BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS 02186 ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA   DAILY DISCUSSION AND CLIMATE SUMMARY THURSDAY, DECEMBER 20, 2007 ALL TIMES ARE IN EASTERN STANDARD TIME   As of 3:00 PM, 5.9 inches of new snow has fallen on Great Blue Hill, bringing the December total snowfall to 26.5 inches.  Below are rankings of the 5 snowiest Decembers; we need another 3.5 inches to get into the top 5.   Snowiest Decembers (inches)    1) 45.2 in 1945  2) 39.5 in 1947  3) 32.0 in 1902  4) 29.7 in 2003  5) 29.0 in 1886   Today's observations:   7 A.M.   Weather: Sky obscured with fog, snow Temperature: 27F, Dew point: 26F, Wind: NW at 12 kts Sea-level pressure: 30.05 inches Hg, rising Visibility: 1 1/2 mile, variable 1-2 miles 6-hour min temp: 27F 24-hour precip: 0.21 ins. 24-hour snowfall: 0.5 ins. Snow on ground: 11 inches BHO SA 1155 W3 X 11/2VS-F 176/27/26/3212/005/ VSBY 1V2 TOTAL NEW SNW PST 24 HRS 0.5 INS/ 8//// 4/011 53003 MANUAL 600X/ ASOS 60013 MANUAL 70021 ASOS 70020 10033 20027    10 A.M. Weather: Sky obscured with snow, fog Temperature: 28F, Dew point: 27F, Wind: NW at 10 kts Sea-level pressure: 30.08 inches Hg, rising Visibility: 1/4 mile, snow/fog 3-hour precip: 0.07 ins. 3-hour snowfall: 0.6 ins. BHO SA 1455 W3 X 1/4SF 186/28/27/3210/008/ TOTAL NEW SNW PST 3 HRS 0.6 INS/ 8//// MANUAL 6007/ ASOS 60006 53010   1 P.M. Weather: Sky obscured with snow, fog Temperature: 29F, Dew point: 28F, Wind: NNW at 11 kts Sea-level pressure: 30.05 inches Hg, falling Visibility: 1 mile, snow/fog 6-hourly max. temp: 29F  6-hour snowfall: 4.5 ins. BHO SA 1755 W3 X 1S-F 176/29/28/3311/005/ S- OCNL S+ THN GLZ SNOINC1 TOTAL NEW SNW PST 6 HRS 4.5 INS STORM TOTAL 5.0 INS/ 8//// 50000 MANUAL 60XX/ ASOS 60026 10029 20026   WEATHER SUMMARY FOR WEDNESDAY, DECEMBER 19   TEMPERATURE (DEGREES F) MAX.....38    NORMAL.....38 MIN.....24    NORMAL.....23 MEAN....31    NORMAL.....30 DEPARTURE FROM 30-YEAR NORMAL...........+1 TOTAL DEPARTURE FOR THE MONTH.........-114 [-6.2 DEGREES/DAY]   HEATING DEGREE DAYS TOTAL HEATING UNITS FOR YESTERDAY............34  DEPARTURE.......-1  TOTAL HEATING UNITS FOR THE MONTH...........725  DEPARTURE.....+119 TOTAL HEATING UNITS FOR THE SEASON.........1805  DEPARTURE..... -90 TOTAL HEATING UNITS LAST SEASON TO DATE....1528  DIFFERENCE....+277   PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY............19 E   AT  7:43 P.M.                     AEROVANE.............18 SE  AT  7:15 A.M.                      ASOS.................16 E   AT  7:42 P.M.                     DAVIS................19 SE  AT  8:43 A.M.   FASTEST MILE FOR YESTERDAY............. 13 SE  AT  8:16 A.M. *  MAXIMUM 2-MINUTE ASOS AVERAGE...........13 ESE AT  7:48 P.M.  MAXIMUM 2-MINUTE DAVIS AVERAGE..........14 ESE AT  8:16 A.M.  AVERAGE WIND SPEED AND DIRECTION..... .8.7 E                     ASOS................8.6                               DAVIS...............8.2 SE [140 deg]        * last of several occurrences   PRECIPITATION (INCHES) THROUGH THIS MORNING (EST) TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.21  DEPARTURE....+0.07                          ASOS..............0.20 TOTAL PRECIPITATION FOR THE MONTH..........3.93  DEPARTURE....+1.16                          ASOS..............4.03  TOTAL PRECIPITATION FOR THE YEAR..........42.77  DEPARTURE....-6.66                          ASOS.............42.25     SNOWFALL (INCHES) THROUGH THIS MORNING (EST) TOTAL SNOWFALL 24 HRS ENDING 7 A.M..........0.5  DEPARTURE.....+0.1 TOTAL SNOWFALL FOR THE MONTH...............21.1  DEPARTURE....+15.2 TOTAL SNOWFALL FOR THE SEASON..............21.9  DEPARTURE....+13.1   PRELIMINARY CLIMATE SUMMARY FOR DECEMBER 2007...CALENDAR DAY DATA DATA REPORTED: DATE: MAX/MIN/MEAN/DEP/PRECIP/SNOW/SUN(MIN.)/SUN(%)/ PEAK GUST/AERO GUST   AERO: Aerovane recording wind system when significant TSTM: Thunderstorm day ....: Data not yet available   12/1  33/15/24/-12/0/0/493/88       54 WNW 12/2  24/15/20/-16/0.03/0.3/000/00  28 WNW 12/3  38/23/31/-4/0.62/1.7/000/00   47 W 12/4  27/17/22/-13/T/T/111/20       48 W       12/5  29/17/23/-12/T/T/244/44       23 WNW 12/6  28/15/22/-12/0/0/554/100      31 WNW 12/7  34/21/28/-6/0.07/0.7/000/00   24 SSW 12/8  41/25/33/0/0/0/452/82         32 W 12/9  33/25/29/-4/0.08/T/000/00     16 NW  12/10 30/26/28/-5/0.10/0/000/00     18 N 12/11 36/22/29/-3/0.09/0/258/47     25 S 12/12 44/22/36/+4/T/0/88/16         39 W 12/13 29/20/25/-7/1.08/9.2/000/00   24 ENE 12/14 37/20/29/-2/0.02/0.2/038/07   28 WSW 12/15 28/15/22/-9/0/0/.../..        31 WNW  12/16 43/23/33/+2/1.62/8.5/000/00   54 NE 12/17 32/15/24/-7/0/0/.../..        62 W 12/18 31/10/21/-9/0/0/.../..        20 W 12/19 38/24/31/+1/.../.../.../..    19 E   12/20 morning low temp. 27F; our normal low is now 22F       total snow and ice on the ground 11 inches    NEW DAILY RECORDS FOR DECEMBER 2007: Dec 13: Record daily snowfall of 9.2 inches surpasses previous record of 9.0 inches in 1902. Dec.16: Record daily snowfall of 8.5 inches surpasses previousE record of 7.0 inches in 1896.   DAILY EXTREMES Temperature and precipitation records back to 1885, and wind records back to 1940 (e = estimated):   RECORDS FOR DECEMBER 20 HIGH 61 IN 1957 LOW -16 IN 1942 PRECIP 1.69 INS. IN 1936 SNOWFALL 8.3 INS. IN 1995 PEAK GUST 75 MPH S IN 2002   RECORDS FOR DECEMBER 21 HIGH 60 IN 1957 LOW -10 IN 1942 PRECIP 2.01 INS. IN 1946 SNOWFALL 11.4 INS. IN 1954 PEAK GUST 77 MPH SSE IN 1957   TODAY'S REPORT PREPARED By: Stephanie Radner