Station Overview Station Location
Station Number MD-MG-62 Latitude 39.08527
Station Name Rockville 1.8 W Longitude -77.1873
County Montgomery Elevation (ft) 422



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 12 3.41 7.25 2 7.25 2 0.00 0 0 2 0 0.0 0 0
Nov 12 3.57 0.00 0 0.00 0 0.00 0 0 0 0 0.0 0 0
Dec 12 3.09 1.92 4 1.92 4 0.00 0 0 3 0 1.2 3 0
Jan 13 2.89 4.16 22 4.16 22 0.00 0 0 12 3 2.2 3 3
Feb 13 2.72 1.01 14 1.01 14 0.00 0 0 7 3 2.3 4 2
March 13 3.70 0.00 0 0.00 0 0.00 0 0 0 0 0.0 0 0
April 13 3.28 0.00 0 0.00 0 0.00 0 0 0 0 0.0 0 0
May 13 4.20 0.00 0 0.00 0 0.00 0 0 0 0 0.0 0 0
June 13 3.77 2.17 1 2.17 1 0.00 0 0 1 0 0.0 0 0
July 13 3.87 0.00 0 0.00 0 0.00 0 0 0 0 0.0 0 0
Aug 13 3.18 0.00 0 0.00 0 0.00 0 0 0 0 0.0 0 0
Sept 13 3.99 0.00 0 0.00 0 0.00 0 0 0 0 0.0 0 0
Water Year Totals: 41.67" 16.51" 43 days 16.51" 43 0.00" 0 days 0 25 days 6 days 5.7" 10 days 5 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
10/1/2012
10/2/2012
10/3/2012
10/4/2012
10/5/2012
10/6/2012
10/7/2012
10/8/2012
10/9/2012
10/10/2012
10/11/2012
10/12/2012
10/13/2012
10/14/2012
10/15/2012
10/16/2012 0.91
10/17/2012
10/18/2012
10/19/2012
10/20/2012
10/21/2012
10/22/2012
10/23/2012
10/24/2012
10/25/2012
10/26/2012
10/27/2012
10/28/2012
10/29/2012
10/30/2012 6.34
10/31/2012
11/1/2012
11/2/2012
11/3/2012
11/4/2012
11/5/2012
11/6/2012
11/7/2012
11/8/2012
11/9/2012
11/10/2012
11/11/2012
11/12/2012
11/13/2012
11/14/2012
11/15/2012
11/16/2012
11/17/2012
11/18/2012
11/19/2012
11/20/2012
11/21/2012
11/22/2012
11/23/2012
11/24/2012
11/25/2012
11/26/2012
11/27/2012
11/28/2012
11/29/2012
11/30/2012
12/1/2012
12/2/2012
12/3/2012
12/4/2012
12/5/2012
12/6/2012
12/7/2012
12/8/2012
12/9/2012
12/10/2012
12/11/2012
12/12/2012
12/13/2012
12/14/2012
12/15/2012
12/16/2012
12/17/2012
12/18/2012
12/19/2012
12/20/2012
12/21/2012
12/22/2012
12/23/2012
12/24/2012
12/25/2012 0.23
12/26/2012 0.04
12/27/2012 1.65
12/28/2012
12/29/2012
12/30/2012
12/31/2012 0.00
Day of YearDaily PrcpMultiday Prcp
1/1/2013 0.00
1/2/2013 0.00
1/3/2013
1/4/2013
1/5/2013
1/6/2013 0.01
1/7/2013
1/8/2013
1/9/2013 0.00
1/10/2013 0.02
1/11/2013 0.00
1/12/2013 0.09
1/13/2013 T
1/14/2013 0.03
1/15/2013 0.33
1/16/2013 0.89
1/17/2013 0.14
1/18/2013 T
1/19/2013 0.00
1/20/2013
1/21/2013
1/22/2013 0.00
1/23/2013
1/24/2013 0.06
1/25/2013 T
1/26/2013 0.07
1/27/2013 0.00
1/28/2013 0.11
1/29/2013 0.05
1/30/2013
1/31/2013 2.36
2/1/2013 0.04
2/2/2013
2/3/2013 0.02
2/4/2013 0.01
2/5/2013 0.00
2/6/2013
2/7/2013
2/8/2013 0.18
2/9/2013 T
2/10/2013
2/11/2013 0.32
2/12/2013 T
2/13/2013 0.00
2/14/2013 0.27
2/15/2013 0.00
2/16/2013 0.17
2/17/2013 0.00
2/18/2013 T
2/19/2013
2/20/2013
2/21/2013
2/22/2013
2/23/2013
2/24/2013
2/25/2013
2/26/2013
2/27/2013
2/28/2013
3/1/2013
3/2/2013
3/3/2013
3/4/2013
3/5/2013
3/6/2013
3/7/2013
3/8/2013
3/9/2013
3/10/2013
3/11/2013
3/12/2013
3/13/2013
3/14/2013
3/15/2013
3/16/2013
3/17/2013
3/18/2013
3/19/2013
3/20/2013
3/21/2013
3/22/2013
3/23/2013
3/24/2013
3/25/2013
3/26/2013
3/27/2013
3/28/2013
3/29/2013
3/30/2013
3/31/2013
Day of YearDaily PrcpMultiday Prcp
4/1/2013
4/2/2013
4/3/2013
4/4/2013
4/5/2013
4/6/2013
4/7/2013
4/8/2013
4/9/2013
4/10/2013
4/11/2013
4/12/2013
4/13/2013
4/14/2013
4/15/2013
4/16/2013
4/17/2013
4/18/2013
4/19/2013
4/20/2013
4/21/2013
4/22/2013
4/23/2013
4/24/2013
4/25/2013
4/26/2013
4/27/2013
4/28/2013
4/29/2013
4/30/2013
5/1/2013
5/2/2013
5/3/2013
5/4/2013
5/5/2013
5/6/2013
5/7/2013
5/8/2013
5/9/2013
5/10/2013
5/11/2013
5/12/2013
5/13/2013
5/14/2013
5/15/2013
5/16/2013
5/17/2013
5/18/2013
5/19/2013
5/20/2013
5/21/2013
5/22/2013
5/23/2013
5/24/2013
5/25/2013
5/26/2013
5/27/2013
5/28/2013
5/29/2013
5/30/2013
5/31/2013
6/1/2013
6/2/2013
6/3/2013
6/4/2013
6/5/2013
6/6/2013
6/7/2013
6/8/2013
6/9/2013
6/10/2013
6/11/2013 2.17
6/12/2013
6/13/2013
6/14/2013
6/15/2013
6/16/2013
6/17/2013
6/18/2013
6/19/2013
6/20/2013
6/21/2013
6/22/2013
6/23/2013
6/24/2013
6/25/2013
6/26/2013
6/27/2013
6/28/2013
6/29/2013
6/30/2013
Day of YearDaily PrcpMultiday Prcp
7/1/2013
7/2/2013
7/3/2013
7/4/2013
7/5/2013
7/6/2013
7/7/2013
7/8/2013
7/9/2013
7/10/2013
7/11/2013
7/12/2013
7/13/2013
7/14/2013
7/15/2013
7/16/2013
7/17/2013
7/18/2013
7/19/2013
7/20/2013
7/21/2013
7/22/2013
7/23/2013
7/24/2013
7/25/2013
7/26/2013
7/27/2013
7/28/2013
7/29/2013
7/30/2013
7/31/2013
8/1/2013
8/2/2013
8/3/2013
8/4/2013
8/5/2013
8/6/2013
8/7/2013
8/8/2013
8/9/2013
8/10/2013
8/11/2013
8/12/2013
8/13/2013
8/14/2013
8/15/2013
8/16/2013
8/17/2013
8/18/2013
8/19/2013
8/20/2013
8/21/2013
8/22/2013
8/23/2013
8/24/2013
8/25/2013
8/26/2013
8/27/2013
8/28/2013
8/29/2013
8/30/2013
8/31/2013
9/1/2013
9/2/2013
9/3/2013
9/4/2013
9/5/2013
9/6/2013
9/7/2013
9/8/2013
9/9/2013
9/10/2013
9/11/2013
9/12/2013
9/13/2013
9/14/2013
9/15/2013
9/16/2013
9/17/2013
9/18/2013
9/19/2013
9/20/2013
9/21/2013
9/22/2013
9/23/2013
9/24/2013
9/25/2013
9/26/2013
9/27/2013
9/28/2013
9/29/2013
9/30/2013



Observation Date Observation Time Precipitation Snowfall Snowfall SWE Snow Depth Snow SWE Notes
10/16/2012 7:00 AM 0.91 0.0 M 0.0 M
10/30/2012 8:12 AM 6.34 0.0 M 0.0 M NEW SINGLE DAY RAINFALL RECORD (1973-PRESENT) ... 812-1115A 0.83" | 1115A-216P 0.90" | 216-523P 1.20" | 523-815P 1.23" | 815-1112P 1.16" | 1112P-100A 0.28" | 100-812A 0.74" ...:... Old Record 6.10" 25 June 2006 ...:... HURRICANE AGNES LIKELY STILL ALL-TIME RECORD HOLDER ~7.40", 21 June 1972.
12/25/2012 7:00 AM 0.23 0.5 M M M -SN 1245-1430LT...-SN/SN 1430-1500LT...MIX of -PE/-RA/-PL/-SN 1500-1530LT...All -RA 1530-1820LT...OCNL -DZ 1820-2000LT...:...Temperature dropping from 36 to 33 during snow, rising to 34 during mix and remaining at 34 thru evening...:...Snow accumulating on most non-paved surfaces, 0.5" at deepest. However, likely 0.8" fell per ~8:1 SLR, hence 33% or more of snow melted as fell.
12/26/2012 8:00 AM 0.04 0.2 M T M -SN/--SN ~620-705LT...-SN/-ICEPL 705-730LT...-ICEPL/-FZRA 730-755LT...-FZRA 755LT-OBS
12/27/2012 8:00 AM 1.65 0.5 M T M 0.40" OBS-1230LT when T=32*F...1.20" 1230LT-OBS...:...STORM TOTAL FROZEN = 0.7"..:...-ZR OBS-855LT (@31*F)...-SNPL/-SN/-ICEPL 855-1015LT (@31*F)...-ICEPL/-FZRA 1015-~1045LT (@30*F)...-FZRA/-ICEPL ~1045-~1115LT (@31*F)...-FZRA ~1115-1230LT (@31-->32*F)...-RA/OCNL RA 1230LT-200LT.
12/31/2012 7:00 AM 0.00 0.0 M 0.0 M
1/1/2013 7:00 AM 0.00 0.0 M 0.0 M
1/2/2013 7:00 AM 0.00 0.0 M 0.0 M
1/6/2013 7:00 AM 0.01 T M 0.0 M A FEW FLAKES 2310-~2350LT...THEN -SN/--SN RESUMES ~0020LT, BUT SOON BECOMES MOSTLY -RA/--RA, LIKELY CONTINUING (OCNL?) THROUGH THE NIGHT, PROBABLY CHANGING BACK TO -SN/--SN BEFORE ENDING PRE-DAWN
1/9/2013 7:00 AM 0.00 0.0 M 0.0 M
1/10/2013 7:00 AM 0.02 0.0 M 0.0 M -RA/--RA 1330-1430LT. SURFACES REMAINING DAMP THROUGH EVENING.
1/11/2013 7:00 AM 0.00 0.0 M 0.0 M
1/12/2013 7:00 AM 0.09 0.0 M 0.0 M OCNL -DZ/sprinkles 1230-0300LT...-RA, mainly steady 1500-1830LT, tapering to OCNL -DZ/few drops after 1830LT-through overnight...FG, somewhat dense thru OBS.
1/13/2013 7:00 AM T 0.0 M 0.0 M
1/14/2013 7:00 AM 0.03 0.0 M 0.0 M Drizzy damp day (13th)
1/15/2013 7:00 AM 0.33 0.0 M 0.0 M Rain in evening of 14th with thunder to west (0.19")...then additional 0.14" morning of 15th.
1/16/2013 7:00 AM 0.89 0.0 M 0.0 M -RA/RA mostly after 1500LT (0.52" by midnight), RA E~0320LT (Additional 0.37").
1/17/2013 7:00 AM 0.14 0.0 M 0.0 M -RA/--RA Returns 2100LT-Pre-dawn (0.13" by Mdnt, Additional 0.01" on 17th).
1/18/2013 7:00 AM T 0.0 M 0.0 M Sprinkle ~1600-1615P from southern storm
1/19/2013 7:00 AM 0.00 0.0 M 0.0 M
1/22/2013 7:00 AM 0.00 0.0 M 0.0 M
1/24/2013 7:00 AM 0.06 1.1 M 1.0 M -SN/--SN 0015LT-OBS. SLR 18:1...:...0200LT SNOW TOTAL = 0.4"...0400LT SNOW TOTAL = 0.6"
1/25/2013 7:00 AM T 0.1 M 0.5 M -SN/--SN becoming slightly convective during its last 2 hours -- sky brightening despite flakes continuing, then dark but light squall arriving from NNW at end. Storm Totals: 0.06", 1.2", SLR 18:1.
1/26/2013 7:00 AM 0.07 1.0 M 1.0 M -SN 1400-1800LT. Snow quickly accumulating to all surfaces per the thoroughly frozen ground. Flakes of various small sizes, SLR 14:1.
1/27/2013 7:00 AM 0.00 0.0 M 0.0 M
1/28/2013 8:00 AM 0.11 T M T 0.00 -FZRA/OCNL MIXED WITH -PE ~0500-OBS. GLAZE ACCUMULATING ON MOST SURFACES, ALTHOUGH LIQUID WATER HEARD DRIPPING DOWN SOME DOWNSPOUTS.
1/29/2013 7:00 AM 0.05 0.0 M 0.0 M -FZRA/(POSSIBLY BUT NOT LIKELY SOME OCNL -PE <900A) BECOMING -RA AS TEMPS RISE ABOVE 32 ~0930LT. -RA/--RA CONTINUING AND TAPERING TO --RA/-DZ IN AFTERNOON, ONLY T >1500LT.
1/31/2013 6:45 AM 2.36 0.0 M 0.0 M 1.90" < Mdnt ... 0.46" > Mdnt
2/1/2013 7:00 AM 0.04 0.8 M 0.5 M
2/3/2013 7:00 AM 0.02 0.6 M 0.5 M --SN/-SN B~1250LT, (AFTER DROPPING A VERY THIN DUSTING TO ALL UNTREATED SURFACES) TAPERING TO A FEW OCNL FLAKES ~1500LT...THEN INTENSITY RESUMING ~1700LT AS -SN, ACCUMULATING TO ALL SFCS WITH BEST "BURSTS" OF -SN 1730-1830LT & 1900-1930LT...THEN --SN/-SN LINGERING UNTIL ~2100LT...FLAKE SIZE INCREASING FROM VERY FINE AT ONSET TO RATHER LARGE DENDRITES DURING AND AFTER LAST BURST....TOTAL LIQUID = ~0.024", TOTAL SLR = 25:1...TEMPS DURING EVENT 27-->25*F, THEN RISING TO MDNT-MDNT MAX OF 28*F AT MIDNIGHT.
2/4/2013 7:00 AM 0.01 0.1 M T M
2/5/2013 7:00 AM 0.00 0.0 M T M
2/8/2013 9:00 AM 0.18 T M M M -RA/-PL by 0300LT, tapering to a few drops off soon after dawn
2/9/2013 7:00 AM T 0.0 M 0.0 M A few drops ~1400-1600LT and OCNL -RA/--RA ~1600-1900LT.
2/11/2013 7:00 AM 0.32 0.0 M 0.0 M -RA B~0100LT, tapering to a few drops by OBS
2/12/2013 7:00 AM T 0.0 M 0.0 M Few drops At and soon after OBS ... then -DZ ~1600-1610LT
2/13/2013 12:00 AM 0.00 0.0 M M M
2/14/2013 7:00 AM 0.27 0.8 T M M [0.24" 1430-2000LT, 0.03" 2000-2200LT]...-RA 1430-1915LT, then wet SN 1915-2000LT, wet -SN 2000-2202LT, --SN/-DZ 2202-2210LT.
2/15/2013 12:00 AM 0.00 0.0 M M M
2/16/2013 7:00 AM 0.17 T M 0.0 M -RA B~1715LT...then oscillations of -RA/wet -SN based on intensity 2130-2220LT...wet -SN/--SN 2220-2330LT.
2/17/2013 12:00 AM 0.00 0.0 M M M
2/18/2013 7:00 AM T T M 0.0 M Likely a flake or two reached the ground 1300-1700LT per copious virga.
6/11/2013 7:00 AM 2.17 0.0 M 0.0 M 2.17" is estimate, actual is within 2.05-2.28" range. Two-day total (6/10-11/2013) is 3.10"...:...Sprinkle 1730-1735LT...-(T)SHRA/SHRA 0045-0050LT (0.05"), quickly tapering to sprinkles...but additional TSHRA/SHRA's bring {0.77" 0100-0320LT, 0.23" 0320-1500LT, 0.26" 1500-1910LT}...then squall line brings 1.79" 1915-2035LT: -TSHRA 1915-1925LT and +TSHRA 1925-1950LT totaling 1.76", and -TSHRA 1950-2035LT (0.03")...:...Minor street curb flooding but previous heavy rains had washed pollen/dead tree twigs and small branches away so no clogged storm drains as was common in summer 2010.



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