textproduct: Elko

KEY MESSAGES

* Chances for monsoon storms return Friday afternoon and lasting through the first half of the week.

* Cooling trend starts today as mid level moisture and increasing cloud cover moves north.

DISCUSSION

(Today through next Friday)

WEATHER PATTERN OVERVIEW:

Upper trough off the California coast will help set the stage for a return of monsoon flow over Nevada. This trough while having no impact on Nevada, will serve to push the upper ridge east while redirecting the upper level flow to a southerly direction. This will allow for moisture to surge north bringing chances for afternoon showers and thunderstorms. Models show this flow pattern persisting at least through Wednesday of next week, giving Nevada a daily 20% to 50% chance of isolated to scattered showers and thunderstorms starting Friday afternoon. It is important to note that there will be a low chance for dry thunder each day, even as forecasts show a high preference for wet storm modes overall. Models show that the upper ridge will try and work its way back west Wednesday evening, shifting the upper flow back to a WSW direction, and cutting off moisture flow by Thursday of next week. Temperatures will a begin a cooling trend Friday as the surge of moisture and the displacement of the ridge will allow highs to cool back into the low 80s to low 90s with lows dropping into the mid 50s to mid 60s. Winds will be breezy through the weekend and into the new week as winds shift more south to southwest at 10 to 20 MPH with gusts up to 30 MPH possible.

FORECAST CONFIDENCE & DEVIATIONS: There is high confidence for the return of southerly flow and monsoonal moisture beginning Friday afternoon, bringing a daily 20% to 50% chance for isolated to scattered showers and thunderstorms for Nevada through Wednesday. There is low confidence of upper pattern evolution after Wednesday as models show either continued monsoon flow or a return of the upper level ridge and warmer temperatures.

AVIATION

VFR conditions look to be the primary flight conditions through Friday evening. Winds will be out of the south to southwest at 5KT to 15KT with gusts to 25KT possible for all terminals. VCTS will be possible Friday afternoon and evening as monsoon flow will bring a 20% to 50% chance for isolated to scattered showers and thunderstorms.

FIRE WEATHER

Friday southerly flow will allow a return of monsoonal moisture to the region, this moisture along with increasing clouds will help with cooling afternoon temperatures, and bring a daily 20% to 50% chance for isolated to scattered showers and thunderstorms. Hazard from storms will include gusty outflow winds up to 50 MPH, Ground lightning strikes, and brief heavy rainfall. As it may take time for moisture to make it fully up north, there will be a window for Humboldt County to see elevated fire weather conditions Friday afternoon, as there will still be very warm temperatures, breezy afternoon winds, and some dry thunder initially. If timing is slower than forecast for the moisture, a fire weather watch may be needed for zone 437 and possibly 424. However when moisture full arrives daily storm chances will keep fire weather conditions low through Wednesday of next week.

LKN Watches/Warnings/Advisories

None.