BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS 02186
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
 
DAILY DISCUSSION AND CLIMATE SUMMARY
TUESDAY, SEPTEMBER 15, 2009 
ALL TIMES ARE IN EASTERN STANDARD TIME
 
SEPTEMBER TEMPERATURE SLIGHTLY BELOW NORMAL
WHILE PRECIPITATION IS SLIGHTLY ABOVE
 
Sunshine today with near normal temperatures
as the first half of the month concludes with
temperatures only a little more than a degree
on the cool side of normal. Precipitation for
the month is about a half inch above average.
 
Today's observations:
 
7 A.M.  
Weather:  Clear, altocumulus, few lenticularis, cirrus
northwest through east 
Temperature: 59F, Dew point: 55F, Wind: SW at 10 kts
Sea-level pressure: 29.86 inches Hg, rising
Visibility: 30 miles
6-hour minimum temp: 56F
24-hour precipitation: 0.00 
BHO SA 1155 CLR 30 110/59/55/2310/986/
AC/FEW ACSL/CI NW-E CI DSNT SE-SW LGT HZ
WND GRDLY VEERING/ 8/041 51006 10059 20056
 
10 A.M.
Weather: Scattered cirrus, cumulus, cumulus with few
moderate tops forming all quadrants 
Temperature: 70F, Dew point: 57F, Wind: W at 11 kts,
Wind: direction variable WSW-NW
Sea-level pressure: 29.90 inches Hg, rising
Visibility: 60 miles
BHO SA 1455 220 SCT 60 124/70/57/2811/990/
CU/FEW CU MDT TOPS FRMG ALQDS WND 25V32/ 8/201 53014  
 
1 P.M.
Weather: Scattered cumulus, moderate cumulus,
scattered cirrus (cirrus distant S-SW)
Temperature: 71F, Dew point: 53F, Wind: WNW at 7 kts,
Wind: direction variable WSW to NNE 
Sea-level pressure: 29.92 inches Hg, rising
Visibility: 70 miles
6-hour max. temp: 74F
BHO SA 1755 45 SCT 250 SCT 70 131/71/53/3007/992/
FEW MDT CU CI LYR DSNT S-SW WND 25V02/ 8/201 51007
10074 20059
 
WEATHER SUMMARY FOR MONDAY, SEPTEMBER 14
 
TEMPERATURE (DEGREES F)
MAX.....74    NORMAL.....72
MIN.....55    NORMAL.....54
MEAN....65    NORMAL.....63
 
DEPARTURE FROM 30-YEAR AVERAGE...........+2
TOTAL DEPARTURE FOR THE MONTH...........-15 [-1.3 DEGREES/DAY]
 
HEATING DEGREE DAYS
TOTAL HEATING UNITS FOR YESTERDAY.............0  DEPARTURE.......-4
TOTAL HEATING UNITS FOR THE MONTH............33  DEPARTURE.......-7
TOTAL HEATING UNITS FOR THE SEASON...........67  DEPARTURE.......-4
TOTAL HEATING UNITS LAST SEASON TO DATE......30  DIFFERENCE.....+37
 
PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY.............22 WSW  AT  2:10 P.M.   
                   AEROVANE..............20 WSW  AT  2:10 P.M.   
                   ASOS..................20 WSW  AT  4:04 P.M.   
                   DAVIS................ 21 WSW  AT  1:46 P.M.   
FASTEST MILE FOR YESTERDAY...............14 WSW  AT  4:11 P.M. 
MAXIMUM 2-MINUTE ASOS AVERAGE............15 WSW  AT  4:11 P.M.     
MAXIMUM 2-MINUTE DAVIS AVERAGE...........15 W    AT  1:52 P.M.    
AVERAGE WIND SPEED AND DIRECTION.......10.4 WSW
                   ASOS................ 9.9
                   DAVIS...............10.2 W [260 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 MONTH..............2.29   DEPARTURE....+0.40
                         ASOS..............2.33
TOTAL PRECIPITATION FOR THE YEAR..........37.06   DEPARTURE....+1.84
                         ASOS.............38.25
 
PRELIMINARY CLIMATE SUMMARY FOR SEPTEMBER 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
 
9/1  71/51/61/-6/0/773/98     17 NW
9/2  76/54/65/-1/0/786/100    22 S
9/3  77/56/67/+1/0/587/75     19 SW
9/4  77/60/69/+3/0/764/98     18 NE
9/5  81/59/70/+5/0/591/76     25 NNW
9/6  64/53/59/-6/0/743/96     31 NNE
9/7  70/52/61/-4/0/709/92     20 WSW
9/8  75/56/66/+1/0/369/48     18 WSW  
9/9  68/55/62/-2/0/352/46     36 NNE  AERO 33 MPH NNE
9/10 65/53/59/-5/0/603/79     31 ENE
9/11 61/54/58/-6/.../000/00   30 NE
9/12 63/60/61/-1/.../000/00   30 NNE
9/13 76/58/67/+4/.../.../..   28 NW 
9/14 74/55/65/+2/0/.../..     22 WSW
 
9/15 our morning low temp: 56F; the normal low is now 54F
 
NEW DAILY RECORDS FOR SEPTEMBER 2009 TO DATE...
None.
 
DAILY EXTREMES
Temperature and precipitation records back to 1885, and
wind records back to 1940 (e = estimated):
 
RECORDS FOR SEPTEMBER 15
HIGH 89F IN 1931
LOW 35F IN 1913
PRECIP 3.93 INCHES IN 1904 (Extra-tropical storm
making landfall in New England on 9/15/1904 passing
east of BHO and bringing a storm total of 4.11 inches
9/14-15/1904)
PEAK GUST 65e MPH NW, WSW IN 1944
(In the wake of Great Atlantic Hurricane)
 
RECORDS FOR SEPTEMBER 16
HIGH 91F IN 1939,1941
LOW 39F IN 1984
PRECIP 5.12 INCHES IN 1933 (Hurricane)
PEAK GUST 59 MPH SSE IN 1999
 
TODAY'S REPORT PREPARED BY: Robert Skilling