BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS 02186
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA

DAILY DISCUSSION AND CLIMATE SUMMARY
FRIDAY, APRIL 10, 2009
ALL TIMES ARE IN EASTERN STANDARD TIME  

Today's Observations:

7 A.M.
Weather: Clear, few altocumulus all quadrants except S-W
Temperature: 46F, Dew point: 25F, Wind: W at 9 kts 
Sea-level pressure: 30.05 inches Hg, rising
Visibility: 35 miles, light haze
6-hour minimum temperature: 41F 
BHO SA 1155 CLR 40 175/46/25/2609/005/ 
FEW AC ALQDS XCPT S-W LGT HZ/ 8/050 53021 10046 20041

10 A.M. 
Weather: Scattered altocumulus, thin broken cirrus, 
patches dense cirrus W-NW
Temperature: 57F, Dew point: 24F, Wind: WSW at 7 kts,
Wind: Directional variability from S to NNW
Sea-level pressure: 30.06 inches Hg, rising
Visibility: 40 miles, light haze
BHO SA 1455 110 SCT 250 -BKN 40 180/57/24/2407/006/ 
PTCHS DENS CI W-NW LGT HZ WND 19V33/ 8/032 51005

1 P.M.  
Weather: Broken altocumulus, broken cirrus, 
patches dense cirrus all quadrants 
Temperature: 64F, Dew point: 24F, Wind: WSW at 14G23 kts,
Wind: Direction variability from S to WNW
Sea-level pressure: 30.03 inches Hg, falling
Visibility: 40 miles, light haze
6-hourly max. temp. 64F
BHO SA 1755 E90 BKN 250 BKN 40 168/64/24/2414G23/003/ 
PTCHS DENS CI ALQDS LGT HZ WND 18V29/ 
8/032 56012 10064 20046

WEATHER SUMMARY FOR THURSDAY APRIL 9, 2009
  
TEMPERATURE (DEGREES F)
MAX.....60    NORMAL.....53
MIN.....34    NORMAL.....35
MEAN....47    NORMAL.....44

DEPARTURE FROM 30-YEAR NORMAL..................+3
TOTAL DEPARTURE FOR THE MONTH.................+20  [+2.0 DEGREE/DAY]

HEATING DEGREE DAYS 
TOTAL HEATING UNITS FOR YESTERDAY.............18  DEPARTURE.........-3
TOTAL HEATING UNITS FOR THE MONTH............181  DEPARTURE........-20
TOTAL HEATING UNITS FOR THE SEASON..........5599  DEPARTURE........-66
TOTAL HEATING UNITS LAST SEASON TO DATE.....5345  DIFFERENCE......+254

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY............36 SSW AT  1:20 P.M. 
                   AEROVANE.............33 SSW AT  1:20 P.M. 
                   ASOS.................35 SW  AT  1:20 P.M. 
                   DAVIS................35 SSW AT  1:19 P.M.   
FASTEST MILE FOR YESTERDAY..............23 SSW AT  1:21 P.M.   
MAXIMUM 2-MINUTE ASOS AVERAGE...........23 SW  AT  1:21 P.M.    
MAXIMUM 2-MINUTE DAVIS AVERAGE..........25 SSW AT  1:21 P.M. 
                   AVERAGE............13.8 SW
                   ASOS...............12.7
                   DAVIS..............12.9 SSW  [213 deg] 
 
PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M.....0.00 DEPARTURE.........-0.15
                         ASOS...............0.00
TOTAL PRECIPITATION FOR THE MONTH...........2.28 DEPARTURE.........+0.93
                         ASOS...............2.36
TOTAL PRECIPITATION FOR THE YEAR...........12.36 DEPARTURE.........-2.62
                         ASOS..............13.49 # 
# Includes erroneous ASOS precipitation data on 1/1/09, 1/2/09 and 2/27/09.

SNOWFALL (INCHES) THROUGH THIS MORNING (EST)
TOTAL SNOWFALL 24 HRS ENDING 7 A.M..........0.0   DEPARTURE.........-0.1
TOTAL SNOWFALL FOR THE MONTH................0.0   DEPARTURE.........-1.0
TOTAL SNOWFALL FOR THE SEASON..............78.7   DEPARTURE........+20.8 *
* Yesterday's climate report had an error in the Seasonal Snowfall 
  Departure which has been corrected in today's report and in the 
  climate archive on the website.

PRELIMINARY CLIMATE SUMMARY FOR APRIL 2009 CALENDAR DAY DATA
DATA REPORTED:
DATE: MAX/MIN/MEAN/DEP/PRECIP/SNOW/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

4/1  43/31/38/-3/0.13/0/015/02       24 SE     
4/2  52/39/46/+4/0.02/0/000/00       20 SSE        
4/3  58/45/52/+10/0.70//000/00       39 SSE   AERO 38 MPH SSE TSTM
4/4  51/38/45/+3/0.01/0/.../..       48 WSW   AERO 48 MPH WSW  
4/5  58/37/48/+5/0/0/551/71          40 W     AERO 37 MPH W 
4/6  55/38/47/+4/1.42/0/047/006      42 SE    AER0 40 MPH SE  TSTM  
4/7  50/34/42/-1/T/0/.../..          36 WSW   AERO 35 MPH WSW 
4/8  45/32/39/-5/0/0/.../..          33 SW    AERO 31 MPH SW
4/9  60/34/47/+3/0/0/.../..          36 SSW   AERO 33 MPH SSW

4/10  morning low temp. 41F; our normal low is now 35F

NEW DAILY RECORDS FOR APRIL 2009...
None to date..

DAILY EXTREMES
Temperature and precipitation records back to 1885, and
wind records back to 1940 (e = estimated):

RECORDS FOR APRIL 10
HIGH 83 IN 1922
LOW 20 IN 1985
PRECIP 2.40 IN. IN 1935
SNOWFALL 10.1 IN. IN 1996
PEAK GUST 66 MPH WNW IN 1967

RECORDS FOR APRIL 11
HIGH 78 IN 1945
LOW 19 IN 1909
PRECIP 1.72 IN. IN 2003
SNOWFALL 9.5 IN. IN 1958
PEAK GUST 65 MPH NW IN 1963

TODAY'S REPORT PREPARED BY: Stephanie Radner