Mammoth Mountain Weather Forecast & Discussion

Saturday, April 1st, 2023 @ 11:30 AM

Expect high clouds at times into Sunday with moderate to strong winds continuing in the 50-75 MPH range in wind-prone locations above the 9000-foot level. 

Then Sunday night into very early Tuesday there will be a chance of snow showers with light accumulations now expected in the 1-4 inch range above the 8500-foot level.

Beyond that time frame, there looks to be a change in the pattern with a ridge of high pressure that will be moving in and peaking in the Pacific North West according to the EPS ensemble model.

That type of pattern will warm up the daytime highs a bit with the N flow keeping things cooler than if the high pressure was right over Mammoth Mountain.

If the EPS model is right with this new pattern, the N to NE wind flow it produces will help preserve the snow in a winter snowpack state up top and possibly mid-mountain down to Main and Canyon Lodges.

How much warming does end up coming in will be the deciding factor on when and at what elevation the snowpack will start to turn to spring conditions. As of now, I suspect winter conditions will mostly be the rule on Mammoth Mountain right through next weekend.  

If you’re going to be out on Mammoth Mountain on Sunday, (NWS has a wind advisory posted for Sunday) expect pt cloudy skies, especially during the PM hours. Temperatures will be in the low to mid-30s by mid-morning with SW winds in the 25-35 MPH range with gusts @ 45-75+ MPH over the higher elevations and in wind-prone locations.

By Monday expect snow showers with light accumulations and temperatures in the upper teens to low 20s. Winds will continue in the moderate to strong range out of the SW. 

Tuesday and Wednesday skies will be mostly sunny with highs still hanging low in the mid to upper 20s. Should be some really good bluebird winter runs to be had under spring skies.

Later on, in the week skies will return to pt cloudy with a slight chance of a stray snow showers with temperatures moving up into the mid-30s to possibly the upper 30s.

For the following holiday weekend, the weather out on Mammoth Mountain looks to be great with highs in the Main Lodge area expected in the mid-30s to possibly the low 40s. Could be the start of the spring meltdown below the 8500-foot level, still a bit far out to trust 100% in next weekend’s outlook data.

Ski Ya Later, Snowman

West Coast and Eastern Pacific Satellite View
West Coast and Eastern Pacific Satellite View

3-29-23 @ 1:55  PM – 10-Day Fantasy Outlook Summary and Long-Range Summer / Fall and Winter 2024 Outlooks.

After Thursday skies will return to mostly clear with dry conditions expected Friday – Sunday. Early next week, an inside slider will be moving into the area with much cooler air and a chance of a dusting to several inches of snow.

As of now, the EPS has the slider early next week riding down close to the spine of the Sierra crest. That type of setup could usher in about 5-10 inches of lighter winter-type powder snow along with the very cold air and gusty winds. Yep, more winter weather for you in the high country.

By days 8 into 10 a ridge of high pressure will be building into the area for what looks like at least a week or longer of clear weather for Mammoth Mountain and the Eastern High Sierra. The ridge initially sets up with a North to North West flow and that will limit how much warming the area gets.

Longer-range models do continue with some weaker troughing for the west coast, which will be good as the result will be a slow snow melt. At some point, that type of pattern could also allow a spring storm or two to make its way thru the area.

Overall I think that the spring and especially the summer will end up being cooler than normal… why you ask? A moderate to strong Eastern-based El Nino will be growing and in play and that tends to bring cooler summers.

By the Fall, El Nino according to the CFSv2 will be in the 1.5+ range, and with it being eastern-based California could be headed for back-to-back well above-normal winters.

Some of the models have the event in Super El Nino Strength. And before you call foul on El Nino, the last super El Nino was centrally based and for those who read my weather stuff, I stated that the season would be a total bust the summer before.

This El Nino pattern would be eastern-based, so watch out and be ready for a possible second extremely wet winter in 23/2024.

For those who have been around a while, this setup for El Nino reminds me of 1983 and 1998. And for those who don’t know 1983 had around 85 inches of precipitation up on Mammoth Pass, this year the pass is at 94 inches and growing.


PS: Yes this is all in the fantasy outlook period so things could change, until they do this is my story and I am sticking to it. 🙂

0- 16 Day - EPS 500 Height Anomaly
Jet Stream Wind Speeds at 300 hPa
GEFS High Anopmply Chart February 27th to March 21st
An Eastern Based El Nino Event is on the Way - If this data is right it will be a strong one.

Long Range Seasonal ECM Model from Early March – Next run on this Model is April 3rd

GEFS High Anopmply Chart February 27th to March 21st
ENSO Outlook – Updated on March 20th

Mammoth Mountain and Eastern Sierra Weather Posts