BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
 
DAILY DISCUSSION AND CLIMATE SUMMARY
WEDNESDAY, DECEMBER 21, 2011
ALL TIMES ARE IN EASTERN STANDARD TIME
 
TEMPERATURES RISING FROM 29F AT MIDNIGHT TO LOW 50'S
LIGHT DRIZZLE THEN LIGHT RAIN BEGAN EARLY AFTERNOON
NEARBY PONDS STILL UNFROZEN FOR THE SEASON
 
After starting out from an early reading of 29F temperatures
have risen quickly through the 40's this morning reaching
51 degrees by 1 P.M.  Today will become the 6th day this
month with double-digit above normal temperatures as the
departure remains at +6 degrees for December. Only three
days have had below normal daily averages.
 
Ponkapoag Pond skimmed over with 9/10 very thin ice early
Monday morning briefly and then began thawing again so I would say
not quite a complete first freeze over of the season and it's
getting late. Houghton's Pond has not come close to freezing
over as yet. 
 
Today's observations:
 
7 A.M. 
Weather: Overcast altocumulus opacus, stratocumulus NW-NE,
few stratocumulus distant SE-S, small breaks in overcast
distant ESE-SSE  
Temperature: 38F, Dew point: 35F, Wind: S at 12 kts,
Sea-level pressure: 30.11 inches Hg, falling
Visibility: 20 miles, except 30 miles SE, light haze all
quadrants
6-hour min. temp: 31F
BHO SA 1155 E70 OVC 20 196/38/35/1712/011/ SC NW-NE FEW SC DSNT SE-S
SML BINOVC DSNT ESE-SSE VSBY SE 30 LGT HZ ALQDS/ 8/57/ 58005
10038 20031
 
10 A.M.
Weather: Broken stratocumulus, overcast high altostratus,
stratocumulus increasing, bright spots in overcast NE-S,
sun dimly visible
Temperature: 46F, Dew Point: 43F; Wind: S at 13 kts,
Sea-level pressure: 30.06 inches Hg, falling
Visibility: 20 miles, except 25 miles WNW, hazy
BHO SA 1455 E20 BKN 170 OVC 20 181/46/43/1713/006/ SC LYR INCR
BRGHT SPTS IOVC NE-S SUN DMLY VSB VSBY WNW 25 HAZY ALQDS/
8/51/ 56017
 
1 P.M.
Weather: Low overcast stratus fractus, nimbostratus layer visible,
light rain, light drizzle, rain began 12:30 P.M. 
Temperature: 51F, Dew Point: 49F; Wind: S at 15G22 kts
Sea-level pressure: 29.93 inches Hg, falling  
Visibility: 6 miles, light rain, light drizzle and fog
6-hour max. temp: 51F
6-hour min. temp: 38F
6-hour precip: trace
BHO SA 1755 E6 OVC 6R-L-F 137/51/49/1915G22/993/ NS LYR VSB
RB30/ 8/72/ 58044 MANUAL 6000/ 10051 20038
 
WEATHER SUMMARY FOR TUESDAY, DECEMBER 20
 
TEMPERATURE (DEGREES F)
MAX.....41    NORMAL.....37
MIN.....29    NORMAL.....22
MEAN....35    NORMAL.....30
 
DEPARTURE FROM 30-YEAR NORMAL......................+5
TOTAL DEPARTURE FOR THE MONTH....................+122 [+5.9 DEGREES/DAY]
 
HEATING DEGREE DAYS
TOTAL HEATING UNITS FOR YESTERDAY.............30   DEPARTURE.........-5
TOTAL HEATING UNITS FOR THE MONTH............524   DEPARTURE.......-117
TOTAL HEATING UNITS FOR THE SEASON..........1431   DEPARTURE.......-499
TOTAL HEATING UNITS LAST SEASON TO DATE.....1857  DIFFERENCE......-426
 
PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY.............28 WNW AT  5:41 A.M.                  
                   AERO..................27 WNW AT 10:41 A.M. 
                   ASOS..................26 NW  AT  6:26 A.M. 
                   DAVIS.................27 W   AT  3:53 A.M.
THE FASTEST MILE FOR YESTERDAY...........20 NW  AT 10:41 A.M.
AXIMUM 2-MINUTE ASOS AVERAGE.............20 NW  AT 10:41 A.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE...........20 WNW AT 10:41 A.M.
AVERAGE WIND SPEED AND DIRECTION.......11.3 NNW
                   ASOS................10.9
                   DAVIS...............10.1 WNW [300 deg]
 
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..........2.78  DEPARTURE..........-0.13
                         ASOS..............2.79
TOTAL PRECIPITATION FOR THE YEAR..........61.47  DEPARTURE.........+11.90
                        ASOS..............61.88**
**ASOS data is in error due to system failure on 1/12-13/11
     
SNOWFALL (INCHES) THROUGH THIS MORNING (EST)
TOTAL SNOWFALL 24 HRS ENDING 7 A.M..........0.0  DEPARTURE.........-0.4
TOTAL SNOWFALL FOR THE MONTH................0.0  DEPARTURE.........-6.3
TOTAL SNOWFALL FOR THE SEASON...............8.5  DEPARTURE.........-0.7
 
PRELIMINARY CLIMATE SUMMARY FOR DECEMBER 2011 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
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  46/33/40/+4/0.00/0.0/560/100   29 NW  AERO 29 MPH NW  RMY 27
12/2  49/31/40/+4/0.00/0.0/481/86    25 NW  AERO 28 MPH NW  RMY 28
12/3  43/30/37/+2/0.00/0.0/467/84    21 NW  AERO 22 MPH NW  RMY N/A
12/4  51/34/43/+8/0.00/0.0/211/38    28 SSW AERO 30 MPH S   RMY 29
12/5  62/44/53/+18/0.00/0.0/155/28   27 SSW AERO 28 MPH SSW RMY 28
12/6  58/49/54/+20/0.34/0.0/000/00   28 SSW AERO 30 MPH SSW RMY 30
12/7  56/43/50/+16/1.45/0.0/000/00   31 NNE AERO 28 MPH NNE RMY N/A
12/8  43/32/38/+5/0.96/0.0/513/93    57 NW  AERO 59 MPH NW  RMY 58  TSTM
12/9  50/31/41/+8/T/0.0/380/68       33 SSW AERO 35 MPH SSW RMY 36
12/10 43/27/35/+2/T/0.0/171/31       25 NW  AERO 28 MPH NW  RMY 27
12/11 36/23/30/-2/0.00/0.0/544/99    23 SSW AERO 23 MPH SSW RMY 24
12/12 47/29/38/+6/0.00/0.0/466/85    22 WSW AERO 22 MPH SW  RMY N/A
12/13 44/28/36/+4/0.00/0.0/520/95    23 WSW AERO 23 MPH WSW RMY N/A
12/14 40/33/37/+6/0.00/0.0/000/00    16 SSE AERO 17 MPH SSE RMY N/A
12/15 51/35/43/+12/0.02/0.0/000/00   47 S   AERO 46 MPH S   RMY N/A
12/16 52/36/44/+13/0.01/0.0/.../..   55 W   AERO 55 MPH W   RMY 49
12/17 41/24/33/+2/0.00/0.0/.../..    25 NNW AERO 25 MPH NNW RMY 26
12/18 26/15/21/-9/0.00/0.0/.../..    23 NNW AERO 22 MPH NNW RMY N/A
12/19 42/14/28/-2/0.00/0.0/.../..    44 SW  AERO 44 MPH SSW RMY 45
12/20 41/29/35/+5/0.00/0.0.../..     28 WNW AERO 27 MPH WNW RMY 28
 
12/21 our morning low temp: 29F since midnight; normal is now 22F 
 
DAILY RECORDS FOR DECEMBER 2011
None so far.
 
DAILY EXTREMES
Temperature and precipitation records back to 1885, and
wind records back to 1940 (e = estimated):
 
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
 
RECORDS FOR DECEMBER 22
HIGH 62 IN 1994
LOW -5 IN 1921
PRECIP 1.52 INS. IN 1975
SNOWFALL 8.8 INS. IN 1975
PEAK GUST 62 MPH WNW IN 1998
 
TODAY'S REPORT PREPARED BY: Robert Skilling