Mammoth Mountain Ski Patrol 2018-19 Storm Summary - Sesame Snow Study Site 9,000' (2,743m)
Date  HN24(") Base Depth SWE Rain % Density StormSnow " Storm SWE " Season Snow Season SWE Season Precip Base Hi Temp Base Lo Temp Notes
10/2/2018 0.0 0.0   0.02             57 43  
10/3/2018 0.0 0.0   0.60             46 38 .47" fell during day 10/2 after morning obs
10/4/2018 0.0 0.0   0.74             46 34 .19" fell during day 10/3. Snow level top ch 1.  Lower on N facing slopes observed during morning obs
10/5/2018 0.0 0.0   0.03           1.86 46 31 .03" during day 10/4.  First frost of the season.
                           
10/7/2018 T T   0.15           2.01 37 27 Afternoon and overnight cells from 10/6  
                           
11/22/2018 12.0 12.0 1.40 0.00 12           34 23 Met one was high.  Good pow but no base 
11/23/2018 3.0 15.0 0.50 0.00 16           28 23 Had some snain around main lodge halfway up ch 1 
11/24/2018 4.0 17.0 0.85 0.00 21 19.0 2.75 19.0 2.75 4.76 31 28 Storm warming trend 
                           
11/28/2018 11.0 24.5 1.45 0.00 13     30.0 4.20 6.21 34 28 4" fell overnight.  Rest fell during ops hrs.  Strong SW winds dimissed  as precip began.
11/29/2018 16.0 38.0 1.97 0.00 12           31 27 8" fell overnight and 8" during day.
11/30/2018 7.5 41.0 0.69 0.00 9 34.5 4.11 53.5 8.31 10.32 29 22 Kind pow fell overnight but affected by wind
Nov. Total 53.5                        
12/1/2018 1.0 39.0 0.13 0.00 13           27 16  
12/2/2018 6.5 42.0 0.48 0.00 13           19 10  
12/3/2018 T 37.5 0.01 0.00             29 16  
12/4/2018 1.5 38.0 0.08 0.00 5           24 11 short break in systems
12/5/2018 4.0 40.0 0.40 0.00 10           26 25  
12/6/2018 2.0 42.0 0.14 0.00 7 15.0 1.24 68.5 9.55 11.56 22 13  
                           
12/17/2018 4.0 34.0 0.50 0.00 13           40 26 Started around 4am continued through midday
12/18/2018 2.0 36.0 0.30 0.00 15 6.0 0.80 74.5 10.35 12.36 40 29 All fell during ops hrs 12/17
Date  HN24(") Base Depth SWE Rain % Density StormSnow " Storm SWE " Season Snow Season SWE Season Precip Base Hi Temp Base Lo Temp Notes
12/21/2018 1.0 35.0 0.10 0.00 10 1.0 0.10 75.5 10.45 12.46 47 26 Angry inch w/ strong SW winds
                           
12/25/2018 4.5 38.0 0.70 0.00 15 4.5 0.70 79.5 11.15 13.16 33 16 White xmas!  All fell overnight
                           
12/28/2018 1.0 38.0 0.05 0.00 5 1.0 0.06 80.5 11.20 13.21 16 6 NE storm.  Town got more snow 3"
Dec. Total 27.5                        
1/6/2019 16.0 52.0 1.40 0.00 9           29 16 1" and .18 fell during ops hrs on 1/5
1/7/2019 19.0 65.0 2.50 0.00 13 35.0 3.90 115.5 15.10 17.11 26 16 Damaging winds overnight.  Pwr loss at Main lodge from 10-12am
                           
1/9/2019 2.5 61.0 0.26 0.00 10           33 26 Snow started around 5am and snowed heavu for ost of the morning
1/10/2019 6.5 64.0 0.84 0.00 13 9.0 1.10 124.5 16.20 17.21 30 20 All but last inch fell during ops hrs on 1/9.  Back ramp Ch 3 closed at noon due to upper mtn wind loading.
                           
1/15/2019 3.0 66.0 0.20 0.00 7 3.0 0.20 127.5 16.40 17.41 23 13  
                           
1//16/2019 12.5 73.0 1.63 0.00 13 12.5 1.63 140.0 18.03 19.04 25 19 definitive clearing mid morning until mid afternoon.  Cleared storm board 
Date  HN24(") Base Depth SWE Rain % Density StormSnow " Storm SWE " Season Snow Season SWE Season Precip Base Hi Temp Base Lo Temp Notes
1/17/2019 18.0 86.5 3.00 Y 17           31 25 all overnight.  Not as much as forecasted.  Lightning ceased snow safety work @ 05:30
1/18/2019 9.0 91.0 1.60 0.00 18 27.0 4.63 167.0 22.63 23.64 31 22 mostly wind transport and light snow showers during ops hrs.
                           
1/21/2019 8.0 90.0 1.03 0.00 13 8.0 1.03 175.0 23.63 24.64 31 13 Great skiing.  Not much avalanche activity
Jan. Total 94.5                        
2/2/2019 12.0 86.5 1.00 0.00 8           40 27  
2/3/2019 32.5 117.0 3.40 0.00 10           29 18 Boom!  16 during day and 16 overnight
2/4/2019 7.5 119.5 0.90 0.00 12           24 18 Getting cold…blower pow alert
2/5/2019 26.0 138.5 2.80 0.00 11           19 9 5.5 fell during ops hours and the rest overnight
2/6/2019 10.0 138.0 0.90 0.00 9 88.0 9.00 263.0 32.63 33.64 9 -3 Still snowing…Skies cleared at sweep.
Date  HN24(") Base Depth SWE Rain % Density StormSnow " Storm SWE " Season Snow Season SWE Season Precip Base Hi Temp Base Lo Temp Notes
2/9/2019 16.0 141.0 0.92 0.00 6           19 10  
2/10/2019 13.0 144.5 0.96 0.00 7           17 14  
2/11/2019 8.0 146.0 0.92 0.00 11 37.0 2.80       16 0  
                           
2/13/2019 5.0 140.0 0.70   14           30 20  
2/14/2019 12.0 145.0 3.50 Y 28           32 23 6" and 1.7" h2o fell during ops hrs 2/13  No lifts opened due to high winds and lightning most of the day 
2/15/2019 13.5 150.5 2.50 Y 19           32 16  
2/16/2019 17.0 159.0 1.19   7           19 9 10" and .84 h2o fell during ops hrs 2/15
2/17/2019 13.0 163.0 0.85   7           16 6 12" and .55"h2o fell during ops 2/16
2/18/2019 5.0 159.0 0.31   6 65.5         16 6 2" and .2 h2o fell during ops 2/17
                           
2/22/2019 5.5 153.5 0.26   4           17 5 Coold smoke!!  More please.  Limited results from ski cuts
2/23/2019 2.0 151.0 0.04   3 7.5 0.30       14 -3 Brrrr.
                           
2/27/2019 4.5 144.5 0.52   12           34 22 Big Time settlement.  Limited results from ski cuts except for Hemlock 
2/28/2019 5.0 148.0 0.83   17 9.5 1.35       29 23 Great skiing, snow has "pop"  Limited to no results from ski cuts.
Feb Total  207.5                        
3/1/2019 2.0 148.0 0.34   17           28 24  
3/2/2019 6.0 152.0 0.50   8           31 24  
3/3/2019 12.5 161.0 1.80   14           29 27  
Date  HN24(") Base Depth SWE Rain % Density StormSnow " Storm SWE " Season Snow Season SWE Season Precip Base Hi Temp Base Lo Temp Notes
3/6/2019 12.0 166.0 2.10   17           29 26  
3/7/2019 6.0 171.0 1.20   20           28 20  
3/8/2019 0.5 171.0 0.14   28           31 15  
3/9/2019 T 171.0 0.05               20 11  
3/10/2019 5.0 172.5 0.25   5           24 11  
                           
3/12/2019 1.0 165.0 0.12   12           34 7  
Units for Base Depth, New Snow, Storm Total, and Season Snowfall are in inches. 
SWE≡Snow Water Equivalent, the amount of water produced from melting a known volume of snow.  Measured in inches of H2O.
Season Precip includes SWE and rain since October 1st.
Units for 24 Hour Base Hi Temp and Base Lo Temp are degrees Fahrenheit.
Line breaks indicate clearing between storms, despite occasional consecutive days.
All data subject to revision.