BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS 02186
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
 
DAILY DISCUSSION AND CLIMATE SUMMARY
MONDAY, APRIL 13, 2009
ALL TIMES ARE IN EASTERN STANDARD TIME 
 
Today's Observations:
 
BLUSTERY COLD EASTER FOLLOWS 0.2 SNOWFALL AT SUMMIT
TEMPERATURES CLOSE TO 10 DEGREES BELOW AVERAGE
CLOSE TO ONE INCH OF PRECIPITATION FRIDAY-SATURDAY
 
The high temperature struggled up to 43F yesterday
afternoon with partial sunshine and very gusty
west winds.  Peak wind gusts reached past 40 MPH
with the maximum speed of 45 MPH WNW at 6:36 P.M.
EDT. The temperature fell to 29F by midnight and
averaged 9 degrees below normal or 36F for the day.
On Saturday, a period of moderate rain began around
noon and began mixing with snow by mid-afternoon
before changing to all snow for a time as the
temperature dropped to 33F.  We measured 0.2 inch of
snowfall before precipitation changed back to rain
again later during the afternoon. The total precipitation
for two events, the first of which began late Saturday, 
was 0.95 inch. Saturday's snow was the first since early 
March and was only measurable right here at the summit 
of Great Blue Hill. 
 
Today's weather observations: 
 
7 A.M.
Weather: Clear (not a cloud visible)
Temperature: 33F, Dew point: 15F, Wind: W at 12G22 kts,
Wind: Peak gust of 26 kts W at 6:35 a.m.,
Wind: Direction variability WSW-NW
Sea-level pressure: 30.04 inches Hg, rising
Visibility: 70 miles 
6-hour minimum temperature: 29F
BHO SA 1155 CLR 70 171/33/15/2712G22/004/ PK WND 2726/35/ 
WND 25V31 53008 10033 20029 
           
10 A.M.
Weather: Clear, few stratocumulus forming distant NW 
Temperature: 43F, Dew point: 16F, Wind: W at 13G28 kts,
Wind: Peak gust of 32 kts W @ 9:43 a.m.,
Wind: Direction variability WSW-NNW 
Sea-level pressure: 30.02 inches Hg, falling
Visibility: 75 miles 
BHO SA 1455 CLR 75 165/43/16/2813G28/002/
FEW SC FRMG DSNT NW PK WND 2832/43/ WND 24V34
8/500 56006
 
1 P.M. 
Weather: Clear, cirrus distant south-southwest 
Temperature: 49F, Dew point: 16F, Wind: WNW at 17G28 kts,
Wind: Peak gust of 29 kts W @ 12:28 p.m.
Wind: Direction variability WSW-NNW 
Sea-level pressure: 29.97 inches Hg, falling
Visibility: 80 miles 
BHO SA 1755 CLR 80 150/49/16/2917G28/997/
FEW CI DSNT S-SW PK WND 2829/28/ WND 24V33/
8/001 56015 10050 10033 
 
WEATHER SUMMARY FOR EASTER SUNDAY, APRIL 12, 2009
 
TEMPERATURE (DEGREES F)
MAX.....43    NORMAL......54
MIN.....29    NORMAL......36
MEAN....36    NORMAL......45
 
DEPARTURE FROM 30-YEAR NORMAL..................-9
TOTAL DEPARTURE FOR THE MONTH.................+14  [+1.9 DEGREE/DAY]
 
HEATING DEGREE DAYS
TOTAL HEATING UNITS FOR YESTERDAY.............29  DEPARTURE........+9
TOTAL HEATING UNITS FOR THE MONTH............248  DEPARTURE.......-14
TOTAL HEATING UNITS FOR THE SEASON..........5666  DEPARTURE.......-60
TOTAL HEATING UNITS LAST SEASON TO DATE.....5378  DIFFERENCE.....+288
 
PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY............45 NW  AT  5:36 P.M.  
                   AEROVANE.............43 WNW AT  5:11 P.M.  
                   ASOS.................44 NW  AT  5:36 P.M.  
                   DAVIS................46 WNW AT  5:35 P.M.    
FASTEST MILE FOR YESTERDAY..............32 WNW AT  5:14 P.M. *   
MAXIMUM 2-MINUTE ASOS AVERAGE...........31 WNW AT  5:16 P.M.    
MAXIMUM 2-MINUTE DAVIS AVERAGE..........34 WNW AT  5:15 P.M.  
                   AVERAGE............20.0 WNW
                   ASOS...............18.4
                   DAVIS..............20.4 WNW [300 deg]
* last of several occurrences...
 
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...........3.23 DEPARTURE.........+1.43
                         ASOS...............3.28
TOTAL PRECIPITATION FOR THE YEAR...........13.31 DEPARTURE.........-2.12
                         ASOS..............14.41 #
# 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................0.2   DEPARTURE.........-1.1
TOTAL SNOWFALL FOR THE SEASON..............78.9   DEPARTURE........+20.7
 
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 65/41/53/+9/../../.../..        37 SSW   AERO 35 MPH SSW 
4/11 44/33/39/-6/../../..            35 N     AERO 30 N
4/12 43/29/36/-9/0/0/.../..          45 NW    AERO 43 WNW
 
4/13  our morning low temp: 29F; the normal low is now 36F
 
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 13
HIGH 85 IN 1945
LOW 22 IN 1939
PRECIP 2.51 IN. IN 2004
SNOWFALL 6.8 IN. IN 1933
PEAK GUST 59 MPH SSW IN 1995
 
RECORDS FOR APRIL 14
HIGH 80 IN 1945
LOW 21 IN 1923
PRECIP 2.22 IN. IN 1895
SNOWFALL 8.4 IN. IN 1953
PEAK GUST 71e MPH W IN 1943
 
TODAY'S REPORT PREPARED BY: Robert Skilling