BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS 02186
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
 
DAILY DISCUSSION AND CLIMATE SUMMARY
MONDAY, APRIL 30, 2007   
ALL TIMES ARE IN EASTERN STANDARD TIME
 
A TOTAL OF TEN DAYS WITHOUT ANY SUNSHINE THIS MONTH
LIGHT SHOWERS LEAVE ONLY A FEW HUNDREDTHS OF AN INCH
APRIL WINDS UP MUCH CLOUDIER, WETTER AND COOLER THAN NORMAL
 
Yesterday became the tenth day during this April to have 
no sunshine and so the month with around 40% of the 
possible sunshine will run ten points below average.
 
Light showers this morning brought only a few hundredths 
of an inch of rainfall but the final day of the month was
the 16th day with measurable rainfall.  Our monthly total 
of close to 8.7 inches or double the monthly average.  
 
Two-thirds of the days during this month of April were 
cooler than normal leaving the month almost 2.5 degrees 
cooler than average.
 
Today's observations:
 
7 A.M.   
Weather: Obscured with fog
Temperature: 46F, Dew point: 46F, Wind: S at 12 kts   
Sea-level pressure: 29.68 inches Hg, falling 
Visibility: 1/8 of a mile 
6-hour min. 42F   
24-hour rainfall: trace   
BHO SA 1155 W3 X 1/8F 077/46/46/1812/976/ 8//// 
58012 10046 20042
 
10 A.M.
Weather: Overcast with light rain showers 
Temperature: 49F, Dew point: 47F, Wind: S at 13 kts 
Sea-level pressure: 29.68 inches Hg, falling 
Visibility: 20 miles, 15 NE-SE, 8 SW 
3-hourly rainfall: 0.04 in.  
BHO SA 1455 E55 OVC 20RW- 052/49/47/1713/968/ 
FEW SC VSBY NE-SE 15 SW 8 / 8/52/ 56025 
MANUAL 6004/ ASOS 60003
 
1 P.M.
Weather: Scattered cumulus/moderate cumulus, scattered dense cirrus 
Temperature: 67F, Dew point: 46F, Wind: W at 22G32 kts 
Peak wind: W @ 32 kts at 54 past hour 
Sea-level pressure: 29.59 inches Hg, falling 
Visibility: 60 miles 
6-hourly rainfall: 0.06 in.  
6-hourly max. temp. 67 deg. 
BHO SA 1755 40 SCT 200 SCT 60 019/67/46/2622G32/959/ 
MDT CU DENSE CI LYR DSNT SE MOVG SE PK WND 2632/54/ 
8/202 56033 MANUAL 6006/ ASOS 60005 10067 20046 
 
WEATHER SUMMARY FOR SUNDAY, APRIL 29
 
TEMPERATURE (DEGREES F)
MAX.....49    NORMAL.....61 
MIN.....42    NORMAL.....41
MEAN....46    NORMAL.....51
DEPARTURE FROM 30-YEAR NORMAL...........-5
TOTAL DEPARTURE FOR THE MONTH..........-63 (-2.4 DEGREES/DAY) 
 
HEATING DEGREE DAYS
TOTAL HEATING UNITS FOR YESTERDAY..........19   DEPARTURE.........+5
TOTAL HEATING UNITS FOR THE MONTH.........6123  DEPARTURE........+64 
TOTAL HEATING UNITS FOR THE SEASON........5606  DEPARTURE.......-420
TOTAL HEATING UNITS LAST SEASON TO DATE...5404  DIFFERENCE......+202
 
PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY............17  NNE AT 1:37 P.M.
                   AEROVANE.............14  NE  AT 1:24 P.M. 
                   ASOS.................15  NE  AT 4:40 P.M.
                   DAVIS................14  NE  AT 12:03 P.M. 
FASTEST MILE FOR YESTERDAY..............10  NE  AT 3:50 P.M.  
MAXIMUM 2-MINUTE ASOS AVERAGE...........13  NE  AT 3:53 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE..........11  NNE AT 1:39 P.M. 
AVERAGE WIND SPEED AND DIRECTION........5.6 NNE   
                    ASOS................6.7    
                    DAVIS...............5.5 N [010 degrees] 
 
PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....trace  DEPARTURE....-0.13
                         ASOS..............0.00
TOTAL PRECIPITATION FOR THE MONTH..........8.62   DEPARTURE.....+4.43  
                         ASOS..............8.28    
TOTAL PRECIPITATION FOR THE YEAR..........20.36   DEPARTURE.....+2.54
                         ASOS.............19.92   
 
SNOWFALL (INCHES) THROUGH THIS MORNING (EST)
TOTAL SNOWFALL 24 HRS ENDING 7 A.M..........0.0  DEPARTURE......-0.1
TOTAL SNOWFALL FOR THE MONTH................0.2  DEPARTURE......-2.8 
TOTAL SNOWFALL FOR THE SEASON..............27.6  DEPARTURE.....-32.3  
    
PRELIMINARY CLIMATE SUMMARY FOR APRIL 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
 
4/1  59/33/46/+5/0.42/0/511/67       30 S
4/2  39/35/37/-5/0.33/0/000/00       27 E
4/3  41/32/37/-5/0.04/0/000/00       28 ENE
4/4  36/32/34/-8/0.90/0.2/000/00     38 E
4/5  43/26/35/-8/0.21/T/163/21       36 WSW
4/6  39/23/31/-12/0/0/590/76         36 WSW
4/7  40/26/33/-10/0/0/405/52         35 W
4/8  40/25/33/-11/0/0/619/79         44 W      Aero 42 MPH W
4/9  50/30/40/-4/0/0/746/95          36 W
4/10 43/30/37/-7/0/0/158/20          28 W 
4/11 51/28/40/-5/0/0/712/90          22 SSE
4/12 39/32/36/-9/0.89/T/000/00       42 E      Aero 40 MPH E
4/13 47/31/39/-6/0/0/096/12          41 W      Aero 42 MPH W
4/14 52/35/44/-2/0/0/392/49          37 W
4/15 44/35/40/-6/1.75/T/000/00       66 E      Aero 64 MPH E  
4/16 50/40/45/-1/1.56/0/000/00       73 E      Aero 73 MPH E 
4/17 40/35/38/-9/0.69/T/000/00       54 NNE    Aero 53 MPH NNE
4/18 39/36/38/-9/0.37/0/000/00       43 N
4/19 49/36/43/-4/0.02/T/285/35       38 NE     Aero 35 MPH NE 
4/20 57/36/47/-1/0/0/815/100         31 N
4/21 74/45/60/+12/0/0/753/92         24 NW
4/22 75/50/63/+14/0/0/779/95         31 SSE     
4/23 85/49/67/+18/0/0/675/82         42 S      Davis 45 MPH S 
4/24 73/50/62/+13/0/0/586/71         39 W      Aero  41 MPH W
4/25 58/43/51/+1/0.23/0/083/10       27 WNW 
4/26 62/39/51/+1/0/0/656/79          30 SSE    Aero  28 SSE
4/27 48/42/45/-5/1.09/0/000/00       25 E
4/28 68/43/56/+5/0.10/0/293/35       17 S   
4/29 49/42/46/-5/0.02/0/000/00       17 NNE
 
4/30 morning low temp. 42 deg; normal now 42 deg.
 

NEW DAILY RECORDS FOR APRIL SO FAR....
 
4/15 - NEW RECORD HIGH PEAK WIND GUST FOR THIS DATE OF 66 MPH E; the previous
record was 59 mph estimated from the S in 1946 and measured from the S in 1980.
NEW RECORD DAILY RAINFALL OF 1.75 INS.; previous record 1.29 ins. in 1990.
 
4/16 - NEW RECORD HIGH PEAK WIND GUST OF 73 MPH E; the previous record for this
date was 63 mph SSE in 1996.       
 
4/23 - EQUALED RECORD HIGH MAXIMUM TEMPERATURE OF 85 DEGREES set in 1908.
 
DAILY EXTREMES
Temperature and precipitation records back to 1885, and
wind records back to 1940 (e = estimated):
 
RECORDS FOR APRIL 30
HIGH 86 IN 1942
LOW 30 IN 1931
PRECIP 1.41 INCHES IN 1991
SNOWFALL 0.3 INCHES IN 1909
PEAK GUST 64e MPH NW IN 1978
 
RECORDS FOR MAY 1
HIGH 87F IN 1899
LOW 29F IN 1978
PRECIP 2.53 INCHES IN 1921
SNOWFALL TRACE IN 1905,1917,1921,1995.
PEAK GUST 57 MPH NW IN 1974
 
TODAY'S REPORT PREPARED By: Robert Skilling