BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS 02186
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
  
DAILY DISCUSSION AND CLIMATE SUMMARY
WEDNESDAY, SEPTEMBER 9, 2009  
ALL TIMES ARE IN EASTERN STANDARD TIME
 
INCREASING NNE WINDS GUSTING 30-36 MPH 
UNUSUALLY CALM 8 DAYS AVERAGED JUST 7.3 MPH
SUNSHINE THROUGH HIGH CLOUDS AGAIN TODAY  
 
After an unusually calm first eight days of 
September during which the average wind speed 
was only 7.3 MPH, a back door frontal passage 
very early this morning brought increasing
NNE winds.  Wind gusts peaked near 30 MPH 
during this morning but reached 36 MPH NNE 
just before 2 p.m. EDT. 
Today was a second day of dense high cloudiness 
but, like yesterday, the cloudiness thinned out 
allowing bright sunshine by early afternoon. 
We've record 85% of the possible bright sunshine
through the first eight days of the month. 
 
Today's observations:
 
7 A.M.   
Weather: Scattered altocumulus, broken altostratus, 
few stratocumulus, dense cirrus, sun dimly visible 
Temperature: 61F, Dew point: 51F, Wind: N at 11G22 kts,
Wind: Peak gust 28 kts from NNE at 6:06 a.m.,
Wind: direction variable NNW to NE  
Sea-level pressure: 30.17 inches Hg, rising 
Visibility: 45 miles  
6-hour minimum temp: 60F
BHO SA 1155 80 SCT E130 BKN 200 OVC 45 215/61/51/0113G22/017/ 
FEW SC FEW AC DENS CI SUN DMLY VSB PK WND 0228/06/ 
WND 34V05/ 8/577 53027 10063 20060 
 
10 A.M. 
Weather: High dense cirrus overcast with few small breaks 
and thin spots in the overcast  
Temperature: 64F, Dew point: 50F, Wind: N at 11G19 kts,
Wind: direction variable NNW to ENE 
Sea-level pressure: 30.20 inches Hg, rising 
Visibility: 25 miles, hazy  
BHO SA 1455 E220 OVC 25 226/65/52/0111G19/020/ 
FEW SC/AC SML DENS CI SML BINOVC OVC PTLY THN 
HAZY/ WND 33V06/ 8/542 51011 
  
1 P.M. 
Weather: Scattered dense cirrus, thin broken cirrus,
few stratocumulus lenticularis forming vicinity of station   
Temperature: 66F, Dew point: 49F, Wind: NNE at 18G31 kts,
Wind: Peak gust 31 kts NNE @ 12:55 p.m., 
Wind: direction variable NNW to ENE    
Sea-level pressure: 30.23 inches Hg, falling
Visibility: 50 miles   
6-hour max. temp: 67F
BHO SA 1756 220 SCT 250 –BKN 300 –BKN 50 236/66/49/0218G31/023/ 
FEW SCSL FRMG OVHD VCTY STN SC DSNT ESE-S FEW SML CU DSNT SW-N 
PTCHS DENS CI AND CC PK WND 0231/55/ WND 34V07/ 
8/802 50010 10067 20061 
 
WEATHER SUMMARY FOR TUESDAY, SEPTEMBER 8
 
TEMPERATURE (DEGREES F)
MAX.....75    NORMAL.....74
MIN.....56    NORMAL.....56 
MEAN....66    NORMAL.....65
 
DEPARTURE FROM 30-YEAR AVERAGE...........+1
TOTAL DEPARTURE FOR THE MONTH............-7 [-1.1 DEGREES/DAY] 
 
PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY.............18 WSW AT 12:22 A.M.   
                   AEROVANE..............17 WSW AT 12:22 A.M.   
                   ASOS..................16 WSW AT 12:22 A.M.   
                   DAVIS................ 15 WSW AT 12-1  A.M.   
FASTEST MILE FOR YESTERDAY...............13 WSW AT 12:18 A.M.   
MAXIMUM 2-MINUTE ASOS AVERAGE............14 WSW AT 12-1  A.M. 
MAXIMUM 2-MINUTE DAVIS AVERAGE...........13 WSW AT 12-1  A.M.   
AVERAGE WIND SPEED AND DIRECTION....... 5.0 ENE 
                   ASOS.................4.9  
                   DAVIS................5.5 NNW [325 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..............0.00   DEPARTURE....-1.05
                         ASOS..............0.00
TOTAL PRECIPITATION FOR THE YEAR..........34.77   DEPARTURE....+0.25
                         ASOS.............35.92 
 
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  our morning low temp: 60F; the normal low is now 55F
 
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 9
HIGH 91F IN 2002
LOW 41F IN 1938
PRECIP 1.97 INCHES IN 1969
PEAK GUST 52 MPH WNW IN 1969, NW IN 1978
 
RECORDS FOR SEPTEMBER 10
HIGH 90F IN 1931,1989
LOW 41F IN 1956
PRECIP 5.60 INCHES IN 1999 (DAILY RECORD FOR SEPTEMBER)
PEAK GUST 48 MPH NW IN 1972
 
TODAY'S REPORT PREPARED BY: Robert Skilling