BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS 02186
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
 
DAILY DISCUSSION AND CLIMATE SUMMARY
MONDAY, MAY 7, 2007   
ALL TIMES ARE IN EASTERN STANDARD TIME
 
LIKELY THE LAST FROST OF THE SEASON THIS MORNING
IN MUCH OF THE LOCAL AREA BUT 39 DEGRESS AT BLUE HILL
 
Occurring around this time during early May, the freezing 
temperatures in the local area early today were not far
from the average date for the last frost of the season. 
Low readings included 30 degrees at Norwood and Taunton,
29 at Plymouth, 28 at New Bedford and 25 degrees at the
usual cold spot at Martha's Vineyard Airport.
 
Here atop Blue Hill the last freeze of the season was way 
back on April 13th at 31 degrees, about a week earlier than
the average date for same. This morning's low of 39 degrees
was our coldest since 36 degrees on April 20th. 
 
Today's observations:
 
7 A.M.   
Weather:  High thin cirrus overcast, break distant SE-S
Temperature: 47F, Dew point: 32F, Wind: W 06 kts 
Sea-level pressure: 30.49 inches Hg, rising
Visibility: 60 miles, 70 miles NW 
6-hour min. 39F 
BHO SA 1155 300 –OVC 60 324/47/32/2806/049/ FEW LWR CI 
BINOVC DSNT SE-S THN K LYR ALG HRZ NNW-NE AND SSW 
INVSN PRSNT/ 8/001 53012 10047 20039 
 
10 A.M.
Weather: High thin cirrus overcast, breaks in overcast   
Temperature: 46F, Dew point: 32F, Wind: SSE at 07 kts
Wind: Direction variability ESE-SSW  
Sea-level pressure: 30.47 Hg, falling   
Visibility: 75 miles  
BHO SA 1455 300 –OVC 75 319/58/29/1507/047/ FEW LWR CI 
BINOVC WND 12V21/ 8/001 58005 
 
1 P.M. 
Weather: high thin cirrus overcast with breaks 
Temperature: 65F, Dew point: 25F, Wind: S at 07 kts
Wind: Direction variability ESE-SSW  
Sea-level pressure: 30.41 Hg, falling   
Visibility: 75 miles  
BHO SA 1755 300 –OVC 75 299/65/25/1707/041/ FEW LWR CI/ 
WND 11V21/ 8/001 57020 10065 20047
 
 
WEATHER SUMMARY FOR SUNDAY, MAY 6
 
TEMPERATURE (DEGREES F)
MAX.....51    NORMAL.....64 
MIN.....42    NORMAL.....44
MEAN....47    NORMAL.....54
DEPARTURE FROM 30-YEAR NORMAL...........-7
TOTAL DEPARTURE FOR THE MONTH..........+ 6 (+0.8 DEGREES/DAY)
 
HEATING DEGREE DAYS
TOTAL HEATING UNITS FOR YESTERDAY...........18  DEPARTURE.........+6
TOTAL HEATING UNITS FOR THE MONTH...........67  DEPARTURE.........-8 
TOTAL HEATING UNITS FOR THE SEASON........5683  DEPARTURE.......-418
TOTAL HEATING UNITS LAST SEASON TO DATE...5482  DIFFERENCE......+201
 
PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY............36  N  AT  3:32 A.M.  
                   AEROVANE.............33  N  AT  3:32 A.M.  
                   ASOS.................31 NE  AT 11:41 A.M.    
                   DAVIS................32 NNE AT  3:08 A.M.    
FASTEST MILE FOR YESTERDAY..............23  NNE AT 3:35 A.M.  
MAXIMUM 2-MINUTE ASOS AVERAGE...........23  NNE AT 3:35 A.M.   
MAXIMUM 2-MINUTE DAVIS AVERAGE..........24  NNE AT 3:35 A.M.   
AVERAGE WIND SPEED AND DIRECTION.......12.4 NNE
                    ASOS...............12.3       
                    DAVIS..............12.4 NE [040 degrees] 
 
PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.00   DEPARTURE....-0.12
                         ASOS..............0.00
TOTAL PRECIPITATION FOR THE MONTH..........0.06   DEPARTURE....-0.71 
                         ASOS..............0.04    
TOTAL PRECIPITATION FOR THE YEAR..........20.48   DEPARTURE....+1.76
                         ASOS.............20.01    
 
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..............27.6  DEPARTURE.....-32.5  
    
PRELIMINARY CLIMATE SUMMARY FOR MAY 2007......CALENDAR DAY DATA
DATA REPORTED:
DATE: MAX/MIN/MEAN/DEP/PRECIP/SNOWFALL/SUN(MIN.)/SUN(%)/ PEAK GUST/AERO GUST
 
AERO: Aerovane recording wind system when significant
TSTM: Thunderstorm day
....: Data not yet available
 
5/1  67/44/56/+4/0/0/624/74      33 NW 
5/2  64/45/55/+3/0.06/0/381/45   36 NW    Aero 33 MPH WNW
5/3  67/42/55/+2/0/0/849/100     38 W     Aero 37 MPH W
5/4  66/44/55/+2/0/0/.../..      39 WNW   Aero 40 MPH WNW 
5/5  65/45/55/+2/0/0/.../..      33 N  
5/6  51/42/47/-7/T/0/514/60      36 N     Aero 33 MPH N
 
5/7  morning low temp. 39 deg; normal now 44 deg.  
      
 
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 
previously 1.15 ins. in 1998 
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: Robert Skilling