BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS 02186
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
 
DAILY DISCUSSION AND CLIMATE SUMMARY
WEDNESDAY, APRIL 11, 2007   
ALL TIMES ARE IN EASTERN STANDARD TIME
 
VERY SUNNY, DRY AND COLDER THAN NORMAL AGAIN TODAY
POSSIBLE SIGNIFICANT SNOWFALL FOR TOMORROW
SOME LATE SEASON SNOWFALLS NOTED...
 
The sunshine is back today after a mostly cloudy 
day yesterday with a high temperature of only 43
degrees, well below the normal of 53 degrees. 
Today will be the 10th consecutive day to average
colder than normal with April 1st being the last 
warmer than normal day at plus 5 degrees.  The 
month averages almost 7 degrees colder than normal
through the first ten days. 
 
The record snowfall for tomorrow, April 12, would be
very hard to beat but it's a long time ago, 12.0 inches
in 1894! Much more recently though, 9.5 inches of snow
fell here at the summit on April 11, 1958. On April 14,
1953, 8.4 inches of snow was recorded. As late as 
April 28, 1987, 10.0 inches of snow fell here at the summit.   
That is the greatest snowfall so late in the season. 
 
Today's observations:
 
7 A.M.   
Weather: Clear 
Temperature: 34F, Dew point: 24F, Wind: NW at 7 kts 
Sea-level pressure: 30.18 inches Hg, rising
Visibility: 55 miles 
6-hour min. temp: 28F
BHO SA 1155 CLR 55 220/34/24/3107/018/ 53013 10034 20028  
  
10 A.M.
Weather: Clear, small Cumulus all quads  
Temperature: 43F, Dew point: 20F, Wind: NW at 8 kts  
Sea-level pressure: 30.18 inches of Hg, falling 
Visibility: 60 miles
BHO SA 1455 CLR 60 221/43/20/3208/018/ SML CU ALQDS 
WND 27V36/ 8/100 50001
 
1 P.M.
Weather: Increasing high clouds [scattered cirrus/cirrostratus],
and few small cumulus  
Temperature: 49F, Dew point: 20F, Wind: W @ 8 kts
Wind: Variable SW to NW  
Sea-level pressure: 30.14 inches of Hg, falling 
Visibility: 60 miles   
6-hour max. temp. 50 deg.  
BHO SA 1755 250 –SCT 60 208/49/20/2608/014/ SML CU ALQDS
CI/CS LYR S-W INCRSNG WND 23V31/ 8/105 56013 10050 20034 
 
WEATHER SUMMARY FOR TUESDAY, APRIL 10
 
TEMPERATURE (DEGREES F)
MAX.....43    NORMAL.....53 
MIN.....30    NORMAL.....35
MEAN....37    NORMAL.....44
DEPARTURE FROM 30-YEAR NORMAL..........- 7
TOTAL DEPARTURE FOR THE MONTH..........-65 (-6.7 DEGREES/DAY) 
 
HEATING DEGREE DAYS
TOTAL HEATING UNITS FOR YESTERDAY..........28   DEPARTURE........+ 7
TOTAL HEATING UNITS FOR THE MONTH.........287   DEPARTURE........+65 
TOTAL HEATING UNITS FOR THE SEASON.......5281   DEPARTURE.......-405
TOTAL HEATING UNITS LAST SEASON TO DATE..5147   DIFFERENCE......+134
 
PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY............28 W   AT 3:29 P.M. * 
                   AEROVANE............ 34 W   AT 3:29 P.M. *
                   ASOS.................25 NW  AT 3:30 P.M. 
                   DAVIS................29 W   AT 2:14 P.M. 
FASTEST MILE FOR YESTERDAY..............20 W   AT 3:31 P.M. 
MAXIMUM 2-MINUTE ASOS AVERAGE...........21 W   AT 3:27 P.M. 
MAXIMUM 2-MINUTE DAVIS AVERAGE..........23 W   AT 1:32 P.M. 
AVERAGE WIND SPEED AND DIRECTION......11.8 W
                    ASOS..............11.6  
                    DAVIS.............12.0 W [280 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..........1.90  DEPARTURE.....+0.40  
                         ASOS..............1.79    
TOTAL PRECIPITATION FOR THE YEAR..........13.64  DEPARTURE.....-1.49
                         ASOS.............13.43   
 
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......-0.9 
TOTAL SNOWFALL FOR THE SEASON..............27.6  DEPARTURE.....-30.4  
    
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   
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 morning low temp. 28 deg; normal low now 36 deg.   
 
DAILY EXTREMES
Temperature and precipitation records back to 1885, and
wind records back to 1940 (e = estimated):
 
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
 
RECORDS FOR APRIL 12
HIGH 82 IN 1945
LOW 17 IN 1926
PRECIP 1.51 IN. IN 1993
SNOWFALL 12.0 IN. IN 1894
PEAK GUST 65e MPH W IN 1978
 
TODAY'S REPORT By: Robert Skilling