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

DAILY DISCUSSION AND CLIMATE SUMMARY
THURSDAY, APRIL 9, 2009
ALL TIMES ARE IN EASTERN STANDARD TIME  

Today's Observations:

7 A.M.
Weather: Scattered cirrus, altocumulus lenticularis north
Temperature: 42F, Dew point: 34F, Wind: S at 11 kts 
Sea-level pressure: 29.81 inches Hg, rising
Visibility: 15 miles, thin fog
6-hour minimum temperature: 34F 
24-hour precipitation: 0.0 ins.
BHO SA 1155 250 SCT 15 096/42/34/1711/981/ 
ACSL N K LYR S-SW THN F/ 8/041 53013 10042 20034

10 A.M. 
Weather: Scattered cirrus, few cumulus E-SW and W-NW
Temperature: 53F, Dew point: 20F, Wind: SW at 16G22 kts,
Wind: Peak wind gust from SSW at 26 kts at 9:26 A.M.,
Wind: Directional variability from SSE to WNW
Sea-level pressure: 29.81 inches Hg, falling
Visibility: 50 miles 
BHO SA 1455 250 SCT 50 094/53/20/2316G22/981/ 
FEW CU E-SW AND W-NW PK WND 2426/13 WND 16V29/ 
8/101 50002

1 P.M.  
Weather: Broken altocumulus, cirrus
Temperature: 58F, Dew point: 19F, Wind: SW at 16G22 kts,
Wind: Direction variable SSE to W      
Sea-level pressure: 29.76 inches Hg, falling
Visibility: 70 miles  
6-hourly max. temp. 58F  
BHO SA 1755 E90 BKN 70 079/58/19/2316G22/976/ 
WND 16V26/ 8/031 56015 10058 20042

WEATHER SUMMARY FOR WEDNESDAY APRIL 8, 2009
  
TEMPERATURE (DEGREES F)
MAX.....45    NORMAL.....53
MIN.....32    NORMAL.....35
MEAN....39    NORMAL.....44

DEPARTURE FROM 30-YEAR NORMAL................. -5
TOTAL DEPARTURE FOR THE MONTH.................+17  [+1.9 DEGREE/DAY]

HEATING DEGREE DAYS 
TOTAL HEATING UNITS FOR YESTERDAY.............26  DEPARTURE.........+5
TOTAL HEATING UNITS FOR THE MONTH............163  DEPARTURE........-17
TOTAL HEATING UNITS FOR THE SEASON..........5581  DEPARTURE........-63
TOTAL HEATING UNITS LAST SEASON TO DATE.....5326  DIFFERENCE......+255

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY............33 SW  AT 12:31 P.M. 
                   AEROVANE.............31 SW  AT 12:31 P.M. 
                   ASOS.................32 SW  AT 12:31 P.M. 
                   DAVIS................33 SW  AT 12:30 P.M.   
FASTEST MILE FOR YESTERDAY..............25 SSW AT 12:38 P.M.   
MAXIMUM 2-MINUTE ASOS AVERAGE...........24 SW  AT 12:39 P.M.    
MAXIMUM 2-MINUTE DAVIS AVERAGE..........26 SSW AT 12:39 P.M. 
                   AVERAGE............13.2 SW	
                   ASOS...............12.1
                   DAVIS..............12.4 SW  [231 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.........+1.08
                         ASOS...............2.36
TOTAL PRECIPITATION FOR THE YEAR...........12.36 DEPARTURE.........-2.47
                         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.........-0.9
TOTAL SNOWFALL FOR THE SEASON..............78.7   DEPARTURE........+20.9

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  morning low temp. 34F; 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 9
HIGH 83 IN 1991
LOW 18 IN 1888
PRECIP 2.38 IN. IN 1935
SNOWFALL 11.0 IN. IN 1917
PEAK GUST 72 MPH WNW IN 1962

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

TODAY'S REPORT PREPARED BY: Stephanie Radner