Flash Flood and Debris Flows in Nevada, August 5 to 6, 2022

Area Forecast Discussion
National Weather Service Elko NV
309 AM PDT Fri Aug 5 2022

.SYNOPSIS...Showers and thunderstorms will bring rain and thunder
to much of northern and central Nevada. Temperatures will be at or
below normal. Look for drier weather for Sunday with temperatures
staying seasonable.

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.SHORT TERM...Today through Saturday night. Radar loop currently
showing shower activity across northern Nevada with an area of
showers and embedded isolated thunderstorms across Lincoln and
southern Nye, moving northwest. This area of showers is associated
with an upper level trough. Surface dewpoints remain abnormally
high, with readings in the 50s. For today, main synoptic elements
include an upper level high pressure sitting over New Mexico and
Texas this morning with the aforementioned inverted trough making
its way around the western side of the high and northward into
central and northern Nevada today. Accompanying this feature is
deep moisture with precipitable water values of greater than one
inch. Storm motions are forecast to be slow with speeds of 5 to 10
mph. Skies are expected to remain mostly cloudy to cloudy over
much of the area and this could inhibit thunderstorm development,
though heating will occur in between breaks in the cloud cover.
Localized heavy rain remains the main threat and previous shifts
have issued flash flood watch and this will be continued with no
changes. Highs will be cooler with readings in the 70s and 80s,
though warmer conditions are expected in Humboldt county with
highs in the mid to upper 80s there. For tonight isolated to
scattered showers and thunderstorms are expected to continue
throughout the overnight period. Lows will be in the 50s and 60s.

The upper trough is anticipated to hang around on Saturday through
Saturday night over the area.

.LONG TERM...Sunday through next Friday.

The trough of low pressure will progress slightly east towards the
OR/CA coastline later Sunday into Monday. This may aid in showers
and Isolated thunderstorms later in the day Monday. Storms mainly
look south of US-50, with showers potentially later spreading
further north. Highs will rebound back to near normal in the mid
80's to mid 90's by Monday with lows remaining in the 50's.

The low pressure will then slowly drift to the north off the west
coast allowing for a deep southerly flow to continue across the
Great Basin. This will bring a strong fetch of tropical moisture
northward in a large monsoonal push into the silver state.
Widespread showers and thunderstorms look to be in store each
afternoon Tuesday through Friday with higher coverage towards east
central NV. The high amounts of moisture will allow for heavy
rainfall with flooding being possible each day. Temperatures are
looking to remain more stable and seasonable.

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.AVIATION...A much heavier push of monsoonal moisture is expected
today creating widespread showers and thunderstorms for the
region. Impact is expected at all terminals with gusty and
erratic winds possible with the development of any thunderstorm
at or near the terminals. However, bigger concern for the day
will be with rainfall rates. Heavy to moderate rainfall is
possible at the terminals resulting in visibility drops into the
MVFR range earlier on stronger storms. Mountain obstruction could
also become problematic with development of rain shafts and lower
cloud decks.

&&

.FIRE WEATHER...A moist air mass will reside over the area through
the weekend. Showers and thunderstorms will be possible as
relative humidity values remain high, though fire zones 437 and
438 will see values drop into the teens with excellent overnight
recoveries expected.

&&

.HYDROLOGY...Very moist conditions are evident over the forecast
area today and this will continue through the weekend. Showers
and thunderstorms will develop and track across the region as
precipitable water values are forecast to increase to 1 to 1.25
inches. All of this adds up to the potential for locally heavy
rainfall. A flash flood watch has been issued and will remain in
effect through Saturday morning.

As a reminder, TURN AROUND AND DON'T DROWN. Flooding can easily
destroy roads and sweep away people and vehicles. Flood waters can
flow in normally dry washes or creeks far away from rainfall
sources. Areas of high runoff such as rocky slopes, steep canyons,
or fire burn scars can flood especially fast.

&&

.LKN WATCHES/WARNINGS/ADVISORIES...
Flood Watch from 6 AM PDT Friday through late Friday night for
Northeastern Nye County-Northwestern Nye County-Ruby Mountains
and East Humboldt Range-South Central Elko County-Southeastern
Elko County-Southern Lander County and Southern Eureka County-
Southwest Elko County-White Pine County.

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86/99/94/86