BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS 02186
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
  
DAILY DISCUSSION AND CLIMATE SUMMARY
WEDNESDAY, DECEMBER 12, 2007
ALL TIMES ARE IN EASTERN STANDARD TIME
 
A RETURN TO COLDER WEATHER ONCE AGAIN AFTER BRIEF 
THAW OVERNIGHT AND LIGHT RAINFALL OF 0.10 INCH
GUSTY WEST WINDS TO NEAR 40 MPH EARLY AFTERNOON
 
Colder and drier is arriving this afternoon on increasingly
gusty west winds.  Overnight, last night, temperature were 
on the rise from the lower 30's early last evening, when a 
little freezing rain occurred, to a high of 44 degrees early
this morning. About 1/2 inch to an inch of snow and ice 
remained on the ground early today after the rain and thawing
temperatures. This was what was left from the light snow and 
icing events so far this month.  
Early this afternoon west winds are gusting close to 40 MPH as
air temperatures hold in the low 40's but dewpoints fall from 
the 30's into the 20's.
 
Today's observations:
 
7 A.M.   
Weather: Low stratus fractus overcast with overcast of 
nimbostratus visible through thin spots in lower layer,
thin fog   
Temperature: 44F, Dew point: 44F, Wind: WSW at 12 kts
Sea-level pressure: 29.78 inches Hg, rising 
Visibility: 5 miles in thin fog  
6-hour min temp: 38F 
24-hour precip: 0.10   
24-hour snowfall: 0.00  
Snow and ice on ground: 1 inch  
BHO SA 1155 E10 OVC 5F 085/44/44/2512/978/ CIG RGD 
HIER OVC NS VSB AT 55 HND PTCHS STEAM FG DRFTG OVR SMT/ 
8/62/ 53002 ASOS 60001 MANUAL 6001/ ASOS 70010 
MANUAL 70010 10044 20038 
  
10 A.M.
Weather: Overcast altocumulus, nimbostratus, virga, very
light rain shower past hour   
Temperature: 42F, Dew point: 37F, Wind: W at 18G29 kts
Wind: peak wind 29 kts from W at 53 past the hour, wind variable 
WSW-WNW 
Sea-level pressure: 29.84 inches Hg, rising 
Visibility: 50 miles,  
Visibility: mountain in cloud 70 NW 
3-hourly precip: trace
BHO SA 1455 E100 OVC 50 105/42/37/2718G29/984/ 
FEW SC/STFRA SE-W AND SC DSNT NW-N ALG HRZN VIRGA 
BINOVC DSNT WNW-NNW VSBY AND MTN INCLD 70 NW  
PK WND 2629/53/ WND 24V30 RB40E45 8/57/ 53020
MANUAL 6000/ 
 
1 P.M.
Weather: Broken middle and high clouds, altocumulus and 
cirrus and dense cirrus, stratocumulus around from SSW-N-ENE  
Clearing from W-N  
Temperature: 41F, Dew point: 29F, Wind: W at 20G32 kts
Sea-level pressure: 29.84 inches Hg, steady 
Visibility: 75 miles    
6-hourly precip: trace
6-hourly max. temp: 44F
BHO SA 1755 140 SCT 180 SCT 220 SCT 250 BKN 75 105/41/29/2620G32/984/
FEW SC SSW-N-ENE FEW CC PTCHS DENS CI SE-WSW CLRG W-N PK WND 2632/51/ 
8/572 53000 MANUAL 6000/ 10044 20041
 
WEATHER SUMMARY FOR TUESDAY, DECEMBER 11
 
TEMPERATURE (DEGREES F)
MAX.....36    NORMAL.....40 
MIN.....22    NORMAL.....25
MEAN....29    NORMAL.....32
DEPARTURE FROM 30-YEAR NORMAL.......... -3 
TOTAL DEPARTURE FOR THE MONTH..........-87 [-8.1 DEGREES/DAY]
 
HEATING DEGREE DAYS
TOTAL HEATING UNITS FOR YESTERDAY............36  DEPARTURE......+ 4  
TOTAL HEATING UNITS FOR THE MONTH...........426  DEPARTURE......+84 
TOTAL HEATING UNITS FOR THE SEASON.........1506  DEPARTURE.....-120
TOTAL HEATING UNITS LAST SEASON TO DATE....1350  DIFFERENCE....+156
 
PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY............25  S  AT 11:40 P.M. *              
                   AEROVANE.............26  S  AT  7:50 P.M. *         
                   ASOS.................25  S  AT  7:51 P.M.                
                   DAVIS................25  S  AT 11:46 P.M.                 
FASTEST MILE FOR YESTERDAY..............20  S   AT  7:47 P.M.          
MAXIMUM 2-MINUTE ASOS AVERAGE...........21  S   AT  7:48 P.M.             
MAXIMUM 2-MINUTE DAVIS AVERAGE..........19  SSW AT 11:58 P.M.               
AVERAGE WIND SPEED AND DIRECTION........9.0 S  
                   ASOS.................9.4         
                   DAVIS................6.6 SW [230 deg] #    
* last of several occurrences...
# Davis malfunctioned due to glaze accumulation
 
PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.10  DEPARTURE....-0.05
                         ASOS..............0.10 
TOTAL PRECIPITATION FOR THE MONTH..........1.00  DEPARTURE....-0.65
                         ASOS..............0.99  
TOTAL PRECIPITATION FOR THE YEAR..........39.84  DEPARTURE....-8.47
                         ASOS.............39.21  
 
SNOWFALL (INCHES) THROUGH THIS MORNING (EST)
TOTAL SNOWFALL 24 HRS ENDING 7 A.M..........0.0  DEPARTURE.....-0.3
TOTAL SNOWFALL FOR THE MONTH................2.7  DEPARTURE.....-0.2 
TOTAL SNOWFALL FOR THE SEASON...............3.5  DEPARTURE.....-2.3
 
PRELIMINARY CLIMATE SUMMARY FOR DECEMBER 2007...CALENDAR DAY DATA
DATA REPORTED:
DATE: MAX/MIN/MEAN/DEP/PRECIP/SNOW/SUN(MIN.)/SUN(%)/ PEAK GUST/AERO GUST
 
AERO: Aerovane recording wind system when significant
TSTM: Thunderstorm day
....: Data not yet available
 
12/1  33/15/24/-12/0/0/493/88       54 WNW 
12/2  24/15/20/-16/0.03/0.3/000/00  28 WNW 
12/3  38/23/31/-4/0.62/1.7/000/00   47 W 
12/4  27/17/22/-13/T/T/111/20*      48 W       
12/5  29/17/23/-12/T/T/244/44*      23 WNW
12/6  28/15/22/-12/0/0/554/100      31 WNW
12/7  34/21/28/-6/0.07/0.7/000/00   24 SSW
12/8  41/25/33/0/0/0/452/82         32 W
12/9  33/25/29/-4/0.08/T/000/00     16 NW  
12/10 30/26/28/-5/0.10/0/000/00     18 N 
12/11 36/22/29/-3/0.09/0/.../..     25 S
 
12/12 morning low temp. 36F midnight to 7 a.m. 
      rainfall: 0.01 inch thru 7 a.m.     
 
* sunshine amount and % changed
 
NEW DAILY RECORDS FOR DECEMBER 2007: NONE
 
DAILY EXTREMES
Temperature and precipitation records back to 1885, and
wind records back to 1940 (e = estimated):
 
RECORDS FOR DECEMBER 12
HIGH 67 IN 1979
LOW -3 IN 1988
PRECIP 3.94 INS. IN 1992
SNOWFALL 20.3 INS. IN 1960
PEAK GUST 74 MPH W IN 2000
 
RECORDS FOR DECEMBER 13
HIGH 60 IN 1984
LOW 0 IN 1893
PRECIP 1.45 INS. IN 1983
SNOWFALL 9.0 INS. IN 1902
PEAK GUST 81e WNW IN 1976
 
TODAY'S REPORT PREPARED By: Robert Skilling