Gusty winds may also produce blowing dust and reduced visibilities at KHTH- KNFL-KLOL Sunday afternoon.

There are likely chances for showers and storms in northeast CA and northern Washoe County in the afternoon on Sunday, which may produce gusts to 40 mph along with reduced visibilities and lower ceilings.

There are low 20% chances for patchy fog at KTRK from 09-15Z Sunday.

-Salas/McKellar

FIRE WEATHER

SW/W gusts of 30-40 mph and RH reductions to 15% or less will support 2-6 hours of critical conditions across valleys and midslope areas of Mono, S. Lyon, and Mineral counties Sunday afternoon. Winds shift to a more westerly direction following a dry frontal passage in the late afternoon and early evening. Nighttime recoveries will be moderate to good (up to 50-70%) Sunday night into Monday, with the exception of the Chalfant Valley where RH struggles to 40%.

Farther north, higher humidity will mitigate fire concerns somewhat, but similar wind gusts will at least elevate fire concerns from the northern Sierra Front into the west-central Nevada Sunday afternoon. -Salas

REV Watches/Warnings/Advisories

NV...Lake Wind Advisory from 11 AM Sunday to 11 PM PDT Monday NVZ001- 002-004.

CA...Lake Wind Advisory from 11 AM Sunday to 11 PM PDT Monday CAZ071>073.