textproduct: Elko

KEY MESSAGES

* A few strong thunderstorms possible in parts of Northern and Central Nevada both this afternoon and Tuesday afternoon

* Monsoon weather pattern for Central and Eastern Nevada expected to persist through the week

* Gradual cooling trend Tuesday through Friday

DISCUSSION

(This evening through next Sunday)

Interesting upper level pattern beginning to develop for the western US as the subtropical high relaxes its grip across the silver state. The summertime subtropical ridge that has been anchored over the eastern great basin is beginning to shift which is allowing some monsoonal moisture to work its way into central Nevada. This will help lower temperatures to more seasonal values and with the moisture rain chances due to afternoon and evening thunderstorms will be prevalent this week. Monday and Tuesday afternoon will have a 20% to 30% chance for thunderstorms mainly along the US 50 corridor. These storms will be slow moving, allowing for a higher chances for rain to reach the ground given the dry surface layer as wet storms may produce up to 0.10 of rain. Still there will be a few dry thunderstorms that form, with an elevated risk for lightning fire starts. Wednesday a digging upper level trough will work its way into California, Models show that this system will help Nevada out in multiple ways, first dropping temperatures significantly through the end of the week with highs returning to the low 80s to low 90s. Second, it will help channel monsoonal moisture flow increasing chances for wetter storm modes. Finally, the added dynamic cooling and dynamic lift will also help to increase overall precipitation chances for mid to late week. The only question that is unresolved is how far north and west the best moisture gets advected over NV. Current thinking has all but far NW Humboldt County seeing a chance at wetting rains (0.10) this week. However, ensemble model members are split on this scenario as some show all of Humboldt getting in on rain, whereas some show most of N NV missing out. After Saturday the upper trough lifts NE into Canada which may lower storm chances a bit for the weekend, but models are split on the upper pattern after Sunday as the GFS favors keeping the western US under some form of troughing aloft, while the ECMWF shows that the upper ridge will again shift back west after a few days in the southern plains.

FORECAST CONFIDENCE & DEVIATIONS: There is high confidence for chances of isolated to scattered mix of wet and dry thunderstorms Through Friday afternoon.

There moderate confidence for isolated to scattered mix of wet and dry thunderstorms for NE Nevada Wednesday through Friday.

There is low confidence for isolated mix of wet or dry thunderstorms for NW Nevada Wednesday through Friday.

There is low confidence in the evolution of the upper pattern after Sunday as models are disagreement as to the strength and location of key upper level features.

AVIATION

VFR conditions look to be the primary flight conditions through Tuesday evening. Areas of FU will be possible for N NV terminals due to regional wildfires with local drops in visibility. For KELY, KTPH, and KENV increasing mid level moisture will bring afternoon VCTS. Hazards include gusty outflow winds up to 45KT, lightning, and brief heavy rainfall. However, chances for direct terminal impacts from -TS are near 10%. Winds will be breezy out of the west at 10KT to 20KT with occasional gusts up to 30KT possible.

FIRE WEATHER

Elevated fire weather concerns possible for northern Nevada Today and Tuesday as breezy west winds of 10 to 20 MPH with a few gust up to 30 MPH possible, will combine with low afternoon RH values. For Central Nevada Monday and Tuesday will see a 20% to 30% chance for a mix of wet and dry thunderstorms. The main hazard from these storms will be gusty outflow winds up to 50 MPH, Ground lightning strikes, and brief heavy rainfall. Wednesday a upper level storm system will move in from the west which will help bring better mid level moisture, raising storm chances to between 50% and 80% for all zones except 437 where a 30% chance for isolated storms reside. Storm chances will continue through at least Sunday as upper level storm exits to the NE.

LKN Watches/Warnings/Advisories

None.