00:00In the forecast feed, we're going to take you west as a powerful Pacific pipeline, the Pineapple Express, returns to
00:06Southern California, bringing rain and some snow to the high elevations of the west this weekend.
00:12We'll look at that. This will eventually kick off some severe weather next week in parts of the south-central
00:16U.S.
00:17Before we dial in exclusively on the west, I wanted to at least give us a chance to briefly look
00:23at three big headlines, three things to know for the weekend, and two-thirds of this are focused on the
00:28west.
00:28But briefly, the northeast dry spell, you know, there was a time when it appeared the interior northeast might begin
00:35to see some rain on Sunday, Sunday night, Monday.
00:38That system is trending farther west and drier, and the dry spell will continue in through probably at least Wednesday.
00:46I don't think we're going to see rain for the big cities of the northeast until Thursday of this coming
00:50week, about a week from now.
00:52So the northeast dry spell continues this Halloween weekend. We're going to fall back. Don't forget to do that with
00:57the clocks.
00:57But a flood risk returns to the desert southwest, initially through Southern California, then into Arizona and beyond.
01:05And we will see a snowy start to November in the central Rockies.
01:09All right, let's get into it. I'm going to take you into the modeling here.
01:12And we have a ridge holding generally in the east here this weekend.
01:18A weak system moving through parts of the Midwest washes out.
01:21High pressure holds. That's going to keep us dry there.
01:24But in the west, big trough, we got low pressure in its various forms across the west.
01:31And that's going to be the big driver here that we really focus in on.
01:34And I know the bright colors, they look kind of ambiguous.
01:38The vivid colors here are a measure of, fancy word, vorticity, or spin in the atmosphere.
01:43And the takeaway here is that if you are near or east of those bright colors and a big trough
01:50in the west,
01:51if you're east of there, you're going to be in a situation where there's a lot of lift and rising
01:55motion in the atmosphere.
01:56We're looking at rain and snow.
01:58All right, so what's that look like here as this pivots through?
02:01Once the base of the trough exits your area by Sunday night, we're dry in Southern California.
02:06Monday, still stormy in the Rockies.
02:08This is coming initially.
02:10It's fueled by moisture from the Pacific.
02:14And this is a look at the precipitable water.
02:16If you took all the moisture in the atmosphere and squeezed it out, how much rain would fall.
02:21And the color scheme here is admittedly a little counterintuitive.
02:26The maroons are actually the really moisture-rich air.
02:29And if you look at this, I'm going to circle Hawaii on the map.
02:33Here's Hawaii.
02:36And there's Hawaii way out there to the west.
02:37Here we have California.
02:40And then we have Mexico here.
02:43And a lot of the eastern tropical Pacific.
02:47If we follow the moisture, look at this.
02:49The wind is directing moisture into Southern California that has DNA.
02:54It can be traced back to Hawaii.
02:56We call this the Pineapple Express.
02:58Sometimes it's oriented a little bit differently.
02:59But this does check that box.
03:01This moisture can be traced back to areas around Hawaii.
03:04And it really just sneaks into Southern California and then eventually gets diverted into Northwest Mexico.
03:09But it's enough that it does move rain into Southern California.
03:13Here we are Saturday morning.
03:15Saturday evening.
03:16Look at this.
03:17Rain returns to L.A.
03:19Sunday.
03:20And it's a quick shot.
03:21It's in and out.
03:22And then it moves in through the Great Basin.
03:24That's the GFS.
03:26Let's look at the NAM, another model.
03:28This one's pretty slim in Southern California.
03:29But it brings some showers there on Sunday morning.
03:32And then the European, a little more robust with that rain.
03:34Here we are Saturday evening, Saturday night, and into Sunday morning, soaking rain for Southern California.
03:41How much rain are we looking at?
03:43Well, if we look at the GFS only through Sunday evening, you can see the little fine print there, 0
03:49.6, 0.7, 6 or 7 tenths of an inch of rain in much of Los Angeles County, eastern Ventura
03:55County.
03:56Not a whole lot up there into areas near the Bay Area, a few tenths of an inch for San
04:01Francisco.
04:02But that would be the GFS.
04:04The NAM was real slim.
04:05Real slim in Southern California.
04:08If we look at this in the mountains and the slopes of the mountains, you get into the midgreen.
04:12It's like 3 to 4 tenths of an inch.
04:14But down near the coastline, with the exception of some of Orange County, well, some of L.A. County itself,
04:21it's a lot of us 3 tenths, 4 tenths of an inch.
04:23If we look at the European, though, look at this.
04:26Here we're getting up close to an inch of rain, 8, 9 tenths, into L.A. County and other areas
04:32around Orange County.
04:33And then into the foothills over an inch of rain for some.
04:36Here's a 1.4 and a 1.6 over parts of southern San Diego County, central San Diego County, into
04:42the foothills and also near Tijuana, Mexico.
04:45So pretty decent rain.
04:47And we take this back to our own forecast.
04:50That was a model product.
04:52But here you can see areas we're highlighting for flood potential.
04:55The highest flood risk is not in L.A. downtown, but it's into the foothills off to the east and
05:01areas around Cajon Pass along Interstate 15.
05:04We're also highlighting the high ground of central and north central Arizona.
05:08I-17 would be here between Phoenix and Flagstaff.
05:12That'd be a problem spot.
05:13By the numbers, this is perhaps more meaningful to you.
05:17We're forecasting under an inch of rain for at least parts of coastal L.A., but one inch plus into
05:24parts of the city, two to four inches for others.
05:26I wanted to quickly take a look at another thing that might be interesting to some of you.
05:29We're going to see some snow out there.
05:31It won't be a ton, but as we play this forward, you can see some snow populate the map.
05:36One to three inches for Donner Pass, four to eight inches into Tioga Pass.
05:40There will be some meaningful snow into the high ground of the Rockies as well.
05:44And again, a lot of this is going to be above 7,000 feet or so.
05:49Overall, this map here shows you the elevation or the altitude, more appropriately, at which, if it's in the sky,
05:58it's altitude.
05:58If it's a mountain, it's elevation, at which you're cold enough for snow.
06:02So the snow levels.
06:04Here we are in the West Coast, and the snow levels are relatively high, but we get into this.
06:09I'm tracing the 6,000 foot and 7,000 foot and 8,000 feet.
06:13If you're above 8,000 feet in South Central California, you're high enough for snow.
06:19If you're down in L.A. County, though, you've got to be above 9,000 or 10,000 feet, way,
06:23way up in the high summits.
06:24If we get into the interior, though, into Sunday and Monday, 6,000 feet might be the threshold there up
06:32into the north-central Rockies.
06:33So there are areas here where you can see some pretty good snow.
06:36It's going to be restricted to the high elevations.
06:38Elko, Nevada, for example, airports over 5,000 feet.
06:42You're going to see snow over 6,500 feet.
06:44But the high peaks, we'll see some snow as well.
06:47That's your forecast feed.
