BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY THURSDAY, JANUARY 3, 2013 ALL TIMES ARE IN EASTERN STANDARD TIME YEAR 2012 WARMEST ON RECORD YEAR TEMP(F) 2012 51.7 2011 51.0 1999 50.9 1998 50.8 2006 50.6 COLDEST TEMPERATURE IN TWO YEARS THIS MORNING AT 2F DEGREES The coldest air mass of the season arrived overnight and after a low temperature 11 degrees yesterday morning our temperature here at the summit dropped from 11 degrees at midnight last night all the way down to 2.0F in the Hazen shelter at 6:40 A.M. This is our coldest low temperature since -7F on January 24, 2011. Last January, 2012, although the month averaged 6 degrees on the warm side of normal when it was all over did have a low temperature of 4F degrees on January 15, 2012. DECEMBER 2012 STATS: Temp. deg. F Av. Max. 42.8 Av. Min. 30.1 Mean 36.5 [+5.2] 24-hr. corr. mean: 36.2 Maximum: 59 on 10th Minimum: 17 on 31st Total heating units: 878 [-165] Total heating season: 2028 [-277] Total precip: 6.52 ins. {+1.63) Snowfall: 9.2 ins. [-4.2 ins.] Max. depth on ground: 7 inches on 30th Av. uncorrected wind speed: 12.7 MPH Av. corr. wind speed 13.0 MPH Peak wind gust: 70 MPH E on 27th Fastest mile: 51 MPH E on 27th Sunshine: Campbell-Stokes minutes: 5520/16470 = 33% Sunshine: Astronomical minutes: 5669/17037 = 33% Today's observations: 7 A.M. Weather: Stratocumulus / few cumulus layer distant offshore NNE-SE, cirrus layer distant ESE-SW with lower dense cirrus distant SE-S, distant haze Temperature: 3F; Dew Point: -5F; Wind: NW at 10 kts Sea-level pressure: 30.10 ins. Hg, falling then rising Visibility: 45 miles, distant haze 6-hour min. temp: 2F Snow on ground: 3 inches BHO SA 1155 CLR 45 192/3/-5/3110/010/ SC/FEW CU LYR DSNT OFFSHR NNE-SE CI DSNT ESE-SW LWR DNS CI DSNT SE-S DSNT HZ/ 8/802 4/003 53000 10010 20002 10 A.M. Weather: Stratocumulus layer distant offshore NNE-SE, cirrus layer ESE-WSW, thin smoke layer WSW-N-E along horizon, distant light haze Temperature: 11F; Dew Point: -1F; Wind: WNW at 8 kts, Wind: Direction variable WSW-N Sea-level pressure: 30.11 ins. Hg, rising then falling Visibility: 60 miles, 70 miles NW BHO SA 1455 220 SCT 60 197/11/-1/3008/011 SC LYR DSNT OFFSHR NNE-SE CI LYR ESE-WSW VSBY NW 70 THN K LYR WSW-N-E ALG HRZN DSNT LGT HZ WND 24V35/ 8/508 50005 1 P.M. Weather: Stratocumulus layer distant offshore NNE-SE, dense cirrus layer distant ESE-WSW and WNW-NE, thin smoke layer NNE-ESE along horizon, distant light haze Temperature: 21F; Dew Point: 1F; Wind: WNW at 9 kts, Wind: direction variable WSW-NNW Sea-level pressure: 30.05 ins. Hg, steady then falling Visibility: 70 miles, distant haze 6-hour max: 21F 6-hour min: 3F BHO SA 1755 220 SCT 70 175/21/1/2909/005 SC LYR DSNT OFFSHR NNE-SE DNS CI LYR DSNT ESE-WSW AND WNW-NE THN K LYR NNE-ESE ALG HRZN DSNT LGT HZ WND 24V34 8/502 58022 10021 20003 WEATHER SUMMARY FOR WEDNESDAY, JANUARY 2 TEMPERATURE (DEGREES F) MAX.....29 NORMAL.....35 MIN.....11 NORMAL.....19 MEAN....20 NORMAL.....27 DEPARTURE FROM 30-YEAR NORMAL......................-7 TOTAL DEPARTURE FOR THE MONTH......................-7 [-3.7 DEGREES/DAY] HEATING DEGREE DAYS TOTAL HEATING UNITS FOR YESTERDAY............45 DEPARTURE.........+7 TOTAL HEATING UNITS FOR THE MONTH............83 DEPARTURE.........+7 TOTAL HEATING UNITS FOR THE SEASON.........2111 DEPARTURE.......-270 TOTAL HEATING UNITS LAST SEASON TO DATE....1801 DIFFERENCE......+310 PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY...............35 WNW AT 3:44 P.M. AERO....................35 WNW AT 3:44 P.M. ASOS....................35 W AT 3:45 P.M. DAVIS...................33 WSW AT 1:27 P.M. RMY: 33 THE FASTEST MILE FOR YESTERDAY.............26 WNW AT 3:45 P.M. MAXIMUM 2-MINUTE ASOS AVERAGE..............25 WNW AT 3:45 P.M. MAXIMUM 2-MINUTE DAVIS AVERAGE.............23 W AT 3:43 P.M. AVERAGE WIND SPEED AND DIRECTION.........13.9 NW ASOS..................12.8 DAVIS.................12.4 WNW [290 deg.] PRECIPITATION (INCHES) THROUGH THIS MORNING (EST) TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.00 DEPARTURE..........-0.14 ASOS..............0.00 TOTAL PRECIPITATION FOR THE MONTH..........0.00 DEPARTURE..........-0.29 ASOS..............0.00 TOTAL PRECIPITATION FOR THE YEAR...........0.00 DEPARTURE..........-0.29 ASOS..............0.00 SNOWFALL (INCHES) THROUGH THIS MORNING (EST) TOTAL SNOWFALL 24 HRS ENDING 7 A.M.........0.0 DEPARTURE...........-0.5 TOTAL SNOWFALL FOR THE MONTH...............0.0 DEPARTURE...........-1.1 TOTAL SNOWFALL FOR THE SEASON.............15.4 DEPARTURE............-1.7 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/-7/0.06/0.8/000/00 16 E AERO 14 MPH E RMY 16 12/2 52/32/42/+6/0.00/0.0/006/01 32 SSW AERO 32 MPH SSW RMY 34 12/3 57/43/50/+14/0.00/0.0/523/94 31 NW AERO 30 MPH NW RMY 32 12/4 56/40/48/+13/0.03/0.0/000/00 37 S AERO 39 MPH S RMY 38 12/5 56/31/44/+9/0.03/0.0/310/56 38 WNW AERO 37 MPH WNW RMY 40 12/6 38/25/32/-3/0.00/0.0/519/94 31 NW AERO 30 MPH NW RMY N/A 12/7 42/30/36/+2/0.02/0.0/000/00 18 SSW AERO 16 MPH SSW RMY 18 12/8 45/41/43/+9/0.35/0.0/000/00 21 ENE AERO 18 MPH ENE RMY N/A 12/9 45/38/42/+8/0.10/0.0/181/33 24 NNW AERO 24 MPH NNW RMY 25 12/10 59/39/49/+16/0.51/0.0/000/00 32 SSW AERO 33 MPH SSW RMY 35 12/11 54/30/42/+9/0.01/0.0/351/64 25 W AERO 25 MPH W RMY 23 12/12 38/26/32/-1/0.00/0.0/126/23 20 NW AERO 18 MPH NW RMY N/A 12/13 42/29/36/+4/0.00/0.0/416/76 18 NW AERO 15 MPH NW RMY N/A 12/14 47/29/38/+6/0.00/0.0/535/98 28 W AERO 25 MPH W RMY 27 12/15 40/31/36/+4/0.00/0.0/530/97 24 NNW AERO 22 MPH NNW RMY 21 12/16 36/31/34/+3/0.25/0.1/000/00 25 E AERO 22 MPH E RMY N/A 12/17 44/36/40/+9/0.65/0.0/000/00 31 ENE AERO 29 MPH ENE RMY 30 12/18 50/40/45/+14/0.61/0.0/000/00 28 E AERO 24 MPH E RMY N/A 12/19 44/35/40/+10/T/0.0/087/16 42 WNW AERO 40 MPN WNW RMY 43 12/20 42/30/36/+6/T/0.0/262/48 25 NNW AERO 23 MPH NNW RMY N/A 12/21 53/35/44/+14/0.90/0.0/000/00 58 E AERO 53 MPH E RMY 57 * 12/22 37/26/32/+3/T/T/136/25 47 W AERO 47 MPH W RMY 43 12/23 37/25/31/+2/0.00/0.0/305/56 44 WNW AERO 44 MPH WNW RMY N/A 12/24 39/28/34/+5/0.00/0.0/452/83 25 W AERO 23 MPH W RMY 22 12/25 33/25/29/+1/0.03/0.4/000/00 21 NNW AERO 21 MPH NNW RMY 19 12/26 35/20/28/+0/0.30/1.0/228/43 39 E AERO 39 MPH E RMY N/A 12/27 45/30/38/+10/1.64/0.3/000/00 70 E AERO 71 MPH E RMY 67 12/28 34/24/29/+1/0.00/0.0/528/99 37 NW AERO 39 MPH NW RMY 36 12/29 34/25/30/+3/0.98/6.0/000/00 39 ENE AERO 39 MPH ENE RMY 40 12/30 27/18/23/-4/0.04/0.6/126/22 50 NW AERO 53 MPH NW RMY 53 12/31 31/17/24/-3/0/00/0.0/048/09 35 WNW AERO 35 MPH WNW RMY 36 1/1 35/18/27/0/0.00/0.0/.../.. 44 WNW AERO 44 MPH WNW RMY 45 1/2 29/11/20/0/0.00/0.0/.../.. 35 WW AERO 35 MPH WNW RMY 33 1/3 morning low 2F, average morning low is 18F * correction: added 0.90 precip: 21st DAILY RECORDS FOR DECEMBER 2012 None DAILY EXTREMES Temperature and precipitation records back to 1885, and wind records back to 1940 (e = estimated): RECORDS FOR JANUARY 3 HIGH 64F IN 2000 LOW -4F IN 1904 PRECIP 1.93 INS. IN 1999 SNOW 11.3 INS. 1996 PEAK GUST 92 MPH S IN 1960 RECORDS FOR JANUARY 4 HIGH 60F IN 2000 LOW -8F IN 1904, 1981 PRECIP 1.79 INS. IN 1982 SNOW 8.6 INS. 1923, 1941 PEAK GUST 84 MPH S IN 1982 TODAY'S REPORT PREPARED BY: Robert Skilling/Forrest Iwanik