BLUE HILL OBSERVATORY MILTON, MA
MILTON, MASSACHUSETTS 02186
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
 
DAILY DISCUSSION AND CLIMATE SUMMARY
THURSDAY, OCTOBER 21, 2010
ALL TIMES ARE IN EASTERN STANDARD TIME
 
ZERO VISIBILITY IN DENSE FOG EARLY THIS MORNING 
SHOWERS ARRIVE DURING NOON HOUR WITH LIGHT RAINFALL
 
Visibility was down to zero between 7 and 8 A.M.
EDT this morning but rose quickly once the low
stratus clouds lifted during the next hour. A
few breaks in the overcast and a brief glimpse
of sunshine was observed before heavy clouds
arrived during the hour before noon EDT.
 
Showers arrived from the west by noontime.
The rainfall amount was small here (0.07 inch)
but downpours were reported in the area. Our
Hingham weather station had one of those down-
pours with a tenth of an inch of rain falling
in about 5 minutes.  Thunderstorms occurred
well to our southwest through southeast. 
 
Today's observations: 
 
7 A.M.
Weather: Obscurement with heavy fog, sun disc visible
Temperature: 45F, Dew point: 45F; Wind: SSE at 13 kts
Sea-level pressure: 29.64 inches Hg, falling 
Visibility: 1/16 mile, increasing, zero past hour
6-hour minimum temp: 44F
BHO SA 1155 W2 X 1/16F 036/45/45/1613/964/ VSBY INCR 
ZERO PST HR SUN DISC VSB/ 8//// 56012 10048 20044 
 
10 A.M.
Weather: Scattered altocumulus, layer increasing, high dense
cirrostratus overcast, dark sky WSW-NNW, few small breaks
and thin spots in overcast distant ESE-S    
Temperature: 55F, Dew point: 48F; Wind: S at 13 kts,
Wind: Gust to 24 kts past hour,
Wind: Direction variable SE to SSW 
Sea-level pressure: 29.57 inches Hg, falling
Visibility: 12 miles, 8 miles W-NW hazy all quadrants 
BHO SA 1455 80 SCT E220 OVC 12 015/55/48/1713/957/ 
FEW SC ALQDS AC LYR SW-NW INCR DRK WSW-NNW SML BINOVC 
THN SPTS IOVC DSNT ESE-S VSBY W-NW 8 HAZY ALQDS WND 14V21 
GST TO 24 KTS PST HR/ 8/557 58021 
 
1 P.M. 
Weather: Scattered stratocumulus, scattered cumulonimbus,
overcast altocumulus, cumulonimbus distant E-SE moving
east-northeast, bright spots in overcast, light rain was
occurring, precipitation very light
Temperature: 52F, Dew point: 49F; Wind: SSW at 13 kts.
Wind: Direction variable S to WSW
Sea-level pressure: 29.51 inches Hg, falling
Visibility: 20 miles, except 15 miles northeast, 8 miles
to the southeast     
6-hour max. temp: 56F 
6-hourly precip: 0.07 in. 
BHO SA 1755 32 SCT E55 BKN 65 OVC 20R- 992/52/49/2113/951/
CBS DSNT E-SE MOVG ENE BRGHT SPTS IOVC VSBY NE 15 SE 8
PCPN VRY LGT WND 18V24/ 8/37/ 58023 MANUAL 6007/ AS0S 60007
10056 20045
 
WEATHER SUMMARY FOR WEDNESDAY, OCTOBER 20
 
TEMPERATURE (DEGREES F)
MAX.....61     NORMAL.....59
MIN.....44     NORMAL.....42
MEAN....53     NORMAL.....50
 
DEPARTURE FROM 30-YEAR NORMAL..............+3
TOTAL DEPARTURE FOR THE MONTH.............-14 [-0.9 DEGREE/DAY]
 
HEATING DEGREE DAYS
TOTAL HEATING UNITS FOR YESTERDAY............12    DEPARTURE........-3
TOTAL HEATING UNITS FOR THE MONTH...........249    DEPARTURE.......+12
TOTAL HEATING UNITS FOR THE SEASON..........328    DEPARTURE.......-78
TOTAL HEATING UNITS LAST SEASON TO DATE.....478    DIFFERENCE.....-150
 
PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY.............21 S   AT 12:56 P.M. 
                   AEROVANE..............23 S   AT 12:56 P.M.
                   ASOS..................21 S   AT 12:56 P.M.  
                   DAVIS.................20 S   AT 12:53 P.M.  
THE FASTEST MILE FOR YESTERDAY...........16 S   AT 12:55 P.M. 
MAXIMUM 2-MINUTE ASOS AVERAGE............17 S   AT 12:57 P.M.  
MAXIMUM 2-MINUTE DAVIS AVERAGE...........16 S   AT 12:54 P.M. 
AVERAGE WIND SPEED AND DIRECTION....... 9.8 SSW 
                   ASOS.................9.9
                   DAVIS............... 8.9 S [190 DEG]
 
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 THE MONTH..........5.50  DEPARTURE........+2.70
                         ASOS..............5.53
TOTAL PRECIPITATION FOR THE YEAR..........53.52  DEPARTURE.......+13.12
                         ASOS.............53.37**
** ASOS missing rainfall due to system failure on 6/24-25
 
PRELIMINARY CLIMATE SUMMARY FOR OCTOBER 2010 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  80/55/68/+11/0.56/035/05  55 SSE  AERO 63 MPH SSE
10/2  65/46/56/0/0.00/688/98    28 WNW  AERO 31 MPH WNW
10/3  55/43/49/-7/T/133/19      35 NNE  AERO 39 MPH NNE
10/4  54/48/51/-5/0.78/000/00   39 NNE  AERO 43 MPH NNE
10/5  57/51/54/-1/0.40/000/00   37 NE   AERO 39 MPH NNE
10/6  57/49/53/-2/1.63/000/00   47 NE   AERO 51 MPH NE
10/7  62/47/55/0/0.00/275/40    37 W    AERO 40 MPH W
10/8  70/47/59/+5/0.00/610/89   35 WSW  AERO 37 MPH WSW
10/9  62/43/53/-1/0.00/675/99   33 WNW  AERO 37 MPH WNW
10/10 64/38/51/-3/0.00/679/100  25 SW   AERO 29 MPH SSW
10/11 68/47/58/+5/0.00/542/80   28 W   
10/12 61/43/52/-1/0.01/297/44   24 ENE
10/13 61/38/50/-2/0.00/663/99   18 NW
10/14 59/45/52/0/0.41/294/44    29 ENE
10/15 51/39/45/-7/1.71/033/05   48 WSW  AERO 50 MPH WSW TSTM *
10/16 55/39/47/-4/0.00/544/82   47 WNW  AERO 54 MPH WNW
10/17 63/38/51/0/0.00/581/88    43 W    AERO 47 MPH W
10/18 57/41/49/-2/0.00/519/79   32 W    AERO 35 MPH W
10/19 57/38/48/-3/0.00/497/76   21 W 
10/20 61/44/53/+3/T/.../..      21 S
 
10/21 our morning low temp: 44F; the normal low is now 41F
 
NEW DAILY RECORDS FOR OCTOBER 2010
None so far.
 
DAILY EXTREMES
Temperature and precipitation records back to 1885, and
wind records back to 1940 (e = estimated):
  
RECORDS FOR OCTOBER 21
HIGH 79 IN 1979
LOW 24 IN 1974
PRECIP 2.39 INCHES IN 1944
SNOWFALL TRACE IN 1895,1907,1940
PEAK GUST 69e MPH S IN 1976
 
RECORDS FOR OCTOBER 22
HIGH 85 IN 1979
LOW 22 IN 1940
PRECIP 1.37 INCHES IN 1898
SNOWFALL TRACE IN 1969
PEAK GUST 67 MPH ESE IN 1988
 
TODAY'S REPORT PREPARED BY: Robert Skilling