BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS 02186 ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY SUNDAY, DECEMBER 6, 2009 ALL TIMES ARE IN EASTERN STANDARD TIME Today's observations: 7 A.M. Weather: Clear with a few cirrus Temperature: 26F, Dew point: 24F, Wind: WNW at 15G20 kt Sea-level pressure: 29.98 inches Hg, rising Visibility: 12 miles 6-hour minimum temp: 26F 24-hour precipitation: 0.88 inches 24-hour snowfall: 5.3 inches BHO SA 1155 CLR 12 153/26/24/2915G20/998/ FEW CI ALQDS TOTAL NEW SNW PST 24 HR 5.3 IN/ 8/001 4/005 53036 6//// 70088 10030 20026 10 A.M. Weather: Clear, hazy Temperature: 29F, Dew point: 25F, Wind: WNW at 16G24 kt Sea-level pressure: 30.08 inches Hg, rising Visibility: 15 miles BHO SA 1455 CLR 15 187/29/25/2916G24/008/ HAZY/ 8/000 51034 1 P.M. Weather: Scattered stratocumulus Temperature: 33F, Dew point: 28F, Wind: W at 12G16 Sea-level pressure: 30.13 inches Hg, rising Visibility: 20 miles 6-hour maximum temp: 33F BHO SA 1755 20 SCT 20 202/33/28/2712G16/013/ HAZY/ 8/200 53015 10033 20026 WEATHER SUMMARY FOR SATURDAY, DECEMBER 5 TEMPERATURE (DEGREES F) MAX.....42 NORMAL.....42 MIN.....30 NORMAL.....27 MEAN....36 NORMAL.....35 DEPARTURE FROM 30-YEAR AVERAGE.............+1 TOTAL DEPARTURE FOR THE MONTH.............+39 [+7.6 DEGREES/DAY] HEATING DEGREE DAYS TOTAL HEATING UNITS FOR YESTERDAY............29 DEPARTURE........-1 TOTAL HEATING UNITS FOR THE MONTH...........109 DEPARTURE.......-39 TOTAL HEATING UNITS FOR THE SEASON.........1269 DEPARTURE......-168 TOTAL HEATING UNITS LAST SEASON TO DATE....1372 DIFFERENCE.....-103 PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY.............36 N AT 3:22 P.M. AEROVANE..............37 NNW AT 11:14 P.M. ASOS..................35 N AT 11:29 P.M. DAVIS.................36 N AT 3:22 P.M. THE FASTEST MILE FOR YESTERDAY...........24 N AT 3:21 P.M. MAXIMUM 2-MINUTE ASOS AVERAGE............24 N AT 11:09 P.M. MAXIMUM 2-MINUTE DAVIS AVERAGE...........22 N AT 3:18 P.M. AVERAGE WIND SPEED AND DIRECTION.......12.7 N ASOS................12.6 DAVIS...............11.8 N [3 DEG] PRECIPITATION (INCHES) THROUGH THIS MORNING (EST) TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.88 DEPARTURE....+0.73 ASOS..............0.90 TOTAL PRECIPITATION FOR THE MONTH..........1.97 DEPARTURE....+1.22 ASOS..............2.07 TOTAL PRECIPITATION FOR THE YEAR..........51.54 DEPARTURE....+4.13 ASOS.............52.83 SNOWFALL (INCHES) THROUGH THIS MORNING (EST) TOTAL SNOWFALL 24 HRS ENDING 7 A.M..........5.3 DEPARTURE.....+5.0 TOTAL SNOWFALL FOR THE MONTH................5.3 DEPARTURE.....+4.2 TOTAL SNOWFALL FOR THE SEASON...............8.3 DEPARTURE.....+4.3 PRELIMINARY CLIMATE SUMMARY FOR DECEMBER 2009 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 41/28/35/-1/0/0/.../.. 29 NW 12/2 51/33/42/+6/../../.../.. 30 SSE 12/3 67/47/57/+22/../../.../.. 69 SSE AERO 73 SSE 12/4 52/40/46/+11/0/../.../.. 26 W 12/5 42/30/36/+1/.../../.../.. 36 N NEW DAILY RECORD FOR DECEMBER 2009 12/3 NEW RECORD HIGH MAXIMUM TEMPERATURE of 67F; surpasses previous record of 61F in 1932, 1950. DAILY EXTREMES Temperature and precipitation records back to 1885, and wind records back to 1940 (e = estimated): RECORDS FOR DECEMBER 6 HIGH 70 IN 2001 LOW 5 IN 1901,1935 PRECIP 2.36 INS. IN 1945 SNOWFALL 12.0 INS. IN 1886, 1981 PEAK GUST 74 MPH NW IN 1981 RECORDS FOR DECEMBER 7 HIGH 74 IN 1998 LOW 6 IN 1906 PRECIP 1.67 INS. IN 1953 SNOWFALL 4.0 INS. IN 1886 PEAK GUST 76e SE IN 1976 TODAY'S REPORT PREPARED BY: Andrew Hoell