Flash Flood Warning 12, NWS Reno, NV

717 
WGUS75 KREV 120051
FFSREV

Flash Flood Statement
National Weather Service Reno NV
551 PM PDT Sun Jun 11 2023

CAC003-051-NVC005-120101-
/O.EXP.KREV.FF.W.0012.000000T0000Z-230612T0045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Alpine CA-Mono CA-Douglas NV-
551 PM PDT Sun Jun 11 2023

...FLASH FLOOD WARNING HAS EXPIRED FOR ALPINE, NORTHERN MONO AND 
DOUGLAS COUNTIES...

The heavy rain has ended. Flooding is no longer expected to pose a 
threat. Please continue to heed remaining road closures.

A Flood Watch remains in effect until 900 PM PDT Monday for portions 
of California and western Nevada.

LAT...LON 3876 11965 3879 11959 3879 11957 3875 11953
      3872 11952 3870 11955 3869 11960 3872 11964

$$

AY

Area Forecast Discussion
National Weather Service Reno NV
148 PM PDT Sun Jun 11 2023

.SYNOPSIS...

Widespread thunderstorm coverage with elevated concerns for flash
flooding continues through Monday. Storms will be capable of
producing heavy rainfall, frequent lightning, small hail, and
gusty outflow winds. Thunderstorm chances decrease slightly
Tuesday and become more isolated from Wednesday through the end of
the week with temperatures warming back towards seasonal levels.

&&

.DISCUSSION...

The closed upper-level low will continue to influence the pattern
through Monday as it slowly traverses eastward through the desert
southwest. This morning's upper air analysis reveals the low
tracking onshore into southern California, which has increased
moist, southeasterly flow over the region. This increased moisture
availability, in conjunction with modest instability (CAPE
approaching 1000 J/kg) and synoptic forcing, will lead to widespread
shower and thunderstorm coverage through Monday.

* The major threat through Monday is the risk for flash flooding,
  mainly for far western Nevada including the Greater Reno-Carson
  City area, the Sierra, and northeast California. High-resolution
  guidance indicates PWATs will increase to 0.7-0.9" today, perhaps
  exceeding 1.0" by Monday. Slightly slower storm motions are
  expected today, and with a favorable environment for more
  organized storms, rainfall rates exceeding 1" per hour are
  possible. As soils are already saturated from snowmelt and recent
  rainfall, it will not take considerable accumulation to trigger
  flash flooding. Take extra care near burn scars or area creeks and
  streams that are already running high, as conditions can rapidly
  deteriorate. A Flash Flood Watch was hoisted through Monday
  evening to highlight this threat.

* The other threat includes potential for severe thunderstorms,
  especially over the west-central Basin & Range this afternoon.
  Forecast soundings over this area shows the most robust
  instability, a dry sub-cloud layer with an inverted-V profile, and
  steep lapse rates. These parameters align with the potential for
  potentially severe wind gusts up to 60 mph this afternoon. The SPC
  has highlighted this area today under a Marginal Risk due to this
  wind threat. Increased moisture across the region decreases
  chances for severe thunderstorms on Monday, but gusty winds, small
  hail, and heavy rainfall are still possible.

On Tuesday, the low will propagate eastward out of our region. While
we won't have support from the synoptic pattern, residual high
moisture availability and surface heating will enable scattered
showers and thunderstorms to develop Tuesday afternoon. Thunderstorm
chances trend downward through the remainder of the week as drier
northwesterly flow prevails over the region. However, blended
guidance suggests 20-30% chances for storms each afternoon through
Friday, mainly for areas south of US-50. -Whitlam

&&

.AVIATION...

* An active thunderstorm pattern is expected at least through
  Monday with a a higher likelihood of MVFR-IFR conditions and
  heavy raining storms. There will be a 50-80% chance for
  thunderstorms this afternoon and early evening. Mostly like
  timeframe for thunderstorms to impact the terminals will be
  between 22z-03z today.

* Storms out in the lower desert areas including KHTH-KNFL-KLOL
  will be capable of hail and strong outflow winds to 45+ kts
  which could stir up blowing dust and a brief period of greatly
  reduced visibility. For storms closer to the Sierra including
  KRNO-KCXP-KMEV, very heavy rain and the possibility of lots of
  small hail will be the primary concerns although erratic wind
  gusts to 30-35 kts will also be possible.

* Widespread thunderstorm will re-fire on Monday with heavy
  rainfall, small hail and gusty outflow winds. Thunderstorm
  coverage should decrease by mid-week with some drying occurring.
  However, we may not completely get out of this stormy pattern
  with isolated showers and storms still possible, particularly
  for areas south of Hwy 50. Fuentes

&&

.HYDROLOGY...

* Flash flooding is the primary concern with potential for heavy
  rain and slow moving storms through Monday. Areas that are
  particularly prone are recent burn areas and creeks and streams
  already near bankfull with ongoing snowmelt. Flash flooding is
  also a concern in areas that received high amounts of rainfall
  on Saturday. Keep in mind that hydrologic modeling for rivers
  cannot fully account for the convective precipitation
  anticipated with storms.

* Otherwise moderate flooding continues along the Walker near
  Mason and is expected to stay fairly level through the weekend
  outside of added runoff from localized thunderstorms. The
  earlier crest at Wabuska will take a day or two to reach Weber
  Reservoir. Additional future rises along the Walker are likely
  with prolonged flooding expected to last into July.

* High flows to continue along the west fork of the Carson, but the
  current forecast keeps the rivers below flood stage. Minor
  flooding is ongoing along the lower Humboldt at Imlay with a few
  inches of water flowing over Tungsten Road. Flows at Imlay are
  expected to rise slightly into next week, remain in minor flood
  stage, before very slowly receding.

* Creeks and streams areawide will continue to run high, cold, and
  fast; with some potentially out of banks especially throughout
  portions of Mono County. As a result, banks may be unstable and
  any debris can send flows into unexpected areas, so take caution
  near waterway edges. -Bardsley/McKellar

&&

.REV Watches/Warnings/Advisories...
NV...Flood Watch through Monday evening NVZ001>003.

CA...Flood Watch through Monday evening CAZ071>073.

&&

Special Weather Statement
National Weather Service Reno NV
220 PM PDT Sun Jun 11 2023

NVZ004-112145-
Western Nevada Basin and Range including Pyramid Lake NV-
220 PM PDT Sun Jun 11 2023

...A strong thunderstorm will impact portions of east central
Churchill County through 245 PM PDT...

At 219 PM PDT, Doppler radar was tracking a strong thunderstorm over
US-50, 10 miles northeast of Middlegate, moving northwest at 5 mph.

HAZARD...Winds in excess of 40 mph and nickel size hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor damage to outdoor objects is
         possible.

This storm will impact US-50 between Middlegate and Cold
Springs.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 3939 11781 3930 11787 3937 11809 3955 11794
TIME...MOT...LOC 2119Z 133DEG 6KT 3937 11785

MAX HAIL SIZE...0.88 IN
MAX WIND GUST...40 MPH

BW