BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY SATURDAY, DECEMBER 8, 2012 ALL TIMES ARE IN EASTERN STANDARD TIME LIGHT RAIN, DRIZZLE AND DENSE FOG TODAY... Measurable light rain began late Friday evening and amounted to 0.21 inch through 7 AM this morning. Light rain and drizzle continued into early afternoon, amounting to another 0.15 inch for the six hours ending at 1 PM. The storm total rainfall since yesterday is 0.36 inch. Dense fog has been the rule on the summit all day today, reaching as low as 0 miles in some directions early this afternoon. Today's observations: 7 A.M. Weather: Sky obscured by dense fog, light drizzle Temperature: 42F; Dew Point: 42F; Wind: E at 5 kts. Sea-level pressure: 30.00 ins Hg, falling then steady Visibility: 1/16 mile, dense fog 6-hour min. temp: 41F 24-hour precip.: 0.21 ins BHO SA 1155 W3 X 1/16L-F 158/42/42/1005/000/ L-B50R-E50 WND LGT/ 8//// 56003 60/// 70021 10042 20041 10 A.M. Weather: Overcast, nimbostratus, sky partly obscured by dense fog, light rain and light drizzle Temperature: 43F; Dew Point: 43F; Wind: ENE at 12 kts. Sea-level pressure: 29.93 ins Hg, falling Visibility: 1/8 mile, dense fog, visibility variable 1/16 to 1/4 mile 3-hour precip.: N/A BHO SA 1455 –X E3 OVC 1/8VR-L-F 137/43/43/0612/993/ R-BCMGR30BCMGR-45 VSBY 1/16V1/4/ 8/72/ 56021 60/// 1 P.M. Weather: Sky obscured by dense fog, light drizzle Temperature: 44F; Dew Point: 44F Wind: NNW at 7 kts, Wind: Direction variable NW-N Sea-level pressure: 29.87 ins Hg, falling then falling more rapidly Visibility: 1/16 mile, dense fog, visibility W-NNE 0 miles 6-hour max. temp: 44F 6-hour precip.: 0.15 ins BHO SA 1755 W2 X 1/16L-F 115/44/44/3407/987/ VSBY W-NNE 0 WND 31V01/ 8//// 58022 6/015 10044 20042 WEATHER SUMMARY FOR FRIDAY, DECEMBER 7 TEMPERATURE (DEGREES F) MAX.....42 NORMAL.....42 MIN.....30 NORMAL.....27 MEAN....36 NORMAL.....34 DEPARTURE FROM 30-YEAR NORMAL.....................+2 TOTAL DEPARTURE FOR THE MONTH....................+34 [+4.7 DEGREES/DAY] HEATING DEGREE DAYS TOTAL HEATING UNITS FOR YESTERDAY............29 DEPARTURE.........-2 TOTAL HEATING UNITS FOR THE MONTH...........173 DEPARTURE........-35 TOTAL HEATING UNITS FOR THE SEASON.........1323 DEPARTURE.......-146 TOTAL HEATING UNITS LAST SEASON TO DATE....1045 DIFFERENCE......+278 PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY..............18 SSW AT 9:12 P.M.* AERO...................16 SSW AT 7:51 P.M.* ASOS...................17 SSW AT 9:24 P.M. DAVIS..................17 S AT 7:53 P.M. RMY 18 THE FASTEST MILE FOR YESTERDAY............14 S AT 2:42 A.M. MAXIMUM 2-MINUTE ASOS AVERAGE.............14 SSW AT 9:13 P.M. MAXIMUM 2-MINUTE DAVIS AVERAGE............13 S AT 9:12 P.M. AVERAGE WIND SPEED AND DIRECTION........10.0 SSW ASOS..................9.5 DAVIS.................8.9 SSW [194 deg] * last of several occurrences PRECIPITATION (INCHES) THROUGH THIS MORNING (EST) TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.21 DEPARTURE..........+0.04 ASOS..............0.20 TOTAL PRECIPITATION FOR THE MONTH..........0.33 DEPARTURE..........-0.82 ASOS..............0.31 TOTAL PRECIPITATION FOR THE YEAR..........35.21 DEPARTURE.........-14.47 ASOS.............35.20 SNOWFALL (INCHES) THROUGH THIS MORNING (EST) TOTAL SNOWFALL 24 HRS ENDING 7 A.M.........0.0 DEPARTURE..........-0.4 TOTAL SNOWFALL FOR THE MONTH...............0.8 DEPARTURE..........-1.3 TOTAL SNOWFALL FOR THE SEASON..............6.8 DEPARTURE..........+2.1 PRELIMINARY CLIMATE SUMMARY FOR DECEMBER 2012 CALENDAR DAY DATA DATA REPORTED: DATE: MAX/MIN/MEAN/DEP/PRECIP/SUN(MIN.)/SUN(%)/ PEAK GUST/AERO GUST AERO: Aerovane wind recording system gust RMY: RMY = R.M. Young wind gust recording system added 8/9/2011 TSTM: Thunderstorm day (thunder heard some time during day) ....: Data not yet available, records not finalized 12/1 34/25/30/-7/0.08/0.8/000/00 16 E AERO 14 MPH E RMY 16 12/2 52/32/42/+6/0.00/0.0/000/00 32 SSW AERO 32 MPH SSW RMY 34 12/3 57/43/50/+14/0.00/0.0/.../.. 31 NW AERO 30 MPH NW RMY 32 12/4 56/40/48/+13/0.03/0.0/.../.. 37 S AERO 39 MPH S RMY 38 12/5 56/31/44/+9/0.03/0.0/.../.. 38 WNW AERO 37 MPH WNW RMY 40 12/6 38/25/32/-3/0.00/0.0/.../.. 31 NW AERO 30 MPH NW RMY N/A 12/7 42/30/36/+2/0.21/0.0/.../.. 18 SSW AERO 16 MPH SSW RMY 18 12/8 morning low temp: 40F; the normal low is now 26F DAILY RECORDS FOR DECEMBER 2012 None so far. DAILY EXTREMES Temperature and precipitation records back to 1885, and wind records back to 1940 (e = estimated): RECORDS FOR DECEMBER 8 HIGH 62 IN 1966 LOW -4 IN 1906 PRECIP 1.54 INS. IN 1969 SNOWFALL 2.5 INS. IN 2001 PEAK GUST 78e W IN 1979 RECORDS FOR DECEMBER 9 HIGH 68 IN 1966 LOW -14 IN 1902 PRECIP 1.52 INS. IN 1956 SNOWFALL 10.8 INS. IN 2005 PEAK GUST 66 SE IN 1973 TODAY'S REPORT PREPARED BY: Mike Iacono, Jonathan O'Brien, Peter Volpe