BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS 02186
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
 
DAILY DISCUSSION AND CLIMATE SUMMARY
WEDNESDAY, JANUARY 7, 2009
ALL TIMES ARE IN EASTERN STANDARD TIME
 
SNOW CHANGED TO SLEET AND FREEZING RAIN THIS
MORNING AND THEN PLAIN RAIN ABOUT 9:35 A.M.
ACCUMULATION OF SNOW AND SLEET WAS 0.8 INCH AND
OVER 1 INCH OF MELTED PRECIPITATION HAD BEEN
MEASURED BY 1 P.M.
 
Precipitation began between midnight and 1 a.m.
as light snow but change to a mixture of snow,
sleet and freezing rain within the next several
hours and accumulation had reached one half inch
by 7 a.m. Maximum glaze accretion was approximately
1/16 inch which was melted away by noon. Winds
have backed from east-northeast to northeast and
were gusting over 30 MPH by early afternoon.
Rainfall has been moderate between 0.12 and 0.15
per hour since 9 a.m. with a daily total of 1.04
inches through 1 p.m. Temperatures have risen
several degrees above freeze to 34 to 35 by
early this afternoon. 
 
7 A.M.
Weather: Low overcast stratus fractus, light freezing rain,
light ice pellets and fog, thin glaze all surfaces   
Temperature: 30F, Dew point: 29F, Wind: ENE at 12G21 kts
Sea-level pressure: 29.66 inches Hg, falling
Visibility: 1 mile, light freezing rain, ice pellets and fog
6-hour minimum temperature: 26F
6-hourly precip: 0.39 in.
24-hourly precip: 0.40 in.
24-hourly snowfall: 0.5 in. 
Snow depth on ground: 4 inches
BHO SA 1155 E4 OVC 1ZR-IP-F 045/30/29/0712G21/966/
TOTAL NEW SNW PST 24 HRS 0.5 IN THN GLZ ALL SFCS/
8/7// 4/004 58046 ASOS 60038 ASOS 70038 MANUAL 6039/
MANUAL 70040 10030 20026
 
10 A.M.
Weather: Moderate rain and fog, freezing rain
ended at 9:35 a.m. 
Temperature: 32F, Dew point: 32F, Wind: ENE at 13 kts
Sea-level pressure: 29.57 inches Hg, falling
Visibility: 1 mile, variable 3/4 to 11/2 miles,
stratus drifting over summit 
3-hourly precip: 0.27 in.
3-hourly snowfall: 0.3 inch
BHO SA 1455 E5 OVC 1VRF 012/32/32/0613/957/
VSBY 3/4V11/2 STRA DRFTG OVR SMT ZRE35
TOTAL NEW SNW 3 HRS 0.3 IN MAX GLZ ACCUM 1/16 IN/
8/7// 55033 ASOS 60025 MANUAL 6027/
 
1 P.M.
Weather: Partial obscurement with fog, low overcast
stratus fractus, drifting over summit, light to moderate rain
and fog  
Temperature: 34F, Dew point: 34F, Wind: NE at 18G29 kts,
Wind: peak wind gust 30 kts NNE at 12:17 p.m.,
Wind: variability in direction N-ENE
Sea-level pressure: 29.33 inches Hg, FALLING RAPIDLY
Visibility: 3/4 mile, variable 1/4 to 1 miles, north 1/8 mile,
southeast 11/2 miles 
6-hour maximum temperature: 35F
6-hourly precip: 0.64 in.
6-hourly snowfall: 0.3 in
BHO SA 1755 –X E5 OVC 3/4VR-F 933/34/34/0518G29/933/
F3 STRA DRFTG OVR SMT VSBY 1/4V1 VSBY N 1/8 SE 11/2
TOTAL NEW SNW PST 6 HRS 0.3 IN MAX GLZ ACCRETION 1/16
IN MELTED OFF PK WND 0330/17 WND 36V07 PRESFR R- OCNL R/
8/7// 58079 ASOS 60063 MANUAL 6064/ 10035 20030
 
   
WEATHER SUMMARY FOR TUESDAY, JANUARY 6
 
TEMPERATURE (DEGREES F)
MAX.....33    NORMAL.....34 
MIN.....21    NORMAL.....19
MEAN....27    NORMAL.....26
 
DEPARTURE FROM 30-YEAR NORMAL...............+1
TOTAL DEPARTURE FOR THE MONTH..............-20  [-3.1 DEGREES/DAY]
 
HEATING DEGREE DAYS
TOTAL HEATING UNITS FOR YESTERDAY.............38  DEPARTURE......... 0
TOTAL HEATING UNITS FOR THE MONTH............249  DEPARTURE........+21
TOTAL HEATING UNITS FOR THE SEASON..........2489  DEPARTURE........-68
TOTAL HEATING UNITS LAST SEASON TO DATE.....2411  DIFFERENCE.......+78
 
PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY............27   W  AT  1:05 A.M.   
                   AEROVANE.............23   W  AT  1:08 A.M. * 
                   ASOS.................25   W  AT  1:06 A.M.    
                   DAVIS................26   W  AT  1:05 A.M.     
FASTEST MILE FOR YESTERDAY..............19   W  AT 12:29 A.M.
MAXIMUM 2-MINUTE ASOS AVERAGE...........18   W  AT  1:07 A.M.     
MAXIMUM 2-MINUTE DAVIS AVERAGE..........18   W  AT  1:07 A.M.      
                   AVERAGE.............8.2  W
                   ASOS................8.0
                   DAVIS...............7.4  WSW [250 deg]  
* last of several occurrences...
 
PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M.....0.40  DEPARTURE.........+0.25
                         ASOS...............0.38
TOTAL PRECIPITATION FOR JANUARY............ 0.46  DEPARTURE.........-0.44
                         ASOS...............1.44 #
TOTAL PRECIPITATION FOR THE YEAR (2009).... 0.46  DEPARTURE.........-0.44
                         ASOS...............1.44 #
# Includes erroneous ASOS precipitation data on 1/1/09 and 1/2/09
 
SNOWFALL (INCHES) THROUGH THIS MORNING (EST)
TOTAL SNOWFALL 24 HRS ENDING 7 A.M..........0.5   DEPARTURE..........0.0
TOTAL SNOWFALL FOR JANUARY................  0.5   DEPARTURE.........-2.5
TOTAL SNOWFALL FOR THE SEASON..............30.9   DEPARTURE........+14.3
 
PRELIMINARY CLIMATE SUMMARY FOR JANUARY 2009 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
 
1/1 16/1/9/-18/0/0/538/98          44 WNW   Aero 44 MPH WNW
1/2 32/9/21/-6/0/T/.../..          28 S
1/3 32/21/27/0/0/0/.../..          43 WNW   Aero 44 MPH WNW
1/4 35/17/26/-1/0/0/.../..         36 W     Aero 33 MPH W
1/5 36/26/31/+4/0.06/0/.../..      30 W   
1/6 33/21/27/+1/0/0/.../..         27 W   
    
1/7 morning low temp: 26F; our normal low is now 18F
    there was 0.40 melted precipitation and 0.5 inch
    of snow and ice pellets midnight thru 7 a.m.
 
NEW DAILY RECORDS FOR JANUARY 2009...
 
..NONE..
 
DAILY EXTREMES
Temperature and precipitation records back to 1885, and
wind records back to 1940 (e = estimated):
 
RECORDS FOR JANUARY 7
HIGH 60F IN 1930
LOW -7F IN 1896
PRECIP 1.97 INS. IN 1977
SNOWFALL 16.0 INS. IN 1977
WIND 74 MPH NW IN 1968
 
RECORDS FOR JANUARY 8
HIGH 65F IN 2008
LOW  -8  IN 1968 
PRECIP 3.00 INS. IN 1956
SNOWFALL 12.5 INS. IN 1996
PEAK GUST 77 MPH NNW IN 1958
 
TODAY'S REPORT PREPARED By: Robert Skilling