BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS 02186 ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY TUESDAY, DECEMBER 25, 2007 ALL TIMES ARE IN EASTERN STANDARD TIME Today's observations: 7 A.M. Weather: Scattered cirrus Temperature: 29F, Dew point: 21F, Wind: SSW at 15G18 kt Sea-level pressure: 30.10 inches Hg, rising Visibility: 20 miles 6-hour min temp: 29F Snow on ground: 2 inches (average of many patches) BHO SA 1155 200 SCT 20 194/29/21/2115G18/010/ 8/040 4/002 53019 10032 20029 10 A.M. Weather: Broken stratocumulus, broken cirrus Temperature: 34F, Dew point: 24F, Wind:SW at 14G20 kt Sea-level pressure: 30.16 inches Hg, rising Visibility: 30 miles BHO SA 1455 40 BKN 200 BKN 30 214/34/24/2214G20/016/ 8/401 51020 WEATHER SUMMARY FOR MONDAY, DECEMBER 24 TEMPERATURE (DEGREES F) MAX.....53 NORMAL.....36 MIN.....32 NORMAL.....21 MEAN....43 NORMAL.....29 DEPARTURE FROM 30-YEAR NORMAL..........+14 TOTAL DEPARTURE FOR THE MONTH..........-90 [-3.6 DEGREES/DAY] HEATING DEGREE DAYS TOTAL HEATING UNITS FOR YESTERDAY............22 DEPARTURE.......+1 TOTAL HEATING UNITS FOR THE MONTH...........879 DEPARTURE......+96 TOTAL HEATING UNITS FOR THE SEASON.........1959 DEPARTURE.....-113 TOTAL HEATING UNITS LAST SEASON TO DATE....1651 DIFFERENCE....+308 PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY............50 S AT 12:01 A.M. AEROVANE.............51 S AT 12:01 A.M. ASOS.................N/A * DAVIS................44 S AT 12:06 A.M. FASTEST MILE FOR YESTERDAY............. 42 S AT 12:01 A.M. MAXIMUM 2-MINUTE ASOS AVERAGE...........N/A * MAXIMUM 2-MINUTE DAVIS AVERAGE..........33 S AT 12:06 A.M. AVERAGE WIND SPEED AND DIRECTION......18.3 SW ASOS...............N/A * DAVIS..............17.9 SE [WSW deg] * ASOS WIND SYSTEM MALFUNCTIONED ON DEC 19. PRECIPITATION (INCHES) THROUGH THIS MORNING (EST) TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.00 DEPARTURE....+0.50 ASOS..............0.00 TOTAL PRECIPITATION FOR THE MONTH..........5.34 DEPARTURE....+1.83 ASOS..............5.42 TOTAL PRECIPITATION FOR THE YEAR..........43.53 DEPARTURE....-5.99 ASOS.............43.64 SNOWFALL (INCHES) THROUGH THIS MORNING (EST) TOTAL SNOWFALL 24 HRS ENDING 7 A.M..........0.0 DEPARTURE.....-0.4 TOTAL SNOWFALL FOR THE MONTH...............28.2 DEPARTURE....+20.3 TOTAL SNOWFALL FOR THE SEASON..............29.0 DEPARTURE....+18.2 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 33/26/30/0/.../../000/00 24 NNW 12/21 28/22/25/-5/.../../000/00 25 N 12/22 32/26/29/0/../../.../.. 21 ESE 12/23 54/33/44/+15/0.64/0/000/00 65 SE Aero 70 MPH SE 12/24 53/32/43/14/0/0/.../.. 50 S Aero 51 MPH S 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 previous 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 25 HIGH 62 IN 1889 LOW -11 IN 1980 PRECIP 1.37 INCHES IN 2002 SNOWFALL 8.5 INCHES IN 2002 PEAK GUST 80 MPH NW IN 1971 RECORDS FOR DECEMBER 26 HIGH 58 IN 1973,1982 LOW -12 IN 1980 PRECIP 3.64 INCHES IN 1969 SNOWFALL 17.5 INCHES IN 1909 PEAK GUST 84 MPH SSE IN 1957 TODAY'S REPORT PREPARED By: Andy Hoell