BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS 02186
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
 
DAILY DISCUSSION AND CLIMATE SUMMARY
TUESDAY, OCTOBER 27, 2009  
ALL TIMES ARE IN EASTERN STANDARD TIME
 
AN OVERCAST DAY WITH NO SUNSHINE RECORDED 
LIGHT RAIN BEGINS EARLY AFTERNOON
 
An overcast has been gradually thickening today
and the sun was only briefly dimly visible
through the clouds at sunrise.  Temperatures
are returning to below normal after a run of
six out of seven days above normal.  The high
had only reached 50F by early afternoon when
the normal high is 56F.  Some light rain began
early this afternoon with winds light from the
north and north-northeast.
 
Today's observations:
 
7 A.M.
Weather: Overcast altocumulus stratiformis undulatus, few
small stratocumulus distant N-NE, higher cloud visible to
the distant NNE-E-SSE
Temperature: 46F, Dew point: 42F, Wind: E at 12  kts
Sea-level pressure: 30.31 inches Hg, rising
Visibility: 40 miles, 50 miles northeast thru southeast,
30 miles above inversion fog southwest thru northwest and
lower below that inversion 
6-hour minimum temp: 43F
24-hour precipitation: 0.00 inches
BHO SA 1155 E140 OVC 40 264/46/42/0912/031/ FEW SC DSNT N-NE 
HIER CLD VSB DSNT NNE-E-SSE PTCHY THN FG/GF BLO INVSN ESE-S-NW
FEW DENS PTCHS VSBY SW-NW ABV INVSN/FG VSBY NE-SE 50/
8/57/ 55002 10046 20043
 
10 A.M.
Weather: Overcast altostratus, few altocumulus distant
west-southwest to west and northwest to north-northeast,
higher clouds visible distant northwest to east,
heavy virga   
Temperature: 47F, Dew point: 43F, Wind: E at 8 kts
Sea-level pressure: 30.27 inches Hg, falling
Visibility: 40 miles, southwest 30, northwest 25,
and northeast 50 miles 
BHO SA 1455 E130 OVC 40 251/47/43/1008/027/
FEW AC DSNT WSW-W AND NW-NNE HIER CLDS VSB DSNT NW-E
HVY VIRGA ALQDS VSBY SW 30 NW 25 NE 50/ 8/07/ 55013 
 
1 P.M.
Weather: Overcast nimbostratus, few stratocumulus to the
distant north, light rain occurring, precipitation is
very light, began unknown   
Temperature: 50F, Dew point: 45F, Wind: N at 8 kts
Sea-level pressure: 30.13 inches Hg, falling
Visibility: 25 miles
6-hour maximum temp: 50F
6-hour precipitation: trace    
BHO SA 1755 E18 OVC 25R- 204/50/45/3608/013/ FEW SC DSNT N 
RBUKN PCPN VRY LGT/ 8/52/ 58047 MANUAL 6000/ 10050 20046 
 
WEATHER SUMMARY FOR MONDAY, OCTOBER 26
 
TEMPERATURE (DEGREES F)
MAX.....59     NORMAL.....57
MIN.....40     NORMAL.....40
MEAN....50     NORMAL.....48
 
DEPARTURE FROM 30-YEAR AVERAGE...........+2
TOTAL DEPARTURE FOR THE MONTH...........-57 [-2.4 DEGREES/DAY]
 
HEATING DEGREE DAYS
TOTAL HEATING UNITS FOR YESTERDAY............15  DEPARTURE.......-2
TOTAL HEATING UNITS FOR THE MONTH...........384  DEPARTURE......+50
TOTAL HEATING UNITS FOR THE SEASON..........541  DEPARTURE......+38
TOTAL HEATING UNITS LAST SEASON TO DATE.....438  DIFFERENCE....+103
 
PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY.............27 NNW  AT 9:22 A.M. *
                   AEROVANE..............25 NNW AT  9:22 A.M. 
                   ASOS..................25 NNW AT  9:22 A.M.  
                   DAVIS.................26 WNW AT  8:09 A.M.  
FASTEST MILE FOR YESTERDAY...............16 NNW AT  9:22 A.M. 
MAXIMUM 2-MINUTE ASOS AVERAGE............18 NNW AT  9:22 A.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE...........19 WNW AT  8:29 A.M.  
AVERAGE WIND SPEED AND DIRECTION....... 9.0 WNW
                   ASOS.................8.7
                   DAVIS................9.5 WNW [295 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 MONTH..............6.17   DEPARTURE....+2.50
                         ASOS..............6.18
TOTAL PRECIPITATION FOR THE YEAR..........44.05   DEPARTURE....+2.78
                         ASOS.............45.24
 
PRELIMINARY CLIMATE SUMMARY FOR OCTOBER 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
 
10/1  56/39/48/-9/0/155/22     27 WSW 
10/2  60/40/50/-6/0/442/63     23 SSE 
10/3  63/51/57/+1/1.10/000/00  32 ESE  AERO 30 MPH ESE 
10/4  67/57/62/+6/0/202/29     21 WSW
10/5  64/49/57/+2/0/595/86     33 W    AERO 31 MPH W
10/6  65/45/55/0/0/628/91      25 W
10/7  67/51/59/+4/0.70/344/50  54 W    AERO 54 MPH W
10/8  61/48/55/+1/0/602/88     43 W    AERO 39 MPH W
10/9  60/48/54/0/0.05/000/00   29 SSE
10/10 62/42/52/-2/0.26/205/30  37 NW
10/11 61/39/50/-3/0/655/97     35 WSW  AERO 33 MPH W 
10/12 53/36/45/-8/T/471/70     23 SSW
10/13 51/36/44/-8/0.20/074/11  35 WNW 
10/14 52/32/42/-10/0/494/74    27 NW
10/15 41/32/37/-15/0.19/000/00 29 NNE
10/16 41/33/37/-14/0.24/000/00 37 NNE  AERO 35 MPH NNE T SNOW
10/17 48/33/41/-10/0/250/38    35 NNE
10/18 46/32/39/-12/1.79/000/00 43 NNE  SNOWFALL 3.0 INS
10/19 52/33/43/-8/0/628/96     25 NNW
10/20 65/38/52/+2/0/566/87     23 W    
10/21 68/48/58/+8/0/363/56     19 W
10/22 74/50/62/+12/0/265/41    30 S
10/23 57/38/48/-1/0/000/00     35 NW   AERO 32 MPH NW
10/24 67/42/55/+6/.../000/00   53 S    AERO 51 MPH S
10/25 64/44/54/+5/.../.../..   35 W    AERO 35 MPH W
10/26 59/40/50/+2/0/.../..     27 NNW
 
10/27 our morning low temp: 43F; the normal low is now 40F
 
NEW DAILY RECORDS FOR OCTOBER 2009
10/7: NEW RECORD WIND GUST 54 MPH W AT 2005E;
      surpasses previous record of 52 MPH ESE in 1972
10/15: NEW RECORD LOW MAXIMUM TEMPERATURE 41;
      surpasses previous 47 set in 1887 and 1896
10/16: NEW RECORD LOW MAXIMUM TEMPERATURE 41;
      surpasses previous 42 set in 1940
10/16: NEW RECORD DAILY SNOWFALL TRACE; 
      surpasses previous zero for the date
10/18: NEW RECORD DAILY SNOWFALL 3.0 INS; 
      surpasses previous trace in 1972
 
DAILY EXTREMES
Temperature and precipitation records back to 1885, and
wind records back to 1940 (e = estimated):
 
RECORDS FOR OCTOBER 27
HIGH 83 IN 1963
LOW 21 IN 1936
PRE 1.79 INCHES IN 1886
SNOW 0.1 INCHES IN 1957
WIND 54 MPH WNW IN 1968
 
RECORDS FOR OCTOBER 28
HIGH 81 IN 1919
LOW 23 IN 1914
PRECIP 2.46 INCHES IN 2006
SNOWFALL TRACE IN 1934,1957,1979
PEAK GUST 71 MPH SSW IN 1995
 
TODAY'S REPORT PREPARED BY: Robert Skilling