River Flood Warning 9, NWS Reno, NV

307 
WGUS85 KREV 081840
FLSREV
FLOOD STATEMENT 
NATIONAL WEATHER SERVICE RENO, NV 
1040 AM PST SUN JAN 8 2017
   

...The flood warning is cancelled for the following rivers in 
California...Nevada...
 
  West Fork Carson River At Woodfords affecting Alpine AND Douglas 
  COUNTIES
  West Walker River Near Coleville affecting Mono COUNTY
  
...The Flood Warning continues for the following rivers in 
California...Nevada...
 
  Susan River At Susanville affecting Lassen COUNTY
  Middle Fork Feather River Near Portola affecting Plumas COUNTY
  Truckee River Near Truckee affecting Nevada AND Placer COUNTIES
  Truckee River At Reno affecting Washoe COUNTY
  Truckee River At Vista affecting Storey AND Washoe COUNTIES
  East Fork Carson River Below Markleeville affecting Alpine AND 
  Douglas COUNTIES
  Carson River Near Carson City affecting Carson City...Churchill...
  Douglas AND Lyon COUNTIES

An atmospheric river is producing intense rainfall with snow levels
near 9000 feet through tonight. Intense rain, saturated soils
and melting snow will combine to produce excess runoff and cause
rivers to flood. Rain and snow levels will decrease on Monday,
however flood impacts will continue into Tuesday.


PRECAUTIONARY/PREPAREDNESS ACTIONS...

This event is ongoing and flood preparations should be in place. Pay
attention to the latest observations and river forecasts. Never drive
through flooded areas and follow the directions of emergency
officials.

The next forecast update for these locations will be issued at about
3 pm today.

&&

CAC057-061-100040-
/O.EXT.KREV.FL.W.0001.000000T0000Z-170110T1040Z/
/TRCC1.3.ER.170108T1936Z.170109T0600Z.170109T1640Z.NO/
1040 AM PST SUN JAN 8 2017

The Flood Warning continues for
  The Truckee River Near Truckee.
* UNTIL LATE MONDAY NIGHT.
* At  9:30 AM Sunday the stage was 3.2 feet.
* Flood stage is 4.5 feet.
* Major flooding is forecast.
* Forecast...Rise above flood stage by late Sunday morning and 
  continue to rise to near 7.1 feet by late Sunday evening. The river
  will fall below flood stage by Monday morning.
* Impact...At 7.0 feet...Major flooding along Truckee River between 
  Bear Creek in the Alpine Meadows area and Truckee...About 5850 cfs.
  Significant damage to some private bridges and low-lying structures
  along the river. 
* Flood history...This crest compares to a previous crest of 7.1
  feet on December 31 2005.


&&

LAT...LON 3918 12021 3932 12022 3939 12010 3938 12009 3919 12019


$$

CAC057-091-NVC031-100040-
/O.ROU.KREV.HY.S.0000.000000T0000Z-000000T0000Z/
/FARC1.N.UU.000000T0000Z.000000T0000Z.000000T0000Z.OO/
1040 AM PST SUN JAN 8 2017

Forecast information for
  Truckee River At Farad.
* At  9:30 AM Sunday the stage was 5.3 feet.
* Flood stage is 11.0 feet.
* Forecast...The river will rise to near 10.0 feet early Monday 
  morning.
* Impact...At 10.0 feet...No flooding from Boca to Mogul...including 
  the Floriston and Verdi areas.
* Flood history...This crest compares to a previous crest of 10.8
  feet on December 31 2005.


&&

LAT...LON 3939 12009 3956 12003 3952 11989 3936 12000 3936 12009


$$

NVC031-100040-
/O.EXT.KREV.FL.W.0002.170108T2222Z-170110T0640Z/
/TRRN2.2.ER.170108T2222Z.170109T0400Z.170109T1240Z.NO/
1040 AM PST SUN JAN 8 2017

The Flood Warning continues for
  The Truckee River At Reno.
* FROM THIS AFTERNOON TO MONDAY EVENING.
* At  9:15 AM Sunday the stage was 7.3 feet.
* Flood stage is 11.0 feet.
* Moderate flooding is forecast.
* Forecast...Rise above flood stage by Sunday afternoon and continue 
  to rise to near 12.6 feet by Sunday evening. The river will fall 
  below flood stage by early Monday morning.
* Impact...At 12.5 feet...Moderate flooding from Mogul to Highway 
  395...including downtown Reno.  River out of banks downtown nearly 
  a foot. Idlewild and Wingfield Parks flood up to 5 feet deep.  
  Significant impacts to roads and many bridges...only I-80...US 
  395...Keystone and Wells bridges are open. 
* Flood history...This crest compares to a previous crest of 13.5
  feet  on December 31 2005.


&&

LAT...LON 3954 11996 3956 11977 3945 11976 3946 11983 3950 11996


$$

NVC029-031-100040-
/O.EXT.KREV.FL.W.0003.170108T2337Z-170110T1715Z/
/VISN2.3.ER.170108T2337Z.170109T1500Z.170109T2315Z.NO/
1040 AM PST SUN JAN 8 2017

The Flood Warning continues for
  The Truckee River At Vista.
* FROM THIS AFTERNOON TO TUESDAY MORNING.
* At  9:15 AM Sunday the stage was 8.2 feet.
* Flood stage is 15.0 feet.
* Moderate to Major flooding is forecast.
* Forecast...Rise above flood stage by Sunday afternoon and continue 
  to rise to near 21.3 feet by Monday morning.the river will fall 
  below flood stage by Monday afternoon.
* Impact...At 21.5 feet...Major flooding from US Highway 395 in Reno 
  to Nixon including Truckee Meadows...Sparks...Lockwood...Tracy and 
  Wadsworth. Significant property, infrastructure and transportation
  damage. Sparks industrial area flooded up to 7 feet deep. Water
  may approach the Reno Airport.
* Flood history...This crest compares to a previous crest of 20.4
  feet  on December 31 2005.


&&

LAT...LON 3954 11979 3989 11937 3967 11924 3957 11933 3943 11976


$$

CAC035-100040-
/O.EXT.KREV.FL.W.0007.170108T2224Z-170110T0320Z/
/SUSC1.1.ER.170108T2224Z.170109T0500Z.170109T0920Z.NO/
1040 AM PST SUN JAN 8 2017

The Flood Warning continues for
  The Susan River At Susanville.
* FROM THIS AFTERNOON TO MONDAY EVENING.
* At 12:00 AM Sunday the stage was 4.7 feet.
* Flood stage is 12.0 feet.
* Minor to moderate flooding is forecast.
* Forecast...Rise above flood stage by Sunday afternoon and continue 
  to rise to near 12.9 feet by late Sunday evening. The river will 
  fall below flood stage by early Monday morning.
* Impact...At 12.5 feet...Minor to moderate flooding in Susanville 
  from Lassen Street downstream along Riverside Drive. Several homes 
  along river affected...especially on Carroll Street. Moderate 
  lowland flooding below Susanville in Johnstonville...Leavitt 
  Lake...Standish and Litchfield areas. Rural roads and bridges begin
  to flood in these areas.
* Flood history...This crest compares to a previous crest of 13.3
  feet on December 2 2012.


&&

LAT...LON 4044 12085 4054 12065 4036 12039 4024 12045 4042 12088


$$

CAC063-100040-
/O.EXT.KREV.FL.W.0008.170109T2100Z-170111T1900Z/
/MFTC1.1.ER.170109T2100Z.170110T1100Z.170111T0100Z.UU/
1040 AM PST SUN JAN 8 2017

The Flood Warning continues for
  The Middle Fork Feather River Near Portola.
* FROM MONDAY AFTERNOON TO WEDNESDAY MORNING.
* At  9:30 AM Sunday the stage was 4.9 feet.
* Flood stage is 8.5 feet.
* Minor flooding is forecast.
* Forecast...Rise above flood stage by early Monday afternoon and 
  continue to rise to near 9.4 feet by early Tuesday morning.the 
  river will fall below flood stage by Tuesday afternoon.
* Impact...At 9.5 feet...Minor to Moderate flooding of
  lowlands...roads and low-lying structures in reach from
  Beckwourth to Sloat including Portola. In Portola...Sleepy Pines
  Motel on highway 70 begins to experience some minor flooding.
  South end of West Street floods...nearing lowest homes. The river
  reaches within about a foot of foundation of Veterans Hall. 
  Highway 89 near Clio flooded.


&&

LAT...LON 3988 12071 3983 12038 3981 12039 3972 12058 3985 12072


$$

CAC003-NVC005-092300-
/O.EXT.KREV.FL.W.0005.170109T0300Z-170109T2300Z/
/CEMC1.1.ER.170109T0300Z.170109T0300Z.170109T0500Z.UU/
1040 AM PST SUN JAN 8 2017

The Flood Warning continues for
  The East Fork Carson River Below Markleeville.
* FROM THIS EVENING TO MONDAY AFTERNOON.
* At  9:00 AM Sunday the stage was 5.8 feet.
* Flood stage is 8.0 feet.
* Forecast...The river is expected to rise to near flood stage Sunday
  evening.
* Impact...At 8.0 feet...Flood stage. Minor lowland flooding in Carson
  Valley. Some low roads...bridges...drainage structures sustain 
  minor damage. Cottonwood Slough begins to flood Lampe Park. Flood 
  prone areas include Washoe Indian Reservation...Carson Valley 
  Country Club...Glenwood Dr...Riverview Dr...Centerville Rd...NV Hwy
  88...Westwood Village...Rocky Slough...Waterloo and Mottsville 
  Lanes.


&&

LAT...LON 3871 11977 3889 11978 3900 11983 3898 11970 3880 11966


$$

NVC001-005-019-510-100040-
/O.EXT.KREV.FL.W.0004.170109T2200Z-170110T1300Z/
/STWN2.1.ER.170109T2200Z.170109T2200Z.170110T0100Z.NO/
1040 AM PST SUN JAN 8 2017

The Flood Warning continues for
  The Carson River Near Carson City.
* FROM MONDAY AFTERNOON TO LATE MONDAY NIGHT.
* At  9:15 AM Sunday the stage was 3.6 feet.
* Flood stage is 10.0 feet.
* Forecast...The river is expected to rise to near flood stage early 
  Monday afternoon.
* Impact...At 10.0 feet...Flood stage.  Minor flooding of lower 
  portions of flood plain from Genoa to Fort Churchill, Nevada, 
  including Carson City and Dayton.  River begins to go out of banks 
  at this stage.  Several homes begin to have flood problems in 
  Genoa, Carson Valley, Stewart and Dayton.  Minor to moderate damage
  to agriculture.


&&

LAT...LON 3900 11984 3924 11973 3940 11921 3933 11907 3898 11978


$$

CAC003-NVC005-081910-
/O.CAN.KREV.FL.W.0009.000000T0000Z-170110T0100Z/
/WOOC1.N.ER.000000T0000Z.000000T0000Z.000000T0000Z.NO/
1040 AM PST SUN JAN 8 2017

The Flood Warning is cancelled for
  The West Fork Carson River At Woodfords.
* At  9:30 AM Sunday the stage was 10.9 feet.
* Flood stage is 14.0 feet.
* Forecast...The river will crest below flood stage with a value of 
  12.8 feet late Sunday evening .
* Impact...At 13.0 feet...Monitoring Stage...no flooding occurs.  
  However...residents along the West Fork Carson River should be 
  prepared for flooding if there are additional rises due to snowmelt
  and/or rainfall runoff.

&&

LAT...LON 3877 11985 3900 11983 3896 11978 3881 11974 3875 11983


$$

CAC051-081910-
/O.CAN.KREV.FL.W.0006.000000T0000Z-170109T2200Z/
/WWBC1.N.ER.000000T0000Z.000000T0000Z.000000T0000Z.NO/
1040 AM PST SUN JAN 8 2017

The Flood Warning is cancelled for
  The West Walker River Near Coleville.
* At  9:30 AM Sunday the stage was 3.1 feet.
* Flood stage is 6.0 feet.
* Forecast...The river will crest below flood stage with a value of 
  4.7 feet late Sunday evening .
* Impact...At 5.5 feet...Monitor Stage...no flooding. Reach: West 
  Walker River Canyon and Antelope Valley CA including 
  Walker/Coleville/Topaz CA.  


&&

LAT...LON 3839 11947 3859 11953 3868 11954 3859 11941 3837 11945


$$

Area Forecast Discussion
National Weather Service Reno NV
736 PM PST Sat Jan 7 2017

.UPDATE...

Below freezing temperatures persist over much of the Basin and
Range...the Mason Valley...the area from Dayton to Silver
Springs...the area from the Mammoth Lakes airport to south of
Crowley Lake...and from just west of Susanville southeast along
the Highway 395 corridor to Doyle. Freezing rain has recently
been reported west of Susanville and snow around the Mammoth Lakes
airport. All of these have in common a lack of significant wind.
Across the Basin and Range and south of Yerington little...if
any...precipitation is currently falling.

As the push of moisture starts to increase later tonight
precipitation will over spread much of the region. These valley
areas that are still below freezing are likely to see periods of
freezing rain. The Winter Weather Advisory for Mono County will be
extended until 4 am and a mention of freezing rain was added to
the forecast. The advisory for northwest Nevada...the Surprise
Valley and the Basin and Range will remain in place until 4 am.
Forecast soundings show Cedarville changing back to snow early
tomorrow. The temperature there is 44 now. Is is doubtful they
will change over completely to snow. Forecast soundings keep a
freezing or snow profile in the Basin and range in the morning. AS
wind increase ahead of the next precipitation surge many of these
locations will start to mix out and rise above freezing.

Elsewhere...snow levels remain in the 8500 to 9000 foot range in
the Sierra and far western Nevada. These may fall briefly as
heavier precipitation moves in late tonight...but then rise by
morning to 9000 feet or better.

We will have updates out soon incorporating the most recent
information. 20

&&

.PREVIOUS DISCUSSION... /Issued 639 PM PST Sat Jan 7 2017/

UPDATE...

Winds have increased on the western edge of the Surprise Valley
this evening and now Cedarville is 43 degrees. There may still be
a few pockets of below freezing temperatures in that area so we
will keep a mention of freezing rain for a few more hours.
Valley locations southeast of Susanville...around the Lovelock
and Fallon areas...and around the Mammoth Lakes airport and
Crowley Lake are also below freezing. That means a continued
threat of light freezing rain in those areas.

Elsewhere...snow levels in the Sierra have climbed to between 8500
and 9000 feet. Showers continue this evening then rain will
increase in intensity and coverage overnight. Even the lower
valleys in western Nevada and Mono County should rise above
freezing by morning. There are still Winter Weather Advisories in
Mono County and parts of the Basin and Range tonight. These will
continue for now. 20

PREVIOUS DISCUSSION... /Issued 324 PM PST Sat Jan 7 2017/

SYNOPSIS...

Wintry mix today will transition to heavy rain and heavy high
mountain snow in most areas tonight, with extreme amounts of rain
Sunday through early Monday. Significant flooding is expected for
mainstem rivers, creeks, and streams Sunday into Monday. Another
atmospheric river event is looking likely for the middle of next
week with a couple of colder storms to follow the end of next
week.

SHORT TERM...

* Significant Atmospheric River event begins tonight lasting
  through Monday morning.
* Widespread flooding anticipated areawide Sunday into Monday.
* Freezing rain possible in valleys below 5500 feet through
  tonight north and east of a Surprise Valley-Lovelock line.
* Poor conditions for travel and other outdoor activities this
  weekend.

Moisture spreading across the region this morning brought a wintry
mix to most areas with snow, ice pellets, and freezing rain being
reported. This rapidly transitioned to all rain in the Tahoe Basin
with other valleys slowly mixing out as well. The only exceptions
at this point are much of Mono County and north central Nevada
mainly north and east of a Surprise Valley-Lovelock line where
cold air is staying trapped in the valleys. Therefore have
dropped the Winter Weather Advisories for all areas outside of
these. A wintry mix remains possible with the most likely location
for ice accumulation in north central Nevada where the coldest air
remains.

Snow levels will continue to rise this evening into Sunday as the
deeper moisture and warmer air arrives. Snow levels are
forecast to peak by early Sunday morning, then remain steady
through Sunday night. This will coincide with the most intense
precipitation. North of I-80 we're looking at snow levels near
8000 feet, near 9000 feet for Reno-Carson-Tahoe, and 9000-10000
feet south of US-50 including Mono County. Snow levels look to
gradually come down Monday morning into the early afternoon. With
the lowering snow levels, snow is expected to impact travel
across all Sierra passes by midday Monday, possibly even into
western Nevada valleys by Monday night. With plenty of standing
water, and then snow falling on top and temperatures dropping
below freezing, travel will be hazardous Tuesday morning,
especially for areas above 5500 feet.

Liquid totals along the Sierra Crest through the foothills west
of US-395 could easily reach 6 to 12 inches over the course of
the event. Along US-395, rain totals could reach 3 inches with up
to 2 inches possible for areas to the east. Snow totals above the
snow line could easily reach 3 to 8 feet with the character of the
snow being very heavy and wet. Avalanche danger high and an
Avalanche Warning has been issued in collaboration with the Sierra
Avalanche Center. Backcountry activities are strongly discouraged
throughout the weekend.

As far as winds, they will be strong and gusty across ridge lines,
as 700 mb winds peak out between 70 and 80 mph. This will lead to
gusts across ridgelines in the 100 to 140 mph range. Lower down,
winds are not anticipated to be as strong with gusts mainly in the
20 to 35 mph range at most. However, a few periodic stronger
gusts are possible, especially tonight into Sunday.

A second system is right on the heels of this first storm, with
snow likely to continue in the Sierra and northeast California
through the middle of the week when yet another storm arrives.
Precipitation will be more showery in western Nevada, but will
still continue as well. More details on the midweek atmospheric
river in the long term forecast. -Dawn

LONG TERM...Tuesday through Saturday...

* Moderate atmospheric river with additional feet of snow expected
  in the Sierra Tuesday through Wednesday.

* Much lower snow levels: no additional river flooding expected with
  only minimal nuisance flooding possible below 6000 feet.

The GFS and EC have some differences with regards to the next AR for
Tue-Wed, but the general idea remains the same. This next one will
be not nearly as as strong, and it will also be colder with snow
levels remaining at or below 6500-7000 feet. The system could bring
stronger winds with it, especially below ridges, but given the
extensive/deep moisture and mainly unfavorable atmospheric profiles,
winds shouldn't be unusually strong. GFS simulated soundings do
indicate brief periods in the Sierra front on Tuesday and Wednesday
where stronger winds could mix down (gusts perhaps 40-55 mph...
strongest foothills) but winds are not expected to be overly strong
for the western Great Basin.

The Tue-Wed storm is coming in two parts with the first part Tuesday
and colder before the stronger, wetter and slightly warmer wave
arrives Tuesday night into Wednesday. The first part will be in the
form of warm air advection, with the wetter and stronger portions
with the core of the atmospheric river. For Tuesday through
Wednesday, another 18 to 36 inches of snow in the Sierra above
7000 feet looks good with around 10 to 20 inches down to 5500 to
6000 feet in northeast California from about Highway 50 north.
With atmospheric river moisture transport solid even inland over
western Nevada, there will be plenty of precip below 5500-6000
feet into Western NV but it looks to be mostly rain. With the much
lower snow levels, flooding should be restricted to the localized
nuisance variety for western NV.

Wednesday night and Thursday, simulations bring in yet another
disturbance. That wave is shown to be colder still than the Tuesday-
Wednesday wave, with a chance for a few inches of snowfall on the
lower valley floors...and perhaps another 6 to 12 inches in the
Sierra. The track of the disturbance is still wobbling around this
far out in the forecast period so any accumulations on the lower
valley floors are quite uncertain for now. Snyder

AVIATION...

Valley cold air has mostly scoured out for the northern Sierra and
far western NV (including KTRK/KTVL/KRNO/KRTS) and road/tarmac
temperatures have risen above freezing this afternoon. Still,
pockets of air remain in the upper 20s to lower 30s (KMEV/KCXP) may
cause a concern for freezing of light rain and drizzle on airframes
for another couple hours.

For lower valleys in far northeast CA (KSVE), out in west-central NV
(KLOL/KNFL), cold air remains trapped near the surface. For areas
near and northeast of a line from the Surprise Valley to
KNFL/Highway 50, the cold air will be difficult to scour out
tonight with -PL and/or -FZRA a distinct possibility into Sunday
morning. For KMMH and the Long Valley area, snow is expected to
mix with and change to rain this evening as a stronger warm air
push moves into that area.

During the day Sunday, we are still expecting heavy rain to affect
all terminals with ponding of water an issue through evening, then a
changeover back to snow is possible from 06-12Z for the Sierra
terminals. SFC Winds are not expected to be much of an issue with
peak gusts 30-35 kts. There will be mtn wave turbulence, but LLWS
is not expected to be significant due to the heavy precip.

For KRNO, there is the possibility of some flooding from Steamboat
and Dry Creeks backing up on the SE portion of the airport for
Sunday afternoon (after ~21Z) and Sunday night.

More impacts are likely Mon-Wed with periods of rain and snow, with
heavy snow possible for Sierra terminals. LLWS and mtn wave
turbulence are also more likely for the Tuesday period.
Snyder/Wallmann

HYDROLOGY...

* High confidence in flood impacts similar to the flood of December
  31, 2005 along the Susan, Middle Fork Feather, Truckee, Carson,
  West Fork Walker and their tributaries.
* High risk for flooding near creeks, streams, urban areas, and
  farmland and burn scars.
* Flood preparations should be completed by this afternoon.
* Intense rain arrives Sunday and Sunday night.

Well advertised atmospheric river is moving into the region with a
period of intense rain and high snow levels tonight to Monday
morning. Even after the rain ends, flood impacts will continue into
Tuesday.

Snow changed over to rain by 10 am around the Tahoe Basin with snow
levels near 8000 feet. Flows are starting to increase on small
creeks with rainfall amounts less than 1/2 inch. Soils are saturated
and it won't take much rainfall to generate flood impacts across the
Sierra and western Nevada. Minor flood impacts could start very
early Sunday morning in some locations, but the big issues will
occur Sunday afternoon into Monday. Flooding is much more difficult
to see at night so those thinking about traveling tomorrow night
should stay home.

Total rainfall amounts from Saturday night through Monday remain on
track with 6-12 inches for areas west of Highway 395 including
Mono County, the Tahoe Basin, Lassen County, Plumas County, the
Carson Range and Reno/Carson City foothills. Farther east in the
lower valleys, 2-4" are possible with 1-2" for the Highway 95
corridor.

The recent 4-8 feet of snow in the higher elevations of the Sierra
will play a role by initially absorbing quite a bit of rain with
some melt off possible. Another factor to add to the mix is the
recent snow at elevations below 6000-7000 that will melt and run
off. Something to keep an eye on, as how this plays out could impact
the severity of the flood impacts. Brong

&&

.REV Watches/Warnings/Advisories...
NV...Winter Weather Advisory until 4 AM PST Sunday NVZ004-005.

     Flood Watch from 4 AM PST Sunday through Monday afternoon
     NVZ002-003.

     Flood Watch from late Sunday night through Tuesday afternoon
     NVZ004.

CA...Flood Watch through late Sunday night CAZ071.

     Winter Weather Advisory until 4 AM PST Sunday CAZ070.

     Flood Watch from 4 AM PST Sunday through Monday morning CAZ073.

     Winter Weather Advisory until 4 AM PST Sunday CAZ073.

     Flood Watch from 4 AM PST Sunday through Monday afternoon CAZ072.

&&

For more information from the National Weather Service visit...
http://weather.gov/reno