Ski Renter Mammoth DiscountPowder Forecast –Friday January 18th, 2019

Ted Schlaepfer CCM  —- Mammoth Mountain WeatherGuy

Forecast Summary:

   Dry weather is expected Saturday and into Sunday with clouds at times, then snowfall develops late afternoon Sunday and continues overnight before ending by dawn with colder temperatures for MLK Holiday.  Dry weather is then expected rest of the week and following weekend with seasonably mild temperatures.  Next chance for snowfall will be toward the end of the month or early February. Overall, powder conditions are now on for the MLK Holiday, then no more powder days likely until February, maybe end of the month.

Next update Tuesday 1/22

Snowfall forecasts are valid at the Sesame snow course (Main Lodge) for the prior 24 hours as reported in the 6-7 AM morning snow report.

Sesame Snow Course

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

Sat 1/19 = 0”
Sun 1/20 = 0”
Mon 1/21 = 8 – 10” (H20 = 0.75” – 1.00”)**3
Tue 1/22 = 0”
Wed 1/23 = 0”
Thu 1/24 = 0”
Fri 1/25 = 0”
Sat – Mon 1/26 – 28 = 0”

January Snowfall = 86.5”
January Forecast = 90 –  110”

Detailed 4-day Snowfall Forecast:

Sat 1/19 —No snowfall expected.

Sun 1/20 —Dry during operations with increasing clouds/wind.  Snow develops late PM/evening and continues overnight before ending by dawn.  Accumulations 8 – 10” by Monday AM, around a foot up top.

Mon 1/21 —A chance for a morning snow shower, then dry and cold/windy.

Tue 1/22 —No snowfall expected.

Forecast Discussion:
Short Term:

 The latest satellite image (below) shows high pressure has built into CA in the wake of the strong storm over the past two days that did not quite deliver the expected snowfall.  However, liquid amounts were closer to the forecast and the mountain received a large amount of base snow overall.

   High pressure will continue to hold over the central part of the state and Mammoth tomorrow and into Sunday as the warm front will move north of Mammoth (just lots clouds at times) . Then a system that is just entering the eastern Pacific will bust through the ridge for a period of snowfall Sunday night.

   The GFS model has now trended toward the ECM solution (image below) with the upper-level trough having a lot more energy upon landfall and also moving farther southward toward the deserts Southwest.   That means the quick moving front will produce a burst of snowfall and gusty winds starting late Sunday afternoon, peaking evening, continuing overnight, and then quickly ending early Monday before the lifts open.

    The GFS model is now the wetter model and shows over an inch of liquid (image below) while the ECM model has only trended slightly wetter with around 0.75”.   Forecast is mostly a blend of the two, leaning a bit toward the ECM solution with around 8-10” for Main and around a foot up top.

    This will be a colder system with snow levels starting around 5500 feet before lowering below 4000 feet by Monday AM when the snow is ending.  It will not be Sierra cement this time, but colder drier type snow and likely quite fluffy overall.  The MLK Holiday will be fun, although it will be breezy and cold.

Long Range:  

  High pressure will slowly build into CA and Mammoth early next week for dry weather and should hold for the rest of next week (image below) and likely through the following weekend as a big trough develops eastern half of US.   Mammoth will be under light northerly flow, so temps should not get too warm, but remain seasonably mild (upper 20s to mid 30s middle and upper mountain and 40s lodges).  Perfect bluebird weather.

    There are no indications that this pattern will break until possibly the last few days of the month if the GFS operational model fantasy range output is even close to correct (image below).  It says there will be enough jet energy to break under the ridge before the month ends.  It is only weakly supported by the model ensembles.

   The CFS climate model (image below) is still indicating that a wet period will develop the first week of February.  The ECM climate model is not as bullish about it, but it does indicate a chance for an undercut.

   These solutions are now in range of the GFS ensemble and it does support some jet energy moving into the West Coast and CA (image below) by the first few days of February.  The ECM ensemble mean is actually a bit more bullish about an undercut.

 That lends better support to the GFS fantasy solution (image below) of having a system move into CA by the first couple days of February.  It is still a long ways out, fingers crossed. WG