BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS 02186
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA

DAILY DISCUSSION AND CLIMATE SUMMARY
SATURDAY, DECEMBER 20, 2008  
ALL TIMES ARE IN EASTERN STANDARD TIME 

FIRST SIGNIFICANT SNOWFALL OF THE SEASON BRINGS 
10.8 INCHES OF SNOW SO FAR...LIGHT SNOW CONTINUES...
Snow began accumulating quickly after it began early
on Friday afternoon, with snowfall rates reaching
1-2 inches per hour during the late afternoon and
early evening.  A total of 9.0 inches was measured
on our snowboards through 7 AM this morning, with
an additional 1.8 inches falling in the six hours
ending at 1 PM today. Light snow continues falling
as of 1:30 PM and there are 11 inches on the summit
as of early afternoon. 

7 A.M. 
Weather: Sky partly obscured with light snow, overcast 
nimbostratus
Temperature: 12F, Dew point: 9F, Wind: NNW at 16 kts
Sea-level pressure: 30.09 inches Hg, rising
Visibility: 1 1/2 miles, light snow
6-hour minimum temperature: 11F
24-hour precipitation: 1.38 inches
24-hour snowfall: 9.0 inches
Snow on ground: 9 inches
BHO SA 1155 –X E10 OVC 11/2S- 189/12/9/3316/009/ S3 TOTAL 
NEW SNW PST 24 HRS 9.0 INS/ 8/6// 4/009 53027 60/// 70138 
10013 20011

10 A.M.
Weather: Sky partly obscured with light snow, overcast
nimbostratus
Temperature: 13F, Dew point: 10F, Wind: NNW at 12 kts
Sea-level pressure: 30.13 inches Hg, rising
Visibility: 2 miles, light snow
3-hour snowfall: 0.8 inch
BHO SA 1455 –X E15 OVC 2S- 202/13/10/3412/013/ S2 TOTAL NEW 
SNW PST 3 HRS 0.8 IN/ 8/6// 53013 60///

1 P.M.
Weather: Sky partly obscured with light snow, overcast
nimbostratus
Temperature: 16F, Dew point: 13F, Wind: N at 14G23 kts
Sea-level pressure: 30.10 inches Hg, falling
Visibility: 2 miles, light snow
6-hour maximum temperature: 16F 
3-hour snowfall: 1.8 inches
BHO SA 1755 –X E15 OVC 2S- 192/16/13/3614G23/010/ S1 TOTAL NEW 
SNW PST 6 HRS 1.8 INS/ 8/6// 4/011 56010 60/// 10016 20011


WEATHER SUMMARY FOR FRIDAY, DECEMBER 19
  
TEMPERATURE (DEGREES F)
MAX.....29    NORMAL.....38
MIN.....14    NORMAL.....23
MEAN....22    NORMAL.....30

DEPARTURE FROM 30-YEAR NORMAL...............-8
TOTAL DEPARTURE FOR THE MONTH..............+48 [+2.3 DEGREES/DAY] 

HEATING DEGREE DAYS
TOTAL HEATING UNITS FOR YESTERDAY.............43  DEPARTURE.........+8
TOTAL HEATING UNITS FOR THE MONTH............563  DEPARTURE........-43
TOTAL HEATING UNITS FOR THE SEASON..........1813  DEPARTURE........-82
TOTAL HEATING UNITS LAST SEASON TO DATE.....1805  DIFFERENCE........+8

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY............46  NE AT  8:10 P.M. *  
                   AEROVANE.............45  NE AT  7:35 P.M. 
                   ASOS.................47 ENE AT  8:11 P.M.   
                   DAVIS................46 ENE AT  8:10 P.M.
FASTEST MILE FOR YESTERDAY..............34  NE AT  7:45 P.M.  
MAXIMUM 2-MINUTE ASOS AVERAGE...........33 ENE AT  7:46 P.M.    
MAXIMUM 2-MINUTE DAVIS AVERAGE..........35 ENE AT  7:46 P.M.
                   AVERAGE............15.9  NE
                   ASOS...............14.3
                   DAVIS..............15.2 NNE [26 deg] 

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M.....1.38   DEPARTURE.......+1.24
                         ASOS...............1.28
TOTAL PRECIPITATION FOR THE MONTH...........6.50   DEPARTURE.......+3.73
                         ASOS...............6.61
TOTAL PRECIPITATION FOR THE YEAR...........56.79   DEPARTURE.......+7.36
                         ASOS..............59.62 #
# Includes erroneous ASOS precipitation data on 2/13/08.

SNOWFALL (INCHES) THROUGH THIS MORNING (EST)
TOTAL SNOWFALL 24 HRS ENDING 7 A.M..........9.0  DEPARTURE.....+8.6
TOTAL SNOWFALL FOR THE MONTH...............11.8  DEPARTURE.....+5.9
TOTAL SNOWFALL FOR THE SEASON..............11.8  DEPARTURE.....+3.0

PRELIMINARY CLIMATE SUMMARY FOR DECEMBER 2008 CALENDAR DAY DATA
DATA REPORTED:
DATE: MAX/MIN/MEAN/DEP/PRECIP/SNOW/SUN(MIN.)/SUN(%)/ PEAK GUST/AERO GUST
AERO: Aerovane recording wind system gust when significant
TSTM: Thunderstorm day (thunder heard some time during day)
....: Data not yet available, records not finalized

12/1  59/43/51/+15/0.12/0.0/374/67   43 SSW  
12/2  47/32/40/+4/0.00/0.0/451/81    33 SSW 
12/3  44/29/37/+2/0.00/0.0/556/100   24 SSW
12/4  53/33/43/+8/T/0.0/122/22       42 SSW   Aero 43 MPH S
12/5  38/26/32/-3/0.00/0.0/404/73    26 WNW
12/6  37/23/30/-4/0.00/0.0/309/56    21 S
12/7  32/20/26/-8/0.12/1.6/000/00    54 W     Aero 53 MPH W 
12/8  21/10/16/-17/0.00/0.0/462/84   50 W     Aero 50 MPH W 
12/9  53/13/33/0/0.01/T/000/00       48 S     Aero 50 MPH S
12/10 60/37/49/+16/0.43/0.0/000/00   55 S     Aero 58 MPH S 
12/11 37/34/36/+4/1.52/T/000/00      38 NNE   Aero 35 MPH NNE
12/12 61/28/45/+13/2.32/0.0/088/16   75 SSE   Aero 76 MPH SSE
12/13 28/17/23/-9/0.00/0.0/531/97    33 W 
12/14 43/17/30/-1/0.00/0.0/.../..    36 S 
12/15 61/43/52/+21/T/0.0/.../..      55 S     Aero 56 MPH S
12/16 57/26/42/+11/.../../000/00     43 W
12/17 38/25/32/+1/.../../000/00      26 E     Aero 22 MPH E
12/18 37/28/33/+3/0.00/0.0/.../..    23 WSW
12/19 29/14/22/-8/.../../000/00      46 NE    Aero 45 MPH NE

12/20 morning low temp through 8AM: 11F; our normal low temp. 22F 

NEW DAILY RECORDS FOR DECEMBER 2008...

12/12 PEAK GUST 75 MPH SSE; PREVIOUS 74 MPH W IN 2000 

DAILY EXTREMES
Temperature and precipitation records back to 1885, and
wind records back to 1940 (e = estimated):

RECORDS FOR DECEMBER 20
HIGH 61 IN 1957
LOW -16 IN 1942
PRECIP 1.69 INS. IN 1936
SNOWFALL 8.3 INS. IN 1995
PEAK GUST 75 MPH S IN 2002

RECORDS FOR DECEMBER 21
HIGH 60 IN 1957
LOW -10 IN 1942
PRECIP 2.01 INS. IN 1946
SNOWFALL 11.4 INS. IN 1954
PEAK GUST 77 MPH SSE IN 1957

TODAY'S REPORT PREPARED By: Mike Iacono