Mammoth Mountain Ski Patrol 2008-09 Storm Summary - Sesame Snow Study Site 9,000' (2,743m)
Date	New Snow	Base Depth	SWE	% Density	Storm Snow	Storm SWE	Season Snow	Season SWE	Base Hi Temp	Base Lo Temp	Notes
10/4/2008	1.0	1.0	0.13	13	1.0	0.13	1.0	0.13	48	33
10/10/2008	4.0	-	0.52	13	4.0	0.52	5.0	0.65	45	26
10/31/2008	5.0	6.5	1.14	23	5.0	1.14	10.0	1.79	52	31
11/1/2008	2.0	4.5	0.43	22	7.0	1.57	12.0	2.22	39	33	After 2" snow, ~2" rain up to 11k', changed to mixed rain & snow at 9k' ~15:00 11/1
11/2/2008	5.5	10.0	1.35	36	12.5	2.92	17.5	3.57	39	28
11/3/2008	1.0	11.0	0.17	26	13.5	3.09	18.5	3.74	31	24
11/4/2008	3.0	11.5	0.53	20	3.0	0.53	21.5	4.27	28	23
11/9/2008	11.0	20.0	1.22	11	11.0	1.22	32.5	5.49	46	21
11/26/2008	1.0	9.5	0.13	13	1.0	0.13	33.5	5.62	41	25
11/27/2008	3.0	13.5	0.26	9	4.0	0.39	36.5	5.88	30	19
12/13/2008	1.0	10.0	0.28	28	1.0	0.28	37.5	6.16	43	18
12/14/2008	7.0	16.0	0.43	6	8.0	0.71	44.5	6.59	21	6
12/15/2008	20.5	31.0	1.51	7	28.5	2.22	65.0	8.10	14	7
12/16/2008	20.5	38.0	0.94	5	48.5	3.16	85.5	9.04	15	7
12/19/2008	6.0	30.0	0.54	9	6.0	0.54	91.5	9.58	22	11
12/20/2008	6.0	32.0	0.92	15	12.0	1.46	97.5	10.50	30	16
Date	New Snow	Base Depth	SWE	% Density	Storm Snow	Storm SWE	Season Snow	Season SWE	Base Hi Temp	Base Lo Temp	Notes
12/22/2008	15.5	41.0	2.09	13	15.5	2.09	113.0	12.59	34	21
12/23/2008	15.0	46.5	1.63	11	30.5	3.72	128.0	14.22	21	11
12/24/2008	1.0	46.0	0.06	6	31.5	3.78	129.0	14.28	22	11
12/25/2008	16.5	58.0	2.28	14	48.0	6.06	145.5	16.56	26	20
12/26/2008	11.5	64.0	2.30	20	59.5	8.36	157.0	18.86	24	7
1/3/2009	4.0	53.0	0.70	18	4.0	0.70	161.0	19.56	30	10
1/22/2009	7.0	51.0	1.04	15	7.0	1.04	168.0	20.60	43	31
1/23/2009	10.0	59.5	1.86	19	17.0	2.90	178.0	22.46	33	32
1/24/2009	19.0	73.0	3.09	16	36.0	5.99	197.0	25.55	37	28	Rain and snow, SWE includes both.  2cm ice crust on new snow board.
1/25/2009	14.0	79.0	1.54	11	50.0	7.53	211.0	27.09	29	17
1/26/2009	8.0	83.0	0.50	6	58.0	8.03	219.0	27.59	18	8
1/27/2009	1.0	80.0	0.05	5	59.0	8.08	220.0	27.64	20	4
2/6/2009	14.5	79.0	1.10	8	14.5	1.10	234.5	28.74	26	22
2/7/2009	9.5	85.0	0.77	8	24.0	1.87	244.0	29.51	25	19
2/8/2009	0.5	83.0	0.03	6	24.5	1.90	244.5	29.54	23	14
2/9/2009	16.0	88.5	1.20	8	40.5	3.10	260.5	30.74	23	9
2/11/2009	10.5	92.0	0.59	10	10.5	0.59	271.0	31.33	30	3
2/12/2009	1.0	89.0	0.07	7	1.0	0.07	272.0	31.40	20	11
Date	New Snow	Base Depth	SWE	% Density	Storm Snow	Storm SWE	Season Snow	Season SWE	Base Hi Temp	Base Lo Temp	Notes
2/14/2009	15.5	98.0	1.14	7	15.5	1.14	287.5	32.54	14	10
2/15/2009	4.0	96.0	0.24	6	19.5	1.38	291.5	32.78	20	11
2/16/2009	4.0	95.0	0.30	8	23.5	1.68	295.5	33.08	23	16
2/17/2009	30.0	120.5	2.19	7	53.5	3.87	325.5	35.27	20	15
2/18/2009	14.5	123.0	0.74	5	68.0	4.61	340.0	36.01	17	5
2/22/2009	0.5	103.5	0.06	12	0.5	0.06	340.5	36.07	41	26	Snow level approximately 7,500'
2/23/2009	17.5	115.5	2.44	14	18.0	2.50	358.0	38.51	31	27
2/24/2009	3.5	118.0	0.41	12	21.5	2.91	361.5	38.92	31	27
2/25/2009	1.0	114.5	0.12	12	1.0	0.12	362.5	39.04	38	24	1" of graupel above 1" pencil hard wind/melt-freeze crust on top of fist hard new snow
2/26/2009	1.5	112.0	0.29	19	2.5	0.41	364.0	39.33	27	23
3/2/2009	15.0	118.0	2.22	15	15.0	2.22	379.0	41.55	38	24	Trace graupel on top of fist hard new snow above wind/melt-freeze crust
3/3/2009	4.0	119.5	0.97	24	19.0	3.19	383.0	42.52	32	21	2-6mm graupel and ice pellets.  Snow level approximately 8,500'
3/4/2009	23.5	136.5	3.01	13	42.5	6.20	406.5	45.53	23	19	Very little avalanche activity on lower mtn.
3/5/2009	3.0	136.0	0.36	12	45.5	6.56	409.5	45.89	18	12	10mm wind crust 20mm down, ice crust on storm board
3/7/2009	0.5	131.0	0.06	12	0.5	0.06	410.0	45.95	20	5
3/8/2009	0.5	128.0	0.03	6	0.5	0.03	410.5	45.98	35	17
3/16/2009	Trace	114.5	0.01	-	Trace	0.01	410.5	45.99	39	27
Date	New Snow	Base Depth	SWE	% Density	Storm Snow	Storm SWE	Season Snow	Season SWE	Base Hi Temp	Base Lo Temp	Notes
3/22/2009	14.5	121.0	1.89	13	14.5	1.89	425.0	47.88	32	18	New snow on top of 4-8mm graupel above sun crust.
3/23/2009	1.5	123.0	0.13	9	16.0	2.02	426.5	48.01	18	2	Extremely cold temps with strong NE wind.
4/4/2009	1.0	99.0	0.05	5	1.0	0.05	427.5	48.06	28	5
4/8/2009	5.0	98.5	0.66	13	5.0	0.66	432.5	48.72	41	18
4/9/2009	4.5	101.0	0.64	14	9.5	1.30	437.0	48.72	25	18	Ice crust on storm board.
4/10/2009	9.5	107.5	1.02	11	19.0	2.32	446.5	50.38	27	21
4/11/2009	1.5	105.0	0.12	8	1.5	0.12	448.0	50.50	30	16
4/14/2009	Trace	96.5	Trace	-	Trace	Trace	448.0	50.50	46	28	Graupel
4/15/2009	1.5	99.0	0.10	7	1.5	0.10	449.5	50.60	30	5
4/24/2009	3.5	84.5	0.41	12	3.5	0.41	453.0	51.01	44	27
4/25/2009	3.5	87.5	0.62	18	7.0	1.03	456.5	51.63	28	16
5/1/2009	0.5	73.5	0.28	56	0.5	0.28	457.0	51.91	50	35	Rain on snow.  Freezing level briefly above 11k'.
5/2/2009	10.5	85.0	1.96	19	11.0	2.24	467.5	53.87	42	29	~0.1" rain followed by ~1.9" SWE.
5/3/2009	0.5	82.5	0.35	70	11.5	2.59	468.0	54.22	34	15	Snow fell throughout most of 5/2, but was constantly melting and consolidating.
5/4/2009	0.0	80.5	0.28	-	11.5	2.87	468.0	54.50	37	34	Snow fell throughout most of 5/4, but was constantly melting and consolidating.
5/5/2009	0.0	79.0	0.05	-	11.5	2.92	468.0	54.55	45	33	Rain afternoon of 5/4
6/5/2009	Trace	0.0	Trace	-	Trace	Trace	468.0	54.55	48	32	Prior to this storm there were several mixed events with trace graupel above 10k'
6/6/2009	2.0	0.5	0.25	13	2.0	0.25	470.0	54.80	34	29
6/7/2009	Trace	0.0	0.03	-	2.0	0.28	470.0	54.83	40	31
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.
Units for 24 Hour Base Hi Temp and Base Lo Temp are degrees Fahrenheit.
Line breaks indicate clearing between storms, despite occasional consecutive days.