textproduct: Elko

KEY MESSAGES

* Periods of valley rain and mountain snow continue thru Friday.

* Thunderstorms will be present this afternoon and evening. A few may be severe.

* Much cooler Friday and Friday night, followed by a modest warming trend and dry weather thru Monday.

DISCUSSION

(Today through next Thursday)

WEATHER PATTERN OVERVIEW: Upper level closed low continues to progress east and into the intermountain west today while concurrently weakening, opening into a deep upper level trof. The trof axis is still projected to be situated over Nevada by tonight after midnight. Moisture continues to be advected into the Great Basin today from the south. Rain showers and thunderstorms will become more prevalent as the morning progresses and activity increases from the southwest in conjunction with the upper level trof moving into the intermountain west, providing additional dynamical forcing to aid in shower and thunderstorm production. Showers and thunderstorms continue thru most of tonight. A few thunderstorms may become severe this afternoon and evening, primarily across the eastern half of the forecast area. The Storm Prediction Center has issued a marginal risk of severe thunderstorms including northeast Nye and White Pine counties, as well as portions of Elko County. Showers will continue through the day Friday, though activity will dissipate from west to east as the upper level trof continues to progress east into Utah. Snow levels lower from around 10,000 feet to around 6,000 to 7,000 feet early Friday morning as cooler air moves into Nevada from the northwest. Significant valley snow accumulation is not expected and a few locales along the Idaho and Oregon borders may see less than an inch of accumulation. Storm total liquid equivalent precipitation accumulation for the four day period that began Tuesday and runs thru Friday is still between one quarter and three quarters of an inch. The high elevations look to reach one inch or more, much of which will fall as snow above 10,000 feet.

The upper level trof is indicated to split into a closed low as reinforcing energy advects south from the PacNW along the upstream side of the trof. The closed low will form over SoCal and western Arizona by Saturday morning while the remainder of the trof itself progresses to the northeast and into Montana. An upper level ridge and high pressure look to reside offshore of the west coast. All that to say weather will be generally fair beginning Saturday and thru the middle of next week. There is potential for light precipitation in the Monday/Monday night timeframe as a weak cold front moves thru the PacNW and clips northern Nevada, though based on the current modeled trajectory of this weak system, will be maintaining dry condtions in the forecast at this time.

Friday and Saturday nights will be the coldest of the forecast period, with widespread lows in the 20s across the area. Mid to upper teens can be expected in the typical colder valleys, especially Saturday night under clearer skies and light to calm winds. A modest warming trend will be present thru the weekend and into Monday, though temperatures remain cool and more seasonal next week.

FORECAST CONFIDENCE & DEVIATIONS: There is high confidence for showers and thunderstorms today and tomorrow with the majority of the activity occurring today.

There is high confidence in the return of fair weather Saturday though moderate confidence in the potential for precipitaton along the OR/ID borders on Monday/Monday night.

Significant edits required within PoP and weather fields to produce a more accurate representation of forecast precipitaton thru Friday.

AVIATION

Periods of SHRA and/or VCSH continue at all terminals thru at least Thursday night as active weather persists across the region thru Friday. An increase in shower activity is expected this morning as an upper level trof moves into the Great Basin. Stronger and more consistent showers will move in from the southwest as the day progresses. CIGS are generally expected to remain within VFR category though may lower into MVFR category for brief periods as stronger showers move on terminal. Reductions in VIS due to SHRA on terminal may also produce periods of MVFR. TS and/or VCTS may also impact terminals this afternoon and evening as thunderstorms will be present across the forecast area. Additionally, there is a marginal risk for severe thunderstorms, defined as being capable of producing one inch hail and wind gusts of 58 mph or greater, at KELY, KENV, and KEKO as per the Storm Prediction Center severe weather outlook for today and tonight. Breezy to locally windy conditions will be present across the area this afternoon and evening under generally south winds. Gusts around 25KT to 30KT are forecast. Winds begin to shift northwesterly in northwest Nevada later tonight as the afore mentioned trof progresses into the Great Basin.

FIRE WEATHER

Upper level system continues to slowly move into the Great Basin from the west today, bringing rain showers, thunderstorms, and mountain snow to all FWZs. An increase in shower activity is expected this morning in conjunction with the system and main band of energy progressing into the Great Basin. Stronger and more consistent showers will move in from the southwest as the day progresses. The Storm Prediction Center maintains a marginal risk for severe thunderstorms this afternoon and evening, primarily within FWZs 425, 469, and 470. Severe thunderstorms are defined as being capable of producing one inch hail and strong and erratic wind gusts of 58 mph or greater. Frequent cloud to ground lightning will also be present under any severe storms. Showers and thunderstorms begin to dissipate from west to east Friday, eventually exiting Nevada Friday night. Widespread wetting rains are still expected over the four day period that began Tuesday and runs thru Friday with 0.25 inches to 0.75 inches of rainfall forecast across all FWZs. Liquid equivalent accumulations of an inch or more are expected across the high terrain. Most of this precipitaton is still expected to fall today. Breezy to locally windy conditions under a generally south wind will also be present today, and gusts as high as 30-40 mph are expected. Winds begin to shift northwesterly later tonight, beginning in northwest Nevada as the afore mentioned upper level system moves into the Great Basin. Wind shift continues thru Friday morning with north- northwesterly winds widespread across the forecast area by Friday afternoon. Much cooler temperatures will be in place by Friday though a modest warming trend will take place thru the weekend with dry and fair weather also present. Weather remains fair into early next week with a low chance for light precipitaton along the OR/ID border on Monday/Monday night. However given the low potential for precip, will be maintaining a dry forecast thru the middle of next week at this time.

LKN Watches/Warnings/Advisories

None.