BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS 02186
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
 
DAILY DISCUSSION AND CLIMATE SUMMARY
MONDAY, DECEMBER 7, 2009
ALL TIMES ARE IN EASTERN STANDARD TIME
 
TEMPERATURES HAVE FALLEN BELOW NORMAL
FOUR INCHES OF SNOW REMAIN FROM THE WEEKEND STORM
 
With the exception of December 1, which averaged just
one degree below normal, yesterday was our first
colder than normal day since the first week of Nov-
ember.  The weekend snowfall was 5.3 inches with
about 4.7 inches through midnight Saturday night
and the additional 0.6 inch in the very early hours
of Sunday. The precipitation total for the event was
0.88 inch. Four inches of snow remain on the summit
today with temperatures continuing colder than
normal and only up to 36F by early afternoon.
There has been just a little sunshine through layers
of dense middle and high cloudiness.  
 
Today's observations:
 
7 A.M.
Weather: Scattered dense cirrus, scattered thin cirrus,
few altocumulus, thin fog all quadrants  
Temperature: 26F, Dew point: 20F, Wind: SW at 8 kts
Sea-level pressure: 30.32 inches Hg, falling
Visibility: 20 miles, thin fog all quadrants
6-hour minimum temp: 25F
24-hour precipitation: 0.00 inches
24-hour snowfall: 0.0 inches
Total snow depth: 4 inches
BHO SA 1155 200 SCT 250 SCT 20 268/26/20/2208/032/
FEW AC THN FG ALQDS INVSN PRSNT/ 8/046 4/004 58004
10026 20025
 
10 A.M.
Weather: Scattered dense cirrus, overcast cirrus and
cirrostratus, thin spots in overcast overhead and north
thru east, partial halo, and parahelion (sun dog)  
Temperature: 33F, Dew point: 23F, Wind: SSW at 8 kts
Sea-level pressure: 30.32 inches Hg, falling
Visibility: 20 miles, hazy
BHO SA 1455 220 SCT E250 OVC 20 267/33/23/2008/032/
THN SPTS IOVC OVHD-N-E PARTIAL HALO PARAHELION HAZY/
8/007 58001 
 
1 P.M.
Weather: Overcast altostratus, few stratocumulus to
the distant SE-SSE, few bright spots in overcast,
sun occasionally dimly visible  
Temperature: 35F, Dew point: 25F, Wind: SSW at 6 kts
Sea-level pressure: 30.24 inches Hg, falling 
Visibility: 25 miles, hazy
6-hour maximum temp: 36F
BHO SA 1755 E140 OVC 25 241/35/25/2006/024/
FEW SC DSNT SSE-S FEW BRGHT SPTS IOVC SUN
OCNL DMLY VSB HAZY ALQDS / 8/52/ 58026 10036 20026  
 
WEATHER SUMMARY FOR SUNDAY, DECEMBER 6
 
TEMPERATURE (DEGREES F)
MAX.....33     NORMAL.....41
MIN.....25     NORMAL.....27
MEAN....29     NORMAL.....34
 
DEPARTURE FROM 30-YEAR AVERAGE.............-5
TOTAL DEPARTURE FOR THE MONTH.............+34  [+5.5 DEGREES/DAY]
 
HEATING DEGREE DAYS
TOTAL HEATING UNITS FOR YESTERDAY............36    DEPARTURE........+5
TOTAL HEATING UNITS FOR THE MONTH...........145    DEPARTURE.......-34
TOTAL HEATING UNITS FOR THE SEASON.........1305    DEPARTURE......-163
TOTAL HEATING UNITS LAST SEASON TO DATE....1407    DIFFERENCE.....-102
 
PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY.............36 NW  AT  1:03 A.M.  
                   AEROVANE..............38 NW  AT  1:07 A.M.
                   ASOS..................38 NNW AT  1:07 A.M.   
                   DAVIS.................40 WNW AT  1:03 A.M. 
THE FASTEST MILE FOR YESTERDAY...........25 NW  AT  1:03 A.M.
MAXIMUM 2-MINUTE ASOS AVERAGE............25 NNW AT  1:05 A.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE...........23 NW  AT  1:05 A.M. 
AVERAGE WIND SPEED AND DIRECTION.......14.6 WNW 
                   ASOS................14.9
                   DAVIS...............13.9 W [280 DEG]
 
PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.00   DEPARTURE....-0.15
                         ASOS..............0.90
TOTAL PRECIPITATION FOR THE MONTH..........1.97   DEPARTURE....+1.07
                         ASOS..............2.07
TOTAL PRECIPITATION FOR THE YEAR..........51.54   DEPARTURE....+3.98
                         ASOS.............52.83
                 
SNOWFALL (INCHES) THROUGH THIS MORNING (EST)
TOTAL SNOWFALL 24 HRS ENDING 7 A.M..........5.3  DEPARTURE.....+5.0
TOTAL SNOWFALL FOR THE MONTH................5.3  DEPARTURE.....+3.9
TOTAL SNOWFALL FOR THE SEASON...............8.3  DEPARTURE.....+4.0
                                               
PRELIMINARY CLIMATE SUMMARY FOR DECEMBER 2009 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  41/28/35/-1/0/0/.../..       29 NW 
12/2  51/33/42/+6/../../.../..     30 SSE
12/3  67/47/57/+22/../../.../..    69 SSE  AERO 73 SSE
12/4  52/40/46/+11/0/../.../..     26 W
12/5  42/30/36/+1/0.79/4.7/000/00  36 N
12/6  33/25/29/-5/0.09/0.6/.../..  36 NW
 
12/7  our morning low temp: 25F; the normal low is now 27F
 
NEW DAILY RECORD FOR DECEMBER 2009
12/3 NEW RECORD HIGH MAXIMUM TEMPERATURE of 67F;
     surpasses previous record of 61F in 1932, 1950.
 
DAILY EXTREMES
Temperature and precipitation records back to 1885, and
wind records back to 1940 (e = estimated):
 
RECORDS FOR DECEMBER 7
HIGH 74 IN 1998
LOW 6 IN 1906
PRECIP 1.67 INS. IN 1953
SNOWFALL 4.0 INS. IN 1886
PEAK GUST 76e SE IN 1976
 
RECORDS FOR DECEMBER 8
HIGH 62 IN 1966
LOW -4 IN 1906
PRECIP 1.54 INS. IN 1969
SNOWFALL 2.5 INS. IN 2001
PEAK GUST 78e W IN 1979
 
TODAY'S REPORT PREPARED BY: Robert Skilling