BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY WEDNESDAY, DECEMBER 30, 2015  ALL TIMES ARE IN EASTERN STANDARD TIME WINTRY MIX TUESDAY FEATURED SNOW, ICE PELLETS, RAIN, FREEZING RAIN AND FREEZING DRIZZLE- TEMPS DROP TO 23F OVERNIGHT, GLAZE AND HOAR ICE ON BLUE HILL Shockingly, after one of the coldest days of the month, temperatures still averaged 4 degrees warmer than normal, making Tuesday the 28th consecutive day with temperatures warmer than normal.  Cold air rushed in after 4:00 PM EST yesterday afternoon, changing rain to freezing rain, then freezing drizzle. Glaze ice coated all surfaces this morning at less than 0.1 inch, with more than an inch of hoar frost forming on most surfaces. Slushy melted snow and ice pellets from yesterday morning froze hard overnight, creating slick surface across Great Blue Hill. Cloudy and cold conditions have prevailed this morning giving way to a lower cloud deck and freezing fog. A brief snow shower left a trace of new snow from 9:57 AM EST to 10:05 AM EST. A maximum temperature of 28F had been reached by the 1:00 PM EST observation. 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) 3) December 29, 2015  (1.3 inches) 5) December 22, 1998  (0.6 inches) 6) December 16, 1973  (0.4 inches) 7) December 15, 1891  (0.3 inches)  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) Today's Observations: 7 A.M. Weather: Overcast stratus, hoar frost on all surfaces, thin glaze ice on all surfaces Temperature: 23F; Dew Point: 21F; Wind: estimated NNW @ 5 kts Wind Speed: Light  Sea-level pressure: 30.35 ins. Hg, falling, then rising but lower still Visibility: 10 miles, thin fog 6-hr Max temp: 24F  6-hr Min temp: 23F 24-hr precip: 0.60 ins. 24-hr snowfall: 0.3 ins.   BHO SA 1155 E7 OVC 10 279/23/21/E3405/035/ THN FG ALQDS NEW SNW PST 24 HRS 0.3 INS HOAR FRST ON ALL SFCS THN GLZ ON ALL SFCS WND LGT/ 8/6// 53012 ASOS 70064 MANUAL 70060 10024 20023 10 A.M. Weather: Freezing fog Temperature: 25F; Dew Point: 23F; Wind: estimated NNW @ 2 kts, Wind Speed: Light Sea-level pressure: 30.42 ins. Hg, rising, then more slowly   Visibility: 1 miles, freezing fog BHO SA 1455 W3 X 1ZF 300/25/23/E3302/042/ WND LGT/ 8//// 51021 1 P.M. Weather: Freezing fog Temperature: 27F; Dew Point: 27F; Wind: estimated N @ 2 kts Wind Speed: Light Sea-level pressure: 30.33 ins. Hg, falling steadily Visibility: 1/2 of a mile, freezing fog 6-hr Max temp: 28F 6-hr Min temp: 23F 6-hr precip: Trace 6-hr snowfall: Trace BHO SA 1755 W3 X 1/2ZF 270/27/27/E0102/033/ NEW SNW PST 3 HRS TRACE WND LGT/ 8/// 57030 MANUAL 6000/ 10028 20023  SUMMARY FOR TUESDAY, DECEMBER 29, 2015    TEMPERATURE (DEGREES F) MAX.....38   NORMAL.....35 MIN.....23   NORMAL.....20  MEAN....31   NORMAL.....27 DEPARTURE FROM 30-YEAR NORMAL......................+4 TOTAL DEPARTURE FOR THE MONTH....................+375  [+12.7 DEGREES/DAY] HEATING DEGREE DAYS (SEASON JUL TO JUN) TOTAL HEATING UNITS FOR YESTERDAY..............34   DEPARTURE..........-4 TOTAL HEATING UNITS FOR THE MONTH.............590   DEPARTURE........-377 TOTAL HEATING UNITS FOR THE SEASON...........1592   DEPARTURE........-637 TOTAL HEATING UNITS LAST SEASON TO DATE......1973   DIFFERENCE.......-381 PEAK GUST AND AVERAGE WIND SPEED (MPH)  PEAK WIND GUST FOR YESTERDAY...................35  ENE AT  1:39 P.M.                     ASOS........................36  NE  AT  2:43 P.M.                      DAVIS.......................33  ENE AT  1:16 P.M. RMY 35 FASTEST MILE FOR YESTERDAY.....................25  E   AT 12:11 P.M.     MAXIMUM 2-MINUTE ASOS AVERAGE..................25  ENE AT 12:11 P.M.   MAXIMUM 2-MINUTE DAVIS AVERAGE.................23  E   AT 12:11 P.M.   AVERAGE WIND SPEED AND DIRECTION..............14.6 E                    ASOS.......................14.2                       DAVIS......................12.0 E [076 Deg.]  PRECIPITATION (INCHES) THROUGH THIS MORNING (EST) TOTAL PRECIPITATION 24 HRS ENDING 7 A.M.....0.60  DEPARTURE......+0.29                          ASOS...............0.64 TOTAL PRECIPITATION FOR THE MONTH...........4.11  DEPARTURE......-0.50                          ASOS...............4.17 TOTAL PRECIPITATION FOR THE YEAR...........43.53  DEPARTURE......-9.62                            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..........0.3  DEPARTURE.......-0.2 TOTAL SNOWFALL FOR THE MONTH................1.3  DEPARTURE......-11.0 TOTAL SNOWFALL FOR THE SEASON...............1.3  DEPARTURE......-13.6 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 52/35/44/+16/..../0.0/000/00          36 NW  RMY 33 12/28 35/27/31/+3/T/T/.../..                33 NW  RMY 33 12/29 38/23/31/+4/..../1.3/000/00           35 ENE RMY 35 12/30 low since midnight is 23F; normal low is now 19F   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 30 HIGH 60 IN 1984 LOW -18 IN 1933 PRECIP 1.48 INS. IN 1891 SNOWFALL 7.5 INS. IN 1956 PEAK GUST 81 MPH WNW IN 1962 RECORDS FOR DECEMBER 31 HIGH 62 IN 1965 LOW -12 IN 1917 PRECIP 0.96 INS. IN 1906 SNOWFALL 7.5 INS. IN 2008 PEAK GUST 78 MPH NW IN 1990 TODAY'S REPORT PREPARED BY: Brian Fitzgerald