BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS 02186
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
 
DAILY DISCUSSION AND CLIMATE SUMMARY
FRIDAY, MAY 4, 2007   
ALL TIMES ARE IN EASTERN STANDARD TIME
 
OBSERVATORY ANNUAL OPEN HOUSE TO BE HELD 
TOMORROW SATURDAY MAY 5, 2007
 
The annual Spring Open House at Blue Hill Observatory  
is scheduled to be held from 10 a.m. to 4 p.m. this 
Saturday, May 5, 2007, here at the summit.
 
 
Today's observations:
 
7 A.M.   
Weather: Clear
Temperature: 50F, Dew point: 25F, Wind: NW at 15G23 kts 
Sea-level pressure: 29.48 inches Hg, rising 
Visibility: 75 miles
6-hour min. 44F 
BHO SA 1155 CLR 75 223/50/25/3115G23/019/ FEW CI DSNT SE-SW/ 
8/001 50004 10050 20044
 
10 A.M.
Weather: Clear
Temperature: 59F, Dew point: 24F, Wind: WNW at 14G24 kts 
Wind: Direction variable WSW-NNW
Sea-level pressure: 30.17 Hg, falling  
Visibility: 75 miles  
BHO SA 1455 CLR 75 217/59/24/2914G24/017/ FEW CU W-N 
FEW CI DSNT S-NW WND 24V34/ 8/101 58006
  
1 P.M.
Weather: Clear, few clouds
Temperature: 64F, Dew point: 24F, Wind: NW at 15G27 kts 
Wind: Peak wind last hour 30 kts W at 12:37 P.M.
Wind: Direction variable WSW-NNE
Sea-level pressure: 30.12 inches Hg, falling 
Visibility: 80 miles 
6-hourly max. temp. 65 deg. 
BHO SA 1755 CLR 80 201/64/24/3115G27/012/ FEW CU ALQDS 
FEW CI DSNT S-W PK WND 2830/37 WND 24V03/ 8/101 58016 10065 20050
 
WEATHER SUMMARY FOR THURSDAY, MAY 3
 
TEMPERATURE (DEGREES F)
MAX.....67    NORMAL.....62 
MIN.....42    NORMAL.....43
MEAN....55    NORMAL.....53
DEPARTURE FROM 30-YEAR NORMAL...........+2
TOTAL DEPARTURE FOR THE MONTH.......... +9 (+2.8 DEGREES/DAY)
 
HEATING DEGREE DAYS
TOTAL HEATING UNITS FOR YESTERDAY...........10  DEPARTURE.........-3
TOTAL HEATING UNITS FOR THE MONTH...........29  DEPARTURE........-10 
TOTAL HEATING UNITS FOR THE SEASON........5645  DEPARTURE.......-420
TOTAL HEATING UNITS LAST SEASON TO DATE...5475  DIFFERENCE......+170
 
PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY............38  W   AT  4:37 P.M. 
                   AEROVANE.............37  W   AT  4:37 P.M. 
                   ASOS.................35  W   AT  4:37 P.M.  
                   DAVIS................37  W   AT  4:34 P.M.  
FASTEST MILE FOR YESTERDAY..............29  W   AT  4:38 P.M. *   
MAXIMUM 2-MINUTE ASOS AVERAGE...........28  W   AT  4:38 P.M. 
MAXIMUM 2-MINUTE DAVIS AVERAGE..........29  W   AT  4:39 P.M.  
AVERAGE WIND SPEED AND DIRECTION........14.2 WNW 
                    ASOS................13.8     
                    DAVIS...............14.5 WNW [292 degrees] 
* LAST OF SEVERAL OCCURRENCES..
 
PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.00   DEPARTURE....-0.13
                         ASOS..............0.00
TOTAL PRECIPITATION FOR THE MONTH..........0.06   DEPARTURE....-0.33 
                         ASOS..............0.04    
TOTAL PRECIPITATION FOR THE YEAR..........20.48   DEPARTURE....+2.14
                         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  morning low temp. 44 deg; normal now 43 deg. 
 
DAILY EXTREMES
Temperature and precipitation records back to 1885, and
wind records back to 1940 (e = estimated):
 
RECORDS FOR MAY 4
HIGH 90F IN 2001
LOW 27F IN 1911 (RECORD FOR MAY)
PRECIP 1.92 INCHES IN 1893
SNOWFALL 0.1 INCHES IN 1920
PEAK GUST 60 MPH NW IN 1966
 
RECORDS FOR MAY 5
HIGH 92F IN 1949
LOW 30F IN 1891
PRECIP 2.74 INCHES IN 1922
SNOWFALL 3.0 INCHES IN 1917
PEAK GUST 58 MPH S IN 1966 & 58e MPH SW IN 1976
TODAY'S REPORT PREPARED By: Stephanie Radner