BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS 02186
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
  
DAILY DISCUSSION AND CLIMATE SUMMARY
SATURDAY, JULY 4, 2009 INDEPENDENCE DAY
ALL TIMES ARE IN EASTERN STANDARD TIME

PARTIAL SUNSHINE TODAY WITH BUILDING CUMULUS...
A few light rain showers on Friday afternoon brought
a trace of rainfall. Slightly drier air today with
a westerly wind has improved the visibility 
dramatically to about 70 miles, though residual
moisture is being lifted into large cumulus that
have been building since mid-morning. Mt. Monadnock
is visible today for the first time since the middle 
of June.  The mean station pressure for June of 
29.18 inches (or 29.88 inches adjusted to sea-level),
ranks as a tie for fourth lowest on record for any
June, which is another indication of the generally 
cloudy and frequently rainy weather last month. 

Lowest June Mean Station Pressure (inches)

1) 29.15 in 1923
   29.15 in 1977
   29.15 in 1998
4) 29.18 in 1932
   29.18 in 1988
   29.18 in 2009

Today's observations:

7 A.M.   
Weather: Scattered altocumulus, scattered cirrus
Temperature: 66F, Dew point: 59F, Wind: W at 13G23 kts 
Sea-level pressure: 29.76 inches Hg, rising
Visibility: 45 miles
6-hour minimum temp: 60F
24-hour rainfall: Trace
BHO SA 1155 80 SCT 250 SCT 45 079/66/59/2613G23/976/ 
FEW HIR AC/ 8/070 51003 10066 20060

10 A.M.   
Weather: Broken cumulus, broken altocumulus, few
cumulus fractus
Temperature: 72F, Dew point: 59F, Wind: WSW at 10 kts 
Sea-level pressure: 29.76 inches Hg, steady
Visibility: 60 miles
BHO SA 1455 30 SCT E55 BKN 120 BKN 60 079/72/59/2410/976/ 
FEW CUFRA/ 8/230 54000

1 P.M.   
Weather: Broken cumulus, broken altocumulus, few
cumulus fractus
Temperature: 72F, Dew point: 59F, Wind: W at 14G23 kts
Wind: Peak gust 23 kts, 26 mph WSW past hour
Wind: Direction variable SW-WNW
Sea-level pressure: 29.75 inches Hg, falling
Visibility: 70 miles
6-hourly max. temp. 76F
BHO SA 1755 E40 BKN 85 BKN 150 BKN 70 074/72/59/2614G23/975/ 
FEW CUFRA PK WND 2426/21 WND 23V29/ 8/230 56005 10076 20066


WEATHER SUMMARY FOR FRIDAY, JULY 3

TEMPERATURE (DEGREES F)
MAX.....75    NORMAL.....80
MIN.....58    NORMAL.....60
MEAN....67    NORMAL.....70

DEPARTURE FROM 30-YEAR NORMAL...........-3
TOTAL DEPARTURE FOR THE MONTH..........-22  [-7.5 DEGREES/DAY]

HEATING DEGREE DAYS
TOTAL HEATING UNITS FOR YESTERDAY.............0  DEPARTURE.......-1
TOTAL HEATING UNITS FOR THE MONTH.............9  DEPARTURE.......+6
TOTAL HEATING UNITS FOR THE SEASON............9  DEPARTURE.......+6
TOTAL HEATING UNITS LAST SEASON TO DATE.......0  DIFFERENCE......+9

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY.............23 WSW AT 11:52 P.M.   
                   AEROVANE..............18 WSW AT 11:52 P.M.    
                   ASOS..................20 WNW AT 11:43 P.M.    
                   DAVIS.................19 SSW AT  3:29 P.M.  
FASTEST MILE FOR YESTERDAY...............14 WSW AT 11:52 P.M. 
MAXIMUM 2-MINUTE ASOS AVERAGE............14   W AT 11:57 P.M.       
MAXIMUM 2-MINUTE DAVIS AVERAGE...........15 SSW AT  8:32 P.M.     
AVERAGE WIND SPEED AND DIRECTION........7.6 SSW
                   ASOS.................7.2
                   DAVIS................6.4  SW [214 DEG]

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M...trace  DEPARTURE....-0.12
                         ASOS..............0.00
TOTAL PRECIPITATION FOR  JULY..............1.54  DEPARTURE....+1.16
                         ASOS..............1.56  
TOTAL PRECIPITATION FOR THE YEAR..........25.18  DEPARTURE....-0.87
                         ASOS.............26.21 
 
PRELIMINARY CLIMATE SUMMARY FOR JULY 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

7/1  62/57/60/-10/.../000/00    25 NNE   TSTM
7/2  66/56/61/-9/.../000/00     29 SSW   AERO 25 MPH SSW TSTM
7/3  75/58/67/-3/T/.../..       23 WSW

7/4  morning low temp: 60F; our normal low is now 60F

NEW DAILY RECORDS FOR JULY 2009 TO DATE...
NONE 
  
DAILY EXTREMES

Temperature and precipitation records back to 1885, and
wind records back to 1940 (e = estimated):

RECORDS FOR JULY 4
HIGH 98F IN 1911, 1919, 1949
LOW 48F IN 1914
PRECIP 1.78 IN 1950
PEAK GUST 50e MPH WNW IN 1949

RECORDS FOR JULY 5
HIGH 98F IN 1911
LOW 48F IN 1920, 1927 & 1979
PRECIP 1.45 INS IN 1922
PEAK GUST 44e N IN 1944

TODAY'S REPORT PREPARED BY: Mike Iacono