Flash Flood Warning and Burn Scar Risk:-
Trekking summer storms and snow.We have storms in the foothills and Sierra and some high elevation snow. Let’s get to those storms first because we’ve actually had a flash flood warning go into effect over the park fire burn scar.
You can see the area right here shaded in red. This is gonna last until midnight with the potential of debris flows. Now, that’s very possible because of the terrain is very vulnerable with the amount of rain that we’ve been seeing the excessive rainfall flowing over. That terrain could cause some mud rock or other land sliding debris flows in that region.
Flash Flood Watch and Thunderstorms:-
We’ll be tracking that through tonight. Here’s a look at the flash flood watch also in effect around that burn scar here, multiple rounds of heavy rainfall. Even a thunderstorm just on the west side of that burn scar here, moving towards Red Bluff right now has been possible because of our low pressure system kind of circulating its way through the state as we expand the view.
You can see how those rain showers generally start to become much less intense moving through the Tahoe Basin and then south of highway 50 in the higher elevations, it actually turns over to snow. Some of the white that you’re seeing here pop up on the radar in the central Sierra. Uh Meaning that we’re seeing some of that high elevation snow.
Snow in Higher Elevations:-
These are some of the highest peaks actually in the Sierra Chain. And that’s why we’re seeing the potential for more active weather in regions around this winter. Weather advisory in place through tomorrow evening, above 8500 ft, 1 to 4 inches of new snow possible at the higher peaks could see even higher amounts of that snowfall in terms of our rain.
Rainfall Totals in the Valley and Foothills:-
It’s been a struggle to get anything in the rain bucket here throughout the valley. We’ve seen some areas of about 2, 1/100 of an inch to about 8, 1/100 of an inch all in all. We’ll call it less than 1/10 of an inch for all locations throughout the central valley and the foothills. But for here, you’re seeing over a half an inch of rain for South Lake Tahoe temperatures.
Forecast for Tonight and Tomorrow:-
They are hovering in the fifties and even low sixties at times. Those are some of the lower peaks in the Sierra. Whereas south of highway 50 once we get into the central Sierra, that’s where we really see some of those uh peaks going as far as about 9000 and above 10,000 ft as far as our future cast for this evening, we’re going to see rain starting to taper off just a few early morning showers in the Tahoe Basin.
There’s a look at that park fire burn scar. You can see up here towards Butte County and that’s where we’re seeing the potential for the more active and dangerous weather developing there. But things are quiet actually, for tomorrow, as we turn our attention to tomorrow afternoon, you can see how some of those isolated thunderstorms once again popping up south of highway 50 a few flurries possible in the Sierra, moving into the early evening hours, we’ll still see areas of some light rain occurring
in the 8050 corridor and just south of highway 50 some more snow showers there near Yosemite and Mammoth Mountain. As far as the valley, the best chance of seeing some of those showers are gonna be on the east side of the valley and then through the northern San Joaquin Valley because the rotation of that low kind of moving its way through the state.
But by Thursday evening into Friday, we start to clear things out. So why is this even significant? Well, it’s because the last time we really saw significant rain and snow was in early May. It’s been several months since we’ve had really measurable rain half an inch or so for downtown Sacramento when we had that May 4th storm roll through and over 26 inches of snow at the central sea or a snow lab there at Soda Springs.
Dry Summer and Growing Drought:-
So drought tends to grow in the summer months. You can see just in a period of a week. We went from a drought severity and coverage index of 63 right here at the bottom of the screen on September 5th on September 18th, that grew to 82. So we’ve seen significant drought in some areas growing not so much in California, but just there on the tip, it’s right here.
Reservoir Levels Above Average:-
It’s where we start to see some of the severe drought growing. It’s not much. But again, with that severity and drought index growing, we’re gonna keep an eye on that, especially as we start to head towards the end of the water year as far as our reservoir levels. That’s a key indicator by the way of drought in California, this is where we hold a lot of our water.
About a third of our water comes from uh snow melt and enters into these reservoirs. We’re above average for almost every reservoir except for Folsom a little bit below average here, but almost every reservoir right now continuing to kind of empty things out serve the state with the water that we need, given that we haven’t had rain since early May and then also uh get ready for the new water year and some of the new water that will be moving into these reservoirs as we move our way through the central valley again,
all of our reservoirs above average, but starting to look very thin at this point in the season. Current uh storage level for Folsom Lake you can see is a little bit below average here in the teal shade. You can see how we really start to peak here during the uh beginning of the summer season. And then we start to empty things out as we’re, our water needs go up during the dry part of the year and we don’t put anything new in there given that the snow has already melted and we don’t see much in the way of precipitation coming our way.
Water Year and Precipitation:-
So, not much in the way of rain run off either. Here’s a look at our statewide precipitation. We started this last October just kind of tracking how much water we’ve seen through the year. We’re gonna wrap things up on September 30th. So just about a week and a half from now and we’re a little bit below average.
We could put more in the rain bucket. But the way that I’m gonna show you, the climate trends are trending towards drier and warmer heading into next week. The first fall rain typically hits us on October 7th with at least 1/10 of an inch of rain. The latest day that we’ve had 1/10 of an inch or more is December 11th.
So we can go all the way until the beginning of December before we start to see really putting some significant rain in the bucket here. The first day, last year that we had 1/10 of an inch or more was October 10th. So we’re pretty close to right on target there for our first fall rain. So far. This year, we have not had anything for the month of September.
At least for downtown Sacramento. We had a couple of sprinkles here or there, but nothing measurable. We only average about 15/100 of an inch of rain. So it’s not that big of a deal if we don’t get anything in the month of September temperature wise, kind of a mixed bag here. We’ve seen anything from a high of 104 to a high of 74.
It’s a wide range in the month of September as we start to really start to see that transition zone again, a few showers possible for tomorrow afternoon, mainly right along that Sierra Spine and through parts of central California. But once that low starts to move its way out here comes the big ridge of high pressure warming back and the outlook by Sunday and early next week, we’ll start to see a little bit in the way of heat risk developing across the bay area in that moderate range that’s going to expand in through the central valley from Monday into Tuesday. We’ll see a few areas that are gonna be flirting with a high of 100 with a likely warmer scenario. To wrap us up for the month of September and head into the beginning of October and a likely drier set up for us as well throughout much of the west. The numbers for tomorrow highs in the sixties for this year, seventies and eighties down low with highs in the sixties across the coast.
Temperature Trends and Heat Risk:-
We move inland. We’re getting to highs in the eighties and we’ll expand that through the valley again. A little bit more cloud cover for the northern San Joaquin Valley. So for places say around Stockton and southward, we’re looking at low to mid eighties. Once we head north of I 80 we’re a little bit closer to around 90 Kusa Yuba City and woodland included in that set up our five day regional forecast.
We’re gonna clear the clouds and bring in some warmth here for the mountains. Highs will be warming into the mid seventies by Sunday and Monday as we’re welcoming in fall, highs in the foothills will be close to 90 on Sunday, low nineties on Monday and even for the coast, highs are getting into the low eighties on Monday afternoon.
So our three day forecast starting to showcase some of the building warmth here by the beginning of the weekend, high near 90 by the end of the week again, mid nineties, upper nineties on Tuesday, that’s gonna be the peak keep, but you can see we’re not done there. We’re gonna keep it right around the low to mid nineties all the way through the end of next week into the beginning of the next weekend.