BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS 02186
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
 
DAILY DISCUSSION AND CLIMATE SUMMARY
TUESDAY, JANUARY 12, 2010
ALL TIMES ARE IN EASTERN STANDARD TIME 
 
CLOUDS CLEARING AWAY EARLY THIS AFTERNOON
WITH TEMPS. RISING INTO THE LOWER 30'S
JANUARY CONTINUES 4 DEGREES ON THE COLD SIDE
THREE VERY SUNNY DAYS--JANUARY SUNSHINE AT 50%
 
Partial sunshine early this morning ended around
10 a.m. as a cloud layer moved in but the same
cloud layer moved out early this afternoon leaving
us with some sunshine before clouds moved in again.   
Temperatures began rising and had reached close
to where they were yesterday or around 32 to 33
degrees. January temperatures continue to average
4 degrees colder than normal while the snow depth
on the ground has decreased slightly to 6 inches.
Three very sunny days starting with last Saturday
pushed the monthly sunshine to 50% of possible or
several points above the January normal after we
recorded much below normal sunshine through the
first week.
 
Today's observations:
 
7 A.M.
Weather: Overcast altostratus, few altocumulus and altocumulus
lenticularis south thru southwest, patches of virga
Temperature: 23F, Dew point: 18F, Wind: W at 9 kts
Sea-level pressure: 29.96 inches Hg, rising slightly
Visibility: 15 miles, 20 miles west-northwest, hazy  
6-hour minimum temp: 22F
Average snow depth: 6 inches
BHO SA 1155 E100 OVC 15 146/23/18/2709/996/
FEW AC/ACSL S-SW PTCHS VIRGA VSBY WNW 20 HAZY ALQDS/
8/07/ 4/006 55002 10023 20022 
 
10 A.M.
Weather: Scattered altocumulus (layer invading), thin
broken cirrus, stratocumulus forming all quadrants 
Temperature: 27F, Dew point: 19F, Wind: W at 10 kts,
Wind: Gradually veering
Sea-level pressure: 29.96 inches Hg, rising
Visibility: 15 miles, hazy
BHO SA 1455 75 SCT 220 –BKN 250 –BKN 15 146/27/19/2810/996/
SC FRMG ALQDS AC LYR INVDNG HAZY WND GRDLY VEERING/
8/551 55000
 
1 P.M.
Weather: Scattered altocumulus translucidus (layer is
extending northeast thru southeast thru southwest) and is
receding with a clearing sky, few stratocumulus, most to
the west through north 
Temperature: 30F, Dew point: 17F, Wind: W at 8 kts 
Sea-level pressure: 29.89 inches Hg, falling
Visibility: 30 miles, except 25 miles northeast-southeast,
hazy all quadrants   
6-hourly max. temp: 30F
BHO SA 1755 80 SCT 30 121/30/17/2708/989/ FEW SC AC LYR 
NE-SE-SW RCDNG SKY CLRG VSBY NE-SE 25 HAZY ALQDS/
8/530 58025 10030 20023 
 
WEATHER SUMMARY FOR MONDAY, JANUARY 11
 
TEMPERATURE (DEGREES F)
MAX.....33     NORMAL.....34
MIN.....12     NORMAL.....18
MEAN....23     NORMAL.....26
 
DEPARTURE FROM 30-YEAR AVERAGE.............-3
TOTAL DEPARTURE FOR THE MONTH.............-40 [-3.8 DEGREES/DAY]
 
HEATING DEGREE DAYS
TOTAL HEATING UNITS FOR YESTERDAY............42    DEPARTURE........+3
TOTAL HEATING UNITS FOR THE MONTH...........464    DEPARTURE.......+41
TOTAL HEATING UNITS FOR THE SEASON.........2708    DEPARTURE.......-44
TOTAL HEATING UNITS LAST SEASON TO DATE....2689    DIFFERENCE......+19
 
PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY.............21 W   AT 12:14 P.M.  
                   AEROVANE..............22 W   AT 11:37 A.M.   
                   ASOS..................22 WSW AT  8:15 A.M.  
                   DAVIS.................23 W   AT 12:21 P.M.  
THE FASTEST MILE FOR YESTERDAY...........16 W   AT 12:14 P.M. * 
MAXIMUM 2-MINUTE ASOS AVERAGE............16 W   AT  1:48 P.M.  
MAXIMUM 2-MINUTE DAVIS AVERAGE...........18 W   AT 12:14 P.M.  
AVERAGE WIND SPEED AND DIRECTION.......12.3 W 
                   ASOS................11.6 W
                   DAVIS...............11.3 W [260 DEG]
* last of several occurrences...
    
PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.00   DEPARTURE....-0.16
                         ASOS..............0.00
TOTAL PRECIPITATION FOR THE MONTH..........0.84   DEPARTURE....-0.84
                         ASOS..............0.74 
TOTAL PRECIPITATION FOR THE YEAR...........0.84   DEPARTURE....-0.84
                         ASOS..............0.74
                 
SNOWFALL (INCHES) THROUGH THIS MORNING (EST)
TOTAL SNOWFALL 24 HRS ENDING 7 A.M..........0.0  DEPARTURE.....-0.5
TOTAL SNOWFALL FOR THE MONTH...............10.7  DEPARTURE.....+5.2
TOTAL SNOWFALL FOR THE SEASON..............40.5  DEPARTURE....+21.4
                                               
PRELIMINARY CLIMATE SUMMARY FOR JANUARY 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
 
1/1  31/23/27/0/0.01/0.1/005/01    24 NW 
1/2  28/19/24/-3/0.45/.../000/00   53 W    AERO 55 W
1/3  25/13/19/-8/0.34/.../000/00   45 W    AER0 44 W
1/4  32/20/26/-1/0/0/397/72        35 W    AERO 28 W
1/5  29/18/24/-3/0/0/000/00        29 WNW
1/6  30/17/24/-2/0/0/554/100       33 W
1/7  37/21/29/+3/0/0/549/99        31 W
1/8  25/16/21/-5/0.04/0.6/000/00   22 WNW
1/9  25/10/18/-8/0/0/557/100       31 WNW
1/10 26/5/16/-10/0/0/508/91        23 WNW
1/11 33/12/23/-3/0/0/526/94        21 W
 
1/12 our morning low temp: 22F; the normal low is now 18F
 
DAILY EXTREMES
Temperature and precipitation records back to 1885, and
wind records back to 1940 (e = estimated):
 
RECORDS FOR JANUARY 12
HIGH 57F IN 1913, 1975
LOW -15F IN 1886
PRECIP 1.46 INS. IN 1900
SNOW 6.0 INS. IN 1923
WIND 84e MPH S IN 1980
 
RECORDS FOR JANUARY 13
HIGH 57F IN 1890,1932
LOW -10F IN 1912,1914
PRECIP 1.54 INS. IN 1979
SNOWFALL 12.6 INS. IN 1964
PEAK GUST 74 MPH NE IN 1964
 
TODAY'S REPORT PREPARED BY: Robert Skilling