BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY SUNDAY, DECEMBER 27, 2015 ALL TIMES ARE IN EASTERN STANDARD TIME FOG, LIGHT RAIN, AND CONTINUED MILD TEMPERATURES TODAY Light rain began at the summit in the overnight hours, and had added up to 0.16 ins. of rain by the 7:00 observation. Light rain and drizzle continued for most of the morning, adding an additional 0.03 ins. of rain. Temperatures have again been well above normal, rising slowly from a low of 42F to a high so far of 48F, and this will mark the 26th day in a row of above normal temperatures. Very dense fog has limited to visibility to only 1/16th of a mile for much of the day. It was a record breaking Christmas holiday here at Blue Hill and throughout the Northeast, with exceptionally warm temperatures making it feel more like early October than late December. December 24th and 25th both set new records for daily maximum and high minimum temperatures. The 67F reading on December 24th broke last year's record of 61F, and the Christmas day maximum of 64F broke a record of 62F set in 1889. The minimum temperature of 52F on the 25th broke the previous high minimum record by six degrees (46F in 1964). Six days this month have had a temperature departure of +20F or greater, including three in a row, both of which are records for December. The +30F departure yesterday was the second largest on record for December. Also impressive have been the dew points, which exceeded 60F for much of the day on the 24th. The temperature departure for December now sits at over +13F, and we are well on our way to the warmest December on record. BHO Largest December Daily Temperature Departure, deg F (1885-2015): 1) +35 on 29 Dec 1984 (72/51/62) 2) +30 on 25 Dec 2015 (64/52/58) 3) +29 on 23 Dec 1990 (62/53/58) +29 on 24 Dec 2015 (67/48/58) 5) +27 on 31 Dec 1965 (62/45/54) +27 on 22 Dec 1990 (58/53/56) 7) +26 on 27 Dec 1949 (57/51/54) +26 on 9 Dec 1966 (68/52/60) +26 on 6 Dec 2001 (70/52/61) (Thanks to Mike Iacono for compiling these statistics.) So far this season, there has been no measurable snow on Blue Hill. This season is now the fourth latest on record for the first occurrence of measurable snowfall. BHO Latest First Measurable Snowfall, (1885-2014) 1) January 13, 2000 (7.0 inches) 2) January 1, 1954 (0.8 inches) 3) December 29, 1941 (0.4 inches) 4) December 22, 1998 (0.6 inches) 5) December 16, 1973 (0.4 inches) 6) December 15, 1891 (0.3 inches) Today's Observations: 7 A.M. Weather: Sky obscured by dense fog, light rain Temperature: 43F; Dew Point: 43F; Wind: WNW @ 7 kts Sea-level pressure: 30.01 ins. Hg, falling then falling more slowly Visibility: 1/16 mile 6-hr Max temp: 43F 6-hr Min temp: 42F 24-hr precip: 0.16 ins. BHO SA 1155 W2 X 1/16R-F 162/43/43/3007/001/ 8//// 56032 ASOS 60016 ASOS 70016 MANUAL 70016 10043 20042 10 A.M. Weather: Sky obscured by dense fog, light drizzle Temperature: 44F; Dew Point: 44F; Wind: estimated NW @ 5 kts, Wind: Light Sea-level pressure: 29.91 ins. Hg, falling then falling more slowly Visibility: 1/16 mile 3-hr precip: 0.03 ins. BHO SA 1455 W2 X 1/16L-F 130/44/44/E3105/991/ WND LGT/ 8//// 56032 ASOS 60003 MANUAL 60003 1 P.M. Weather: Sky obscured by dense fog Temperature: 48F; Dew Point: 48F; Wind: WNW @ 9 kts Sea-level pressure: 29.78 ins. Hg, falling then falling more slowly Visibility: 1/16 mile 6-hr Max temp: 48F 6-hr Min temp: 42F 6-hr precip: 0.03 ins. BHO SA 1755 W3 X 1/16F 084/48/48/2609/978/ 8//// 56046 ASOS 60003 MANUAL 60003 10048 20042 SUMMARY FOR SATURDAY, DECEMBER 26, 2015 TEMPERATURE (DEGREES F) MAX.....53 NORMAL.....36 MIN.....40 NORMAL.....20 MEAN....47 NORMAL.....28 DEPARTURE FROM 30-YEAR NORMAL.....................+19 TOTAL DEPARTURE FOR THE MONTH....................+352 [+13.3 DEGREES/DAY] HEATING DEGREE DAYS (SEASON JUL TO JUN) TOTAL HEATING UNITS FOR YESTERDAY..............18 DEPARTURE.........-30 TOTAL HEATING UNITS FOR THE MONTH.............501 DEPARTURE........-354 TOTAL HEATING UNITS FOR THE SEASON...........1503 DEPARTURE........-614 TOTAL HEATING UNITS LAST SEASON TO DATE......1897 DIFFERENCE.......-394 PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY...................26 NNW AT 3:53 A.M. ASOS........................27 NNW AT 3:53 A.M. DAVIS.......................24 N AT 1:41 A.M. RMY N/A FASTEST MILE FOR YESTERDAY.....................18 NNW AT 3:55 A.M. MAXIMUM 2-MINUTE ASOS AVERAGE..................17 NNW AT 3:56 A.M. MAXIMUM 2-MINUTE DAVIS AVERAGE.................15 N AT 1:13 A.M. AVERAGE WIND SPEED AND DIRECTION..............8.3 N ASOS.......................8.9 DAVIS......................7.3 NE [046 Deg.] PRECIPITATION (INCHES) THROUGH THIS MORNING (EST) TOTAL PRECIPITATION 24 HRS ENDING 7 A.M.....0.16 DEPARTURE.......0.00 ASOS...............0.16 TOTAL PRECIPITATION FOR THE MONTH...........2.96 DEPARTURE......-1.22 ASOS...............2.99 TOTAL PRECIPITATION FOR THE YEAR...........42.38 DEPARTURE.....-10.34 ASOS................N/A *** *** ASOS annual total not available due to erroneous readings 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......-10.7 TOTAL SNOWFALL FOR THE SEASON.............TRACE DEPARTURE......-13.3 PRELIMINARY CLIMATE SUMMARY FOR DECEMBER CALENDAR DAY DATA DATA REPORTED: DATE: MAX/MIN/MEAN/DEP/PRECIP/SUN(MIN.)/SUN(%)/ PEAK GUST/RMY GUST RMY: R.M. Young wind gust recording system TSTM: Thunderstorm day (thunder heard some time during day) ....: Data not yet available, records not finalized 12/1 42/30/36/-1/..../0.0/000/00 19 NNE RMY 19 12/2 53/37/45/+9/..../0.0/000/00 25 SSE RMY 25 12/3 53/37/45/+9/..../0.0/162/29 43 WNW RMY 42 12/4 47/32/40/+5/0.00/0.0/444/80 32 NW RMY 32 12/5 50/33/42/+7/0.00/0.0/548/99 21 W RMY N/A 12/6 57/35/46/+11/0.00/0.0/531/96 22 SW RMY N/A 12/7 54/37/46/+12/0.00/0.0/353/64 31 NE RMY N/A 12/8 42/35/39/+5/0.01/0.0/000/00 32 NE RMY 31 12/9 44/34/39/+5/..../0.0/044/08 28 SSE RMY N/A 12/10 57/41/49/+16/T/0.0/209/38 29 SE RMY N/A 12/11 56/44/50/+17/0.00/0.0/049/09 28 SSW RMY 28 12/12 59/46/53/+20/0.00/0.0/367/67 23 W RMY N/A 12/13 54/44/49/+17/0.00/0.0/000/00 18 ESE RMY 19 12/14 60/43/52/+20/..../0.0/000/00 32 S RMY N/A 12/15 61/45/53/+21/..../0.0/371/68 48 W RMY 51 12/16 45/34/40/+9/0.00/0.0/415/76 25 N RMY N/A 12/17 53/36/45/+14/..../0.0/000/00 29 SE RMY 28 12/18 50/35/43/+12/..../0.0/000/00 29 NW RMY 30 12/19 38/30/34/+4/0.00/0.0/.../.. 39 W RMY 40 12/20 40/28/34/+4/0.00/0.0/.../.. 24 W RMY N/A 12/21 51/31/41/+11/T/0.0/.../.. 38 SSW RMY 42 12/22 57/49/53/+24/0.28/0.0/000/00 35 SW RMY 35 12/23 56/47/52/+23/..../0.0/.../.. 30 E RMY 27 12/24 67/48/58/+29/..../0.0/.../.. 37 SSW RMY 39 12/25 64/52/58/+30/..../0.0/.../.. 23 N RMY N/A 12/26 53/40/47/+19/..../0.0/.../.. 26 NNW RMY N/A 12/27 low since midnight is 42F; normal low is now 20F DAILY RECORDS FOR DECEMBER 2015 **12/13/2015- NEW DAILY RECORD HIGH MINIMUM TEMPERATURE OF 44F, BREAKS PREVIOUS RECORD OF 43F SET IN 1919, TIED 1983 **12/24/2015- NEW DAILY RECORD MAXIMUM TEMPERATURE OF 67F, BREAKS PREVIOUS RECORD OF 61F SET IN 2014 **12/24/2015- NEW DAILY RECORD HIGH MINIMUM TEMPERATURE OF 48F, BREAKS PREVIOUS RECORD OF 46F SET IN 1900 **12/25/2015- NEW DAILY RECORD MAXIMUM TEMPERATURE OF 64F, BREAKS PREVIOUS RECORD OF 62F SET IN 1889 **12/25/2015- NEW DAILY RECORD HIGH MINIMUM TEMPERATURE OF 52F, BREAKS PREVIOUS RECORD OF 46F SET IN 1964 DAILY EXTREMES Temperature and precipitation records back to 1885, and wind records back to 1940 (e = estimated): RECORDS FOR DECEMBER 27 HIGH 57 IN 1895,1949 LOW -4 IN 1903 PRECIP 2.43 INS. IN 1969 SNOWFALL 11.2 INS. IN 1947 PEAK GUST 73 S IN 2011 RECORDS FOR DECEMBER 28 HIGH 60 IN 1982 LOW -2 IN 1933 PRECIP 2.16 INS. IN 1967 SNOWFALL 9.5 INS. IN 1967 PEAK GUST 89 MPH SSE IN 1983 TODAY'S REPORT PREPARED BY: Jonathan O'Brien