BLUE HILL METEOROLOGICAL OBSERVATORY 
MILTON, MASSACHUSETTS
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
 
DAILY DISCUSSION AND CLIMATE SUMMARY
FRIDAY, DECEMBER 24, 2010
ALL TIMES ARE IN EASTERN STANDARD TIME
 
MERRY CHRISTMAS....
A WHITE ONE WITH A COUPLE INCHES OF SNOW
ON THE GROUND
 
THE SECOND SNOWFALL EVENT OF THIS SEASON EXTENDED
OVER TWO CALENDAR DATES...December 22-23. 
 
This second snowfall has assured us of a white
Christmas despite a very late start to the snow-
fall season. 
 
The total for the last event was 2.5 inches and
0.25 inch melted so exactly a 10:1 ratio.
This brought the monthly total to 6.0 inches
which is still 1.5 inches less than normal for
the December to date.  The season has 4.3 inches
less than normal with at 6.1 inches.
 
This continues to be a slight colder [-2.1 deg]
and drier December [-0.33 inch]
 
Today's observations: 
 
7 A.M.
Weather: High thin scattered cirrus, two levels, stratocumulus layer along and
offshore northeast thru southeast thru distant south-southeast
Temperature: 24F, Dew point: 16F; Wind: WNW at 12 kts,
Wind: Gust to 20 kts past hour
Wind: Direction variable W to NNW
Sea-level pressure: 29.91 inches Hg, rising
Visibility: 50 miles 
6-hour minimum temp: 24F
24-hour precip: 0.01 inch
24-hour snowfall: 0.1 inch
2-day storm total 2.5 ins.
Snow depth: 3 inches  
BHO SA 1155 250 –SCT 300 –SCT 50 130/24/16/3012/991/
SC LYR ALG/OFFSHR NE-DSNT SSE WND 28V34 GST 20 KTS PST HR
TOTAL NEW SNW PST 24 HRS 0.1 IN STORM TOTAL 2.5 INS/
8/501 4/003 53015 10027 20024  
 
10 A.M.
Weather: Thin broken cirrus, few altocumulus lenticularis to the
southeast thru south and west thru west-northwest
Temperature: 28, Dew point: 14F; Wind: WNW at 12G20 kts
Wind: Direction variable W to NNW
Sea-level pressure: 29.96 inches Hg, rising
Visibility: 65 miles, NW 70 miles, light distant haze
BHO SA 1455 250 –SCT 300 –BKN 60 144/28/14/3012G20/996/
FEW ACSL SE-S AND W-WNW VSBY NW 70 LGT DSNT HZ WND 28V34/
8/041 51014
 
WEATHER SUMMARY FOR THURSDAY, DECEMBER 23
 
TEMPERATURE (DEGREES F)
MAX.....36     NORMAL.....37
MIN.....27     NORMAL.....22
MEAN....32     NORMAL.....29
 
DEPARTURE FROM 30-YEAR NORMAL.................+3
TOTAL DEPARTURE FOR THE MONTH................-44 [-2.1 DEGREES/DAY]
 
HEATING DEGREE DAYS
TOTAL HEATING UNITS FOR YESTERDAY............33    DEPARTURE........-3
TOTAL HEATING UNITS FOR THE MONTH...........797    DEPARTURE.......+50
TOTAL HEATING UNITS FOR THE SEASON.........1957    DEPARTURE.......-79
TOTAL HEATING UNITS LAST SEASON TO DATE....1954    DIFFERENCE.......+3
 
PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY..............36 NW  AT  5:00 P.M.   
                   AEROVANE...............38 NW  AT  5:43 P.M. *  
                   ASOS...................35 NW  AT  5:00 P.M.  
                   DAVIS..................42 WNW AT  4:59 P.M.  
THE FASTEST MILE FOR YESTERDAY............25 NW  AT  5:01 P.M. * 
MAXIMUM 2-MINUTE ASOS AVERAGE.............25 NW  AT  5:02 P.M.   
MAXIMUM 2-MINUTE DAVIS AVERAGE............28 WNW AT  3:16 P.M.   
AVERAGE WIND SPEED AND DIRECTION........18.5 NW  
                   ASOS.................17.5        
                   DAVIS................18.8 WNW [300 DEG]
* last of several occurrences
 
PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.01  DEPARTURE........-0.14
                         ASOS..............0.01
TOTAL PRECIPITATION FOR THE MONTH..........3.03  DEPARTURE........-0.33
                         ASOS..............3.14 
TOTAL PRECIPITATION FOR THE YEAR..........61.06  DEPARTURE.......+11.04
                         ASOS.............61.05**
** ASOS missing rainfall due to system failure on 6/24-25
 
SNOWFALL (INCHES) THROUGH THIS MORNING (EST)
TOTAL SNOWFALL 24 HRS ENDING 7 A.M..........0.1  DEPARTURE.....-0.3
TOTAL SNOWFALL FOR THE MONTH................6.0  DEPARTURE.....-1.5
TOTAL SNOWFALL FOR THE SEASON...............6.1  DEPARTURE.....-4.3 
 
PRELIMINARY CLIMATE SUMMARY FOR DECEMBER 2010 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 when significant
TSTM: Thunderstorm day (thunder heard some time during day)
....: Data not yet available, records not finalized
 
12/1  55/43/49/+13/0.49/0.0/000/00  55 SE   AERO 61 MPH SE
12/2  48/29/39/+3/0.00/0.0/540/100  30 W
12/3  38/29/34/-1/0.00/0.0/050/09   25 WNW
12/4  40/28/34/-1/0.00/0.0/516/93   27 WNW
12/5  34/23/29/-6/0.00/0.0/127/23   24 W
12/6  32/22/27/-7/0.00/0.0/447/81   37 WSW  AERO 38 MPH WSW
12/7  33/23/28/-6/0.00/0.0/463/84   35 W    AERO 37 MPH W
12/8  31/19/25/-8/0.00/0.0/550/100  39 W    AERO 40 MPH W
12/9  26/14/20/-13/0.00/0.0/550/100 29 WNW
12/10 25/9/17/-16/0.00/0.0/181/33   17 SSE
12/11 44/25/35/+3/0.00/0.0/460/84*  23 WSW
12/12 55/33/44/+12/1.57/0.0/000/00  55 SE   AERO 69 MPH SE
12/13 55/33/44/+12/0.35/0.0/027/05  50 SSE  AERO 58 MPH SSE
12/14 33/16/25/-6/T/T/120/22        30 W
12/15 19/13/16/-15/0.02/0.2/038/07  33 WNW  AERO 38 MPH WNW 
12/16 32/15/24/-7/0.00/0.0/491/90   25 SSW
12/17 34/17/26/-5/0.00/0.0/.../..   22 WNW
12/18 37/22/30/0/0.00/0.0/.../..    20 N
12/19 34/25/30/0/0.00/0.0/.../..    17 N
12/20 30/23/27/-3/0.34/3.2/.../..   33 NW   AERO 37 MPH NW
12/21 38/23/31/+1/0.02/0.2/.../..   38 NW
12/22 36/28/32/+3/0.14/1.4/../..    31 NW   AERO 35 MPH NW
12/23 36/27/32/+3/0.11/1.1/.../..   36 NW   AERO 38 MPH NW
 
* 12/11 - a correction has been added increasing the
  daily mins. of sunshine from 400 to 460 and 84%
  remains the same        
 
12/24 - our morning low temp: 24F; the normal low is now 21F
      a lower temp. of 23F occurred after 7 a.m.  
 
DAILY RECORDS FOR DECEMBER 2010
 
12/15 - NEW RECORD LOW MAXIMUM TEMP. OF 19F;
this surpasses the previous record of 20F  
in 1903,1905,1931, and 1962 
 
DAILY EXTREMES
Temperature and precipitation records back to 1885, and
wind records back to 1940 (e = estimated):
 
RECORDS FOR DECEMBER 24
HIGH 58 IN 1996
LOW -6 IN 1943
PRECIP 2.21 INS. IN 1994
SNOWFALL 12.3 INS. IN 1961
PEAK GUST 79e MPH SE IN 1941
 
RECORDS FOR DECEMBER 25 [MERRY CHRISTMAS]
HIGH 62 IN 1889
LOW -11 IN 1980
PRECIP 1.37 INS. IN 2002
SNOWFALL 8.5 INS. IN 2002
PEAK GUST 80 MPH NW IN 1971
 
TODAY'S REPORT PREPARED BY: Robert Skilling