BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS 02186
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
 
DAILY DISCUSSION AND CLIMATE SUMMARY
WEDNESDAY, NOVEMBER 18, 2009
ALL DATA IN EASTERN STANDARD TIME
 
HEAVY EARLY MORNING FROST THEN A CLOUDY
SKY UNTIL LATE MORNING FOLLOWED BY CLEARING
 
Heavy frost formed on grassy and wooden
surfaces at ground level while the low
temperature reading in the instrument
shelter this morning was 34F. A layer of low
stratocumulus clouds formed by sunrise and
these clouds did not clear away until late this
morning.  Clear sky and bright sunshine pre-
vailed by this afternoon. 
 
Today's observations:
 
7 A.M.
Weather: Broken stratocumulus, thin fog below inversion all 
quadrants, patches steam fog over ponds ESE-SE
Temperature: 36F, Dew point: 32F, Wind: NNW at 7 kts
Sea-level pressure: 30.50 inches Hg, rising
Visibility: 30 miles, SE-SW 20, W-NW 50 above inversion 
6-hour minimum temp: 34F
24-hour precipitation: 0.00 
BHO SA 1155 E20 BKN 30 330/36/32/3407/050/ THN FG BLO INVSN 
ALQDS PTCHS STEAM FG OVR PONDS ESE-SE VSBY SE-SW 20 W-NW 50 
ABV INVSN HVY FROST/GRASSY AND WOOD SFCS/ 8/500 53010 10038 
20034  
 
10 A.M.
Weather: Overcast stratocumulus with breaks in the overcast,
few lower cumulus forming distant west, thin fog below an
inversion S-W, thin smoke layer along the horizon from the
northwest through east  
Temperature: 42F, Dew point: 35F, Wind: S at 2 kts(estimated)
Sea-level pressure: 30.54 inches Hg, rising
Visibility: 20 miles, hazy, 15 NE, 45 above inversion WNW   
BHO SA 1455 E18 OVC 20 342/42/35/E1802/054/
BINOVC ALQDS FEW LWR CU FRMG DSNT W THN FG BLO INVSN S-W
THN K ALG HRZN NW-E HAZY VSBY NE 15 WNW 45 ABV INVSN
WND LGT/ 8/8// 51012
 
1 P.M.  
Weather: Clear, few stratocumulus offshore distant NE-E
Temperature: 48F, Dew point: 36F, Wind: SW at 6 kts,
Wind: Light
Sea-level pressure: 30.49 inches Hg, falling
Visibility: 45 miles light haze
6-hour max. temp: 48F 
BHO SA 1755 CLR 45 326/48/36/2306/049/ PTCH SC DSNT OFFSHR 
NE-E THN K WNW-NE LGT HZ/ 8/500 58016 10048 20036
 
WEATHER SUMMARY FOR TUESDAY, NOVEMBER 17
 
TEMPERATURE (DEGREES F)
MAX.....47     NORMAL.....49
MIN.....35     NORMAL.....34
MEAN....41     NORMAL.....41
 
DEPARTURE FROM 30-YEAR AVERAGE..............0
TOTAL DEPARTURE FOR THE MONTH.............+66 [+3.7 DEGREES/DAY]
 
HEATING DEGREE DAYS
TOTAL HEATING UNITS FOR YESTERDAY............24    DEPARTURE........ 0
TOTAL HEATING UNITS FOR THE MONTH...........291    DEPARTURE.......-67
TOTAL HEATING UNITS FOR THE SEASON..........912    DEPARTURE.......-37
TOTAL HEATING UNITS LAST SEASON TO DATE.....820    DIFFERENCE......+92
 
PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY.............28 WNW AT 12:42 A.M.     
                   AEROVANE..............25 NW  AT 12:48 A.M. *   
                   ASOS..................N/A     
                   DAVIS.................28 WNW AT 12:44 A.M.      
FASTEST MILE FOR YESTERDAY...............17 NW  AT 12:46 A.M.  
MAXIMUM 2-MINUTE ASOS AVERAGE............17 NW  AT 12:48 A.M.      
MAXIMUM 2-MINUTE DAVIS AVERAGE...........19 WNW AT 12:44 A.M.      
AVERAGE WIND SPEED AND DIRECTION....... 9.4 NW
                   ASOS.................9.3
                   DAVIS................9.5 N [360 DEG]
* last of several occurrences...
 
PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.00   DEPARTURE....-0.16
                         ASOS..............0.00
TOTAL PRECIPITATION FOR MONTH  ............2.20   DEPARTURE....-0.44
                         ASOS..............2.23
TOTAL PRECIPITATION FOR THE YEAR..........47.31   DEPARTURE....+2.65
                         ASOS.............48.54
                 
SNOWFALL (INCHES) THROUGH THIS MORNING (EST)
TOTAL SNOWFALL 24 HRS ENDING 7 A.M..........0.0  DEPARTURE.....-0.1
TOTAL SNOWFALL FOR THE MONTH................0.0  DEPARTURE.....-1.4
TOTAL SNOWFALL FOR THE SEASON...............3.0  DEPARTURE.....+1.4
                                               
PRELIMINARY CLIMATE SUMMARY FOR NOVEMBER 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
 
11/1  58/44/51/+4/0.05/167/27   22 WNW  
11/2  49/42/46/0/T/099/16       29 NE
11/3  57/36/47/+1/0/474/77      32 W    AERO 32 MPH W    
11/4  49/34/42/-4/0/514/84      24 W
11/5  46/36/41/-4/0.01/006/01   21 N
11/6  47/31/39/-6/0/419/69      38 WNW  AERO 38 MPH WNW
11/7  49/29/39/-6/0/575/95      33 S
11/8  66/42/54/+10/0/549/91     31 SSW
11/9  68/49/59/+15/0/486/81     35 S    AERO 35 MPH S
11/10 62/50/56/+12/0/000/00     23 SW 
11/11 50/43/47/+4/0/113/19      31 NNE
11/12 49/41/45/+2/0/125/21      34 NE   AERO 31 MPH NNE
11/13 49/44/47/+4/0/000/00      39 NNE  AERO 37 MPH NNE
11/14 59/49/54/+12/2.08/000/00  39 NE   AERO 38 MPH NE
11/15 60/52/56/+14/0.06/012/02  18 W
11/16 56/43/50/+8/0/527/90      30 NW   AERO 31 MPH NW
11/17 47/35/41/0/0/576/99       28 WNW
 
11/18 our morning low temp: 34F; the normal low is now 34F 
 
NEW DAILY RECORD FOR NOVEMBER 2009
A new daily rainfall record set for November 14 at 2.08 inches;
the previous record was 1.87 inches in 1972. 
 
DAILY EXTREMES
Temperature and precipitation records back to 1885, and
wind records back to 1940 (e = estimated):
 
RECORDS FOR NOVEMBER 18
HIGH 72 IN 1963
LOW 10 IN 1936
PRECIP 1.80 INS IN 1929
SNOWFALL 6.3 INS IN 1980
PEAK GUST 60 SW IN 1987
 
RECORDS FOR NOVEMBER 19
HIGH 72 IN 1941
LOW 10 IN 1936
PRECIP 1.92 INCHES IN 1926
SNOWFALL 11.0 INS IN 1986
PEAK GUST 59e E IN 1945
 
TODAY'S REPORT PREPARED BY: Robert Skilling