Area Forecast Discussion

KEY MESSAGES

* Critical fire weather conditions this afternoon

* Fair weather and cooler conditions Sunday

* Elevated fire weather conditions ahead of the cold front Monday

* Chance of precipitation Monday evening thru Tuesday night

DISCUSSION

(This afternoon through next Saturday)

WEATHER PATTERN OVERVIEW: Cold front associated with an upper level trough to the north is pushing through Nevada with winds strengthening throughout the day on an already dry surface which has promtpet Red Flag Warnings across the region until 11 PM today. Sustained west-southwesterly wind gusts near 35 mph with relative humidity below 10%. Winds will shift from a west/southwest to a more northerly flow as the front passes over as well as dissipating to lower speeds overnight. There is still a low chance (below 10%) for some dry thunderstorms this evening and into the early morning hours with best potential over White Pine County and Elko County, however confidence remains low and will not include in the gridded forecast at this time. High temperatures this afternoon in the upper 70s to 80s with cooler temperatures starting to enter over northern Nevada this evening. Overnight lows in the 40s to 50s with parts of northern Nevada along the state border dropping into the 30s.

Tomorrow, fair weather conditions expected throughout the day as the front has passed over Nevada, with lighter winds than the day prior but still seeing gusts up to 15-20 mph. Cooler temperatures with highs in the 70s across the region, 60s north of I-80.

Monday, a second upper level trough with a cold front will move across Nevada in the afternoon. Ahead of the front, winds are expected to increase again with sustained west/southwesterly winds up to 15-25 mph, and gusts as high as 25-40 mph. The strongest winds are expected in central Nevada and eastern Elko County. Elevated fire weather conditions expected as winds with dry surface with relative humidity below 10% will prompt a Fire Weather Watch for central and eastern Nevada from 11 am to 11 pm. Conditions will lessen in the evening has humidity levels increase to well above thresholds as moisture is expected to enter the state with the passing front. Chances for precipitation increase with northern Nevada (mainly along the I-80 corridor) seeing a 40-50% chance of light rain up to 0.01 with a 20% probability of seeing up to 0.05 inches of rain. South of the I-80 corrdior, Eureka has a 20% chance of light precipitation, however the rest of US-50 corridor and central Nevada see less than 10% chance which will keep the area dry. Fire weather conditions improve across the state as humidity levels rise above 15% with winds becoming lighter. High temperatures slightly higher as warmer temperatures move back in just before the cold front in the 70s to 80s.

Chances of precipitation continue into Tuesday and dissipate by the afternoon as the trough weakens and moves north. By late afternoon into the evening, fair weather conditions take hold over Nevada with cooler temperatures as highs expected to be in the 70s.

Rest of the week, fair weather conditions with warming temperatures back into the 80s. Winds expected to be light each day.

FORECAST CONFIDENCE & DEVIATIONS: High confidence of critical fire weather conditions this afternoon and evening. Moderate confidence of elevated fire weather conditions Monday afternoon ahead of the second cold front. Moderate confidence for periods of precipitation across northern Nevada Monday evening through Tuesday. Moderate confidence fair weather conditions return Tuesday evening through the rest of the week. No changes to the grids at this time.

AVIATION

Look for VFR conditions across all terminals over the next 24 hour period. Strong gusty winds affecting all terminals as a cold front passes over with west/southwesterly winds up to 10-20 kts, gusts as high as 20-30 kts. Strong winds may cause BLDU conditions at terminals. Winds this evening will shift from west/southwesterly to a more northerly direction and dissipate to lighter speeds below 10 kts with the exception of KENV staying above 10-15 kts. Build up in clouds with CIG levels between FL100-150 over the eastern terminals as mid-level moisture increases with a 10% chance for dry thunderstorm activity this evening and overnight near KELY, KEKO and KENV, however confidence remains low at this time and will keep dry thunderstorms out of the TAFs.

FIRE WEATHER

Critical fire weather conditions across all zones this afternoon and evening as strong gusty west/southwesterly winds up to 30-40 mph with min RH values below 10% as a cold front pushes over Nevada. Red Flag Warning is in effect until 11 pm this evening for all fire zones. There is a low probability (10% or less) for a dry thunderstorm or two this afternoon or evening. The best potential will be within zones 425, 469 and 470. At this time, the thunderstorms will be omited from the forecast as confidence remain low for the scenario to occur. This will increase cloud cover over the area. Winds will shift from a west/southwesterly to a more northerly direction as the front passes over. Fair weather and cooler temperatures Sunday with some light breezes. A second upper level trough will move into Nevada Monday and bring increasing chances for precipitation across the northern zones, while central zones remain dry. Ahead of the front, elevated fire weather conditions as wind increase with dry conditions of min RH below 10% throughout the day. Fire weather watch has been issued for zones 425, 426, 427, and 470 for Monday from 11 am to 11 pm. By the evening, fire weather conditions will improve as RH values increase above critical thresholds with winds dissipating once the cold front passes over.

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.

Fire Weather Watch in effect from 11 AM through 11 PM PDT Monday for NVZ425-426-427-470.