BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
 
DAILY DISCUSSION AND CLIMATE SUMMARY
MONDAY, DECEMBER 31, 2012
ALL TIMES ARE IN EASTERN STANDARD TIME
 
YESTERDAY MARKS FIRST COOLER THAN NORMAL DAY SINCE DEC.12
MORNING LOW OF 17F COLDEST SINCE MARCH 16TH
PEAK GUST OF 50 MPH YESTERDAY AFTERNOON
 
Temperatures have ranged between the mid and upper 20's for most of the day due
to mostly cloudy to overcast skies. At approximately 12:30 PM clouds began to
break, allowing temperatures to surpass 30F for a short while before becoming
overcast again shortly after 1:00 PM. Visibility has been around 40 miles today
due to a persistent haze that can be seen off in the distance. This morning's low
temperature of 17F marks the lowest temperature up here since March 16th (16F).
Today is also the first day since December 12th where the average daily temperature
has finished below normal.  A peak gust of 50 mph was recorded here yesterday
afternoon as a strong low that brought snow to New England has moved off into the
Canadian Maritimes. Ponkapoag Pond and Houghton's Pond both show considerable
ice cover but have yet to fully freeze over at the same time.
 
Today's observations:
 
7 A.M.
Weather: Broken cirrus spissatus, broken thin cirrostratus, stratocumulus layer
distant NE-S, few cumulus fractus distant NE-S, few altocumulus cumulogenitus
distant SSW-NW, few altocumulus standing lenticularis distant NNW-S, few cirrus
undulatus NE-SE, contrails NE-SE, hazy
Temperature: 19F; Dew Point: 11F; Wind: WSW at 13 kts,
Wind: Direction variable SSW-W
Sea-level pressure: 30.04 ins. Hg, steady then increasing  
Visibility: 40 miles, hazy
6-hour min. temp: 17F
Snow on ground: 4 inches
BHO SA 1155 E200 BKN 250 –BKN 40 173/19/11/2413/004/ SC LYR DSNT NE-S FEW CUFRA
DSNT NE-S FEW ACCU DSNT SSW-NW FEW ACSL DSNT NNW-S FEW CI UNDULATUS NE-SE
CONTRAILS NE-SE HAZY WND 20V28/ 8/547 4/004 53003 10019 20017
 
10 A.M.
Weather: Overcast stratocumulus, stratocumulus layer distant NE-ESE, very distant
altocumulus standing lenticularis beyond overcast layer N, smoke layer distant N-E,
hazy
Temperature: 25F; Dew Point: 16F; Wind: WSW at 14 kts,
Wind: Direction variable SSW-W
Sea-level pressure: 30.04 ins. Hg, increasing then steady
Visibility: 40 miles, SSE 30 miles, hazy
BHO SA 1455 E45 OVC 40 174/25/16/2514/004/ SC LYR DSNT NE-ESE VRY DSNT ACSL BYND
OVC LYR N K LYR DSNT N-E HAZY VSBY LWR SSE 30 WND 21V28/ 8/5// 51001
 
1 P.M.
Weather: Broken stratocumulus, broken dense cirrostratus, broken thin cirrus,
few cumulus fractus all quadrants, contrails all quadrants, hazy
Temperature: 30F; Dew Point: 22F; Wind: W at 16G22 kts
Sea-level pressure: 29.94 ins. Hg, decreasing
Visibility: 45 miles, W-NW 35 miles, hazy
6-hour max: 31F
6-hour min: 19F
BHO SA 1755 E45 BKN 200 BKN 250 –BKN 45 139/30/22/2716G22/994/ FEW CUFRA ALQDS 
CONTRAILS ALQDS HAZY VSBY LWR W-NW 35/ 8/505 58035 10031 20019
 
WEATHER SUMMARY FOR SUNDAY, DECEMBER 30
 
TEMPERATURE (DEGREES F)
MAX.....27      NORMAL.....35
MIN.....18      NORMAL.....19
MEAN....23      NORMAL.....27
 
DEPARTURE FROM 30-YEAR NORMAL......................-4
TOTAL DEPARTURE FOR THE MONTH....................+166 [+5.3 DEGREES/DAY]
 
HEATING DEGREE DAYS
TOTAL HEATING UNITS FOR YESTERDAY............42    DEPARTURE.........+4
TOTAL HEATING UNITS FOR THE MONTH...........837    DEPARTURE.......-168
TOTAL HEATING UNITS FOR THE SEASON.........1987    DEPARTURE.......-280
TOTAL HEATING UNITS LAST SEASON TO DATE....1723    DIFFERENCE......+264
 
PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY...............50 NW  AT  3:58 P.M.
                   AERO....................53 NW  AT  4:06 P.M. *
                   ASOS....................51 NW  AT  4:06 P.M.
                   DAVIS...................50 NW  AT  4:06 P.M. RMY: 53 
THE FASTEST MILE FOR YESTERDAY.............35 NW  AT  3:56 P.M. * 
MAXIMUM 2-MINUTE ASOS AVERAGE..............36 WNW AT  4:01 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE.............36 WNW AT  4:01 P.M.
AVERAGE WIND SPEED AND DIRECTION.........20.9 WNW
                   ASOS..................19.7
                   DAVIS.................18.5 WNW [304 deg.]
* 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..........6.52   DEPARTURE..........+1.77
                         ASOS..............6.59
TOTAL PRECIPITATION FOR THE YEAR..........41.40   DEPARTURE.........-11.88
                         ASOS.............41.48
 
SNOWFALL (INCHES) THROUGH THIS MORNING (EST)
TOTAL SNOWFALL 24 HRS ENDING 7 A.M.........0.0     DEPARTURE..........-0.5
TOTAL SNOWFALL FOR THE MONTH...............9.6     DEPARTURE..........-3.2
TOTAL SNOWFALL FOR THE SEASON..............15.6    DEPARTURE..........+0.2   
 
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/-7/0.08/0.8/000/00     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/+14/0.00/0.0/000/00    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/+5/0.01/0.2/452/83     25 W   AERO 23 MPH W   RMY 22
12/25 33/25/29/+1/0.02/0.4/000/00     21 NNW AERO 21 MPH NNW RMY 19 
12/26 35/20/28/0/..../1.0/228/43      39 E   AERO 39 MPH E   RMY N/A
12/27 45/30/38/+10/..../0.3/.../..    70 E   AERO 71 MPH E   RMY 67
12/28 34/24/29/+1/0.00/0.0/000/00     37 NW  AERO 39 MPH NW  RMY 36
12/29 34/25/30/+3/0.98/6.0/.../..     39 ENE AERO 39 MPH ENE RMY 40
12/30 27/18/23/-4/0.04/0.6/.../..     50 NW  AERO 53 MPH NW  RMY 53
 
12/31 morning low temp: 17F; the normal low is now 19F
 
DAILY RECORDS FOR DECEMBER 2012
None so far.
 
DAILY EXTREMES
Temperature and precipitation records back to 1885, and
wind records back to 1940 (e = estimated):
 
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
 
RECORDS FOR JANUARY 1
HIGH 58F IN 1966
LOW -6F IN 1918
PRECIP 1.45 INS. IN 1982
SNOWFALL 7.2 INS. IN 1938
PEAK GUST 90e MPH S IN 1945
 
TODAY'S REPORT PREPARED BY: George Tabeek