Mammoth Mountain & Eastern Sierra Weather Forecast

Recreational Weather for Mammoth Mountain and the Eastern Sierra

9-4-2022 @ 11:11 AM Good morning, time to take a look at the weather and what’s going on with the heat wave, when will it end, and what’s coming next weekend.

At this time there is a large dome of high pressure over the western us with the center of the high east of the Eastern Sierra region. This pattern will continue to be the main weather story right through the week now.

Expect highs at the Resort levels (8900feet) in the upper 70s with Mammoth Lakes in the low to mid-80s. Bishop will be hot into Thursday reaching the century mark each day.

Overnight lows for the High Country will be in the mid-50s with the High Deserts reaching into the low 60s well past midnight.

Winds this week will be light during the morning hours with afternoon winds in the 10-20 MPH range possible in all areas.

There will continue to be some isolated build-ups mainly south of Mammoth Mountain the next few days.

By next weekend there will be a return of the southerly flow with an increased chance of some rain showers and cooler weather. Read more below in the 10-Day Outlook sections.

Here are the links to the specific highs, lows, and wind speeds for many of the major recreation points in the Eastern Sierra: Mammoth Mountain Main Lodge, Top of Mammoth Mountain, Mammoth Lakes, June Lake, Crowley Lake, Toms Place, Rock Creek Lake, Bishop & Mill Pond, South Lake. 

Please Note: Fire Restrictions are in place on all National Forest Service and BLM Lands in the Eastern Sierra.

**Below is the EPS and GEFS ensemble weather model for early on Wednesday. This image shows the 589 MB high-pressure doom centered to the east of Mammoth Mountain and the Eastern Sierra.

Take notice of the tropical system off the Baja Coast as the remnants of this system just might get pulled north into California, the Sierra, and the Owens Valley. This pattern will continue to be the main weather story right through the week now.

Current Satellite View

10 Day Mammoth Mountain Weather Outlook

Sunday September 4th at 3 PM – The heat wave continues across the West with a 589 MB high-pressure doom that is centered to the east of Mammoth Mountain and the Eastern Sierra.

This pattern will continue to be the main weather story right through the week now. Look for a slow cooling trend to begin around Thursday with much cooler weather next weekend.

By late next weekend replacing the high will be the first decent low off coast of the Fall season. Both the GEFS and the EPS ensemble solutions have the low drawing up moisture from the tropical system to our south.

Models have been showing a decent push of rain for the Sierra with the Owens Valley possibly getting into the action as well. Let’s hope and pray that entire state gets some decent rain and not just dry lightning strikes.

At this point, confidence is very low how next weekend into early the following week pans out.

Expect some wild and wet model runs only to see them back off on the next run. Ha Ha, what’s new… With remnants of a tropical system you never know what you’re in for.

Let’s hope the outcome is wet for the whole state as that would really put a damper on the fire danger that is entering extreme mode right now.

I don’t often use the CFS, but took a look and found this in the weeklies version.

EPS Ensemble Mean – 500 h Pa Height & Anomaly

GEFS Ensemble Mean – 500 h Pa Height & Anomaly

November into February Trends

A weak La Nina will be gaining some strength into late Fall and then is forecast to start to weaken and then go neutral sometime by late December into early February.

How this all plays out for winter is still up in the air. I have seen the CFS with some wet months, but then the runs go dry again. Same with the EPS, the good news if you’re a model rider the overall trend is not a dire drought.

My guess for the winter is unless we get a return of multiple AR events or 3-week wet cycles, we will below the average mean again.

Yes, You can still have an epic ski season and there is a 30-40% chance we get some big AR events like last December once again. Even when we had 90 days of no snow the groomers up on the hill from the top down to the bottom were a ton of fun.

Again long range data is not a forecast just an outlook, I personally like to look at all the data and see what the trends are. When the runs look like lots of snow you can’t help daydreaming for a bit.

The good news from what we are seeing right now is the longest-range models are not day in and day out dry like we were seeing at this time last year. At that time the only month that looked wet was December and the rest showed nothing but drought.

As of 9-4-22, we are waiting for the newest run from the EPS that goes out through next winter and into the spring. Once it’s out I will update this information again.

For now, we have the CFS that has been showing over the last 21 days that the area could see an average to a bit above average for the months of December. The image below is a blend of the last 21 days.

The next image is one of the one-run wonders you get from the CFS. Yes, it’s a fantasy outlook but of course, we need to post it since all we have had to look at for months is brown outlooks. Blue is my favorite color for a reason followed by white.  This of course would be a multiple AR month if central California ended up at 20 inches above average for one month. Sounds kinda like 2017.

Here is the CFS for January of 2023

Here is the CFS for February 2023

ENSO - La Nina & El Nino

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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