textproduct: Elko

KEY MESSAGES

* Monsoonal moisture will promote showers and thunderstorms nearly every afternoon and evening this week.

* Marginal risk of excessive rainfall Tuesday through Thursday

DISCUSSION

(This evening through next Sunday)

WEATHER PATTERN OVERVIEW:

Monsoonal moisture continues to stream northward early this morning thanks in part to remnant convection across the Southwest U.S. over the weekend. The main feature driving this moisture axis is a large longwave upper ridge centered over the upper Midwest states. A cutoff upper low of the Pacific Northwest coast is also aiding in funneling this deep subtropical moisture tap across the Southwest into the Great Basin.

For today, southerly flow will continue to bring in an anomalously moist air mass across the area. Model precipitable water values are forecast to be at or over an inch. With respect to climatology, this amounts to near the maximum value for July 14. Forecast surface-based CAPE will be between 200 to 600 J/kg with the highest values centered across Lander, Eureka, and Elko Counties. Scattered to numerous showers and scattered thunderstorms are expected to develop Tuesday. There is an above average potential for localized heavy rain given the moist atmosphere. A Flash Flood Watch remains in effect for much of the forecast area through late Tuesday evening. Highs will be slightly cooler thanks to increased cloud cover and precipitation in the 80s to near 90 degrees with relatively light winds. Look for the convective activity to continue into the early overnight, tapering off from south to north with lows in the 50s.

Hi-resolution ensemble members and the NBM have been honing in on areas with the greatest chances for at least a quarter of an inch of rainfall today across southern Lander and Eureka Counties into White Pine and northward into central Elko Counties. This appears to be the general consensus for thunderstorm evolution through this evening.

On Wednesday, a drier air mass will move into the forecast area. Leftover showers and isolated thunderstorms are expected mainly in the east-central portions of the area. Highs will be in the 80s to low 90s. Winds will remain on the light side with gusts to 15 mph. Look for the showers to dissipate by evening with clouds scattering. Overnight low temperatures will be in the 50s.

Thursday through the weekend, long range ensemble clusters suggest that the center of the strong ridge will begin shifting westward from the Midwest to the central Rockies, leading to height rises across the Great Basin and warmer temperatures. Highs will once again climb back into the low to upper 90s through this period with isolated to scattered showers and isolated thunderstorms will each afternoon. Overnight lows will favor the 50s and 60s.

FORECAST CONFIDENCE & DEVIATIONS:

Nudged PoP grids towards current trends in radar activity through the early morning. Confidence is high in the moisture push, but confidence is lower in exact storm formation and tracking that will result in highest rainfall totals. Latest hi resolution ensemble guidance places highest likelihood for heaviest rainfall totals across southern Lander and Eureka Counties eastward into White Pine County with a zone of higher totals extending northward through central Elko County. Overall confidence is moderate in excessive rainfall potential through Thursday.

AVIATION

Primarily VFR conditions through tonight with vicinity showers and isolated thunderstorms due to monsoonal moisture push across the region. Winds primarily from the southwest but turning gusty and erratic with stronger showers and thunderstorms from 19Z through 06Z with thunderstorm activity primarily starting in central Nevada and ending across northern Nevada and into southern Oregon and Idaho.

FIRE WEATHER

Monsoonal moisture continues to move across northern and central Nevada with widespread showers and thunderstorms today. High atmospheric moisture amounts will bring widespread areas of at least 25% chances of wetting rains today with locally moderate to heavy rainfall at times. Anomalous precipitable water amounts remain in place through the remainder of the week resulting in continued afternoon showers and thunderstorms, especially across eastern Nevada.

LKN Watches/Warnings/Advisories

Flood Watch from 8 AM PDT this morning through this evening NVZ031-033>041.