BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS 02186
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
 
DAILY DISCUSSION AND CLIMATE SUMMARY
MONDAY, OCTOBER 19, 2009  
ALL TIMES ARE IN EASTERN STANDARD TIME
 
SNOWFALL 3.0 INCHES FOR SUNDAY, 18 OCTOBER, WAS
THE MOST DURING ANY OCTOBER DAY SINCE OCTOBER 10, 1979
AND 3RD GREATEST SO EARLY IN THE SEASON
 
Yesterday's nor'ester brought rain changing to
snow during the afternoon with the final snowfall
accumulation measured on the boards here this morning
at 3.0 inches.  ASOS reports the daily and storm
precipitation total of 1.75 inches while the standard
gage had 1.79 inches.
.
THE GREATEST OCTOBER SNOWFALLS AT BLUE HILL:
(inches)
 
1. 10/10/1979......6.8
2. 10/13/1934......4.2
3. 10/18/2009......3.0
   10/26/1962......3.0
   10/24-25/1960...3.0 [event total]
   10/23/1891......3.0
   
The last measurable snowfall during October was
1.5 inches in 2005 on 29 October. 
 
The recent spell of unseasonably cold mid-October weather 
has brought the monthly average temperature down to close
to 5 degrees colder than normal.   
 
Today's observations:
 
7 A.M.
Weather: Clear, stratocumulus distant NE-E along and
offshore, altocumulus layer NNE-SSE
Temperature: 34F, Dew point: 32F, Wind: NW at 9 kts
Sea-level pressure: 30.09 inches Hg, rising
Visibility: 60 miles, NE-SE 30 miles, NW 70 miles
6-hour minimum temp: 34F
24-hour precipitation: 1.72 inches
24-hour snowfall: 3.0 inches
BHO SA 1155 CLR 60 191/34/32/3109/009/ FEW SC ALG/OFFSHR DSNT 
NE-E AC LYR NNE-SSE VSBY NE-SE 30 NW 70 TOTAL NEW SNOW 24 HRS 
3.0 INS/ 8/530 4/002 53015 ASOS 70169 MANUAL 70172 10035 20034
 
10 A.M.
Weather: Clear, stratocumulus distant NE-S 
Temperature: 44F, Dew point: 34F, Wind: NNW at 12G22 kts,
Wind: Direction variable W to N
Sea-level pressure: 30.10 inches Hg, rising
Visibility: 75 miles
BHO SA 1455 CLR 75 197/44/34/3312G22/010/ SC LYR DSNT ALG/OFFSHR 
NE-S/ WND 28V36/ 8/500 51006
 
1 P.M.   
Weather: Clear, stratocumulus layer distant ENE-SE, along
and offshore, small cumulus all quadrants  
Temperature: 50F, Dew point: 36F, Wind: NW at 8 kts,
Wind: Direction variable west thru north 
Sea-level pressure: 30.09 inches Hg, falling
Visibility: 80 miles 
6-hour maximum temp: 50F
BHO SA 1755 CLR 80 191/50/36/3208/009/ SC LYR DSNT ALG/OFFSHR ENE-SE
SML CU ALQDS WND 27V36/ 8/800 58006 10050 20034
 
WEATHER SUMMARY FOR SUNDAY, OCTOBER 18
 
TEMPERATURE (DEGREES F)
MAX.....46    NORMAL.....60
MIN.....32    NORMAL.....42
MEAN....39    NORMAL.....51
 
DEPARTURE FROM 30-YEAR AVERAGE..........-12
TOTAL DEPARTURE FOR THE MONTH...........-83 [-4.8 DEGREES/DAY]
 
HEATING DEGREE DAYS
TOTAL HEATING UNITS FOR YESTERDAY............26  DEPARTURE......+12
TOTAL HEATING UNITS FOR THE MONTH...........286  DEPARTURE......+79
TOTAL HEATING UNITS FOR THE SEASON..........443  DEPARTURE......+67
TOTAL HEATING UNITS LAST SEASON TO DATE.....292  DIFFERENCE....+151
 
PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY.............43 NNE AT  11:13 A.M.
                   AEROVANE..............40 NNE AT  11:25 A.M. 
                   ASOS..................40 NNE AT  11:58 A.M.  
                   DAVIS.................41 NNW AT  12:52 P.M.
FASTEST MILE FOR YESTERDAY...............25 NNE AT  12:00 P.M. 
MAXIMUM 2-MINUTE ASOS AVERAGE............25 NNE AT  12:01 P.M. 
MAXIMUM 2-MINUTE DAVIS AVERAGE...........26 NNE AT  12:01 P.M.
AVERAGE WIND SPEED AND DIRECTION.......17.0 NNW 
                   ASOS................16.0
                   DAVIS...............15.6 N [10 DEG]
 
PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....1.72   DEPARTURE....+1.58
                         ASOS..............1.69
TOTAL PRECIPITATION FOR MONTH..............4.53   DEPARTURE....+2.01
                         ASOS..............4.50
TOTAL PRECIPITATION FOR THE YEAR..........42.41   DEPARTURE....+2.29
                         ASOS.............43.56
 
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/.../..    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/.../.../..  35 NNE
10/18 46/32/39/-12/1.79/000/00 43 NNE  SNOWFALL 3.0 INS
 
10/19 our morning low temp: 33F; the normal low is 42F
 
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
10/18: 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 19
HIGH 81F IN 1945
LOW 21F IN 1922
PRECIP 3.64 INCHES IN 1932
SNOWFALL 1.0 INCHES IN 1972
PEAK GUST 66 MPH SSW IN 1967
 
RECORDS FOR OCTOBER 20
HIGH 78 IN 1965,1984
LOW 24 IN 1972
PRECIP 7.10 INCHES IN 1996 (RECORD FOR MONTH)
SNOWFALL TRACE IN 1934,1943
PEAK GUST 63 MPH W IN 1966
 
TODAY'S REPORT PREPARED BY: Robert Skilling