Nov 12: Western Rain & Snow, November Warmth, NE Rain

The West will be where most of the active weather is through the rest of the week as a slow-moving upper level low cuts off across the Southwest, pumping moisture into the region, especially California:

Much of the entire region will receive beneficial rain and mountain snow:

Due to the position of the upper low, Southern California will actually receive some of the biggest amounts with over 3" possible across the normally dry region:

In fact, starting on Thursday, the state has a chance of flash flooding each day:

While the rainy season has begun across the west, it is still a bit early for this significant rainfall across southern California. Take a look at the monthly average rainfall for Los Angeles for example, it is typically highest in January and February with November typically average less than an inch of rain:

  We have several stations across southern California to watch the storm and even one in the foothills of the Sierra, track the conditions:

https://oxnard.weatherstem.com

https://calaveras.weatherstem.com/bretharte

It will take awhile for any of this Western storminess to make it to the Eastern US but there will be a sneaky system that streaks across the Northeast this weekend with rain, snow, and even some icing possible. The image below is valid at 1 am Sunday morning and shows the widespread precipitation types possible:

So why is there ice possible? Let's take a look at a forecast upper-air sounding for a Saranac Lake, NY Early Sunday AM. There's a warm layer of air aloft where any precipitation would melt followed by a shallow layer of below freezing air at the surface which would allow the precip to refreeze, either as sleet or freezing rain:

Continue to monitor the forecast for that region as freezing rain can cause way more problems than an inch of snow will!

Across the rest of the country, the big story will be the mild temperatures. Below is the 7 day temperature anomaly from Nov 13 - Nov 20 with widespread above average temperatures expected everywhere except the Northeast:

But there are signs that December will usher in a period of colder weather. In the extended forecast for the first full week of December, much of the country is below average:

That's a long way from now but if you look at the last 15 model runs for that week, the trend is for the temperatures to be colder: 

As we head into the Winter months, we will track the potential for cold weather outbreaks and snow. Signs are pointing to Winter getting off to a hot start right out of the gates, so stay tuned!