Area Forecast Discussion

KEY MESSAGES

* Critical fire weather conditions this afternoon

* Fair and cooler Sunday

* Chance of precipitation Monday evening thru Tuesday night

DISCUSSION

(Today through next Saturday)

WEATHER PATTERN OVERVIEW: Upper level trof and attendant surface dry cold front will pass thru the forecast area from northwest to southeast today. This has prompted a Red Flag Warning for the entire forecast area from 11 AM PDT this morning until 11 PM PDT this evening due to sustained west-southwesterly wind gusts near 35 mph and minimum relative humidity as low as 9 percent. Winds shift west-northwesterly this evening and overnight in conjunction with the frontal passage with winds also easing overnight. Patchy blowing dust will be present today as well given the elevated winds. There is a low chance (10% or less) for a dry thunderstorm or two embedded along the front this afternoon and evening. Based on latest prognostics, the best potential for a thunderstorm or two will be within White Pine and eastern Elko Counties, though this continues to remain a low confidence scenario and have opted to not include thunderstorms in the gridded forecast at this time. The main effect will be an increase in cloud cover. Otherwise, daytime high temperatures this afternoon will be in the upper 70s to upper 80s with overnight lows mostly in the 40s.

Generally fair weather expected Sunday with lighter winds and cooler temperatures though the typical afternoon breezes will be present. Daytime high temperatures will be spread from north to south with mid to upper 60s across northern Humboldt and Elko Counties and upper 70s to low 80s across northern Nye County. Cumulus buildups will be likely across the eastern half of White Pine County Sunday afternoon but not expecting any thunderstorms as atmospheric moisture looks quite limited.

A robust upper level trof will influence the western U.S. and the forecast area early next week and will bring precipitation into the area Monday evening thru Tuesday night, primarily across northern Nevada. Valley rainfall accumulations currently look to be around 0.10 inches or less. The best chance for thunderstorms will be Tuesday afternoon. Elevated afternoon winds will also be present. Dry weather will return Wednesday and persist thru the end of the week under a more benign northwesterly flow regime as a broad region of high pressure resides off the west coast.

FORECAST CONFIDENCE & DEVIATIONS: High forecast confidence in critical fire weather conditions this afternoon and evening. Moderate forecast confidence regarding precipitation Monday evening thru Tuesday night. Have opted for a blend of NBM, WPC guidance, and Euro early next week for probability of precipitation and weather fields.

AVIATION

VFR conditions will prevail thru tonight and the main concern will be for elevated south-southwesterly winds with gusts 25KT to 30KT this afternoon and evening at all terminals. Winds will shift west-northwesterly this evening and overnight while concurrently easing. Potential for BLDU at all terminals which may temporarily reduce VIS to MVFR or IFR, though not enough confidence to communicate such within the TAF.

FIRE WEATHER

Critical fire weather conditions this afternoon and evening with west-southwesterly wind gusts near 35 mph as an upper level trof and attendant dry surface cold front move thru from northwest to southeast. Winds shift west-northwestrerly this evening and overnight in conjunction with the frontal passage while concurrently easing. Minimum afternoon relative humidity will reside as low as 9 percent. This has prompted a Red Flag Warning for all FWZs that is in effect from 11 AM PDT this morning thru 11 PM PDT tonight. Will maintain a low chance (10% or less) for a dry thunderstorm or two embedded along the front this afternoon and evening. Based on latest prognostics, the best potential for a thunderstorm or two will be within FWZs 425, 469, and 470. Though this continues to remain a low confidence scenario and have opted to not include thunderstorms in the official forecast at this time. The main effect will be an increase in cloud cover. Fair and cooler weather Sunday though the typical afternoon breezes will be present. Cumulus buildups will be likely across the eastern half of FWZ 425 Sunday afternoon but not expecting any thunderstorms as atmospheric moisture looks quite limited. A robust upper level trof will bring precipitation back into the forecast Monday evening thru Tuesday night, primarily across northern Nevada with central Nevada expected to remain dry. Valleys will be hard pressed to see a wetting rain based on current indications. There will also be chances of thunderstorms Tuesday afternoon. Elevated afternoon winds will be present Monday and Tuesday as well.

LKN Watches/Warnings/Advisories

Red Flag Warning in effect from 11 AM through 11 PM PDT today for NVZ424-425-426-427-437-438-469-470.