BLUE HILL METEOROLOGICAL OBSERVATORY  MILTON, MASSACHUSETTS ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY TUESDAY, DECEMBER 30, 2014      ALL TIMES ARE IN EASTERN STANDARD TIME MERCURY DROPS OVERNIGHT TO 19F, PLENTIFUL SUNSHINE ONCE AGAIN Winds shifted from W to NNW overnight allowing additional cold and dry air to enter the region with a morning low of 19F, the coldest reading since the 8th of the month. This marked only the 3rd day for the month of December that the mercury had reached the teens. The coldest reading of the season still remains at 16F which also occurred on December 8th. With cold temperatures and  dew points remaining in the upper single digits to lower teens today, snow guns have been going full blast at  the ski area today. By the 1:00 PM EST observation two layers of cirrus were scattered covering 4/8 of the sky with plenty of cool, dry air in place. Visibility ranged from 70 to 80 plus miles in the NW with a maximum of 27F recorded so far. Today's Observations: 7 A.M. Weather: Broken cirrus, few stratocumulus distant  offshore NE-SE Temperature: 20F; Dew Point: 9F; Wind: NNW at 7 kts Sea-level pressure: 30.32 ins. Hg, increasing, then more quickly                       Visibility: 70 miles 6-hr max temp: 25F 6-hr min temp: 19F  24-hr precip.: 0.00 ins  BHO SA 1155 E200 BKN 70 267/20/9/3307/032/ FEW SC DSNT OFFSHR NE-SE/ 8/504 53010 10025 20019 10 A.M.  Weather: Broken cirrus, few stratocumulus distant  offshore NE-SE, few cumulus distant NW Temperature: 25F; Dew Point: 12F; Wind: NW at 8 kts Sea-level pressure: 30.14 ins. Hg, rising, then more quickly Visibility: 70 miles, except 80 miles WNW-NNE BHO SA 1455 E200 BKN 70 277/25/12/3208/035/ VSBY WNW-NNE 80 MI FEW SC DSNT OFFSHR NE-SE FEW CU DSNT NW/ 8/504 53010 1 P.M. Weather: Scattered cirrus, scattered cirrus lower, few stratocumulus distant offshore ENE-SE Temperature: 27F; Dew Point: 10F; Wind: estimated W at 6 kts, Wind Speed: Light Sea-level pressure: 30.28 ins. Hg, rising, then falling and lower Visibility: 70 miles, except 80 miles WSW-NNE 6-hr max temp: 27F 6-hr min temp: 20F BHO SA 1755 200 SCT 250 SCT 80 255/27/10/E2806/028/ VSBY WSW-NNE 80 MI FEW SC DSNT OFFSHR ENE-SE WND LGT/ 8/501 58022 10027 20020 SUMMARY FOR MONDAY, DECEMBER 29, 2014  TEMPERATURE (DEGREES F) MAX.....41   NORMAL.....35 MIN.....26   NORMAL.....20 MEAN....34   NORMAL.....27 DEPARTURE FROM 30-YEAR NORMAL..........................+7 TOTAL DEPARTURE FOR THE MONTH........................+129 [+4.2 DEGREES/DAY]  HEATING DEGREE DAYS (SEASON JUL TO JUN) TOTAL HEATING UNITS FOR YESTERDAY..............31  DEPARTURE...........-7 TOTAL HEATING UNITS FOR THE MONTH.............821  DEPARTURE.........-146      TOTAL HEATING UNITS FOR THE SEASON...........1980  DEPARTURE.........-249 TOTAL HEATING UNITS LAST SEASON TO DATE......2193  DIFFERENCE........-213 PEAK GUST AND AVERAGE WIND SPEED (MPH)  PEAK WIND GUST FOR YESTERDAY..................23  WNW  AT  12:48 P.M.                           ASOS.......................24  W    AT  12:57 P.M.                          DAVIS......................22  WNW  AT  12:48 P.M. RMY 23 FASTEST MILE FOR YESTERDAY....................17  WNW  AT  12:33 P.M.       MAXIMUM 2-MINUTE ASOS AVERAGE.................18  W    AT   3:55 P.M.        MAXIMUM 2-MINUTE DAVIS AVERAGE................16  W    AT  11:59 P.M.        AVERAGE WIND SPEED AND DIRECTION.............10.3 WNW                     ASOS......................10.7                       DAVIS.....................8.7 WNW [287 degrees]   * last of several occurrences...                 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..........7.21  DEPARTURE.....+2.60                          ASOS..............7.44   TOTAL PRECIPITATION FOR THE YEAR..........54.97  DEPARTURE.....+1.83                          ASOS.............55.63    SNOWFALL (INCHES) THROUGH THIS MORNING (EST) TOTAL SNOWFALL 24 HRS ENDING 7 A.M..........0.0  DEPARTURE......-0.5 TOTAL SNOWFALL FOR THE MONTH................2.3  DEPARTURE.....-10.0  TOTAL SNOWFALL FOR THE SEASON..............11.0  DEPARTURE......-3.9   PRELIMINARY CLIMATE SUMMARY FOR DECEMBER CALENDAR DAY DATA DATA REPORTED: DATE: MAX/MIN/MEAN/DEP/PRECIP/SNOWFALL/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  63/37/50/+13/0.01/0.0/391/70             28 WNW RMY 31 12/2  37/30/34/-2/0.10/T/000/00                26 E   RMY 29 12/3  49/34/42/+6/0.31/0.0/000/00              40 W   RMY 43  12/4  41/27/34/-1/0.00/0.0/505/91              29 WNW RMY N/A  12/5  42/23/33/-2/0.12/0.0/382/69              21 E   RMY 22 12/6  43/36/40/+5/0.99/0.0/000/00              25 NNW RMY N/A 12/7  36/18/27/-7/0.15/0.0/193/35              31 N   RMY 34 12/8  25/16/21/-13/0.01/0.1/000/00             24 N   RMY N/A 12/9  48/25/37/+3/3.23/0.0/000/00              48 ENE RMY 52 12/10 47/35/41/+8/0.43/0.0/000/00              35 NNE RMY 37  12/11 35/29/32/-1/0.05/0.5/000/00              27 SW  RMY 27   12/12 36/26/31/-2/0.00/0.0/230/42              23 WNW RMY 25 12/13 40/27/34/+2/0.00/0.0/191/35              28 NW  RMY 28  12/14 43/28/36/+4/0.00/0.0/377/69              20 NW  RMY 20 12/15 41/28/35/+3/0.00/0.0/536/98              17 NW  RMY 17 12/16 42/33/38/+7/T/T/011/02                   17 E   RMY N/A 12/17 45/37/41/+10/0.43/0.0/000/00             27 W   RMY N/A  12/18 41/32/37/+6/0.02/T/213/39                35 WNW RMY 38    12/19 34/25/30/0/0.00/0.0/000/00               26 NW  RMY 29 12/20 32/24/28/-2/..../.../164/30              21 NNE RMY 23  12/21 31/29/30/+0/..../.../000/00              20 NNE RMY 22 12/22 42/29/36/+7/..../0.0/.../..              23 E   RMY N/A 12/23 44/39/42/+13/..../0.0/000/00             28 ENE RMY 30  12/24 61/40/51/+22/..../0.0/000/00             32 SSW RMY 41  12/25 61/41/51/+23/..../0.0/.../..             37 W   RMY 43 12/26 47/35/41/+13/0.00/0.0/.../..             24 WSW RMY 28 12/27 50/35/43/+15/0.00/0.0/.../..             21 SSW RMY N/A 12/28 49/35/42/+14/0.02/0.0/.../..             31 W   RMY 36 12/29 41/26/34/+7/0.00/0.0/.../..              23 WNW RMY 23 12/30 morning low temp: 19F since midnight; normal low is now 19F DAILY RECORDS FOR DECEMBER 2014: -DAILY PRECIPITATION RECORD FOR DECEMBER 9 2014 Old record of 1.51 inches set in 1952, replaced with new record of 3.23 inches. -DAILY TEMPERATURE RECORD FOR DECEMBER 24 2014         Old record of 58F set in 1996,         replaced with new record of 61F. 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