BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS 02186 ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY SUNDAY, DECEMBER 16, 2007 ALL TIMES ARE IN EASTERN STANDARD TIME HEAVY SNOW ON THE SUMMIT THIS MORNING... Today's observations: 7 A.M. Weather: Sky obscured in heavy snow and fog Temperature: 27F, Dew point: 27F, Wind: ENE at N/A Sea-level pressure: N/A Visibility: N/A 6-hour min temp: 22F 24-hour precip: 0.35 inch 24-hour snowfall: 3.5 inches Snow on ground: 12 inches 10 A.M. Weather: Sky obscured in heavy snow and fog Temperature: 30F, Dew point: 30F, Wind: ENE at N/A Sea-level pressure: N/A Visibility: N/A 1 P.M. Weather: Temperature: 35F, Dew point: N/A, Wind: ENE at N/A Sea-level pressure: N/A Visibility: N/A 6-hourly max. temp: 35F 6-hour precip: 0.97 inch 6-hour snowfall: 5.0 inches WEATHER SUMMARY FOR SATURDAY, DECEMBER 15 TEMPERATURE (DEGREES F) MAX.....28 NORMAL.....39 MIN.....15 NORMAL.....24 MEAN....22 NORMAL.....31 DEPARTURE FROM 30-YEAR NORMAL...........-9 TOTAL DEPARTURE FOR THE MONTH.........-101 [-6.9 DEGREES/DAY] HEATING DEGREE DAYS TOTAL HEATING UNITS FOR YESTERDAY............43 DEPARTURE......+10 TOTAL HEATING UNITS FOR THE MONTH...........574 DEPARTURE.....+105 TOTAL HEATING UNITS FOR THE SEASON.........1654 DEPARTURE.....-104 TOTAL HEATING UNITS LAST SEASON TO DATE....1434 DIFFERENCE....+220 PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY............31 WNW AT 6:57 A.M. AEROVANE.............32 WNW AT 6:23 A.M. ASOS.................30 NW AT 6:67 A.M. DAVIS................31 WNW AT N/A FASTEST MILE FOR YESTERDAY..............21 WNW AT 6:19 A.M. MAXIMUM 2-MINUTE ASOS AVERAGE...........21 NW AT 6:23 A.M. MAXIMUM 2-MINUTE DAVIS AVERAGE..........22 WNW AT N/A AVERAGE WIND SPEED AND DIRECTION.......10.7 NW ASOS.................9.6 DAVIS...............10.4 NW [318 deg] PRECIPITATION (INCHES) THROUGH THIS MORNING (EST) TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.35 DEPARTURE....+0.21 ASOS..............0.37 TOTAL PRECIPITATION FOR THE MONTH..........2.45 DEPARTURE....+0.24 ASOS..............2.65 TOTAL PRECIPITATION FOR THE YEAR..........41.29 DEPARTURE....-7.58 ASOS.............40.87 SNOWFALL (INCHES) THROUGH THIS MORNING (EST) TOTAL SNOWFALL 24 HRS ENDING 7 A.M..........3.5 DEPARTURE.....+3.1 TOTAL SNOWFALL FOR THE MONTH...............15.6 DEPARTURE....+11.3 TOTAL SNOWFALL FOR THE SEASON..............16.4 DEPARTURE.....+9.2 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 morning low temp. 23F; our normal low is now 24F total snow and ice on the ground xx 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. DAILY EXTREMES Temperature and precipitation records back to 1885, and wind records back to 1940 (e = estimated): RECORDS FOR DECEMBER 16 HIGH 61 IN 1971 LOW -2 IN 1930 PRE 1.67 INS. IN 1960 SNOW 7.0 INS. IN 1896 WIND 73 MPH SSE IN 1982 RECORDS FOR DECEMBER 17 HIGH 63 IN 2000 LOW -10 IN 1942 PRECIP 3.03 INS. IN 1888 SNOWFALL 7.5 INS. IN 1988 PEAK GUST 78 MPH SSE IN 2000 TODAY'S REPORT PREPARED By: Mike Iacono/Stephanie Radner