textproduct: Elko

KEY MESSAGES

* Subtropical moisture remains over much of the area through the balance of the week.

* Isolated to scattered shower and thunderstorms over eastern and east-central Nevada through Saturday.

* A marginal risk of excessive rainfall continues across portions of eastern and east-central Nevada through Saturday

* Temperatures will generally run near normal through the balance of the week.

DISCUSSION

(This afternoon through next Tuesday)

WEATHER PATTERN OVERVIEW:

A few isolated thunderstorms are exiting northern Nevada into southern Idaho early this morning where remnant instability remains uncapped. These have been sub-severe and though have been dropping brief heavy rainfall of up to 2 inches per hour, have been moving northward enough to preclude any additional Flood Advisories at this time. Allowed the Flash Flood Watch to expire on schedule late yesterday evening.

For Wednesday, the upper ridge will slide to the west and position itself across the Inter-mountain West. Model output is trying to keep the precipitable water values at or above three-quarters of an inch by tomorrow afternoon across eastern Nevada, especially where values are in the 90-95th percentile for mid-July. The best CAPE values are once again expected across portions of eastern Nevada (Elko and White Pine Counties). 700-500mb storm motions continue to remain on the light side at about 5 to 10 knots. Again, there could be localized moderate rain with some of the cells that form tomorrow. Hi-res guidance begins firing storms by 11 am to the noon timeframe. Winds will generally be light except for highly localized breezes and gusts in stronger thunderstorms. Highs will be in the upper 80s to mid 90s. Convective activity is expected to wane during the early overnight with lows in the 50s and 60s.

The upper level ridge circulation is expected to remain out in the Inter-mountain West region Thursday creating a very similar forecast compared to today. Models continue to depict a rather moist airmass across much of eastern Nevada with precipitable water values at or above three- quarters of an inch. In addition, forecast surface- based CAPE values of 300-700J/kg are seen over the eastern half of the forecast area. Some of these showers and thunderstorms could produce moderate to locally heavy rainfall during the afternoon. There is concern regarding the possibility of a multi-day rain event in the eastern half of the forecast area and this will need to be monitored closely in regards to where thunderstorms form and pass. Highs are expected to climb into the mid to upper 90s for Thursday with overnight lows in the 50s and 60s.

Model simulations continue to show not much movement with respect to the upper level ridge as the center of circulation remains across Utah, Wyoming, and Colorado. The flow across the forecast area is expected to remain weak through the weekend, keeping a rather moist environment over the region. Will need to maintain a vigilant watch for heavy rain and flooding due to storms that form over the same area and drop rain. Highs through this timeframe will be in the 90s, though no triple digits are yet in the forecast. Overnight lows will be in the 50s and 60s.

FORECAST CONFIDENCE & DEVIATIONS:

No changes to the NBM were made to the forecast this morning. Confidence remains high with regards to the short term wet forecast with thunderstorms favored each afternoon across Elko and White Pine Counties especially. Confidence is moderate in excessive rainfall potential through Thursday. Long range ensemble cluster solutions start to bring a longwave trough into the Pacific Northwest Sunday into early next week, but disagreement exists in how amplified it remains in regards to wind impacts to our region. Should it remain more amplified in the less likely scenario, stronger winds would be favored into early next week.

AVIATION

VFR conditions through the TAF period with light and variable winds 10 kt or less. Isolated thunderstorms once again from 19Z through 03Z with localized brief gusty and erratic winds. Highest confidence for thunderstorm impacts to terminals at EKO, ELY, and ENV where instability and moisture content will be greater.

FIRE WEATHER

Deep subtropical moisture remains in place across northern and central Nevada with minimum RH values remaining mostly above 20 percent. Isolated showers and thunderstorms once again this afternoon and scattered coverage over zone 425. Unsettled weather continues with afternoon showers and more wet than dry thunderstorms nearly every afternoon through Saturday for most fire weather zones through the period. The one notable exception is near critical conditions Thursday for northwestern zone 437 Thursday as southwest winds increase and drier air moves in with minimum RH values dropping below 15 percent.

LKN Watches/Warnings/Advisories

None.