We've been talking about the ner
historic snowpack in the Sierra
and the big snowmelt underway,
yet some reservoirs are still very low.
We're going to be in packing it.
I'm ABC10 Chief Meteorologist Ma
Woods in Northern California out
of the capital city of Californ.
Now the Department of Water Resources
recently increased releases out of Oroville.
It's one of our larger reservois
in the state.
It happens to be more in the
northern part of the state and
feeds into the Feather River.
So you can see the huge release.
Coming out of there,
that spray of water creating kif
that misty cloud over right offe
to it's right if you're looking at the
dam over to the right that is going to be,
this is the spillway that's goig
to be the dam right there and it
is the largest in the country.
So they got to be very careful
on how much water they hold.
In Oroville,
you might remember back in 2017 we had
the Oroville spillway situation where
part of it collapsed and it caud
great concern for downstream residents.
All right,
let's take a look at Millerton .
This is more towards the central and southern
part of the state that looks nearly empty.
That came from Valley Dumpster.
They were out there not necessay
for reservoir situation,
but they happen to snap these ps
where you can see how low everything is,
kind of that dry Creek bed there with
some of the sand starting to sh.
This is where the water would normally
be and it's incredibly low right now.
And the Millerton Lake area.
Is part of that whole conveyance area
that has the historic snow packn
parts of the central and southern Sierra.
So again you can see how
incredibly low that is.
Yet from Millerton Lake,
Bryant Dam is releasing
large volumes of water.
the US Bureau of Reclamation
increasing those releases to hep
manage storage in Millerton reservoir.
Now you may be thinking why are
they releasing that water is
barely anything in there well.
It's because of,
like I said,
that historic snowpack in the Sierra running
at about 235 to over 400% of average,
putting our statewide average at
over 300% for this point in the year.
All of that is eventually going
to melt down into the lower
elevations feeding into the riv,
the Kings, the San Joaquin.
And many others.
Tuolumne,
Mccollumne,
all of that will eventually move in through
the Central Valley and so managing that flow,
how much snow pack is coming ou,
how much the rivers can handle it and
all the rivers are not the same size,
so their channel capacity chang.
Wind dynamics from area to area.
The most vulnerable is going to be the
central and southern part of the state.
So we'll go over some of these
advisories for flooding as well as the
watches and warnings that are in place.
First of all,
we're going to go over the flood
warning in effect until
10:00 AM on Wednesday.
This is going to be the ongoing
flooding issues that we're seei.
And now we've got floodgate
releases happening, meaning riv,
Creek streams and flood prone locations will
continue to be flooding and sandbagging
operations will continue low wa.
Crossings also inundated with
water and may not be passable.
So this is going to be through the central
and southern part of the San Joaquin Valley,
extending all the way into the Corcoran area.
Right now we move a little
bit farther to the north.
This is going to be a flood advisory.
Again.
Floodgate releases happening ths
coming out of the Friant Dam into Miller,
out of Millerton.
And for downstream areas,
minor flooding of rivers,
streams and roads possible the
farther you go to the South.
The more difficult it is to
deal with the flooding once we
start moving our way up north,
we have bigger rivers and they
just can handle bigger flows
coming out of those reservoirs.
So some areas just aren't managd
with big upstream reservoirs.
And so everything coming down the hill
is basically going to have to se
into the lowest elevations or we
it finds capacity to just kind of settle in.
That is happening for the Merced River.
At Pahono Bridge at Yosemite,
we've been talking about the closures at
the east and for a couple of the campsites.
Now Yosemite is saying until further notice,
we're going to close those campsites.
Until Wednesday,
but it's very likely going to
continue and we're going to taka
look at why beautiful waterfall,
by the way.
In Yosemite, you can see the hue
rush of water coming down the h,
making for a beautiful sight th.
But once it gets downstream,
the rivers are incredibly high.
You can see the tree line right over here
and how high that water is coming up.
And then when you take a look
at some of the campsites, well,
this is just one of the structu.
There's the fence right there
and how high that.
Water is we've been hearing from
some folks that were saying,
yeah we were out there camping and got
out kind of just in time because
could almost see that water stag
to come up near the campground.
So it's just out of precaution
that you somebody saying,
all right let's just make sure t
people are safe where they're dg
some camping so they don't go to sleep
overnight and then suddenly it's
some of our their belongings ar.
Basically underwater in some pl.
So we've got 81 conditions that
are normal throughout the state,
but nine above flood stage.
We'll zoom in a little bit clos,
especially around the Yosemite
area and also right along 395 on
the West Walker River.
Farther up to the north,
we've got the Carson River that's going to
be on both the Nevada and California side.
That's getting awfully high.
And then of course,
we're talking about the Merced River.
So a look at how those flows kind of ebb
and flow throughout the course of the days,
you can see how it starts to Crest just.
After the afternoon hours and tn
start to recede as we head throh
the morning and then once the
daytime heating affects it agai,
we start to see those numbers go up back
into flood stage and at Pohono Bridge.
This is the one that we've been monitoring,
expected to get to that flood s.
By late tonight,
early tomorrow morning and then
continue to be kind of up and dn
pattern here but stay above flod
stage for the foreseeable futur.
So it's one of those situations we're just
going to have to monitor continually.
Part of this is due to these temperatures
throughout the state well above average.
Let's take Sacramento for examp,
our normal high this time of year 80 degrees.
Today we reached a high of 94.
We were 72 for South Lake Tahoe in places
like Palm Springs over 100 degr.
Now it's not necessarily a one to one ratio.
If we get the warm temperatures then we're
automatically going to see the snow melting.
There are other factors that come into
play and we're going to take a k
at some of those in just a mome,
one of which is going to be rai.
We have some thunderstorms occug
in through parts of the centrald
Southern Sierra and it's very ly
we'll see that once again for tomorrow.
It's appearing more like a summ.
Like pattern throughout the West with
a Ridge of high pressure over te
desert Southwest, the four corn.
And so with that clockwise circulation,
we just kind of take some of that moisture
that's occurring right now in Arizona,
New Mexico and pump it up through the Sierra.
So our snow melt is still roughly about 6
to 12 inches in about a three day period.
So cold water and swift current
certainly downstreams.
And everybody's being advised no
cross any flooded roadways because the
the amount of water that are one
roads is not necessarily apparent just
from the visuals coming from a vehicle
always wearing a life jacket as well.
And officials are saying even deep into
the season we may be talking about don't
even go on those waterways because of
how much snow is coming down the hill
and will continue to come down the hill.
A look at that snow comparison n
about the past month and now whI
want to point out here is just e
color contours that we were loog
at just about a month ago.
You can see how far it extends kind of
up and down the Ridge and that Sierra
spine going into the lower elevations.
Just about a month ago,
we actually had snow down to about 3000 feet.
So we were still putting a litte
bit of fresh powder in places in
the Sierra foothills.
Now compare that to our current
situation and we've not only lost a lot
of that snow water equivalent, .
A lot of that is occurring on te
lower elevations, the higher snowpack.
It's a little bit more difficult
to actually melt that down and l
out that snow water equivalent,
that water that is held within the snowpack.
You can see they're still trying to clear
areas in and around the Yosemite area,
but when we talk about the snowmelt process,
this is a little bit of the
flood signs that goes into it.
We'll start off with distributi.
It's the path of weather systems
that come through during our wir
and spring season and how they
accumulate because that has a big fact.
Those are big factors.
When we talk about where is
the distribution of that snow,
Is it in lower elevations that perhaps
it's going to melt off a little
bit quicker or is it in the higr
elevations that tends to have a
colder temperature profile throughout
the course of the spring season.
The characteristics of that sno,
what's the snow water equivalen?
Is it super high where once we
start to melt that snow,
we're going to get big volumes of water?
And what's the temperature of the snowpack?
That also plays a big factor
because if that snowpack is sup,
super cold inside,
it's got to get to at least aboe
32 degrees before it even starts
to melt into some of the.
Lower elevation streams, creeks and rivers.
Also the energy exchange.
What are the weather conditions surrounding
some of the snowpack weather fa,
Wind, dew point temperatures?
What are the ambient conditions,
the atmosphere conditions that are going
to be affecting it and also location.
Where does that water go?
Is there room for it to be stord
in the ground?
Is it going to percolate or is it going
to run off or does it become jammed with ice?
You know,
we have those big blocks of ice
and then it gets jammed up.
That could create a flood as we.
So it's a lot of different facts
that go into is it going to be flooding
based on the snowpack running o?
Let's take a look at when we combine.
Everything that I just talked a,
the reservoir storage and the snow pack and
pretty much anywhere you're going to look,
it's going to be well above ave.
This is the Western water stored across the
Western Sierra reservoirs in 28 locations.
When we break it down individuay
for Northern California,
running well above average,
you can see the orange line right here.
We'll look at Central Californi,
same situation.
A little bit higher above avera.
And then the Southern Sierra ist
where we have these huge numbers going on.
That is why when you saw those
pictures of Millerton Lake,
it is so very low.
They've got to make room for alf
this snow pack running down the hill.
Our Northern see our Northern California
reservoirs are really looking good and
they're staying super full right now.
Shasta is our biggest one
and it's at 98% full.
We are coming off of what was.
Near historic low numbers for te
Northern California reservoirs n
these numbers are looking super
healthy right now Orville at 96% full.
When we take a look at perhaps e
central and southern part of the state,
that's where these numbers
start to drop dramatically.
Only 67% full right now for new Melonis.
72 for Don Pedro San Luis,
which is shared by both the fedl
and the state water agencies,
is 98% full.
And again,
that's a great number right thee
because many people rely on the water
coming out of these reservoirs o
help them through the dry seaso.
This is where we really get
to some stark numbers.
Millerton and Pine Flat,
where you can see right here Pie
Flat flowing into the Kings Riv,
which has had huge flooding pros
with the Tulare Lake Basin 33% .
And that is again because they'e
got to keep that storage down to
make room for the snow pack and
the melting that will happen.
Now these are some interesting
lines that we've been following.
And what I wanted to point out is the 2016,
2017 year,
we did have flooding downstreamd
unfortunately some of those lev,
the earthen levees did fail.
Some of them have been reinforc,
but the lines for how the
reservoirs have been filling.
Are very similar.
Look at how we got to right around that
April first average and here wee
Lake Shasta filling at almost the same pace.
We'll take a look at the
Central Sierra at Don Pedro,
almost the exact same line here.
And you can see how those releases are
happening almost in the same fashion.
That is true as well for Pine F,
where we go up,
we peak and then the releases happen.
Looks like we'll see another
surge potentially coming our way
in about the next month or so.
What I mean to say here is water managers
pretty much know what they're d.
History sometimes does repeat itself.
And so all three phases
of flooding are happening.
Preparedness, response,
recovery,
financial help is not only
being given right now,
but also the agencies are workin
finding more financial help for everybody
that is affected by the floodin.
There's challenges and opportuns
with track traffic tracking that rapid
snow melt but also groundwater recharge,
which has been one of the
hardest hit areas of our water
portfolio throughout the state.
Under the Ridge of high pressur,
we're going to see continued warming,
the risk of thunderstorms in this era,
and very likely more rapid snowt
happening and flooding concerns growing.
Our highs are going to stay in the 90s,
well above average at least for
central California through Mond,
Little bit cooler by the following work week.