BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS 02186 ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY MONDAY, DECEMBER 24, 2007 ALL TIMES ARE IN EASTERN STANDARD TIME STRONG TO GALE FORCE SE WINDS GUSTS REACHED 65-70 MPH RAINFALL OF 2/3 INCH AND TEMPS. MID 50'S RESULTED IN A RAPID SNOW-MELT FROM OVER ONE FOOT DOWN TO 3 INCHES! A peak gust to 70 MPH SE was recorded on our Aerovane wind at 9:34 P.M. last evening. The highest sustained wind for two minutes was 48 MPH SE on the Davis wind system which occurred at 9:35 p.m. Other gusts included: 70 MPH on Maximum, Inc. Maestro, 65 MPH SE on the 420C, and 64 MPH SE on the Davis system. All of these peak gusts occurred at the same time. A total of 0.65 inch of rainfall was recorded including 0.01 early today. A maximum hourly amount of 0.43 inch occurred in the hour ending at 11:30 p.m. A high temperature of 54 degrees for yesterday occurred just before midnight, while 53 degrees for today occurred right at midnight. A great amount of snow, something like 11 inches, melted away dropping the on-ground total from 14 inches early yesterday down to only 3 inches this morning. That total of 3 inches is an average of barespots and up to 6 inches in places on the summit. Black ice was forming on the road to the summit in the hour just before sunrise as the temperature dropped rapdily from the low 50's at 1 a.m. this morning down to 32 degrees before 7 a.m. Today's observations: 7 A.M. Weather: Clear, stratocumulus cloud along horizon distant E-SSW Temperature: 33F, Dew point: 23F, Wind: WSW 12 kts Sea-level pressure: 29.80 inches Hg, rising Visibility: 60 miles 6-hour min temp: 32F Snow on ground: 3 inches BHO SA 1155 CLR 60 091/33/23/2512/980/ SC LYR DSNT E-S-SSW ALG HRZN/ 8/500 4/003 51030 MANUAL 6001/ ASOS 60001 ASOS 70068 MANUAL 70065 10052 20032 10 A.M. Weather: Clear, stratocumulus clouds distant WNW-N Temperature: 38F, Dew point: 21F, Wind: SSW at 15G24 kts Sea-level pressure: 29.83 inches Hg, steady Visibility: 60 miles BHO SA 1455 CLR 60 100/38/21/2015G24/983/ FEW SC DSNT WNW-NW/ 8/500 50009 WEATHER SUMMARY FOR SUNDAY, DECEMBER 23 TEMPERATURE (DEGREES F) MAX.....54 NORMAL.....37 MIN.....34 NORMAL.....22 MEAN....44 NORMAL.....29 DEPARTURE FROM 30-YEAR NORMAL.........+ 15 TOTAL DEPARTURE FOR THE MONTH.........-104 [-4.7 DEGREES/DAY] HEATING DEGREE DAYS TOTAL HEATING UNITS FOR YESTERDAY............21 DEPARTURE.......+1 TOTAL HEATING UNITS FOR THE MONTH...........857 DEPARTURE.....+110 TOTAL HEATING UNITS FOR THE SEASON.........1937 DEPARTURE......-99 TOTAL HEATING UNITS LAST SEASON TO DATE....1628 DIFFERENCE....+309 PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY............65 SE AT 9:34 P.M. AEROVANE.............70 SE AT 9:34 P.M. ASOS.................N/A * DAVIS................64 SE AT 9:34 P.M. FASTEST MILE FOR YESTERDAY............. 49 SE AT 9:35 P.M. MAXIMUM 2-MINUTE ASOS AVERAGE...........N/A * MAXIMUM 2-MINUTE DAVIS AVERAGE..........48 SE AT 9:35 P.M. AVERAGE WIND SPEED AND DIRECTION.......20.5 SE ASOS.................N/A * DAVIS...............21.2 SE [140 deg] * ASOS WIND SYSTEM MALFUNCTIONED ON DEC 19. PRECIPITATION (INCHES) THROUGH THIS MORNING (EST) TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.65 DEPARTURE....+0.50 ASOS..............0.68 TOTAL PRECIPITATION FOR THE MONTH..........5.34 DEPARTURE....+1.90 ASOS..............5.42 TOTAL PRECIPITATION FOR THE YEAR..........43.53 DEPARTURE....-5.84 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....+20.7 TOTAL SNOWFALL FOR THE SEASON..............29.0 DEPARTURE....+18.6 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 morning low temp. 32F; normal low is now 21F morning rainfall: 0.01 inch 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 24 HIGH 58 IN 1996 LOW -6 IN 1943 PRECIP 2.21 INCHES IN 1994 SNOWFALL 12.3 INCHES IN 1961 PEAK GUST 79e MPH SE IN 1941 RECORDS FOR DECEMBER 25 HIGH 62 IN 1889 LOW -11 IN 1980 PRECIP 1.37 INS. IN 2002 SNOWFALL 8.5 INS. IN 2002 PEAK GUST 80 MPH NW IN 1971 TODAY'S REPORT PREPARED By: Robert Skilling