BLUE HILL METEOROLOGICAL OBSERVATORY 
MILTON, MASSACHUSETTS
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
 
DAILY DISCUSSION AND CLIMATE SUMMARY
THURSDAY, DECEMBER 9, 2010
ALL TIMES ARE IN EASTERN STANDARD TIME
 
LOW TEMPERATURE DROPS TO 15F THIS MORNING
COLDEST TEMPERATURE SINCE 10F, FEBRUARY 7.  
RECORD LONG PERIOD OF TEMPS. 21F OR HIGHER
COMES TO AN END WITH DECEMBER 7.
 
The coldest air mass of the season brought
a minimum temperature of 19F by midnight
last night, December 8, and a low of 15F
this morning and was the coldest since 10F way
back on February 7, this year.
It appears both nearby ponds, Ponkapoag and
Houghtons, have frozen over this morning after
both had all open water yesterday.
 
Also the longest stretch of days (297) with low
temperatures 21F or higher ended the day
before yesterday, on December 7.
 
Please see the records below:
 
Longest continuous periods at Blue Hill
with temperature of 21 deg F or higher:
 
1) 297 days (Feb 14 - Dec 7, 2010)
2) 292 days (Mar 1 - Dec 17, 1973)
3) 284 days (Feb 24 - Dec 4, 1902)
4) 283 days (Feb 22 - Dec 1, 1945)
5) 279 days (Feb 22 - Nov 27, 1931)
   279 days (Feb 24 - Nov 29, 1958)
 
Today's observations: 
 
7 A.M.
Weather: Clear, stratocumulus layer with moderate cumuloform tops and
few lower cumulus along and offshore northeast thru southeast,
altocumulus, few lenticular altocumulus distant NNW-NNE and
distant ESE-S
Temperature: 15F, Dew point: 9F; Wind: WSW at 10 kts
Sea-level pressure: 30.08 inches Hg, rising
Visibility: 35 miles, 20 miles northeast thru southeast,
50 miles west-northwest 
6-hour minimum temp: 15F
BHO SA 1155 CLR 35 187/15/9/2510/008/ SC LYR MDT CUFRM TOPS/FEW LWR CU
NE-SE AC AND FEW ACSL DSNT NNW-NNE AC DSNT ESE-S VSBY NE-SE 20 WNW 50
DSNT HZ ALQDS/ 8/840 53018 10018 20015
 
10 A.M.
Weather: Clear, few cumulus, stratocumulus all quadrants.
stratocumulus layer offshore distant ENE-ESE 
Temperature: 22F, Dew point: 10F; Wind: W at 13G19 kts,
Sea-level pressure: 30.12 inches Hg, rising
Visibility: 60 miles, light distant haze   
BHO SA 1455 CLR 60 199/22/10/2813G19/012/
FEW CU/SC ALQDS SC LYR OFFSHR DSNT NE-ESE
LGT DSNT HZ/ 8/800 51012
 
1 P.M.
Weather: Clear, few cumulus fractus, few small cumulus,
and few stratocumulus all quadrants, stratocumulus
layer offshore northeast thru east-southeast  
Temperature: 25F, Dew point: 8F; Wind: W at 14 kts,
Wind: Direction variable WSW to NW   
Sea-level pressure: 30.10 inches Hg, rising
6-hourly max. temp: 25F
Visibility: 60 miles, light distant haze
BHO SA 1755 CLR 60 194/25/8/2814/010/ FEW CUFRA FRMG FEW SML CU AND FEW
SC ALQDS SC LYR OFFSHR NE-ESE WND 25V31/
8/800 55005 10025 20015
 
WEATHER SUMMARY FOR WEDNESDAY, DECEMBER 8
 
TEMPERATURE (DEGREES F)
MAX.....31     NORMAL.....41
MIN.....19     NORMAL.....26
MEAN....25     NORMAL.....33
 
DEPARTURE FROM 30-YEAR NORMAL................-8
TOTAL DEPARTURE FOR THE MONTH...............-13 [-1.8 DEGREES/DAY]
 
HEATING DEGREE DAYS
TOTAL HEATING UNITS FOR YESTERDAY............40    DEPARTURE........+9
TOTAL HEATING UNITS FOR THE MONTH...........255    DEPARTURE.......+14
TOTAL HEATING UNITS FOR THE SEASON.........1415    DEPARTURE......-115
TOTAL HEATING UNITS LAST SEASON TO DATE....1372    DIFFERENCE......+43
 
PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY..............39 W   AT 11:36 A.M. 
                   AEROVANE...............40 W   AT 11:36 A.M.  
                   ASOS.................. 40 W   AT 11:35 A.M.    
                   DAVIS..................42 W   AT 11:35 A.M.   
THE FASTEST MILE FOR YESTERDAY............32 W   AT 11:37 A.M.
MAXIMUM 2-MINUTE ASOS AVERAGE.............30 W   AT 11:37 A.M.    
MAXIMUM 2-MINUTE DAVIS AVERAGE............30 W   AT 11:37 A.M.    
AVERAGE WIND SPEED AND DIRECTION..........17.0 W
                   ASOS...................16.7      
                   DAVIS..................15.5 W [260 DEG]
 
 PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.00  DEPARTURE........-0.15
                         ASOS..............0.00
TOTAL PRECIPITATION FOR THE MONTH..........0.49  DEPARTURE........-0.71
                         ASOS..............0.53 
TOTAL PRECIPITATION FOR THE YEAR..........58.52  DEPARTURE.......+10.66
                         ASOS.............58.44**
** ASOS missing rainfall due to system failure on 6/24-25
 
SNOWFALL (INCHES) THROUGH THIS MORNING (EST)
TOTAL SNOWFALL 24 HRS ENDING 7 A.M..........0.0  DEPARTURE.....-0.3
TOTAL SNOWFALL FOR THE MONTH................0.0  DEPARTURE.....-2.0
TOTAL SNOWFALL FOR THE SEASON...............0.1  DEPARTURE.....-4.8 
 
PRELIMINARY CLIMATE SUMMARY FOR DECEMBER 2010 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  55/43/49/+13/0.49/0.0/000/00  55 SE   AERO 61 MPH SE
12/2  48/29/39/+3/0.00/0.0/540/100  30 W
12/3  38/29/34/-1/0.00/0.0/050/09   25 WNW
12/4  40/28/34/-1/0.00/0.0/516/93   27 WNW
12/5  34/23/29/-6/0.00/0.0/127/23   24 W
12/6  32/22/27/-7/0.00/0.0/447/81   37 WSW  AERO 38 MPH WSW
12/7  33/23/28/-6/0.00/0.0/463/84   35 W    AERO 37 MPH W
12/8  31/19/25/-8/0.00/0.0/.../..   39 W    AERO 40 MPH W
 
12/9 our morning low temp: 15F; the normal low is now 26F
 
NEW DAILY RECORDS FOR DECEMBER 2010
None
 
DAILY EXTREMES
Temperature and precipitation records back to 1885, and
wind records back to 1940 (e = estimated):
 
RECORDS FOR DECEMBER 9
HIGH 68 IN 1966
LOW -14 IN 1902
PRECIP 1.52 INS. IN 1956
SNOWFALL 10.8 INS. IN 2005
PEAK GUST 66 SE IN 1973
 
RECORDS FOR DECEMBER 10
HIGH 62 IN 1946
LOW -6 IN 1902
PRECIP 1.67 INS. IN 1907
SNOWFALL 6.0 INS. IN 1905
PEAK GUST 66e SW IN 1940
 
TODAY'S REPORT PREPARED BY: Robert Skilling