BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY TUESDAY, DECEMBER 4, 2012 ALL TIMES ARE IN EASTERN STANDARD TIME THICK MORNING FOG GIVES WAY TO AFTERNOON SHOWERS Thick fog rolled in overnight, leaving us with less than one sixteenth of a mile visibility for the A.M. hours. As the fog began to lift shortly after noon, we were afforded visibility close to 12 miles, though the city remained out of sight. Light rain showers began just after 1:00 P.M., providing a couple of hundredths of an inch of much needed precipitation. A stark temperature inversion was in place across the area this morning, as by local morning lows: Blue Hill 40F, Hingham 29F, Norwood 25F. Freezing fog was reported in some locations. November ended on a chilly note and the cold month breaks the stretch of 21 consecutive warmer than average months compared to the 120-year average. The warm streak stretched from February 2011 to October 2012. Longest Number of Consecutive Months Above 120-Year Mean (using corrected mean temperature), and average departure in that time 1) 21 months, Feb 2011 - Oct 2012; +3.8 deg F 2) 15 months, Jun 1990 - Aug 1991; +3.1 deg F 3) 15 months, Jul 1998 - Sep 1999; +3.0 deg F 4) 13 months, Nov 2009 - Nov 2010; +3.7 deg F Despite a colder than average November, the year-to-date for 2012 remains the warmest on record. BHO Warmest Jan-Nov, deg F (1885-2012) 1) 53.1 in 2012 2) 53.0 in 2010 3) 52.4 in 1999 4) 52.0 in 1991 52.0 in 1998 NOVEMBER 2012 PRELIMINARY STATS TEMPERATURE: Average Max Temp: 47.0F [-3.0F] Average Min Temp: 33.0F [-0.5F] Mean Temp: 40.0F [-1.7F] 24-hr. Corr. Mean Temp: 39.2F Max Temp: 66F on 12th Min Temp: 25F on 6th Total heating degree day units (month): 742 [+44] Total heating degree day units (season): 1,150 [-111] *start July 1 PRECIPITATION: Total precipitation: 1.68 ins. [-3.08 in.] Greatest 24-hr precipitation: 1.03 ins. on 7th/8th Total snowfall: 6.0 inches [+3.4 inch] *using 1890-2010 mean WIND: Avg wind speed: 11.9 MPH Avg corrected wind speed: 12.3 MPH Prevailing wind direction: N [17%] Peak gust: 48 MPH NNE on 7th Peak fastest mile: 33 MPH N on 8th SUNSHINE: Total astronomical minutes: 9,506 of possible 17,650 or 54% Total Campbell-Stokes card minutes: 9,176 or 54% Today's observations: 7 A.M. Weather: Sky obscured by dense fog, stratus drifting over summit, heavy dew all surfaces Temperature: 40F; Dew Point: 40F; Wind: SE at 10 kts. Sea-level pressure: 30.32 ins. Hg, rising Visibility: 1/16 mile, dense fog 6-hour min. temp: 40F BHO SA 1155 W2 X 1/16F 267/40/40/1410/032/ STRA DRFTNG OVR SMT HVY DEW ALL SFCS/ 8//// 51007 10043 20040 10 A.M. Weather: Sky obscured by dense fog, stratus drifting over summit Temperature: 43F; Dew Point: 43F; Wind: S at 9 kts Sea-level pressure: 30.32 ins. Hg, falling slightly Visibility: 1/16 mile, dense fog BHO SA 1455 W3 X 1/16F 266/43/43/1709/032/ STRA DRFTNG OVR SMT 8//// 58001 1 P.M. Weather: Scattered stratus fractus, broken stratocumulus, overcast stratus, stratus fractus N-E-S and overhead, few small cumulus in the distant SE, thin fog in all quadrants, light rain shower SW-W and NNW-NNE moving E Temperature: 48F; Dew Point: 46F Wind: S at 13 kts, Wind: Direction variable SSE-SSW Sea-level pressure: 30.23 ins. Hg, falling Visibility: 12 miles, NNW-NNE 8 miles, thin fog all quadrants 6-hour max. temp: 48F BHO SA 1755 5 SCT E20 BKN 30 OVC 12 238/48/46/1813/023/ STFRA N-E-S AND OVHD FEW SML CU DSNT SE THN FG ALQDS VSBY NNW-NNE 8 SHRA SW-W AND NNW-NNE MOVG E WND 15V21/ 8/7// 58028 10048 20040 WEATHER SUMMARY FOR MONDAY, DECEMBER 3 TEMPERATURE (DEGREES F) MAX.....57 NORMAL.....44 MIN.....43 NORMAL.....28 MEAN....50 NORMAL.....36 DEPARTURE FROM 30-YEAR NORMAL....................+14 TOTAL DEPARTURE FOR THE MONTH....................+13 [+4.1 DEGREE/DAY] HEATING DEGREE DAYS TOTAL HEATING UNITS FOR YESTERDAY............15 DEPARTURE........-14 TOTAL HEATING UNITS FOR THE MONTH............73 DEPARTURE........-14 TOTAL HEATING UNITS FOR THE SEASON.........1223 DEPARTURE.......-125 TOTAL HEATING UNITS LAST SEASON TO DATE.....985 DIFFERENCE......+238 PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY..............31 NW AT 11:15 A.M. AERO...................30 NW AT 11:15 A.M. ASOS...................31 NW AT 11:16 A.M. DAVIS..................29 NW AT 10:53 A.M. RMY 32 THE FASTEST MILE FOR YESTERDAY............24 NW AT 11:15 A.M. MAXIMUM 2-MINUTE ASOS AVERAGE.............22 NW AT 11:18 A.M. MAXIMUM 2-MINUTE DAVIS AVERAGE............22 WNW AT 11:17 A.M. AVERAGE WIND SPEED AND DIRECTION........11.8 NW ASOS.................11.8 DAVIS................10.6 WNW [289 deg] PRECIPITATION (INCHES) THROUGH THIS MORNING (EST) TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.00 DEPARTURE..........-0.17 ASOS..............0.00 TOTAL PRECIPITATION FOR THE MONTH..........0.06 DEPARTURE..........-0.43 ASOS..............0.06 TOTAL PRECIPITATION FOR THE YEAR..........34.94 DEPARTURE.........-14.08 ASOS.............34.95 SNOWFALL (INCHES) THROUGH THIS MORNING (EST) TOTAL SNOWFALL 24 HRS ENDING 7 A.M.........0.0 DEPARTURE..........-0.3 TOTAL SNOWFALL FOR THE MONTH...............0.8 DEPARTURE...........0.0 TOTAL SNOWFALL FOR THE SEASON..............6.8 DEPARTURE..........+3.4 PRELIMINARY CLIMATE SUMMARY FOR NOVEMBER & 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 11/1 56/42/49/+3/0.00/371/60 28 SW AERO 28 MPH SW RMY 27 11/2 51/41/46/0/0.02/000/00 24 WNW AERO 22 MPH WNW RMY 22 11/3 52/37/45/-1/0.00/319/52 29 NW AERO N/A RMY 28 11/4 52/34/43/-2/0.00/587/96 27 NW AERO 25 MPH NW RMY 26 11/5 45/28/37/-8/0.00/292/48 25 NW AERO 25 MPH NW RMY 25 11/6 40/25/33/-12/0.00/600/99 22 ENE AERO 20 MPH ENE RMY N/A 11/7 42/29/36/-9/0.78/3.5/000/00 48 NNE AERO 52 MPH NNE RMY 51 11/8 36/29/33/-11/0.26/0.5/000/00 43 N AERO 50 MPH N RMY 44 11/9 51/34/43/-1/0.00/0.0/569/95 33 NW AERO 35 MPH NW RMY 32 11/10 53/36/45/+1/0.00/0.0/561/94 25 W AERO 23 MPH W RMY 23 11/11 62/40/51/+8/0.00/0.0/357/60 28 SSW AERO 27 MPH SSW RMY 28 11/12 66/50/58/+15/0.00/0.0/385/65 33 SSW AERO 33 MPH S RMY N/A 11/13 63/37/50/+7/0.43/0.0/000/00 45 S AERO 45 MPH S RMY N/A 11/14 44/33/39/-3/0.00/0.0/559/95 27 NNE AERO 23 MPH N RMY 24 11/15 39/32/36/-6/0.00/0.0/082/14 23 N AERO 21 MPH N RMY 25 11/16 45/31/38/-4/0.00/0.0/216/37 18 NNW AERO 17 MPH NNW RMY 19 11/17 47/32/40/-1/0/00/0/0/553/95 20 N AERO 20 MPH N RMY N/A 11/18 46/30/38/-3/0.00/0.0/487/84 22 ENE AERO 21 MPH ENE RMY 20 11/19 47/30/39/-2/0.00/0.0/451/78 20 NNE AERO 16 MPH NNE RMY N/A 11/20 48/32/40/0/0.00/0.0/415/72 18 ENE AERO 15 MPH ENE RMY 17 11/21 49/35/42/+2/0.00/0.0/184/32 21 NE AERO 17 MPH ENE RMY 18 11/22 52/37/45/+5/0.00/0.0/549/96 16 S AERO 16 MPH SSE RMY 15 11/23 52/37/45/+6/0.00/0.0/200/35 26 S AERO 24 MPH S RMY N/A 11/24 44/30/37/-2/T/0.0/364/64 42 W AERO 39 MPH W RMY 41 11/25 38/27/33/-6/0.00/0.0/323/57 40 W AERO 38 MPH W RMY 39 11/26 44/29/37/-1/0.00/0.0/526/93 37 W AERO 37 MPH W RMY 37 11/27 35/31/33/-5/0.19/2.0/000/00 18 WNW AERO 15 MPH WNW RMY N/A 11/28 34/27/31/-7/T/T/000/00 23 NNE AERO 22 MPH NNE RMY 23 11/29 41/27/34/-3/0.00/0.0/511/91 28 SW AERO 31 MPH SW RMY 33 11/30 35/29/32/-5/0.00/0.0/045/08 21 SW AERO 24 MPH SW RMY 24 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 morning low temp: 40F; the normal low is now 28F DAILY RECORDS FOR NOVEMBER 2012 11/7 - NEW DAILY RECORD MAXIMUM SNOWFALL OF 3.5 INCHES; surpasses the previous record of 1.0 inch in 1967 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 4 HIGH 67 IN 1998 LOW -4 IN 1940 PRECIP 1.87 INS. IN 1968 SNOWFALL 6.0 INS. IN 1907 PEAK GUST 73 MPH WNW IN 1980 RECORDS FOR DECEMBER 5 HIGH 65 IN 2001 LOW -1 IN 1926 PRECIP 2.86 INS. IN 1993 SNOWFALL 7.0 INS. IN 1926, 1981 PEAK GUST 67 MPH WNW IN 1961, S IN 1973 TODAY'S REPORT PREPARED BY: Sean Fankhauser/Forrest Iwanik