BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS 02186
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
 
DAILY DISCUSSION AND CLIMATE SUMMARY
MONDAY, OCTOBER 12, 2009, COLUMBUS DAY  
ALL TIMES ARE IN EASTERN STANDARD TIME
 
Sunshine through increasing high cloudiness
but excellent visibility of 80 miles today.
Temperatures dropping significantly below
normal starting today and that trend is
expected to continue.  This morning's low
of 36F was the coldest of the season to date
and was 8 degrees colder than average.
 
Today's observations:
 
7 A.M.
Weather: Clear, few stratocumulus distant offshore,
distant ENE-SE, few cirrus filosus except west through
northwest 
Temperature: 37F, Dew point: 29F, Wind: WNW at 10 kts
Sea-level pressure: 30.38 inches Hg, rising
Visibility: 80 miles
6-hour minimum temp: 36F
BHO SA 1155 CLR 80 286/37/29/3010/038/
FEW SC DSNT OFFSHR ENE-SE FEW CI XCPT W-NW/
8/001 51017 10039 20036
 
10 A.M.
Weather: Thin broken cirrus fibratus and radiatus,
small cumulus distant ESE-SSE  
Temperature: 48F, Dew point: 29F, Wind: NNW at 5 kts,
Wind: direction light and variable
Sea-level pressure: 30.38 inches Hg, falling
Visibility: 80 miles
BHO SA 1455 250 –BKN 80 288/48/29/3405/038/
FEW CU DSNT ESE-SSE WND L/V/ 8/101 50002
 
1 P.M.   
Weather: Scattered increasing altocumulus translucidus layer,
thin broken cirrus, thin overcast cirrus, break in overcast
is large clear sky band northwest thru northeast 
Temperature: 51F, Dew point: 27F, Wind: WSW at 5 kts
Sea-level pressure: 30.34 inches Hg, falling
Visibility: 80 miles
6-hour maximum temp: 52F
BHO SA 1755 170 SCT 250 –BKN 300 –OVC 80 274/51/27/2505/034/
FEW CU DSNT ESE-SSE BINOVC/CLR SKY BND DSNT NW-NE/
8/151 58014 10052 20037  
 
WEATHER SUMMARY FOR SUNDAY, OCTOBER 11
 
TEMPERATURE (DEGREES F)
MAX.....61    NORMAL.....62
MIN.....39    NORMAL.....44
MEAN....50    NORMAL.....53
 
DEPARTURE FROM 30-YEAR AVERAGE...........-3
TOTAL DEPARTURE FOR THE MONTH............-6 [-0.6 DEGREES/DAY]
 
HEATING DEGREE DAYS
TOTAL HEATING UNITS FOR YESTERDAY............15  DEPARTURE.......+3
TOTAL HEATING UNITS FOR THE MONTH...........116  DEPARTURE.......+2
TOTAL HEATING UNITS FOR THE SEASON..........268  DEPARTURE......-10
TOTAL HEATING UNITS LAST SEASON TO DATE.....220  DIFFERENCE.....+53
 
PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY.............35 WSW AT  3:32 P.M.
                   AEROVANE..............32 W   AT  3:43 P.M.
                   ASOS..................33 WSW AT  3:32 P.M. 
                   DAVIS.................35 WSW AT  3:24 P.M.
FASTEST MILE FOR YESTERDAY...............24 W   AT  3:50 P.M. *
MAXIMUM 2-MINUTE ASOS AVERAGE............24 W   AT  3:48 P.M. 
MAXIMUM 2-MINUTE DAVIS AVERAGE...........24 W   AT  3:40 P.M. 
AVERAGE WIND SPEED AND DIRECTION.......13.6 W
                   ASOS................12.7
                   DAVIS...............12.8 W [260 DEG]
 
* last of several occurrences....
 
PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.00   DEPARTURE....-0.14
                         ASOS..............0.00
TOTAL PRECIPITATION FOR MONTH..............2.11   DEPARTURE....+0.57
                         ASOS..............2.14
TOTAL PRECIPITATION FOR THE YEAR..........39.99   DEPARTURE....+0.85
                         ASOS.............41.20
 
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/.../000/00    29 SSE
10/10 62/42/52/-2/.../.../..   37 NW
10/11 61/39/50/-3/0/.../..     35 WSW  AERO 33 MPH W 
 
10/12 our overnight low temp: 36F; the normal low is now 44F
 
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
 
DAILY EXTREMES
Temperature and precipitation records back to 1885, and
wind records back to 1940 (e = estimated):
 
RECORDS FOR OCTOBER 12
HIGH 87 IN 1954
LOW 31 IN 1906
PRECIP 1.53 INCHES IN 1948
SNOWFALL TRACE IN 1941
PEAK GUST 55 MPH NW IN 1963
 
RECORDS FOR OCTOBER 13
HIGH 84 IN 1930,1954
LOW 30 IN 1934,1936,1988
PRECIP 5.92 INCHES IN 1895
SNOWFALL 4.2 INCHES IN 1934
PEAK GUST 46e MPH W IN 1950
 
TODAY'S REPORT PREPARED BY: Robert Skilling