BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS 02186
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
 
DAILY DISCUSSION AND CLIMATE SUMMARY
WEDNESDAY, DECEMBER 2, 2009
ALL TIMES ARE IN EASTERN STANDARD TIME
 
NOVEMBER 2009 MONTHLY STATS
Temp: Deg. F
 
Av.Max. 52.9
Av.Min. 40.7 
Mean    46.8 [+5.0]
Mean corrected to 24 hours: 46.4 
Highest: 68 on 9th
Lowest:  29 on 7th
Total heating units: 539  [-159]
Total this season:   1160 [-129]
Total precipitation: 4.46 ins. [-0.18] 
Total snowfall:      0.0  ins. [-2.7 ]
Seasonal total:      3.0  ins. [+0.1 ]
Sunshine: total astronomical minutes: 6828 or 113.8 hours or 39%
Sunshine: total Campbell-Stokes card minutes: 6594 or 109.9 hours or 39%   
Average November sunshine on long-term record: 47%
Average wind speed: 12.1 MPH (uncorrected) and 12.5 MPH (corrected)
Prevailing direction: W 15%
Peak gust: 55 MPH W on 28th.
 
The warmth is the story for November, especially the minimum temperatures. 
The month ties for the 3rd warmest on record, and the average minimum
temperature of 40.7 ties for the warmest on record. Also, the November
average minimum temperature was only 1.0 degree below the average minimum
for October 2009 of 41.7.  This is the smallest difference on record between
the average minimum temperatures in October and November.  On average,
November minimums are nearly 10 degrees colder than October.  The lowest
temperature during November of 29 was the warmest on record, surpassing 28
set in 1998.  There were only 2 days with minimum temperatures at or below
freezing during November (the 6th with 31 and the 7th with 29). This ties 
a record for the fewest number of freezing days in November previously set 
in 1948.
 
Warmest November Mean Temperature (deg F)
 
1) 47.4 in 1975
2) 47.1 in 2006
3) 46.4 in 1948
   46.4 in 1979
   46.4 in 2009
6) 46.0 in 2001
 
Warmest November Average Minimum Temp (deg F)
 
1) 40.7 in 2006
   40.7 in 2009
3) 40.2 in 1948
4) 40.1 in 1975
5) 39.3 in 1979
 
Warmest November Monthly Minimum Temp (deg F)
 
1) 29 in 2009
2) 28 in 1998
3) 27 in 1975
   27 in 1983
5) 26 in 1953
   26 in 2006
 
Fewest Number of Days in November at or Below Freezing
 
1) 2 in 1948
   2 in 2009
3) 5 in 1979
4) 6 in 1970
5) 7 in 1931
   7 in 1953
   7 in 2006
 
Precipitation in November was unremarkable with 4.46 inches,
which is slightly more than the long-term average, except for
a daily rainfall record set on the 14th with 2.08 inches.
This surpassed 1.87 inches in 1972 on that date.  There was
no measurable snowfall in November, which happens about
one-third of the time.

The corrected mean wind speed of 12.5 mph W ties for the 3rd
slowest on record with 2006.  The mean wind speed for the year
to date is 12.3 mph, which is just slightly higher than the
12.2 mph for Jan-Nov set in 2008. 
 
Lowest November Wind Speed (mph)
 
1) 12.1 in 1992
   12.1 in 2000
3) 12.5 in 2006
   12.5 in 2009
5) 12.8 in 1996
 
November sunshine of 39 percent is well below the 110-year
average of 47 percent, but this is not among the ten lowest
(16th cloudiest).  Sunshine for the year to date is 51%,
which is about 1 percent below the long-term average.
 
Today's observations:
 
7 A.M.
Weather: Clear, cirrus southeast thru southwest
Temperature: 35F, Dew point: 29F, Wind: SSW at 8 kts,
Sea-level pressure: 30.20 inches Hg, rising
Visibility: 20 miles, very thin fog below inversion, hazy 
6-hour minimum temp: 33F
24-hour precipitation: 0.00
BHO SA 1155 CLR 20 226/35/29/2108/020/ CI SE-SW VRY THN FG BLO 
INVSN HAZY/ 8/001 53015 10035 20033
 
10 A.M.
Weather: High thin overcast  
Temperature: 42F, Dew point: 31F, Wind: SSW at 7 kts,
Sea-level pressure: 30.21 inches Hg, steady
Visibility: 15 miles, hazy, thin smoke layer NW-NE,
double layered inversion visible NW-NE
BHO SA 1455 220 SCT 250 –OVC 15 230/42/31/2107/021/ BINOVC N-NE DOUBLE
INVSN ESTMD TOP LWR 8 HND UPPER ESTMTD 15 HND OVR CTY N THK K LYR
NW-NE HAZY ALQDS/ 8/007 51004
 
1 P.M.
Weather: High dense overcast cirrus and cirrostratus with
a few thin spots in overcast overhead
Temperature: 50F, Dew point: 39F, Wind: S at 10 kts,
Wind: Direction variable SSE-SSW
Sea-level pressure: 30.13 inches Hg, falling
Visibility: 20 miles, hazy, thin smoke layer NW-NE 
6-hour maximum temp: 50F
BHO SA 1755 220 SCT E250 OVC 20 203/50/39/1810/013/
FEW LWR DENS CI FEW THN SPTS IOVC OVHD THN K LYR NW-NE
HAZY ALQDS WND 15V21/ 8/007 58027 10050 20035
 
WEATHER SUMMARY FOR TUESDAY, DECEMBER 1
 
TEMPERATURE (DEGREES F)
MAX.....41     NORMAL.....43
MIN.....28     NORMAL.....29
MEAN....35     NORMAL.....36
 
DEPARTURE FROM 30-YEAR AVERAGE.............-1
TOTAL DEPARTURE FOR THE MONTH..............-1  [-1.0 DEGREES/DAY]
 
HEATING DEGREE DAYS
TOTAL HEATING UNITS FOR YESTERDAY............30    DEPARTURE........+1
TOTAL HEATING UNITS FOR THE MONTH............30    DEPARTURE......-158
TOTAL HEATING UNITS FOR THE SEASON.........1190    DEPARTURE......-128
TOTAL HEATING UNITS LAST SEASON TO DATE....1264    DIFFERENCE......-74
 
PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY.............29 NW  AT  2:38 A.M. *  
                   AEROVANE..............28 NW  AT  2:38 A.M. * 
                   ASOS..................28 NNW AT  2:39 A.M.   
                   DAVIS................ 30 WNW AT  2:20 A.M.   
THE FASTEST MILE FOR YESTERDAY...........19 NW  AT  2:37 A.M.
MAXIMUM 2-MINUTE ASOS AVERAGE............20 NW  AT  2:40 A.M.      
MAXIMUM 2-MINUTE DAVIS AVERAGE...........21 NW  AT  2:40 A.M.    
AVERAGE WIND SPEED AND DIRECTION.........11.9  SW 
                   ASOS................  11.1
                   DAVIS...............  11.1  W [270 DEG]
* last of several occurrences
 
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..........0.00   DEPARTURE....-0.15
                         ASOS..............0.00
TOTAL PRECIPITATION FOR THE YEAR..........49.57   DEPARTURE....+2.76
                         ASOS.............50.76
                 
SNOWFALL (INCHES) THROUGH THIS MORNING (EST)
TOTAL SNOWFALL 24 HRS ENDING 7 A.M..........0.0  DEPARTURE.....-0.2
TOTAL SNOWFALL FOR THE MONTH................0.0  DEPARTURE.....-2.9
TOTAL SNOWFALL FOR THE SEASON...............3.0  DEPARTURE.....-0.1
                                               
PRELIMINARY CLIMATE SUMMARY FOR NOVEMBER 2009 CALENDAR DAY DATA
DATA REPORTED:
DATE: MAX/MIN/MEAN/DEP/PRECIP/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
 
11/1  58/44/51/+4/0.05/167/27   22 WNW  
11/2  49/42/46/0/T/099/16       29 NE
11/3  57/36/47/+1/0/474/77      32 W    AERO 32 MPH W    
11/4  49/34/42/-4/0/514/84      24 W
11/5  46/36/41/-4/0.01/006/01   21 N
11/6  47/31/39/-6/0/419/69      38 WNW  AERO 38 MPH WNW
11/7  49/29/39/-6/0/575/95      33 S
11/8  66/42/54/+10/0/549/91     31 SSW
11/9  68/49/59/+15/0/486/81     35 S    AERO 35 MPH S
11/10 62/50/56/+12/0/000/00     23 SW 
11/11 50/43/47/+4/0/113/19      31 NNE
11/12 49/41/45/+2/0/125/21      34 NE   AERO 31 MPH NNE
11/13 49/44/47/+4/0/000/00      39 NNE  AERO 37 MPH NNE
11/14 59/49/54/+12/2.08/000/00  39 NE   AERO 38 MPH NE
11/15 60/52/56/+14/0.06/012/02  18 W
11/16 56/43/50/+8/0/527/90      30 NW   AERO 31 MPH NW
11/17 47/35/41/0/0/576/99       28 WNW
11/18 49/34/42/+1/0/313/54      15 SSW
11/19 59/41/50/+9/0/226/39      30 SE
11/20 65/44/55/+15/0.57/219/38  40 W    AERO 41 MPH W
11/21 55/41/48/+8/0/373/65      25 SW 
11/22 49/38/44/+4/0/292/51      28 ENE 
11/23 47/42/45/+6/0.22/000/00   33 NE   AERO 31 MPH ENE
11/24 46/44/45/+6/0.11/000/00   33 NE   AERO 30 MPH NE
11/25 47/43/45/+6/0.10/000/00   21 N
11/26 50/44/47/+9/0.01/000/00   22 N
11/27 44/39/42/+4/0.93/000/00   48 W    AERO 48 MPH W
11/28 49/38/44/+7/0.08/191/34   55 WNW  AERO 54 MPH W
11/29 52/37/45/+8/0/561/100     29 WSW
11/30 53/36/45/+8/0.24/011/02   29 SSE 
 
12/1  41/28/35/-1/0/0/.../..    29 NW 
12/2  our morning low temp: 33F; the normal low temp. is now 28F
 
NEW DAILY RECORD FOR NOVEMBER 2009
11/14: NEW RECORD DAILY RAINFALL 2.08 INCHES;
      surpasses previous 1.87 inches in 1972.  
 
DAILY EXTREMES
Temperature and precipitation records back to 1885, and
wind records back to 1940 (e = estimated):
 
RECORDS FOR DECEMBER 2
HIGH 61 IN 1998
LOW 3 IN 1890
PRECIP 2.09 INS. IN 1974
SNOWFALL 5.0 INS. IN 1894,1929
PEAK GUST 89e MPH SSE IN 1942
 
RECORDS FOR DECEMBER 3
HIGH 61 IN 1932,1950
LOW  -1 IN 1890
PRECIP 2.10 INS. IN 1986
SNOWFALL 6.0 INS. IN 1963
PEAK GUST 73e MPH W IN 1942
 
TODAY'S REPORT PREPARED BY: Robert Skilling