Mammoth Mountain Weather Forecast — Friday May 12th, 2017

Powder Forecast — Friday May 12th, 2017

Ted Schlaepfer CCM  —- Mammoth Mountain WeatherGuy

Forecast Summary:

  Mostly cloudy today with a chance for light snow or flurries through this afternoon and into this evening above 8500 feet before any snow showers end tonight.  Dry weather returns tomorrow followed by another chance for light snow showers Sunday.   Powder conditions are not expected through this weekend and into Monday next week.  A stronger storm is possible Tuesday next week for a chance for powder conditions with dry and warmer weather returning by the end of next week and following weekend back to spring conditions.   Generally seasonably weather with just a slight chance for an infrequent storm is then expected through early June.

Next update Friday 5/19

Snowfall forecast are for the Sesame snow course (Main Lodge)

**Snowfall forecast confidence ranges from very low (1) to very high (5)

Amounts Update Monday 5/15 @ 1PM

Tue 5/16 = 2 – 4” (H2O = 0.30” – 0.50”)**4

Wed 5/17 = 2 – 3” (H2O = 0.20” – 0.30”)**3

Thu 5/18 = 0”

Fri 5/19 = 0”

Sat – Mon 5/20 – 5/22 = 0”

May Snowfall = 5.5”
May Forecast = 10 – 15”

Seasonal Snowfall = 624.5”
Seasonal Forecast = 630 – 640”

Detailed 5-day Snowfall Forecast:

Sat 5/13 — No snowfall expected.

Sun 5/14 — Snow showers or flurries are possible by the afternoon/evening hours, ending overnight.  Accumulations up to 1” by Monday AM

Mon 5/15 — Snow flurries are possible during the afternoon/evening.  No accumulation expected.

Tue 5/16 — Snow probably develops during the morning hours and continues into Tuesday night, probably ending Wednesday AM.  Accumulations up to 5 – 10” by Wednesday AM

Forecast Discussion:

Short Term:  

Satellite imagery (below) shows the southern end of a weak cold front being currently dragged through the central Sierra with the front moving into Mammoth this afternoon.   It is cloudy and foggy mid-mountain upward this afternoon and that should give way to light snow or flurries this afternoon and evening, ending overnight.  Not expecting any meaningful accumulation.

Mammoth is in between systems Saturday for sunny and seasonably cool temperatures before a weak trough (image below) slides southward into CenCal on Sunday.   That will lower temperatures some more on the mountain (conditions could stay firm all day up top) and also produce a chance for light snow during the afternoon and evening hours.   Not expecting any meaningful accumulation.

Snow showers or flurries are also possible again Monday under continued seasonably cold temperatures before a stronger storm is possible around Tuesday next week which could be a May surprise.   The ECM model (image below) is now is better agreement with the GFS model (two images below) about the trajectory and strength of an upper level low pressure system moving southward from the Gulf of Alaska.

The low isn’t taking a great trajectory down the coast to inject a lot of needed moisture, but it does appear quite dynamic for this time of year and also rather cold with snow levels possibly getting down to near 4K on the back end of the storm.  Models say snow may start Tuesday morning and continue overnight and into early Wednesday.

The GFS model backed off a bit on the amounts for the storm on the 12Z run (image below), now showing about half an inch after depicting around an inch in earlier runs.   The ECM model was drier than the GFS over the last couple of days, but now shows almost 0.75” liquid.   However, the latest run of the Canadian has the low as an insider slider and no significant snowfall for Mammoth.

   Still a bit early for an accurate forecast with the current forecast a blend of guidance and recent model runs.   A slightly westward track than currently projected by the models and Mammoth could see over a foot, but right now best guess is around 6” or so.   I will update the forecast numbers on Monday if the current forecast of 5-10” is bunk or still valid.

Long Range:

The numerical guidance moves the upper low eastward by Thursday next week with high pressure building into CA in its wake for a pattern change back to more seasonable weather.  The ECM model moves the ridge into CA on Friday (image below) and holds it over CA through the weekend for fair and warmer weather back to spring conditions.

The GFS ensemble mean is then forecasting more seasonable weather for the following week.  It moves the jet back northward (image below) with weak high pressure remaining over CA through the almost of the end of the month.

That model does move the trough closer to the coast heading into the last parts of May which would probably result in just cooler weather and maybe wind as any storm will probably remain well north of Mammoth, although you can’t rule out an stray storm moving southward at any point, but probably not enough for powder conditions again.  Next Tuesday might be it.

The CFS model (image below) does keep the longwave trough along the West Coast into early June and that would probably mean no big heat waves and not necessarily storms.   June powder days are extremely rare as snow levels are usually just too high by that time of year if any storm does indeed drop southward into CA.  WG

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5-10-2016 – Mammoth Mountain & Mammoth Lakes Weather Report

5-10-2017 – 9AM – Hello from Mammoth Mountain and Mammoth Lakes, California.

At this time we have clear skies with morning lows in the 40s

Today we will have highs in town in the 60s, with winds out of the south west 5-15 MPH during the afternoon hours. There is a 20% chance of a stray shower today with snow levels above 9000 feet.

Thursday and into the weekend outlook is calling for clear skies with highs in the 60s in town and 50s out on Mammoth Mountain. Winds up on the hill will be 15-25+ MPH out of the SW.

By Sunday a dry cold front moves thru and highs with drop into the 40s in town with 30s over Mammoth Mountain.


Looking West to Mammoth Mountain - Cal Trans Cam Looking SE at SB US 395

Mammoth Lakes Weather Forecast @ 7800 Feet

Main Lodge Weather Forecast @ 8900 Feet

Snowman’s Live Cam at 8175 Feet on Canyon Blvd

Mammoth Mountain Satelight

Mammoth Mountain RadarMammoth Mountain Jet StreamMammoth Mountain 10 Day Precipitation OutlookMammoth Mountain Temperature OutlookMammoth Mountain 14 Day Rain and Snow OutlookMammoth Mountain 14 Day Temperature OutlookMJO Outlook Chart GFSPacific SST

Mammoth Mountain & Mammoth Lakes Weather

Looking Back at some Big H20 Winters 

2017 beat all of these with 100+ inches of H20

1. 1983 91.0″ H2O (83.7″ @ 4-1-83)

2. 1969 86.5″ H2O

3. 1995 80.0″ H2O

4. 1967 78.1″ H2O (55.4″ @ 4-1-67)

5. 2006 76.0″ H2O (63.6″ @ 4-1-06) ***

6. 1978 76.0″ H2O (67.8″ @ 4-1-78)

7. 1938 75.2″ H2O

8. 1986 74.0″ H2O (64.0″ @ 4-1-86)

9. 1952 73.7″ H2O

10. 1982 73.0″ H2O

11. 2005 72.5″ H2O (68.5″ @ 4-1-05)

12. 1993 67.1″ H2O

13. 1980 65.8″ H2O

14. 1941 64.0″ H2O

15. 1958 62.0″ H2O


Steve TaylorSteve Taylor – The Mammoth Snowman: Over the last 30+ years, Snowman have spent countless hours studying and learning about mammoth mountain weather and snow conditions first hand.

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 his Video & Photo Blog reports. (No You Tube back then)

Snowman has had his reports, videos and photos featured on both local TV Stations here in Mammoth, along with Fox, ABC, CBS and NBC News. ________________________________________________________

Ted Schlaepfer – CCM – The Mammoth Weather GuyTed Schlaepfer – CCM – The Mammoth Weather Guy: Bio: Always 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 Mountain in 1979 as a youth, and have been a regular visitor since.

Putting together the Powder Outlook has been a lot of fun over the last 7 snow seasons.


Mammoth Mountain Weather Forecast

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