Mammoth Mountain & Eastern Sierra Weather Forecast

Mammoth Mountain & Eastern Sierra Weather Forecast

Mammoth Mountain & Eastern Sierra Recreational Weather Forecast

Wednesday, October 6th, 2021 @ 8:42 AM

Good morning, checking the window cast we have moderate smoke and haze in the area from Mammoth Lakes to Bishop.

Taking a look at local conditions the last couple of days. Yesterday at the top of Mammoth Mountain there was a high of 45, the low this morning was 30. The peak wind gust on Tuesday was 25 MPH out of the WSW. This morning’s peak gust has been 31 MPH out of the WSW.

In Mammoth Lakes, the temperature peaked at 61 degrees on Tuesday with a low of 46 degrees this morning. Winds in town have been out of the WSW with peak gusts of 10-15 MPH on Tuesday.

Down in Bishop on Tuesday, there was a temperature of 82 degrees with a low of 46 degrees this morning. Winds have been light in the Bishop and Round Valley areas.

Precipitation and Snowfall: Thursday there is a chance of rain and snow with snow levels at 9000 rising above 9500 feet during the day. Thursday night into Friday evening look for snow showers with 1-2+ inches of wet snow possible above 8500 – 9000 feet.

Temperatures:  As we go thru the week temperatures will be coming down a good 10-15 degrees by Friday, with more cooling this weekend. Looks like below-average highs will be with us into mid-month.

Mammoth Mountain and the Mammoth Lakes Basin area for Wednesday highs will be in the low 50s with upper 40s for Thursday. 

Mammoth Lakes today will have highs in the upper 60s to near 70 with night times lows in the upper 30s to low 40s.

Bishop and Round Valleys look for highs in the low 80s today with nighttime lows in the mid-40s.  Wednesday and Thursday highs will be in the 70s and then 60s on Friday and Saturday.

Winds: Southwest wind 10 to 15 mph, with gusts as high as 30 mph with high gusts over the higher elevations and ridgetops.

Here are the links to the local NWS Forecasts for Main Lodge & the Mammoth Lakes BasinMammoth LakesJune LakeCrowley Lake, and Bishop.


Today’s Weather Story and The 10 Day Outlook​

10-6-21 @ 7:08 AM The Weather Story

Two weather systems are forecast to affect Eastern Sierra weather over the next week. The first system will start to effect us today with a shift and increase in the winds. Those winds will start to blow out all the smoke in the area.

On Thursday and more likely on Friday the higher elevations above 7500 – 8000 feet will get snow showers and their first real accumulated dusting of snow for the season. Not looking for much more then 1-3 inches of snow as of this mornings update.

The second system is dropping in over land and is not forecast to bring much more then a dusting of snow to an inch at best. If there is a course change there could possibly be more snow early next week. The main effects will be colder air from that system.

In the gif below you can see the whole process of lows 1 and 2 over the next 7 days.

Taking a closer look at the next week. The first system is a cut-off low that is forecast to pinch off from the main low hitting the Pacific North West at this time. You can see that cut-off low pinch of and form on the gif below.

The cut-off low will work its way inland Thursday into late Friday. The best chance for accumulating snowfall from the first system will be Friday as the colder air has moved in along with some convective activity going on during the day.

Snowfall amounts will be in the 1-2+ inch range for the higher elevations with the snow a heavy wet slush.   

QPF amounts are in the .10-.30 range with a chance for a bit higher amounts. This is a cut-off low so it can be the weather man’s woe tricking us and doing what it wants and not what we forecast.

Here are the snowfall amounts that are foretasted on the EPS Ensemble Mean. The Mammoth Mountain Summit is right on the first blue line. That’s right at 2 inches of snow with most of it from the first system moving in. Don’t be surprised if there is more snowfall then the couple inches in the forecast.

Over the weekend the low will move to our east on Saturday and there will be a north to northeast flow in the area and that will keep the Eastern Sierra nice, clear and cool.

Looks like a good chilly weekend to take in some Fall Colors with some snow on the local area peaks. Look for higher elevation leaf burn with the snow and freezing temperatures above 9000 feet.

There will be a slight warm-up in the area on Sunday a head of the next system coming in.

The second low drops down into the area with a path from the direct north, overland. That is a dry but very cold pattern. Not expecting much snowfall over a dusting with that one.

Tuesday is a long ways off so be aware that this lows path is going to change a bit over the next several days. Snowman

Going to stay nice and cool for the next 10 days and beyond. Soon there will be temperature section set up in here so You can take a daily look at the Snowmaking opportunities for the Mammoth Mountain Ski Area.

Fantasy Long Range Weather Outlook

Back in October 2004 we had on of the greatest early season starts ever. The Weatherguy sent me the Mojo images back from 2004 this week and compared them to this year at this time. Let’s hope this years pattern delivers some decent snowfall after mid October like that seasons storms did. We all could use a decent early season base to get started this season. Turns get everyone smiling. 🙂 

Updated 10-6-2021 @ 8:49 AM

ECMWF Seasonal Ensemble Mean – Monthly Update from 10-1-2021

Mammoth Mountain and Eastern Sierra Weather Posts

Who Are We?

Steve Taylor – Mammoth Snowman Over the last 30+ years, Snowman has spent countless hours studying and learning about Mammoth Mountain Weather and Snow Conditions first hand. He has been skiing around the hill with marked ski poles since March of 1991 so he can measure the fresh snowfall amounts out on the hill. 

Snowman started blogging this information back in 1990 on the old Mammoth BBS system, then the RSN Forums and then on to in 2004 with Video & Photo Blog report. (No YouTube back then). Facebook got added to the fold back in 2008 and then the Facebook Group in 2016. 

Reports, videos, and photos from the website have been featured on both local TV Stations here in Mammoth, along with AP, Fox, ABC, CBS, and NBC News.

Ted Schlaepfer – Mammoth WeatherGuy – The Powder Forecast – Posted Tuesday and Fridays at 5 PM November into Mid May. These forecasts are now responsible for many people getting multiple powder days on Mammoth Mountain over the years.  

Ted’s Bio: Ted has been a full-time Meteorologist (CCM) for the past 25+ years. He has always been fascinated with the weather,” skiing was just a natural extension of my love for snow and rain. I started skiing at age 5,  first discovered Mammoth in 1979 as a youth, and have been a regular visitor since the late ’80s.”.

Here is the link to The WeatherGuys Powder Forecast Page. 

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