BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY SUNDAY, DECEMBER 26, 2010 ALL TIMES ARE IN EASTERN STANDARD TIME PRECIPITATION BEGINS AS LIGHT SNOW GRAINS EARLY THIS MORNING AND THEN LIGHT SNOW AND SNOW GRAINS ACCUMULATES TO ALMOST ONE INCH BY MID-MORNING AS BEGINNINGS OF AN EXPECTED MAJOR DECEMBER SNOWSTORM GETS UNDERWAY After a mostly cloudy but white Christmas (3 inches of snow on the ground) and a two day break from precipitation snow was back and began between 6 and 7 A.M. this morning— the start of an expected blizzard. Christmas Day was cold with a high temperature of only 29F and just some glimpses of sunshine which totaled 60 minutes. Today's observations: 7 A.M. Weather: Low overcast stratus, very light snow grains and thin fog, ceiling, visibility lowering, snow began 6:30 a.m. Temperature: 26F, Dew point: 25F; Wind: N at 10 kts, Sea-level pressure: 29.95 inches Hg, rising Visibility: 10 miles, 5 miles northwest thru north and 15 miles south to southwest, very light snow grains and thin fog, conditions lowering 6-hour minimum temp: 23F Snow depth: 3 inches BHO SA 1155 E5 OVC 10SG- 143/26/25/0110/995/ CIG/VSBY LWRG NW-N 5 S-SW 15 SB30 PCPN VRY LGT SG/ 8/6// 4/003 55002 MANUAL 6000/ 10026 20023 10 A.M. Weather: Broken stratus fractus, overcast nimbostratus, light snow grains and light snow occurring Temperature: 26F, Dew point: 25F; Wind: N at 12 kts, Sea-level pressure: 29.94 inches Hg, falling Visibility: 1.75 miles light snow grains, light snow 3-hourly snowfall 0.8 inch 3-hourl precip: 0.08 inch BHO SA 1455 E3 BKN 7 OVC 13/4SG-S-F 138/26/25/3612/994/ TOTAL NEW SNW PST 3 HRS 0.8 IN WND 33V03/ 8/72/ 58005 MANUAL 6XXX/ ASOS 60008 1 P.M. Weather: N/A WEATHER SUMMARY FOR SATURDAY, DECEMBER 25, CHRISTMAS DAY TEMPERATURE (DEGREES F) MAX.....29 NORMAL.....36 MIN.....18 NORMAL.....21 MEAN....24 NORMAL.....29 DEPARTURE FROM 30-YEAR NORMAL.................-5 TOTAL DEPARTURE FOR THE MONTH................-49 [-2.2 DEGREES/DAY] HEATING DEGREE DAYS TOTAL HEATING UNITS FOR YESTERDAY............41 DEPARTURE........+5 TOTAL HEATING UNITS FOR THE MONTH...........874 DEPARTURE.......+55 TOTAL HEATING UNITS FOR THE SEASON.........2034 DEPARTURE.......-74 TOTAL HEATING UNITS LAST SEASON TO DATE....2029 DIFFERENCE.......+5 PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY..............20 WNW AT 12:39 A.M. AEROVANE...............22 NW AT 2:12 A.M. * ASOS...................20 WNW AT 2:01 A.M. DAVIS..................21 WNW AT 1:40 A.M. THE FASTEST MILE FOR YESTERDAY............16 NW AT 2:28 A.M. MAXIMUM 2-MINUTE ASOS AVERAGE.............16 WNW AT 2:18 A.M. MAXIMUM 2-MINUTE DAVIS AVERAGE............24 WNW AT 3:39 A.M. AVERAGE WIND SPEED AND DIRECTION........ 7.4 NW ASOS..................7.6 DAVIS.................8.2 WNW [300 DEG] * last of several occurrences PRECIPITATION (INCHES) THROUGH THIS MORNING (EST) TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....trace DEPARTURE........-0.15 ASOS..............0.00 TOTAL PRECIPITATION FOR THE MONTH..........3.03 DEPARTURE.........-0.63 ASOS..............3.14 TOTAL PRECIPITATION FOR THE YEAR..........61.06 DEPARTURE........+10.74 ASOS.............61.05** ** ASOS missing rainfall due to system failure on 6/24-25 SNOWFALL (INCHES) THROUGH THIS MORNING (EST) TOTAL SNOWFALL 24 HRS ENDING 7 A.M.........trace DEPARTURE.....-0.4 TOTAL SNOWFALL FOR THE MONTH................6.0 DEPARTURE.....-2.3 TOTAL SNOWFALL FOR THE SEASON...............6.1 DEPARTURE.....-5.1 PRELIMINARY CLIMATE SUMMARY FOR DECEMBER 2010 CALENDAR DAY DATA DATA REPORTED: DATE: MAX/MIN/MEAN/DEP/PRECIP/SNOW/SUN(MIN.)/SUN(%)/ PEAK GUST/AERO GUST AERO: Aerovane wind recording system gust when significant TSTM: Thunderstorm day (thunder heard some time during day) ....: Data not yet available, records not finalized 12/1 55/43/49/+13/0.49/0.0/000/00 55 SE AERO 61 MPH SE 12/2 48/29/39/+3/0.00/0.0/540/100 30 W 12/3 38/29/34/-1/0.00/0.0/050/09 25 WNW 12/4 40/28/34/-1/0.00/0.0/516/93 27 WNW 12/5 34/23/29/-6/0.00/0.0/127/23 24 W 12/6 32/22/27/-7/0.00/0.0/447/81 37 WSW AERO 38 MPH WSW 12/7 33/23/28/-6/0.00/0.0/463/84 35 W AERO 37 MPH W 12/8 31/19/25/-8/0.00/0.0/550/100 39 W AERO 40 MPH W 12/9 26/14/20/-13/0.00/0.0/550/100 29 WNW 12/10 25/9/17/-16/0.00/0.0/181/33 17 SSE 12/11 44/25/35/+3/0.00/0.0/460/84 23 WSW 12/12 55/33/44/+12/1.57/0.0/000/00 55 SE AERO 69 MPH SE 12/13 55/33/44/+12/0.35/0.0/027/05 50 SSE AERO 58 MPH SSE 12/14 33/16/25/-6/T/T/120/22 30 W 12/15 19/13/16/-15/0.02/0.2/038/07 33 WNW AERO 38 MPH WNW 12/16 32/15/24/-7/0.00/0.0/491/90 25 SSW 12/17 34/17/26/-5/0.00/0.0/.../.. 22 WNW 12/18 37/22/30/0/0.00/0.0/.../.. 20 N 12/19 34/25/30/0/0.00/0.0/.../.. 17 N 12/20 30/23/27/-3/0.34/3.2/.../.. 33 NW AERO 37 MPH NW 12/21 38/23/31/+1/0.02/0.2/.../.. 38 NW 12/22 36/28/32/+3/0.14/1.4/../.. 31 NW AERO 35 MPH NW 12/23 36/27/32/+3/0.11/1.1/.../.. 36 NW AERO 38 MPH NW 12/24 35/23/29/0/0.00/0.0/.../.. 31 NW 12/25 29/18/24/-5/0.00/0.0/060/11 20 WNW 12/26 our morning low temp. 23F; the normal low is now 21F DAILY RECORDS FOR DECEMBER 2010 12/15 - NEW RECORD LOW MAXIMUM TEMP. OF 19F; this surpasses the previous record of 20F in 1903,1905,1931, and 1962 DAILY EXTREMES Temperature and precipitation records back to 1885, and wind records back to 1940 (e = estimated): RECORDS FOR DECEMBER 26 HIGH 58 IN 1973,1982 LOW -12 IN 1980 PRECIP 3.64 INS. IN 1969 SNOWFALL 17.5 INS. IN 1909 PEAK GUST 84 MPH SSE IN 1957 RECORDS FOR DECEMBER 27 HIGH 57 IN 1895,1949 LOW -4 IN 1903 PRECIP 2.43 INS. IN 1969 SNOWFALL 11.2 INS. IN 1947 PEAK GUST 53e W IN 1957,1978; WNW 1976 TODAY'S REPORT PREPARED BY: Robert Skilling