BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
 
DAILY DISCUSSION AND CLIMATE SUMMARY
WEDNESDAY, DECEMBER 18, 2013
ALL TIMES ARE IN EASTERN STANDARD TIME
 
SNOWSTORM YESTERDAY ADDS 5.5 INCHES 
MONTHLY TOTAL REACHES 15 INCHES
SUNSHINE PREVAILING TODAY
FRIGID AIR MASS RELEASING ITS GRIP
 
The snow which began early yesterday afternoon totaled
up to 5.5 inches (0.53 melted) by the time it ended late
last evening. I've added 0.9 inch of snow to the Saturday-
Sunday storm total to make it 6.8 inches to account for
melting before ob time on Sunday morning.
As sunshine prevails today the temperature is steadily
approaching the melting point and the the spell of very
cold weather is finally coming to an end.
 
Today's Observations:
 
7 A.M.
Weather: Overcast stratocumulus, thin fog, hazy
Temperature: 20F; Dew Point: 18F; Wind: NW at 12 kts,
Sea-level pressure: 29.91 ins. Hg, rising then more slowly
Visibility: 25 miles, thin fog and hazy 
6-hr. min temp: 15F 
24-hr precip: 0.53 inch
24-hr snowfall: 5.5 inches
Snow on ground: 11 inches
BHO SA 1155 E20 OVC 25 129/20/18/3212/991/ HAZY TOTAL NEW SNW
PST 24 HRS 5.5 INS/ 8/5// 4/011 51016 ASOS 70055 MANUAL 70053
100// 20015
 
10 A.M. 
Weather: Thin broken cirrus, patches dense cirrus NE-E,
few distant altocumulus lenticularis 
Temperature: 27F; Dew Point: 19F; Wind: NW at 15 kts,
Sea-level pressure: 29.91 ins. Hg, rising slightly 
Visibility: 30 miles, hazy 
BHO SA 1455 220 SCT 250 –BKN 30 130/27/19/3215/991/ FEW DSNT ACSL
PTCHS DNS CI NE-E SKY CLRG/ 8/042 53002
 
1 P.M.
Weather: Clear, few stratocumulus distant offshore ENE-ESE
Temperature: 31F; Dew Point: 18F; Wind: WNW at 11 kts,
Wind: Gust to 24 kts past hour
Sea-level pressure: 29.89 ins. Hg, falling slightly
Visibility: 40 miles, light distant haze
6-hr max. temp. 32F
BHO SA 1755 CLR 40 128/31/18/3011/989/ FEW SC DSNT OFFSHR ENE-ESE
WND GUST 24 KTS PST HR DSNT HZ/ 8/500 55002 10032 20020
 
WEATHER SUMMARY FOR TUESDAY, DECEMBER 17, 2013
 
TEMPERATURE (DEGREES F)
MAX.....23    NORMAL.....39
MIN......7    NORMAL.....23
MEAN....15    NORMAL.....31
 
DEPARTURE FROM 30-YEAR NORMAL.....................-16
TOTAL DEPARTURE FOR THE MONTH.....................-67 [-4.1 DEGREES/DAY]
 
HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY..............50  DEPARTURE........+16
TOTAL HEATING UNITS FOR THE MONTH.............599  DEPARTURE........+46
TOTAL HEATING UNITS FOR THE SEASON...........1823  DEPARTURE........+28
TOTAL HEATING UNITS LAST SEASON TO DATE......1581  DIFFERENCE......+242
 
PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY..................28 N   AT  8:18 P.M. 
                   AERO.......................30 N   AT  8:18 P.M. 
                   ASOS.......................31 N   AT  8:25 P.M. 
                   DAVIS......................28 N   AT  8:24 P.M. RMY 28
FASTEST MILE FOR YESTERDAY....................22 M   AT  8:40 P.M.  
MAXIMUM 2-MINUTE ASOS AVERAGE.................23 N   AT  8:39 P.M. 
MAXIMUM 2-MINUTE DAVIS AVERAGE................20 NNW AT  8:20 P.M. 
AVERAGE WIND SPEED AND DIRECTION............11.0 N
                   ASOS.....................11.4
                   DAVIS.....................9.9 N  [360 degrees]
 
PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.53  DEPARTURE.............+0.38
                         ASOS..............0.55
TOTAL PRECIPITATION FOR THE MONTH..........3.25  DEPARTURE.............+0.48
                         ASOS..............3.27
TOTAL PRECIPITATION FOR THE YEAR..........49.85  DEPARTURE.............-1.45
                         ASOS..............N/A**
** ASOS malfunctioned during storm on 2/8-9, leading to erroneous totals
 
SNOWFALL (INCHES) THROUGH THIS MORNING (EST)
TOTAL SNOWFALL 24 HRS ENDING 7 A.M.......5.5     DEPARTURE.............+5.0
TOTAL SNOWFALL FOR THE MONTH............15.0*    DEPARTURE.............+8.7
TOTAL SNOWFALL FOR THE SEASON...........15.2     DEPARTURE.............+6.3
 
The recent storm total of 5.9 now corrected to 6.8 ins. 
 
PRELIMINARY CLIMATE SUMMARY FOR DECEMBER 2013 CALENDAR DAY DATA
DATA REPORTED:
DATE: MAX/MIN/MEAN/DEP/PRECIP/SNOW/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  45/30/38/+1/0.28/T/000/00           22 SSE AERO 23 MPH SSE RMY 23
12/2  38/34/36/0/T/0.0/000/00             15 NW  AERO 15 MPH NW  RMY 16
12/3  45/32/39/+3/0.00/0.0/284/51         18 NNW AERO 18 MPH NNW RMY 20
12/4  43/29/36/+1/0.00/0.0/389/70         21 WNW AERO 21 MPH WNW RMY 21
12/5  53/38/46/+11/0.02/0.0/000/00        36 S   AERO 40 MPH S   RMY 39
12/6  55/33/44/+9/0.38/T/000/00           25 SSW AERO 28 MPH SSW RMY N/A
12/7  40/26/33/-1/0.12/T/287/52           23 NW  AERO 25 MPH NW  RMY N/A
12/8  30/22/26/-8/T/T/039/07              25 NW  AERO 27 MPH NW  RMY N/A
12/9  41/25/33/-1/0.35/0.6/000/00         28 E   AERO 28 MPH E   RMY 24
12/10 33/21/27/-6/0.14/2.1/000/00         28 W   AERO 28 MPH W   RMY 28
12/11 28/19/24/-9/0.00/0.0/345/63         27 SW  AERO 28 MPH SW  RMY 27
12/12 23/14/19/-14/0.00/0.0/.../..        28 WNW AERO 31 MPH NW  RMY 30
12/13 28/14/21/-11/0.00/0.0/.../..        31 W   AERO 32 MPH W   RMY 33
12/14 28/9/19/-13/..../../000/00          30 E   AERO 26 MPH E   RMY N/A
12/15 36/21/29/-3/..../../.../..          48 NE  AERO 50 MPH NE  RMY 51 
12/16 27/14/21/-10/0.00/0.0/.../..        AVAILABLE LATER AFTER REVIEW  
12/17 23/7/15/-16/0.53/5.5/.../..         28 N   AERO 30 MPH N   RMY 28
 
12/18  morning low temp: 20F; the normal low is now 23F
 
DAILY RECORDS FOR DECEMBER 2013
None so far.                                   
 
DAILY EXTREMES
Temperature and precipitation records back to 1885, and
wind records back to 1940 (e = estimated):
 
RECORDS FOR DECEMBER 18
HIGH 59 IN 1928
LOW -11 IN 1919
PRECIP 1.44 INS. IN 1915
SNOWFALL 7.0 INS. IN 1904
PEAK GUST 76e W IN 1978
 
RECORDS FOR DECEMBER 19
HIGH 59 IN 1899
LOW -1 IN 1919
PRECIP 2.06 INS. IN 1986
SNOWFALL 14.1 INS. IN 1945
PEAK GUST 68 NE IN 1986
 
TODAY'S REPORT PREPARED BY: Robert Skilling