Station Overview Station Location
Station Number CO-BO-30 Latitude 39.9915
Station Name Boulder 1.9 SE Longitude -105.2403
County Boulder Elevation (ft) 5368



Month 30 Yr Avg by PRISM Total Prcp Sum Days Covered By All Observations Daily Prcp Sum Daily Observation Count Multiday Prcp Sum Days Covered by Multiday Observations Multiday Observation Count Days With Prcp Days With Trace Total Snowfall Days With Snowfall Days With Snow On Ground
Oct 19 1.39 2.16 31 2.16 31 0.00 0 0 10 1 21.2 7 9
Nov 19 1.04 2.36 30 2.36 30 0.00 0 0 7 4 26.5 6 15
Dec 19 0.79 0.30 31 0.30 31 0.00 0 0 4 4 3.0 3 13
Jan 20 0.64 0.00 31 0.00 31 0.00 0 0 0 5 0.0 0 0
Feb 20 0.63 1.76 29 1.76 29 0.00 0 0 12 1 26.8 10 24
March 20 1.86 2.81 31 2.81 31 0.00 0 0 8 3 15.1 5 8
April 20 2.34 2.68 30 2.68 30 0.00 0 0 9 2 31.8 6 9
May 20 2.66 2.09 31 2.09 31 0.00 0 0 10 5 0.0 0 0
June 20 2.16 2.14 30 2.14 30 0.00 0 0 13 1 0.0 0 0
July 20 1.67 0.56 31 0.56 31 0.00 0 0 7 5 0.0 0 0
Aug 20 1.76 0.58 31 0.58 31 0.00 0 0 9 4 0.0 0 0
Sept 20 1.61 1.38 30 1.38 30 0.00 0 0 5 1 4.6 1 1
Water Year Totals: 18.55" 18.82" 366 days 18.82" 366 0.00" 0 days 0 94 days 36 days 129.0" 38 days 79 days



Days in Water Year Cell Color Key
        Daily Observation with Prcp         Missing Day
        Multiday Observation         Daily/Multiday Observation Conflict

Day of Year Daily Prcp Multiday Prcp
10/1/2019 0.01
10/2/2019 0.29
10/3/2019 0.01
10/4/2019 0.00
10/5/2019 0.00
10/6/2019 0.00
10/7/2019 0.00
10/8/2019 0.00
10/9/2019 0.00
10/10/2019 0.12
10/11/2019 0.20
10/12/2019 0.00
10/13/2019 0.00
10/14/2019 0.00
10/15/2019 0.00
10/16/2019 0.00
10/17/2019 0.00
10/18/2019 0.00
10/19/2019 0.00
10/20/2019 0.00
10/21/2019 0.00
10/22/2019 0.00
10/23/2019 0.00
10/24/2019 0.60
10/25/2019 0.00
10/26/2019 0.00
10/27/2019 0.10
10/28/2019 0.44
10/29/2019 0.14
10/30/2019 0.25
10/31/2019 T
11/1/2019 0.00
11/2/2019 0.00
11/3/2019 0.00
11/4/2019 0.00
11/5/2019 0.00
11/6/2019 0.00
11/7/2019 0.10
11/8/2019 0.00
11/9/2019 0.00
11/10/2019 0.00
11/11/2019 0.11
11/12/2019 T
11/13/2019 0.00
11/14/2019 T
11/15/2019 0.00
11/16/2019 0.00
11/17/2019 T
11/18/2019 0.00
11/19/2019 0.00
11/20/2019 0.00
11/21/2019 0.20
11/22/2019 0.21
11/23/2019 T
11/24/2019 0.00
11/25/2019 0.00
11/26/2019 1.44
11/27/2019 0.24
11/28/2019 0.00
11/29/2019 0.00
11/30/2019 0.06
12/1/2019 0.00
12/2/2019 0.00
12/3/2019 0.00
12/4/2019 0.00
12/5/2019 0.00
12/6/2019 0.12
12/7/2019 0.00
12/8/2019 0.00
12/9/2019 T
12/10/2019 0.00
12/11/2019 0.00
12/12/2019 0.00
12/13/2019 0.00
12/14/2019 T
12/15/2019 0.02
12/16/2019 0.00
12/17/2019 0.00
12/18/2019 0.00
12/19/2019 0.00
12/20/2019 0.00
12/21/2019 0.00
12/22/2019 0.00
12/23/2019 0.00
12/24/2019 0.00
12/25/2019 0.00
12/26/2019 T
12/27/2019 T
12/28/2019 0.10
12/29/2019 0.06
12/30/2019 0.00
12/31/2019 0.00
Day of YearDaily PrcpMultiday Prcp
1/1/2020 0.00
1/2/2020 0.00
1/3/2020 0.00
1/4/2020 0.00
1/5/2020 0.00
1/6/2020 0.00
1/7/2020 0.00
1/8/2020 0.00
1/9/2020 0.00
1/10/2020 0.00
1/11/2020 T
1/12/2020 0.00
1/13/2020 0.00
1/14/2020 T
1/15/2020 0.00
1/16/2020 0.00
1/17/2020 0.00
1/18/2020 T
1/19/2020 0.00
1/20/2020 0.00
1/21/2020 0.00
1/22/2020 0.00
1/23/2020 0.00
1/24/2020 0.00
1/25/2020 0.00
1/26/2020 0.00
1/27/2020 0.00
1/28/2020 0.00
1/29/2020 0.00
1/30/2020 T
1/31/2020 T
2/1/2020 0.00
2/2/2020 0.00
2/3/2020 0.05
2/4/2020 0.44
2/5/2020 0.05
2/6/2020 0.00
2/7/2020 0.15
2/8/2020 0.10
2/9/2020 0.09
2/10/2020 0.20
2/11/2020 0.31
2/12/2020 0.00
2/13/2020 0.19
2/14/2020 0.00
2/15/2020 0.00
2/16/2020 0.00
2/17/2020 0.00
2/18/2020 0.02
2/19/2020 0.00
2/20/2020 0.15
2/21/2020 0.00
2/22/2020 0.00
2/23/2020 0.00
2/24/2020 0.01
2/25/2020 T
2/26/2020 0.00
2/27/2020 0.00
2/28/2020 0.00
2/29/2020 0.00
3/1/2020 0.00
3/2/2020 0.35
3/3/2020 0.00
3/4/2020 0.00
3/5/2020 0.00
3/6/2020 0.00
3/7/2020 0.00
3/8/2020 0.00
3/9/2020 0.16
3/10/2020 0.00
3/11/2020 0.00
3/12/2020 0.00
3/13/2020 0.00
3/14/2020 0.12
3/15/2020 T
3/16/2020 0.00
3/17/2020 0.01
3/18/2020 0.00
3/19/2020 0.19
3/20/2020 1.60
3/21/2020 0.02
3/22/2020 0.00
3/23/2020 0.00
3/24/2020 T
3/25/2020 0.00
3/26/2020 0.00
3/27/2020 0.00
3/28/2020 0.36
3/29/2020 0.00
3/30/2020 0.00
3/31/2020 T
Day of YearDaily PrcpMultiday Prcp
4/1/2020 0.00
4/2/2020 0.05
4/3/2020 0.11
4/4/2020 0.00
4/5/2020 0.00
4/6/2020 0.00
4/7/2020 0.00
4/8/2020 0.00
4/9/2020 0.00
4/10/2020 0.00
4/11/2020 0.00
4/12/2020 0.35
4/13/2020 0.49
4/14/2020 0.11
4/15/2020 0.00
4/16/2020 1.00
4/17/2020 0.50
4/18/2020 0.00
4/19/2020 T
4/20/2020 0.00
4/21/2020 0.00
4/22/2020 0.00
4/23/2020 T
4/24/2020 0.02
4/25/2020 0.05
4/26/2020 0.00
4/27/2020 0.00
4/28/2020 0.00
4/29/2020 0.00
4/30/2020 0.00
5/1/2020 T
5/2/2020 T
5/3/2020 0.21
5/4/2020 0.05
5/5/2020 0.00
5/6/2020 0.00
5/7/2020 0.00
5/8/2020 0.03
5/9/2020 0.00
5/10/2020 0.00
5/11/2020 0.00
5/12/2020 0.11
5/13/2020 0.00
5/14/2020 0.00
5/15/2020 0.26
5/16/2020 0.09
5/17/2020 0.00
5/18/2020 0.00
5/19/2020 0.00
5/20/2020 T
5/21/2020 0.00
5/22/2020 0.00
5/23/2020 0.00
5/24/2020 T
5/25/2020 1.13
5/26/2020 0.00
5/27/2020 0.00
5/28/2020 0.09
5/29/2020 0.04
5/30/2020 T
5/31/2020 0.08
6/1/2020 0.03
6/2/2020 0.00
6/3/2020 0.04
6/4/2020 0.00
6/5/2020 0.01
6/6/2020 0.01
6/7/2020 0.08
6/8/2020 0.00
6/9/2020 0.31
6/10/2020 0.00
6/11/2020 0.00
6/12/2020 0.00
6/13/2020 0.00
6/14/2020 0.03
6/15/2020 0.00
6/16/2020 0.00
6/17/2020 0.00
6/18/2020 0.00
6/19/2020 0.86
6/20/2020 0.12
6/21/2020 0.00
6/22/2020 0.19
6/23/2020 0.00
6/24/2020 0.00
6/25/2020 0.05
6/26/2020 T
6/27/2020 0.39
6/28/2020 0.00
6/29/2020 0.02
6/30/2020 0.00
Day of YearDaily PrcpMultiday Prcp
7/1/2020 0.12
7/2/2020 0.00
7/3/2020 0.00
7/4/2020 0.00
7/5/2020 0.00
7/6/2020 0.00
7/7/2020 0.00
7/8/2020 T
7/9/2020 0.00
7/10/2020 0.00
7/11/2020 0.00
7/12/2020 0.00
7/13/2020 0.00
7/14/2020 0.02
7/15/2020 0.02
7/16/2020 0.00
7/17/2020 0.00
7/18/2020 0.00
7/19/2020 0.00
7/20/2020 T
7/21/2020 0.00
7/22/2020 0.00
7/23/2020 0.03
7/24/2020 T
7/25/2020 0.27
7/26/2020 0.08
7/27/2020 T
7/28/2020 0.00
7/29/2020 0.02
7/30/2020 0.00
7/31/2020 T
8/1/2020 0.06
8/2/2020 0.01
8/3/2020 T
8/4/2020 T
8/5/2020 0.03
8/6/2020 0.21
8/7/2020 0.01
8/8/2020 0.00
8/9/2020 0.00
8/10/2020 0.00
8/11/2020 0.00
8/12/2020 0.00
8/13/2020 0.00
8/14/2020 0.00
8/15/2020 0.00
8/16/2020 0.00
8/17/2020 0.00
8/18/2020 0.00
8/19/2020 0.00
8/20/2020 T
8/21/2020 0.03
8/22/2020 0.00
8/23/2020 0.00
8/24/2020 0.00
8/25/2020 0.00
8/26/2020 0.00
8/27/2020 T
8/28/2020 0.15
8/29/2020 0.07
8/30/2020 0.01
8/31/2020 0.00
9/1/2020 0.08
9/2/2020 0.00
9/3/2020 0.00
9/4/2020 0.00
9/5/2020 0.00
9/6/2020 0.00
9/7/2020 0.00
9/8/2020 0.25
9/9/2020 0.96
9/10/2020 0.07
9/11/2020 0.00
9/12/2020 0.00
9/13/2020 0.00
9/14/2020 0.00
9/15/2020 0.00
9/16/2020 0.00
9/17/2020 0.00
9/18/2020 0.00
9/19/2020 0.00
9/20/2020 0.00
9/21/2020 0.00
9/22/2020 0.00
9/23/2020 T
9/24/2020 0.00
9/25/2020 0.00
9/26/2020 0.00
9/27/2020 0.00
9/28/2020 0.02
9/29/2020 0.00
9/30/2020 0.00



Observation Date Observation Time Precipitation Snowfall Snowfall SWE Snow Depth Snow SWE Notes
10/1/2019 7:00 AM 0.01 0.0 M 0.0 M Drizzle began ~0600 MDT 01 Oct 2019. Precip .01" by 0700 MDT.
10/2/2019 7:00 AM 0.29 0.0 M 0.0 M Low clouds, chilly, and nearly continuous precip during past 24 hours. .04" by 0830 MDT 01 Oct, +.07" by 1900 MDT, and +.18" by 0700 MDT 02 Oct, for a 24-h total of 0.29". Most precip fell late on the night of 01 Oct as R-. Drizzle, sometimes thick, for the rest of the time.
10/3/2019 7:00 AM 0.01 0.0 M 0.0 M Drizzle in progress at beginning of obs period (0700 MDT 02 Oct 2019) ended by 0830 MDT. Precip .01".
10/4/2019 7:00 AM 0.00 0.0 M 0.0 M
10/5/2019 7:00 AM 0.00 0.0 M 0.0 M
10/6/2019 7:00 AM 0.00 0.0 M 0.0 M
10/7/2019 7:00 AM 0.00 0.0 M 0.0 M
10/8/2019 7:00 AM 0.00 0.0 M 0.0 M
10/9/2019 7:00 AM 0.00 0.0 M 0.0 M
10/10/2019 7:00 AM 0.12 0.5 M 0.5 M Following strong cold front passage at 1650 MDT 09 Oct 2019, light drizzle began dampening the pavement at 2200 MDT. The temperature fell below freezing ~2315 MDT, marking start of freezing drizzle. At 0400 MDT 10 Oct, a few snow pellets on the deck with thin layer of glaze ice. SW- began ~0600 MDT, becoming S½ by 0705 MDT with the temperature at 22° (min so far). Precip so far (at 0705 MDT) .12". Snow accumulation 0.5", the first of the season.
10/11/2019 7:00 AM 0.20 3.2 M 2.6 M Moderate snow in progress S 1/2 at start of observing period. At 0950 MDT 10 Oct 2019, S- and 21° (morning min). Precip since 0705 MDT .16", total accumulation 3.2" measured on snowboard (max measured), of which 2.7" fell after 0705 MDT. S- or S-- ended 1130 MDT with 0.5" additional accumulation and +.04" precip. A few SW-- during the afternoon (trace precip, no new accumulation). Snow depth had settled to 2.9" on snowboard by 2200 MDT. The min at 0615 MDT 11 Oct was 15.5 deg F. If the official min was less than 20 deg, it will be a new date record for Boulder.
10/12/2019 7:00 AM 0.00 0.0 M T M Patchy snow remains in shaded areas.
10/13/2019 7:00 AM 0.00 0.0 M 0.0 M
10/14/2019 7:00 AM 0.00 0.0 M 0.0 M
10/15/2019 7:00 AM 0.00 0.0 M 0.0 M
10/16/2019 7:00 AM 0.00 0.0 M 0.0 M
10/17/2019 7:00 AM 0.00 0.0 M 0.0 M
10/18/2019 7:00 AM 0.00 0.0 M 0.0 M
10/19/2019 7:00 AM 0.00 0.0 M 0.0 M
10/20/2019 7:00 AM 0.00 0.0 M 0.0 M
10/21/2019 7:00 AM 0.00 0.0 M 0.0 M
10/22/2019 7:00 AM 0.00 0.0 M 0.0 M
10/23/2019 7:00 AM 0.00 0.0 M 0.0 M
10/24/2019 7:00 AM 0.60 6.3 M 6.3 M Occasional RW-- (tiny drops) after 1500 MDT 23 Oct 2019. Trace precip. Measurable precip began ~1815 MDT and became snow almost immediately. A little over 1” snow on deck rails by 2130 MDT, with the temperature at 32°. S½-¾ 2230-2330 MDT, otherwise S-, which ended at 0330 MDT 24 Oct. Accumulation 6.3" on snow board. Precip 0.60", the most in 24 hours since 01 July 2019. Thu 24 Oct 19 S- ended ~0330L.
10/25/2019 7:00 AM 0.00 0.0 M 3.0 M 3.0" on snow remains on open ground.
10/26/2019 7:00 AM 0.00 0.0 M 0.0 M
10/27/2019 7:00 AM 0.10 0.1 M 0.1 M Light freezing drizzle began 0100 MDT 27 Oct 2019, following max temperature of 72 deg F yesterday. Precip changed to snow ~0500 MDT. At 0700 MDT, S- was falling, 23 deg F, precip .10, mostly freezing drizzle, which did not freeze to pavement due to stored heat, snow accumulation 0.1".
10/28/2019 7:00 AM 0.44 5.9 M 6.0 M Snow, mostly light, fell continuously from 0700 MDT 27 Oct thru 0700 MDT 28 MDT. The exception was SW1/2 from 1645-1700 MDT 27 Oct. Otherwise S- with visibility between 1-2 miles. At 2110 MDT 27 Oct, 19° (lowest so far), S-1, accumulation 3.5" on snowboard (+3.4" since 0700 MDT, precip +.18 since 0700 MDT. S- continued all night with tiny flakes. At obs time, S-1, 6.0" accumulation on snow board, 5.9" in 24 h ending at 0700 MDT 28 Oct, precip +.26 since 2110 MDT 27 Oct, 24-h total .44.
10/29/2019 7:15 AM 0.14 1.9 M 6.0 M S- in progress at start of observing period, 0700 MDT, 28 Oct 2019. This ended at 0900 MDT, with 0.2" new snow, 6.2 total on the ground, and .01" precip. S- began 0500 MDT 29 Oct 2019. S¾-1 0530-0630 MDT bracketed frontal passage at 0610 MDT. At obs time, 0715 MDT, S-1, +1.8" new snow, 6.0" total on ground, new precip +0.13"
10/30/2019 7:00 AM 0.25 3.3 M 7.7 M Light snow at start of observing period, 0715 MDT 29 Oct 2019. S-1-2 or S-- all day (radar echoes ~10 DBZ) except for short periods of S-3/4 ~1400 MDT and again 1630 MDT. At 1710 MDT, 11.5° (min so far), S-1½, new accumulation +1.7, precip +.12 since 0715 MDT, total on the ground 6.8". Snow ended ~ 0500 MDT 30 Oct. At 0700 MDT, 7° with breaks in the overcast. Min was 6° at 0630 MDT, which, if official, ties record minimum for the date. New accumulation +1.6" since 1710 MDT 29 Oct, precip +.13. Total on ground 7.7", max measured.
10/31/2019 7:00 AM T T M 6.0 M SW-- 0850-0910 MDT 30 Oct 2019. Trace precip, trace accumulation. Six inches of snow remains on the ground at obs time.
11/1/2019 7:00 AM 0.00 0.0 M 4.5 M 4.5" of snow remains on the ground at obs time.
11/2/2019 7:00 AM 0.00 0.0 M 3.5 M 3.5" of snow remains on the ground at obs time.
11/3/2019 7:00 AM 0.00 0.0 M 3.0 M 3.0" of snow remains on open ground at obs time
11/4/2019 7:00 AM 0.00 0.0 M 1.0 M 1" of snow remains on open ground with 60% coverage.
11/5/2019 7:00 AM 0.00 0.0 M T M Snow remains only in shaded areas. Open ground completely clear.
11/6/2019 7:00 AM 0.00 0.0 M T M Snow remains in shaded areas.
11/7/2019 7:00 AM 0.10 0.0 M T M Drizzle began 1550 MDT 06 Nov 2019, became freezing drizzle (ZL-) ~1800 MDT as temperature fell to 32 deg. ZL- ended ~0200 07 Nov. Precip .10. Glace ice on exposed surfaces but not on pavement. At obs time, patchy snow remains in shaded areas.
11/8/2019 7:00 AM 0.00 0.0 M 0.0 M
11/9/2019 7:00 AM 0.00 0.0 M 0.0 M
11/10/2019 7:00 AM 0.00 0.0 M 0.0 M
11/11/2019 7:50 AM 0.11 2.8 M 2.8 M Strong cold front passage at 1850 MST 10 Nov 2019. Freezing drizzle began 2300 MST, changed to S- at 0030 MST 11 Nov. S- still in progress at obs time, 0750 MST. At this time, 13 deg F, having fallen from 71 deg at 1330 MST on 10 Nov, a drop of 58 deg in just over 18 hours. 2.8" of snow on the ground. 24-h precip 0.11".
11/12/2019 7:00 AM T T M 1.5 M Very light snow at start of observing period at 0750 MST 11 Nov 2019. After a couple of brief very light snow showers, precip ended at 0930 MST. Trace accumulation, trace precip.
11/13/2019 7:00 AM 0.00 0.0 M T M Patchy snow remains in well shaded areas.
11/14/2019 7:00 AM T 0.0 M 0.0 M RW-- 0130-0215 MST 14 Nov 2019. Trace precip.
11/15/2019 7:00 AM 0.00 0.0 M 0.0 M
11/16/2019 7:00 AM 0.00 0.0 M 0.0 M
11/17/2019 7:00 AM T 0.0 M 0.0 M Brf RW-- sometime between 1830 and 1930 MST 16 Nov 2019. Trace precip.
11/18/2019 7:00 AM 0.00 0.0 M 0.0 M
11/19/2019 7:00 AM 0.00 0.0 M 0.0 M
11/20/2019 7:00 AM 0.00 0.0 M 0.0 M
11/21/2019 8:40 AM 0.20 0.6 M 0.6 M R- began 1445 MST 20 Nov 2019. At 1540 MST, R- and 40°. R-S- by 1605 MST and 37°. Quarter-size flakes in S- by 1700 MST. S- became S-- ~1800 MST with temperature at 33° and an accumulation of 0.5". Light to very light freezing drizzle began 2100 MST and continued thru the night, probably amounting to a few hundredths inch of precip. At obs time of 0840 MST 21 Nov, very light freezing drizzle, snow accumulation 0.6" with a brittle icy crust on top of the snow.
11/22/2019 7:00 AM 0.21 2.9 M 3.5 M
11/23/2019 7:00 AM T M M 3.0 M Very light snow ended by 0930 MST 22 Nov 2019. Trace precip. 3.0" of snow remains on open ground.
11/24/2019 7:00 AM 0.00 0.0 M 1.0 M About one inch of snow remains in open areas with 50% coverage.
11/25/2019 7:00 AM 0.00 0.0 M T M Snow remains in shaded areas.
11/26/2019 7:00 AM 1.44 17.0 M 17.0 M Measurable precip began 1440 MST 25 Oct 2019. Ground became white by 1530 MST. S1/2 1600-1700 MST, then back to S-1-2. At 2210 MST, 26° (min so far), S-3/4, now larger flakes, whereas earlier crystals were small and partially rimed, accumulation on snow board 5.0", water content .59". S1/2-3/4 thru 0230L, by which time snow depth estimated at 9” and 26°. S+1/4 after 0230 MST. Snow fell at the rate of 1.5-2.0” per hour. At obs time, 0700 MST, 23° (min so far), S+1/4, accumulation 17.0" on snowboard. Precip +.85 since 2210 MST 25 Nov. 24-h precip 1.44".
11/27/2019 7:00 AM 0.24 2.7 M 16.5 M S+1/4 (heavy snow) falling at start of observing period. Decreasing snowfall after 0830 MST 26 Nov. Snow ended at noon. Max depth on snowboard and open grassy area 19.7" at 1145L. This was the 2nd greatest snowfall in < 24 h since we moved to Boulder in 1971. 16.5" remains on ground at obs time.
11/28/2019 7:00 AM 0.00 0.0 M 13.0 M 13.0" snow remained on ground at obs time.
11/29/2019 7:00 AM 0.00 0.0 M 11.5 M 11.5" of snow remains on ground at obs time.
11/30/2019 7:00 AM 0.06 0.5 M 11.0 M SW- began ~1900 MST 29 Nov 2019. S-- still falling at 2015L, ending by 2100 MST. New accumulation 0.5", precip .06". At end of observing period, 11.0" of snow remained on the ground.
12/1/2019 7:00 AM 0.00 0.0 M 8.5 M
12/2/2019 7:00 AM 0.00 0.0 M 8.5 M 8.5" snow remains on ground at obs time. Very little melting yesterday.
12/3/2019 7:00 AM 0.00 0.0 M 6.0 M 6.0" of slushy snow remains on open ground at obs time.
12/4/2019 7:00 AM 0.00 0.0 M 4.5 M 4.5" of dense snow cover remains on ground at obs time.
12/5/2019 7:00 AM 0.00 0.0 M 4.0 M 4.0" of dense snow cover remains on ground at obs time.
12/6/2019 7:00 AM 0.12 T M 3.5 M R-- began ~1000 MST 05 Dec 2019 with R- during the afternoon, changing to wet snow S- ~1630 MST as temperature slowly fell to a daytime min of 33°. Snow did not stick. Only a trace on the surface of the old snow. Precip ended ~1800 MST. Precip .12", Trace accumulation. 3.5" of snow left at obs time, so crusty you can almost walk on its surface.
12/7/2019 7:00 AM 0.00 0.0 M 3.0 M
12/8/2019 7:00 AM 0.00 0.0 M 1.5 M Lots of snow melted yesterday as west wind blew and temperature reached 61 deg F. 1.5" remains on open ground at obs time with 50% coverage.
12/9/2019 7:00 AM T 0.0 M T M Dissipating showers moving off foothills brought sprinkles at 1545 and 1745 MST. Trace precip. Snow remains in shaded areas.
12/10/2019 7:00 AM 0.00 0.0 M T M Snow remains in shaded areas.
12/11/2019 7:00 AM 0.00 0.0 M T M Snow remains in shaded areas.
12/12/2019 7:00 AM 0.00 0.0 M T M Snow remains in shaded areas.
12/13/2019 7:00 AM 0.00 0.0 M T M Snow remains in shaded areas.
12/14/2019 7:00 AM T T M T M SW-- ~0500 MST 14 Dec 2019, enough to whiten pavement but not grass. Snow remains in shaded areas.
12/15/2019 7:00 AM 0.02 0.2 M 0.2 M Dim sunshine thru clouds late morning 14 Dec 2019, with occasional flakes in the air 1000-1430 MST, then steady S- as a narrow band of snow, oriented E-W passed overhead. S- ended at 1520 MST. Accumulation 0.2", precip 0.02". Old snow still remains in shaded areas.
12/16/2019 7:00 AM 0.00 0.0 M T M Old snow remains in shaded areas.
12/17/2019 7:00 AM 0.00 0.0 M T M Old snow remains in shaded areas.
12/18/2019 7:00 AM 0.00 0.0 M T M Snow remains in shaded areas.
12/19/2019 7:00 AM 0.00 0.0 M T M Old snow remains in shaded areas.
12/20/2019 7:00 AM 0.00 0.0 M T M Old snow remains in shaded areas.
12/21/2019 7:00 AM 0.00 0.0 M T M Old snow remains in shaded areas
12/22/2019 7:00 AM 0.00 0.0 M T M Patchy snow remains in well shaded areas.
12/23/2019 7:00 AM 0.00 0.0 M T M Patchy snow still remains in well shaded areas.
12/24/2019 7:00 AM 0.00 0.0 M T M Patchy old snow remains in well shaded area.
12/25/2019 7:00 AM 0.00 0.0 M T M Patchy old snow remains in well shaded areas.
12/26/2019 7:00 AM T 0.0 M 0.0 M Sprinkles of rain between 1230 and 1300 MST 25 Dec 2019. Trace precip. A few ice needles, 1-2 mm long, fell from fog between 0600 and 0700 MST 26 Dec 2019. Trace pcpn, but enough to dampen pavement.
12/27/2019 7:00 AM T 0.0 M 0.0 M A few ice needles, 1-2 mm long, fell from fog between 0700 and 0800 MST 26 Dec 2019. Trace precip. No accumulation.
12/28/2019 7:00 AM 0.10 1.7 M 1.7 M S- began ~0230 MST 28 Dec. At obs time (0700 MST), S-1, 1.7" accumulation on snowboard and .10" precip.
12/29/2019 7:00 AM 0.06 1.1 M 2.0 M S-3/4 in progress at obs time, 0700 MST 28 Dec 2019. This tapered off to very light snow by 1000 MST, with 1.1" new and total on the ground of 2.8". Precip since 0700 MST .06". Snow ended completely by noon. 2.0" remains on ground at obs time.
12/30/2019 7:00 AM 0.00 0.0 M 1.5 M 1.5" of snow remains on the ground.
12/31/2019 7:00 AM 0.00 0.0 M 1.5 M 1.5" of snow remains in open areas at obs time.
1/1/2020 7:00 AM 0.00 0.0 M T M Snow cover on open ground (about one inch) decreased to 40% on the afternoon of 31 Dec 2019.
1/2/2020 7:00 AM 0.00 0.0 M T M Patchy snow remains in shaded areas.
1/3/2020 7:00 AM 0.00 0.0 M T M Patchy snow remains in well shaded areas.
1/4/2020 7:00 AM 0.00 0.0 M T M Spotty snow remains in well shaded areas.
1/5/2020 7:00 AM 0.00 0.0 M 0.0 M
1/6/2020 7:00 AM 0.00 0.0 M 0.0 M
1/7/2020 7:00 AM 0.00 0.0 M 0.0 M
1/8/2020 7:00 AM 0.00 0.0 M 0.0 M
1/9/2020 7:00 AM 0.00 0.0 M 0.0 M
1/10/2020 7:00 AM 0.00 0.0 M 0.0 M
1/11/2020 7:00 AM T 0.0 M 0.0 M A few snowflakes in the air 1130-1200 MST, 10 Jan 2020. Trace precip. No accumulation.
1/12/2020 7:00 AM 0.00 0.0 M 0.0 M
1/13/2020 7:00 AM 0.00 0.0 M 0.0 M
1/14/2020 7:00 AM T 0.0 M 0.0 M A few snowflakes in the air ~1400 MST 13 Jan 2020. Trace precip. No accumulation.
1/15/2020 7:00 AM 0.00 0.0 M 0.0 M
1/16/2020 7:00 AM 0.00 0.0 M 0.0 M
1/17/2020 7:00 AM 0.00 0.0 M 0.0 M
1/18/2020 7:00 AM T 0.0 M 0.0 M Brief SW-- 1100-1130 MST 17 Jan 2020, enough to wet pavement. Trace precip, no accumulation. A few flakes in the air at 1430 MST. Trace precip, no accumulation.
1/19/2020 7:00 AM 0.00 0.0 M 0.0 M
1/20/2020 7:00 AM 0.00 0.0 M 0.0 M
1/21/2020 7:00 AM 0.00 0.0 M 0.0 M
1/22/2020 7:00 AM 0.00 0.0 M 0.0 M
1/23/2020 7:00 AM 0.00 0.0 M 0.0 M
1/24/2020 7:00 AM 0.00 0.0 M 0.0 M
1/25/2020 7:00 AM 0.00 0.0 M 0.0 M
1/26/2020 7:00 AM 0.00 0.0 M 0.0 M
1/27/2020 7:00 AM 0.00 0.0 M 0.0 M
1/28/2020 7:00 AM 0.00 0.0 M 0.0 M
1/29/2020 7:00 AM 0.00 0.0 M 0.0 M
1/30/2020 7:00 AM T 0.0 M 0.0 M SPW-- (a few snow pellets in the air) at 1850 MST 29 Jan 2020 with the temperature at 36°. Trace precip, no accumulation
1/31/2020 7:00 AM T T M 0.0 M Tiny ice needles about the size of iron filings, fell from the fog 0750-0755 MST, 30 January 2020, and intermittently after that until about 0815 MST, depositing dusting on pavement. Trace precip, trace accumulation. A few flakes reached our neighborhood from the foothills ~1630 MST. Trace precip. No accumulation.
2/1/2020 7:00 AM 0.00 0.0 M 0.0 M
2/2/2020 7:00 AM 0.00 0.0 M 0.0 M
2/3/2020 7:00 AM 0.05 0.0 M 0.0 M Strong frontal passage at 2110 MST 02 Feb 2020 after an afternoon record max of 75 deg F. Freezing drizzle began at 0330 MST 03 Feb and was still falling at 0700 MST with a temperature of 25 deg F. A thin coating of ice on exposed surfaces but warm pavement only wet.
2/4/2020 7:00 AM 0.44 8.1 M 8.1 M Continuous precip throughout 24-hour observation period. Freezing drizzle at the start (0700 MST 03 Feb 2020). Rimed flakes began falling by 0715 MST. All S- by 0800 MST. By 1030 MST, snowfall intensified. Moderate snow, visibility 3/8 to 1/2 mile, 1030-1200 MST, during which time ~2" of snow fell. Quarter-size flakes of dendrite crystals during this time. After 1200 MST, S-, visibility 3/4 to 1.5 miles. S- continued steadily through the rest of the observing period. At 2000 MST, S-1, very small individual crystals falling, total accumulation 6.0", precip since 0700 MST +.23". At 0700 MST 04 Feb 2003, S-1, 12 deg F (minimum so far), total accumulation 8.1", precip since 2000 MST 03 Feb +.21" for a 24-h total of 0.44" and a storm total so far of 0.49".
2/5/2020 7:00 AM 0.05 0.5 M 6.0 M S- in progress at start of observing period. Sun dimly visible by 0845 MST 04 Feb 2020L, when measurable snow stopped, but occasional S-- continued until midday. Additional precip .05", accumulation 0.5", but this did not add to the total on the ground, 8.1" as measured at 0700 MST 04 Feb. 6.0" on the ground at 0700 MST 05 Feb.
2/6/2020 7:00 AM 0.00 0.0 M 5.0 M
2/7/2020 7:00 AM 0.15 1.6 M 6.8 M S- began ~2000 MST 06 Feb and continued for the next 90 min with visibility ~1.5 miles. S-3/4 to S1/2 from 2130-2200 MST. Est accumulation by 2200 MST 1.0". S- ended by 0030 MST 07 Feb with 1.6" new snow, 0.15" precip, and total on the ground of 6.8".
2/8/2020 7:00 AM 0.10 1.1 M 7.5 M Snow began again shortly after 0700 MST 07 Feb 2020. At 0825 MST 0.2” of new snow, precip so far .01", and 7.0” total on the ground with S-1 still falling, tiny crystals. Lull in snowfall 1100-1430 MST, then S- til 1630 MST. Heavy snow bands, especially S of Boulder during the day, but we were not affected. S-- after from 1630 to 1930 MST. 24-h snowfall 1.1" with a water content of .10". 7.5" of snow on the ground at time of observation.
2/9/2020 7:00 AM 0.09 1.0 M 7.0 M S- began ~0530 MST 09 Feb 2020 and continues at observation time: S-3/4, 27° (minimum so far), new accumulation 1.0", precip .09", total depth on the ground 7.0".
2/10/2020 7:00 AM 0.20 2.7 M 8.5 M S-3/4 in progress at start of observing period. Snowfall S-3/4, occasionally, S1/2 until noon. Mostly S-- after 1200 MST. At 1700 MST, 26°, S-2, precip since 0700 MST .19", accumulation since 0700 MST 2.6". Max depth on the ground measured at this time: 9.1". S-- ended by 1800 MST with 0.1" additional accumulation, .01 additional precip. 8.5" remained on ground at obs time this morning.
2/11/2020 7:00 AM 0.31 5.4 M 11.5 M S- began 1745 MST 10 Feb 2020. At 2150 MST, 2.8” measured new accumulation,S-3/4, 24°. Light or moderate snowfall ended 0300 MST 11 Feb. Clearing before dawn with a minimum temperature of 5 deg F. At obs time, 5.4" new snow, total on ground 11.5", precip 0.31".
2/12/2020 7:00 AM 0.00 0.0 M 10.0 M
2/13/2020 7:00 AM 0.19 2.1 M 11.5 M Flakes in the air by 1315 MST 12 Feb 2020. S-3/4 1430-1515 MST, then off and on S-- until 2015 MST, when S- began again. At 2110 MST, S-3/4, accumulation so far today 1.6” (precip not measured). Measurable snow stopped ~2300 MST, and S-- stopped ~0100 MST 13 Feb. Totals for this snowfall: 2.1" new accumulation and 0.19" precip. 11.5" snow on the ground at obs time.
2/14/2020 7:00 AM 0.00 0.0 M 10.0 M
2/15/2020 7:00 AM 0.00 0.0 M 7.5 M Max temperature 58 deg F on the afternoon of 15 Feb 2020, with downslope breezes 10G20. This melted significant snow, but still 7.5" on the ground at obs time.
2/16/2020 7:00 AM 0.00 0.0 M 6.5 M 6.5" of crusty snow remains on the ground at obs time.
2/17/2020 7:00 AM 0.00 0.0 M 6.0 M 6.0" of crusty snow remains on the ground at obs time.
2/18/2020 7:00 AM 0.02 0.2 M 5.0 M S- began ~2045 MST 17 Feb 2020 and, by 2130 MST, was enough to wet the pavement. Snow ended ~2330 MST. New accumulation 0.2", precip .02". 5.0" of snow remained on the ground at obs time.
2/19/2020 7:00 AM 0.00 0.0 M 5.0 M 5.0" of crusty snow remains on the ground at obs time.
2/20/2020 7:00 AM 0.15 4.1 M 8.5 M A few flakes in the air during the morning of 19 Feb 2020. Measurable snow, S-1-2, began ~1230 MST but did not accumulate on pavement. Bare ground started to turn white ~1430 MST. Between 1545 and 1730 MST, S-3/4, briefly S1/2, with falling temperature. Snow very fluffy. S-1-2 after 1730 MST. At 2030 MST, 4.0” new on snowboard, total of 9.0" on the ground (max measured). 0.1" more snow before it ended around 2245 MST, with minute ice crystals in the air and stars coming out. Water content of all snow just 0.15", for a snow to liquid ratio of about 27:1. 8.5" remained on the ground at obs time, 0700 MST 20 Feb.
2/21/2020 7:00 AM 0.00 0.0 M 6.0 M 6.0" of snow remains on the ground at observation time.
2/22/2020 7:00 AM 0.00 0.0 M 4.0 M 4.0" of snow remains in open areas.
2/23/2020 7:00 AM 0.00 0.0 M 3.5 M 3.5" of snow remains in open areas.
2/24/2020 7:00 AM 0.01 0.0 M 2.5 M SW- for about 10 minutes, starting at 1025 MST (.01" precip, melting as it fell). Occasional S-- for next two hours. Trace precip. No accumulation. At obs time 2.5" of snow remains on open ground, but the ground is already bare under and near trees.
2/25/2020 7:00 AM T 0.0 M 2.0 M SW-- 0755 to 0800 MST 24 Feb 2020. Trace precip with just a few flakes in the air. No accumulation.
2/26/2020 7:00 AM 0.00 0.0 M 2.0 M 2" of crusty snow remains in open areas at obs time.
2/27/2020 7:00 AM 0.00 0.0 M 1.0 M 1.0" of crusty snow remains on open ground with 70% coverage.
2/28/2020 7:00 AM 0.00 0.0 M T M 27 Feb began with about an inch of snow covering 80% of open ground. By mid afternoon the coverage had shrunk to 20%, ending a 24-day continuous stretch of 1" snow cover or more.
2/29/2020 7:00 AM 0.00 0.0 M T M 1-3" of snow remains in shaded areas. Ground is bare in open areas.
3/1/2020 7:00 AM 0.00 0.0 M T M A couple of inches of snow remains in shaded areas at obs time.
3/2/2020 7:00 AM 0.35 4.2 M 4.2 M A few small snow pellets were in the air ~1300 MST 01 Mar 2020, but only occasional SW-- until measurable snow began at 1700 MST. Visibility generally 3/4 mile but occasionally 1/2 mile thru the evening as S- continued. S- ended ~0100 MST 02 March and S-- ended by 0200 MST. Storm total accumulation 4.2", precipitation 0.35".
3/3/2020 7:00 AM 0.00 0.0 M 1.0 M 1.0" of snow remains on open ground.
3/4/2020 7:00 AM 0.00 0.0 M T M Snow remains in shaded areas at obs time.
3/5/2020 7:00 AM 0.00 0.0 M T M Snow remains in shaded areas.
3/6/2020 7:00 AM 0.00 0.0 M T M Patchy snow remains in well shaded areas.
3/7/2020 7:00 AM 0.00 0.0 M 0.0 M All snow melted yesterday, 06 March 2020, even in the shade as temperature reached 67 deg F.
3/8/2020 7:00 AM 0.00 0.0 M 0.0 M
3/9/2020 7:00 AM 0.16 0.0 M 0.0 M Two periods of RW-, the first from 2030-2115 MDT 08 Mar 2020, brought most of the evening’s rainfall. The second, from 2230-2245 MDT, delivered a few hundredths. Total .16”
3/10/2020 7:00 AM 0.00 0.0 M 0.0 M
3/11/2020 7:00 AM 0.00 0.0 M 0.0 M
3/12/2020 7:00 AM 0.00 0.0 M 0.0 M
3/13/2020 7:00 AM 0.00 0.0 M 0.0 M
3/14/2020 7:00 AM 0.12 1.0 M 0.8 M S-/S-- with visibility 2-3 miles began 0955 MST 13 Mar 2020L. Snow was just enough to keep the pavement damp. It ended ~1230 MST. Trace precip. An area of snow showers (20-30 dBZ radar echoes) moved NE over Boulder between 1725 and 1915 MST. Large flakes, some nearly an inch across, predominated, SW½, briefly SW+¼. About 1.0” accumulation of wet snow (temperature did not fall below 33°) with a water content of .12". 0.8" of snow remains on the ground at obs time .
3/15/2020 7:00 AM T 0.0 M 0.0 M Very light drizzle, probably between 0300 and 0600 MST 15 Mar 2020. Trace precip.
3/16/2020 7:00 AM 0.00 0.0 M 0.0 M
3/17/2020 7:00 AM 0.01 0.0 M 0.0 M Occasional drizzle between 0300 and 0600 MST 17 Mar 2020. Precip .01".
3/18/2020 7:00 AM 0.00 0.0 M 0.0 M
3/19/2020 7:00 AM 0.19 0.0 M 0.0 M Drizzle began ~0200 MST 19 Mar 2020. R- began ~0300 MST. By 0400 MST, pcpn .02 with R- continuing. At 0700 MST, moderate rain, precip so far .19, and 37°.
3/20/2020 7:00 AM 1.60 8.5 M 8.5 M Moderate rain at start of observing period, 0700 MST 19 Mar 2020. At 0845 MST, 34°, moderate rain and snow mixed, visibility 1 mile, precip since 0700 MST .28". By 1015 MST, estimated 1.5” accumulation and S 1/2. At 1115 MST, very large flakes, 1.0-1.5” in diameter in the air, each containing hundreds of smaller crystals. Quite a sight! At 1220 MST, S 3/8, 5.5” accumulation on the lawn, water content since 0845 MST +.77, smaller flake size. Very dense, wet snow. Temperature has still not fallen below 33°. By 1430 MST, snowfall had slackened some with smaller flakes. At 1930 MST, S-, 1 mile visibility, temperature had finally fallen to 32° (min so far), 8.0” accumulation on the lawn, water content +.35 since 1220 MST. Snow became very light by 2100 MST and ended ~0300 MST 20 Mar. Max depth 8.5". Precip since 1930 MST 19 Mar +0.20". 24-h total 1.60".
3/21/2020 7:00 AM 0.02 0.2 M 6.5 M Starting ~1230 MST 20 Mar 2020, tiny crystals of snow began to fall from low stratus in intermittent showers. This continued until ~1345 MST. For the next 90 minutes there were a couple of SW-. Sun dimly visible near end of SW-, but low overcast never broke. Cells moved slowly E. Precip .02, new accumulation +0.2. 6.5" of snow remains on ground at obs time, the bottom 2" very dense.
3/22/2020 7:00 AM 0.00 0.0 M 4.0 M 4.0" of very crusty snow remains on ground at obs time.
3/23/2020 7:00 AM 0.00 0.0 M 1.5 M About 1.5" of snow remains in open areas at 0700 MST 23 Mar 2020.
3/24/2020 7:00 AM T 0.0 M T M Snow in open areas was gone by 1400 MST 23 Mar 2020. Snow remains at obs time only in shaded areas. RW-- 1750-1755 MST 23 Mar. Trace precip.
3/25/2020 7:00 AM 0.00 0.0 M 0.0 M
3/26/2020 7:00 AM 0.00 0.0 M 0.0 M
3/27/2020 7:00 AM 0.00 0.0 M 0.0 M
3/28/2020 7:00 AM 0.36 1.2 M 1.1 M R-- began ~1515 MST 27 Mar 2020. Pavement wet by 1700 MST. R- changed to S- between 1730 and 1800 MST. Perhaps a few hundredths precip fell as rain. Grass and rooftops white by 1830 MST. At 1915 MST, S½, accumulation ~0.5", no wind, 33°. S½ did not last long, maybe an hour. At 2200 MST S-1, acc 1.1” (precip not measured), still 33°. Sidewalks and streets just wet. S-- ended 2330L MST with estimated +0.1 accumulation. Storm total .36". Max depth 1.2".
3/29/2020 7:00 AM 0.00 0.0 M 0.0 M All snow melted by mid afternoon on 28 March 2020.
3/30/2020 7:00 AM 0.00 0.0 M 0.0 M
3/31/2020 7:00 AM T 0.0 M 0.0 M Brief RW-- ~1500 MST 30 March 2020, enough to dampen the pavement, but it evaporated within minutes. Trace precip.
4/1/2020 7:00 AM 0.00 0.0 M 0.0 M
4/2/2020 7:00 AM 0.05 0.0 M 0.0 M Drizzle began 0100 MST 02 Apr 2020, changed to ZL- ~0400 MST as the temperature fell to 32°. At 0700 MST, 28° (min so far), ZL-, pcpn .05.
4/3/2020 7:00 AM 0.11 0.6 M 0.6 M Light freezing drizzle (ZL-) throughout the morning of 02 April 2020, enough to keep the pavement wet, but drizzle froze only on trees, shrubs, and lawns. A few small heavily rimed pellets in the air by 1130 MST as the temperature fell to 24°. All S-- by 1400 MST. Pavement remained damp. Unrimed S- by 1515 MST, began to whiten grass by 1530 MST, but snowfall remained very light until two 10-min snowshowers: SW 1/2 starting at 1655 MSTL and another SW? 3/4 starting at 1910L. S-- continued until 2000 MST. Precip since 0700 MST .11”. Max accumulation 0.6". S-- 0000 to 0200 MST 03 April. Trace precip.
4/4/2020 7:00 AM 0.00 0.0 M 0.0 M
4/5/2020 7:00 AM 0.00 0.0 M 0.0 M
4/6/2020 7:00 AM 0.00 0.0 M 0.0 M
4/7/2020 7:00 AM 0.00 0.0 M 0.0 M
4/8/2020 7:00 AM 0.00 0.0 M 0.0 M
4/9/2020 7:00 AM 0.00 0.0 M 0.0 M
4/10/2020 7:00 AM 0.00 0.0 M 0.0 M
4/11/2020 7:00 AM 0.00 0.0 M 0.0 M
4/12/2020 7:00 AM 0.35 6.5 M 6.5 M Strong frontal passage at 2230 MDT 11 Apr 2020 with temperature at 58 deg F. Snow began ~0130 MDT 12 Apr with temperature already down to 32°. By 0230 MST S-1, 27°, ground dusted white. Moderate to heavy snow fell as a 30-mile wide band of snow, reflectivity 25-30 dBZ, passed over, best guess from 0300-0500 MST. At 0700 MST, 21°, S-1, accumulation 6.5" of fairly fluffy snow on front lawn with a water content of 0.35". Almost no wind.
4/13/2020 7:00 AM 0.49 6.5 M 13.0 M S-3/4 at start of observing period (0700 MDT 12 Apr 2020). Accumulating snow ended by 0845 MDT. After that occasional SW-- and sun dimly visible thru stratus clouds. Pavement dry for part of the time from 0930 thru 1400 MDT. S-/SW- with visibility 3/4 to 1 mile began ~1450 MDT and continued for the rest of the afternoon. At 1940 MDT, 23°, S-1½, accumulation 7.5" on the front lawn, precip since 0700 MDT 0.17". S- continued until a weak secondary push of cold air arrived ~0230 MDT 13 April, with a drop in temperature from 22° to 18°, a N breeze 4-8 mph, and an increase in snowfall rate to S1/2 which probably continued for at least two hours. Steady S- from 0430 to obs time. At 0700 MDT 13 Apr 2020, 15 deg F (minimum so far), S-1 falling, 13.0" on front lawn, precip since 1940 MDT 12 April 0.32", 24-h total precip 0.49, new snow in past 24 h, 6.5".
4/14/2020 7:00 AM 0.11 1.5 M 9.5 M S-1 in progress at start of observing period (0700 MDT 13 Apr 2020). Accumulating snow stopped at 0710 MDT. Streets and pavement had less than an inch of slush on them. This melted by 1000 MDT. After 0710 MDT, conditions varied from S--3 to SW-1. By 1100 MDT, snow became more steady at S-1½. Mostly S-- after 1300 MDT. At 1600 MDT sun bright enough thru stratus overcast to cast shadows, and steam rose from the wet street. S-- finally ended 1730 MDT. At 1940 MDT, 23°, 10.5" accumulation on the lawn, precip since 0700 MDT 0.11", new snowfall estimated at 1.5”, but settling rate far exceeded accumulation rate during the day. The minimum temperature at dawn on 14 Apr was 10 deg F, a new daily record minimum. 9.5" on the ground at 0700 MDT.
4/15/2020 7:00 AM 0.00 0.0 M 3.0 M Nearly six inches of snow melted during the day on 14 April 2020. 3.0" of crusty snow remained at 0700 MDT 15 April.
4/16/2020 7:00 AM 1.00 12.0 M 12.0 M 3.0” of crusty snow remained on the ground at 0700 MDT 15 Apr 2020. Snow cover in open areas dropped to <50% by noon. Ground bare in open areas by 1600 MDT as temperature reached max of 49 deg F. Abrupt cold front passage at 1652 MDT. R- began at 1900 MDT with temperature at 40 deg F. 0.02" precip fell as rain. Grass became white by 2030 MDT at 34°. Thereafter snow fell at the rate of 1" per hour thru obs time (0700 MDT 16 Apr). 12.0" new snow now on ground with a water content of 0.98. Storm total so far 1.00".
4/17/2020 7:00 AM 0.50 4.7 M 14.5 M At start of observing period (0700 MDT 16 April 2020), S1/2 (small crystals, some of them rimed), 27° (min so far), 12” of snow on the ground. Accumulation stopped at 0800 MDT , but S-- continued, occasionally S- with small crystals and riming. At 1145 MDT, S-3/4, and accumulation resumed. At 1300L snowfall rate increased to moderate (S1/2). This lasted until 1600 MDT when snowfall became light, S-3/4. At 1700 MDT, S-1½, 29°, accumulation 14.8" (max measured), precip since 0700 MDT 0.44" and new snowfall 4.0". 2045 MDT: S- ended. The last hour or so featured unrimed dendrites. Very fluffy. +0.7 accumulation, +.06 precip. Clearing before 0000 MDT 17 April, calm wind, and colder. Min of 9° at dawn set a new late-season record min for Boulder.
4/18/2020 7:00 AM 0.00 0.0 M 7.0 M 7.0" of crusty snow remained at obs time.
4/19/2020 7:00 AM T 0.0 M 4.0 M Brief RW-- between 1500 and 1600 MDT 18 Apr 2020, only a few droplets. Trace precip. 4.0 inches of crusty snow remained at obs time.
4/20/2020 7:00 AM 0.00 0.0 M T M Snow cover on open ground completely melted by 1700 MDT 19 Apr 2020. Snow remains in shaded areas.
4/21/2020 7:00 AM 0.00 0.0 M 0.0 M All snow melted yesterday, even in shady areas.
4/22/2020 7:00 AM 0.00 0.0 M 0.0 M
4/23/2020 7:00 AM T 0.0 M 0.0 M A few drops of rain 1300-1330 MDT 22 Apr 2020. Trace precip. RW-- 1345-1410L (T) just enough to dampen the pavement. Trace precip.
4/24/2020 7:00 AM 0.02 0.0 M 0.0 M RW- 2300-2400 MDT 23 April 2020. Precip 0.02".
4/25/2020 7:00 AM 0.05 0.0 M 0.0 M RW-- ~1000 MDT 24 Apr 2020. Trace precip. RW- 1100-1115 MDT. Brief RW- ~1315 MDT. Precip from both showers .05". RW-- ~0145 MDT 25 Apr. Trace precip.
4/26/2020 7:00 AM 0.00 0.0 M 0.0 M
4/27/2020 7:00 AM 0.00 0.0 M 0.0 M
4/28/2020 7:00 AM 0.00 0.0 M 0.0 M
4/29/2020 7:00 AM 0.00 0.0 M 0.0 M
4/30/2020 7:00 AM 0.00 0.0 M 0.0 M
5/1/2020 7:00 AM T 0.0 M 0.0 M A few raindrops ~2000 MDT 30 April 2020. Trace precip.
5/2/2020 7:00 AM T 0.0 M 0.0 M A few raindrops ~1600 MDT 01 May 2020. Trace precip.
5/3/2020 7:00 AM 0.21 0.0 M 0.0 M A few drops of rain ~0900 MDT 02 May. Trace precip. Another RW-- 1435-1445 MDT Trace precip. Brief RW 1800-1805 MDT brought a quick .09" precip. Another round of RW- 2040-2110 MDT. Precip +.12".
5/4/2020 7:00 AM 0.05 0.0 M 0.0 M RW-- at 1815 MDT 03 May 2020 with a few large drops. Trace precip. Two rumbles of thunder 2230-2300 MDT, the first of the season and lighting visible E. Also a few drops of rain during this time. Trace precip. RW- between 0000 and 0100 MDT 04 May, perhaps measurable, then RW- 0400-0630 MDT. Overnight (and 24-hour) precip .05".
5/5/2020 7:00 AM 0.00 0.0 M 0.0 M
5/6/2020 7:00 AM 0.00 0.0 M 0.0 M
5/7/2020 7:00 AM 0.00 0.0 M 0.0 M
5/8/2020 7:00 AM 0.03 0.0 M 0.0 M R- or L- from 0430 to 0600 MDT 08 May 2020. Precip .03".
5/9/2020 7:00 AM 0.00 0.0 M 0.0 M
5/10/2020 7:00 AM 0.00 0.0 M 0.0 M
5/11/2020 7:00 AM 0.00 0.0 M 0.0 M
5/12/2020 7:00 AM 0.11 0.0 M 0.0 M Occasional RW- 1045-1500 MDT 11 May 2020. Precip .10". Drizzle 0400-0600 MDT 12 May. Precip +.01.
5/13/2020 7:00 AM 0.00 0.0 M 0.0 M
5/14/2020 7:00 AM 0.00 0.0 M 0.0 M
5/15/2020 7:00 AM 0.26 0.0 M 0.0 M RW-- ~1000 MDT and again ~1200 MDT 14 May 2020. Trace precip. Brief TRW+ 1415-1425 MDT. Precip .21". RW- 1815-1830 MDT. Precip +.05".
5/16/2020 7:00 AM 0.09 0.0 M 0.0 M RW-- between 1200 and 1300 MDT 15 May 2020. Trace precip. Thunder heard 1730-1830 MDT as storm passed just N of Boulder ~1745 MDT and again 1815-1845 MDT as another thunderstorm passed to the SE. Intermittent RW-- or RW- 1800-1930 MDT. Precip .03". RW- 0200-0300 MDT 16 May 2020. Precip +.06".
5/17/2020 7:00 AM 0.00 0.0 M 0.0 M
5/18/2020 7:00 AM 0.00 0.0 M 0.0 M
5/19/2020 7:00 AM 0.00 0.0 M 0.0 M
5/20/2020 7:00 AM T 0.0 M 0.0 M A few drops of rain ~1600 MDT 19 May 2020. Trace precip.
5/21/2020 7:00 AM 0.00 0.0 M 0.0 M
5/22/2020 7:00 AM 0.00 0.0 M 0.0 M
5/23/2020 7:00 AM 0.00 0.0 M 0.0 M
5/24/2020 7:00 AM T 0.0 M 0.0 M RW-- ~1630 MDT 23 May 2020. Trace precip. RW-- again ~1830 MDT. Trace precip.
5/25/2020 7:00 AM 1.13 0.0 M 0.0 M RW- began 1015 MDT 24 May 2020. Rain became moderate and mostly steady after 1200 MDT. 0.91" precip by 1552 MDT with R continuing. Rainfall slackened to R- by 1630 MDT and ended ~1800 MDT. Precip +.20". Brief RW- ~2030 MDT brought +.02" precip for a 24-h total of 1.13".
5/26/2020 7:00 AM 0.00 0.0 M 0.0 M
5/27/2020 7:00 AM 0.00 0.0 M 0.0 M
5/28/2020 7:00 AM 0.09 M M M M RW-- ~1400 MDT 27 May 2020. Trace precip. Thunder heard 1815-1915 MDT. TRW- 1855-1920 MDT. Precip .09", ending with bright full rainbow and dim secondary.
5/29/2020 7:00 AM 0.04 0.0 M 0.0 M RW- ~2130 MDT 28 May 2020. Precip .04".
5/30/2020 7:00 AM T 0.0 M 0.0 M Thunder heard once ~ 1615 MDT 29 May 2020. RW-- ~1630 MDT. Trace precip.
5/31/2020 7:00 AM 0.08 0.0 M 0.0 M A few sprinkles ~1800 and again 2015 MDT. Trace precip. TRW- 2040-2100 MDT. Precip .08".
6/1/2020 7:00 AM 0.03 M M M M TRW- 1555-1630 MDT 31 May 2020. Precip .03"
6/2/2020 7:00 AM 0.00 0.0 M M M
6/3/2020 7:00 AM 0.04 M M M M TRW- 1545-1605 MDT 02 June 2020. Precip .04". A couple of cloud-to-ground lightning strikes nearby.
6/4/2020 7:00 AM 0.00 0.0 M M M
6/5/2020 7:00 AM 0.01 M M M M Dissipating shower moved off mountains ~1315 MDT, producing stiff outflow winds (G35) and some large raindrops, enough to wet the pavement by 1325 MDT, when rain ended. Precip .01".
6/6/2020 7:00 AM 0.01 M M M M A couple of rumbles of thunder in cloud 1450-1500 MDT 05 June 2020. RW- 1500-1515L. Precip .01". Cell moved ENE.
6/7/2020 7:00 AM 0.08 M M M M RW-- 0900-0915 MDT 06 June 2020. Trace precip. TRW 1525-1535 MDT. Precip .08". Strong outflow winds with gusts to 40 mph.
6/8/2020 7:00 AM 0.00 0.0 M M M
6/9/2020 7:00 AM 0.31 M M M M RW-/R- 2330 MDT 08 Jun 2020 thru 0430 MDT 09 Jun. Precip .31".
6/10/2020 7:00 AM 0.00 0.0 M M M
6/11/2020 7:00 AM 0.00 0.0 M M M
6/12/2020 7:00 AM 0.00 0.0 M M M
6/13/2020 7:00 AM 0.00 0.0 M M M
6/14/2020 7:00 AM 0.03 M M M M RW-- for a couple of minutes at 1230 MDT 13 Jun 2010, then TRW-- 1300-1315 MDT. Trace precip both times. TRW- 1555-1625 MDT with a few cloud-to-ground lightning strikes. Precip .03". Brief RW-- sometime between 2330 MDT 13 Jun and 0100 MDT 14 Jun. Trace precip.
6/15/2020 7:00 AM 0.00 0.0 M M M
6/16/2020 7:00 AM 0.00 0.0 M M M
6/17/2020 7:00 AM 0.00 0.0 M M M
6/18/2020 7:00 AM 0.00 0.0 M M M
6/19/2020 7:00 AM 0.86 M M M M R-- began at 1345 MDT 18 Jun 2020, enough to dampen pavement. R- by 1500 MDT. Precip .10" by 1630 MDT. Intermittent RW- thru 1845 MDT brought total to .20". At 2140 MDT, precip .33". R- quit ~2400 MDT, with total so far 0.51". More R-/RW 0430-0630 MDT 19 Jun. New precip .35", bringing 24-h total to .86".
6/20/2020 7:00 AM 0.12 0.0 M M M Narrow line of TRW, oriented NE-SW, passed over south Boulder 1430-1450 MDT 19 Jun 2020, coincident with a mid-level trough passage. Two close hits of cloud-to-ground lightning, the 2nd one causing a one-hour power outage. Fairly heavy rain initially, quickly tapering off. Precip .12".
6/21/2020 7:00 AM 0.00 0.0 M M M
6/22/2020 7:00 AM 0.19 M M M M TRW 1715-1740 MDT 21 Jun 2020 with lightning mostly in-cloud bit a couple of cloud-to-ground strokes. Precip 0.19".
6/23/2020 7:00 AM 0.00 0.0 M M M
6/24/2020 7:00 AM 0.00 0.0 M M M
6/25/2020 7:00 AM 0.05 M M M M Thunder heard 1820-1850 MDT 24 Jun 2020. All lightning in clouds. Sprinkles and gusty outflow winds SW 20G35 by 1830 MDT. Dark. Finally enough rain to wet pavement by 1920 MDT, while cooling gusty winds continued. 66° by 1930 MDT. Bright, full double rainbow at 1945 MDT, just before the rain stopped. Precip .05".
6/26/2020 7:00 AM T M M M M A few drops of rain ~1950 MDT during rather strong outflow (wind gusts to 35 mph) from dissipating showers passing off foothills. Trace precip.
6/27/2020 7:00 AM 0.39 M M M M RW-- 1230-1240 MDT 26 Jun 2020. Trace precip. RW- 1430-1445 MDT. Precip .01". Thunder heard starting 1520 MDT. TRW- began 1535 MDT. Pea-sized hail for ~2 min at 1627 MDT. TRW- ended 1645 MDT. Precip +.27". TRW/TRW- 1915-1935 MDT. Precip +.11". 24-h total .39".
6/28/2020 7:00 AM 0.00 0.0 M M M
6/29/2020 7:00 AM 0.02 0.0 M M M TRW- 1515-1530 MDT 28 Jun 2020. Precip .02".
6/30/2020 7:00 AM 0.00 0.0 M M M
7/1/2020 7:00 AM 0.12 M M M M RW- began 0925 MDT 30 Jun 2020. RWA 0943-0947 MDT, pea-sized hail. No thunder. Gusty SW winds to 25 mph during hail, and temperature fell to the daily minimum of 56°. RW- ended 0955 MDT. Precip .12".
7/2/2020 7:00 AM 0.00 0.0 M M M
7/3/2020 7:00 AM 0.00 0.0 M M M
7/4/2020 7:00 AM 0.00 0.0 M M M
7/5/2020 7:00 AM 0.00 0.0 M M M
7/6/2020 7:00 AM 0.00 0.0 M M M
7/7/2020 7:00 AM 0.00 0.0 M M M
7/8/2020 7:00 AM T M M M M A few drops of rain at 1100 MDT 07 Jul 2020. Trace precip. One rumble of thunder at 1240 MDT, then RW-- (big drops). Trace precip. RW-- with a few small drops at 1445-1500 MDT. Trace precip.
7/9/2020 7:00 AM 0.00 0.0 M M M
7/10/2020 7:00 AM 0.00 0.0 M M M
7/11/2020 7:00 AM 0.00 0.0 M M M Hottest day of the year so far: 99 deg F at 1545 MDT 10 July 2020.
7/12/2020 7:00 AM 0.00 0.0 M M M
7/13/2020 7:00 AM 0.00 0.0 M M M
7/14/2020 7:00 AM 0.02 M M M M TRW-A (hail diameter 1/8-1/4”) 1220-1230 MDT 13 Jul 2020. from a small cell passing to the E overhead with reflectivity of 50 dBZ. Just a couple of rumbles of thunder. Precip .02".
7/15/2020 7:00 AM 0.02 M M M M Brief RW- 2345-2400 MDT 14 July 2020. 0.02" precip.
7/16/2020 7:00 AM 0.00 0.0 M M M
7/17/2020 7:00 AM 0.00 0.0 M M M
7/18/2020 7:00 AM 0.00 0.0 M M M
7/19/2020 7:00 AM 0.00 0.0 M M M
7/20/2020 7:00 AM T M M M M Intermittent RW-- 1600-1700 MDT 19 Jul 2020. Trace precip.
7/21/2020 7:00 AM 0.00 0.0 M M M
7/22/2020 7:00 AM 0.00 0.0 M M M
7/23/2020 7:00 AM 0.03 M M M M TRW- (all lightning in clouds) 1800-1830 MDT 22 Jul 2020. Precip .03" with gusty outflow winds (G25). RW-- ~ 1930 MDT. Trace precip.
7/24/2020 7:00 AM T M M M M RW--, just a few drops ~1900 MDT 23 July 2020. Trace precip.
7/25/2020 7:00 AM 0.27 M M M M TRW- 1345-1445 MDT 24 Jul 2020. Precip .10". Then intermittent R- 1600-1745 MDT and one low rumble of thunder. Precip +.07". R- 2015-2230 MDT. Precip +.10". 24-h total .27".
7/26/2020 7:00 AM 0.08 M M M M RW- 1500-1600 MDT 25 Jul 2020. Precip .08".
7/27/2020 7:00 AM T M M M M Occasional sprinkles during the afternoon on 26 Jul 2020, ending at 1600 MDT. Trace precip.
7/28/2020 7:00 AM 0.00 0.0 M M M
7/29/2020 7:00 AM 0.02 M M M M A few brief RW- with large drops between 1400 and 1500 MDT 28 Jul 2020. Precip .02"
7/30/2020 7:00 AM 0.00 0.0 M M M
7/31/2020 7:00 AM T M M M M Light sprinkles 1600-1630 MDT 30 July 2020. Trace precip.
8/1/2020 7:00 AM 0.06 M M M M TRW- beginning at 1550 MDT 31 Jul 2020L. Thunder rumbled softly. RW- ended 1620 MDT. Precip .05". Large drops. RW-- ~1720 MDT. Trace precip. TRW- 2300-2330 MDT. Precip +.01".
8/2/2020 7:00 AM 0.01 M M M M RW-- (just a few drops) ~1500 MDT 01 Aug 2020. Trace precip. RW-- 1630-1650 MDT. Trace precip. RW- between 2030 and 2130 MDT. Precip .01". Brief RW-- ~2300 MDT. Trace precip.
8/3/2020 7:00 AM T M M M M A few drops of rain ~1415 MDT 02 Aug 2020. Trace precip.
8/4/2020 7:00 AM T M M M M A few drops of rain at 1330 MDT from a dissipating cloud. Trace precip. Brief TRW-- 2030-2045 MDT. Trace precip. All lightning in clouds.
8/5/2020 7:00 AM 0.03 M M M M RW- with large drops 1630-1645 MDT. Precip .03".
8/6/2020 7:00 AM 0.21 M M M M TRW- began at 1545 MDT 05 Aug 2020. TRW for ~15 min starting at 1600 MDT, then tapering and ending 1630 MDT. Precip .21". Lightning in cloud and cloud-to-ground in this storm.
8/7/2020 7:00 AM 0.01 M M M M A few drops of rain and outflow breezes at 1430 MDT 06 Aug 2020. Trace precip. RW- 1745-1750 MDT with sun shining. Precip .01".
8/8/2020 7:00 AM 0.00 0.0 M M M
8/9/2020 7:00 AM 0.00 0.0 M M M
8/10/2020 7:00 AM 0.00 0.0 M M M
8/11/2020 7:00 AM 0.00 0.0 M M M
8/12/2020 7:00 AM 0.00 0.0 M M M
8/13/2020 7:00 AM 0.00 0.0 M M M
8/14/2020 7:00 AM 0.00 0.0 M M M
8/15/2020 7:00 AM 0.00 0.0 M M M
8/16/2020 7:00 AM 0.00 0.0 M M M
8/17/2020 7:00 AM 0.00 0.0 M M M
8/18/2020 7:00 AM 0.00 0.0 M M M
8/19/2020 7:00 AM 0.00 0.0 M M M
8/20/2020 7:00 AM T M M M M Light sprinkles ~1630 MDT 19 Aug 2020. Trace precip.
8/21/2020 7:00 AM 0.03 M M M M A few drops of rain 1450 MDT 20 Aug 2020. Trace precip. Thunder heard NW at 1540 MDT. RW- 1548-1556 MDT. Precip .03". Brief gusts from the NE ~15 mph during the rain.
8/22/2020 7:00 AM 0.00 0.0 M M M
8/23/2020 7:00 AM 0.00 0.0 M M M Smoky, hazy skies for the past week, continuing still.
8/24/2020 7:00 AM 0.00 0.0 M M M
8/25/2020 7:00 AM 0.00 0.0 M M M
8/26/2020 7:00 AM 0.00 0.0 M M M
8/27/2020 7:00 AM T M M M M A few drops of rain 1500-1600 MDT 26 Aug 2020. Occasional rumbles of thunder and sprinkles 1600-1700 MDT. Cells drifted very slowly east. RW-- ~1840 MDT, almost enough to wet pavement. Each event delivered only a trace of precip.
8/28/2020 7:00 AM 0.15 M M M M TRW 1725-1740 MDT, 27 Aug 2020. Precip. .15".
8/29/2020 7:00 AM 0.07 M M M M TRW-- ~1530 MDT. Trace precip. Cells movd E. RW- 1730-1830 MDT. Precip .07".
8/30/2020 7:00 AM 0.01 M M M M RW-- 0810 MDT 29 Aug 2020. Trace precip. Brief RW-- early afternoon. Trace precip. RW- ~1930 MDT. Precip .01".
8/31/2020 7:00 AM 0.00 0.0 M M M
9/1/2020 7:00 AM 0.08 M M M M RW- 1500-1530MDT 31 Aug 2020. More steady RW- began 2000 MDT, ended 2200 MDT. Precip +.07".
9/2/2020 7:00 AM 0.00 0.0 M M M
9/3/2020 7:00 AM 0.00 0.0 M M M
9/4/2020 7:00 AM 0.00 0.0 M M M
9/5/2020 7:00 AM 0.00 0.0 M M M
9/6/2020 7:00 AM 0.00 0.0 M M M
9/7/2020 7:00 AM 0.00 0.0 M M M
9/8/2020 6:50 AM 0.25 T M T M Strong cold front arrived in two waves, the first at 1630 MDT 07 Sep 2020, the second at 1935 MDT, with steadily falling temperatures from a daytime max of 88 deg F. R- began here at 2250 MDT with the temperature at 51°. Rain fell through the rest of the night. By midnight, 42 deg and .09 precip so far. At 0650 MDT 08 Sep, R-, 35° (min so far), trace of what looks like ice pellets on the deck rails. Precip +.16 since midnight.
9/9/2020 7:00 AM 0.96 4.6 M 3.7 M 24 hours of continuous precip. R-,occasionally mixed with SW- during the morning of 08 Sep 2020 but no accumulation. Precip 0700 thru 1345 MDT 0.27. All solid precip after 1345 MDT, sometime very light, but no accumulation until after 1530 MDT, when snowfall became steady and increased. S½ for a time between 1600 and 1700 MDT, otherwise S-. At 1910 MDT, S-1, 32° (minimum so far), accumulation 1.5" on snowboard, precip since 1345 MDT +.35. At 2215 MDT, I beat snow off golden elderberry and flowering crab. They were drooping, but hopefully no broken branches. Depth on snow board 4.0”, 32° (minimum so far), calm, precip since 1910 MDT +.17. S-1½ still falling. Light pcpn was probably continuous thru the night as S- and ZL-. At 0700 MDT 09 Sep, 32°, S- falling very lightly as ice needles. Total accumulation 3.7" on snowboard. New accumulation 0.6" since 2215 MDT 08 Sep. Bottom melting is occurring. Precip since 2215 MDT 08 Sep 0.17". 24-h total 0.96". This is the earliest measurable snowfall in the Boulder record, dating back to 1894. Officially, Boulder set a late-season record for heat at 99 deg on Sunday 06 Sep and an early-season record for cold this morning (09 Sep) at 30 deg.
9/10/2020 7:00 AM 0.07 0.0 M T M S- in progress at start of observing period (0700 MDT 09 Sep 2020), falling as ice needles. Occasional light or very light precip until late morning, mostly drizzle. Precip .05". R- 0330-0530 MDT 10 Sep 2020. Precip .02". Snow cover was largely gone by daybreak due to above-freezing temperatures overnight (min 36 deg) and warm ground.
9/11/2020 7:00 AM 0.00 0.0 M 0.0 M All snow melted during the day 10 Sep 2020 as max temperature reached 51 deg.
9/12/2020 7:00 AM 0.00 0.0 M 0.0 M
9/13/2020 7:00 AM 0.00 0.0 M 0.0 M
9/14/2020 7:00 AM 0.00 0.0 M 0.0 M
9/15/2020 7:00 AM 0.00 0.0 M 0.0 M
9/16/2020 7:00 AM 0.00 0.0 M 0.0 M
9/17/2020 7:00 AM 0.00 0.0 M 0.0 M
9/18/2020 7:00 AM 0.00 0.0 M 0.0 M
9/19/2020 7:00 AM 0.00 0.0 M 0.0 M
9/20/2020 7:00 AM 0.00 0.0 M 0.0 M
9/21/2020 7:00 AM 0.00 0.0 M 0.0 M
9/22/2020 7:00 AM 0.00 0.0 M 0.0 M
9/23/2020 7:00 AM T 0.0 M 0.0 M Virga, brief gusty winds and the slightest sprinkles (tiny drops) at 1300 MDT 22 Sep 2020. Trace precip.
9/24/2020 7:00 AM 0.00 0.0 M 0.0 M
9/25/2020 7:00 AM 0.00 0.0 M 0.0 M
9/26/2020 7:00 AM 0.00 0.0 M 0.0 M
9/27/2020 7:00 AM 0.00 0.0 M 0.0 M
9/28/2020 7:00 AM 0.02 0.0 M 0.0 M R- 1730-1900 MDT 27 Sep 2020. Precip .02".
9/29/2020 7:00 AM 0.00 0.0 M 0.0 M
9/30/2020 7:00 AM 0.00 0.0 M 0.0 M



Start Date End Date & Time Duration in Days Precipitation Snow Depth Snow Depth SWE Notes



Observation Date Observation Time Notes Largest Stone Size Average Stone Size Smallest Stone Size Stone Consistency Duration Minutes Durration Accuracy Damage Timing More Rain than Hail Hail Started Largest Hail Started Angle of Impact Number of Stones on Pad Distance Between Stones on Pad Depth of Stones on Ground