BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS 02186
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
 
DAILY DISCUSSION AND CLIMATE SUMMARY
THURSDAY, MAY 7, 2009 
ALL TIMES ARE IN EASTERN STANDARD TIME
 
LOW STRATUS CLOUDS PERSIST AFTER THE EARLY
MORNING RAINFALL OF A LITTLE OVER A HALF INCH
 
Through early afternoon there have been only a
few brief glimpses of the sun but no rain since
early this morning when we measured 0.56 inch
of rainfall.
 
Today's observations:
 
7 A.M.   
Weather: Sky obscured with fog, light rain showers
Temperature: 54F, Dew point: 54F, Wind: SSE at 12 kts 
Sea-level pressure: 29.82 inches Hg, falling
Visibility: 1/16 mile
6-hour minimum temp: 49F
24-hour precipitation: 0.56 ins.
BHO SA 1155 W1 X 1/16R-F 097/54/54/1512/982/
8//// 58021 MANUAL 60XX/ ASOS 60055
MANUAL 70056 ASOS 70056 10054 20049
 
10 A.M.  
Weather: Overcast stratus, few lower stratus
drifting over and below summit
Temperature: 61F, Dew point: 61F, Wind: S at 12 kts
Sea-level pressure: 29.79 inches Hg, falling
Visibility: 2 miles, variable 1-3 miles
6-hourly precipitation: trace
BHO SA 1455 E5 OVC 2VF 089/61/61/1912/979/
FEW LWR STRA DRFTG OVR/BLO SMT VSBY 1V3/
8/6// 56008 MANUAL 6000/
 
1 P.M.  
Weather: Low overcast stratus
Temperature: 65F, Dew point: 60F, Wind: S at 12 kts,
Wind: gust to 25 kts past hour
Sea-level pressure: 29.77 inches Hg, falling
Visibility: 20 miles, hazy 
6-hour maximum temp: 66F  
6-hour precip: trace 
BHO SA 1755 E18 OVC 20 081/65/60/1912/977/
HAZY GST TO 25 KTS PST HR/  8/6//
58008 MANUAL 600/ 10066 20054
 
WEATHER SUMMARY FOR WEDNESDAY, MAY 6
 
TEMPERATURE (DEGREES F)
MAX.....63    NORMAL.....64
MIN.....43    NORMAL.....44
MEAN....53    NORMAL.....54
 
DEPARTURE FROM 30-YEAR NORMAL...........-1
TOTAL DEPARTURE FOR THE MONTH..........+15 [+2.3 DEGREES/DAY]
 
HEATING DEGREE DAYS
TOTAL HEATING UNITS FOR YESTERDAY............12  DEPARTURE........0
TOTAL HEATING UNITS FOR THE MONTH............58  DEPARTURE......-17
TOTAL HEATING UNITS FOR THE SEASON.........5954  DEPARTURE.....-147
TOTAL HEATING UNITS LAST SEASON TO DATE....5705  DIFFERENCE....+249
 
PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY............24 SSE AT  9:13 P.M.  
                   AEROVANE.............22 S   AT  7:16 P.M.   
                   ASOS.................23 S   AT  9:13 P.M.   
                   DAVIS................21 S   AT  7:16 P.M. 
FASTEST MILE FOR YESTERDAY..............17 S   AT 10:00 P.M. *
MAXIMUM 2-MINUTE ASOS AVERAGE...........18 S   AT  9:14 P.M.    
MAXIMUM 2-MINUTE DAVIS AVERAGE..........17 S   AT  9:14 P.M. 
AVERAGE WIND SPEED AND DIRECTION.......7.6 SSE
                   ASOS................7.4  
                   DAVIS...............7.3 ESE [103 DEG]
* last of several occurrences
 
PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.56  DEPARTURE....+0.44
                         ASOS..............0.56
TOTAL PRECIPITATION FOR THE MONTH..........1.97  DEPARTURE....+1.20
                         ASOS..............1.96 
TOTAL PRECIPITATION FOR THE YEAR..........16.58  DEPARTURE....-2.14
                         ASOS.............17.64  
 
SNOWFALL (INCHES) THROUGH THIS MORNING (EST)
TOTAL SNOWFALL 24 HRS ENDING 7 A.M..........0.0  DEPARTURE..... 0.0
TOTAL SNOWFALL FOR THE MONTH................0.0  DEPARTURE.....-0.1
TOTAL SNOWFALL FOR THE SEASON..............78.9  DEPARTURE.....18.8 
 
PRELIMINARY CLIMATE SUMMARY FOR MAY 2009 CALENDAR DAY DATA
DATA REPORTED:
DATE: MAX/MIN/MEAN/DEP/PRECIP/SUN(MIN.)/SUN(%)/ PEAK GUST/AERO GUST
AERO: Aerovane recording wind system gust when significant
TSTM: Thunderstorm day (thunder heard some time during day)
....: Data not yet available, records not finalized
 
5/1 64/53/59/+7/T/.../..          37 SSW   AERO 37 MPH SSW
5/2 68/52/60/+8/0.05/.../..       32 WNW
5/3 64/48/56/+3/T/.../..          25 S
5/4 64/48/56/+3/0.01/009/01       17 SSW
5/5 52/44/48/-5/.../000/00        43 NNE   AERO 40 MPH NNE
5/6 63/43/53/-1/.../.../..        24 SSE
 
5/7 morning low temp: 49F; our normal low is now 44F
 
NEW DAILY RECORDS FOR MAY 2009...
NONE
 
DAILY EXTREMES
 
Temperature and precipitation records back to 1885, and
wind records back to 1940 (e = estimated):
 
RECORDS FOR MAY 7
HIGH 93F IN 1930
LOW 33F IN 1970
PRECIP 1.19 INCHES IN 2005
SNOWFALL TRACE IN 1967
PEAK GUST 66e MPH WNW IN 1940
 
RECORDS FOR MAY 8
HIGH 89F IN 2000
LOW 29F IN 1956
PRECIP 1.48 INCHES IN 1886
SNOWFALL TRACE IN 1898, 1947
PEAK GUST 68e MPH NNW IN 1943
 
TODAY'S REPORT PREPARED BY: Stephanie Radner/Robert Skilling