BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS 02186
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
  
DAILY DISCUSSION AND CLIMATE SUMMARY
TUESDAY, APRIL 15, 2008
ALL TIMES ARE IN EASTERN STANDARD TIME UNLESS NOTED
 
PERFECTLY CLEAR SKY WITH 80 MILES VISIBILITY
 
Today is one of those rare days when not a cloud is to be 
seen from horizon to horizon here at the summit. Visibility 
is up around 80 miles and the bright high angle mid-April 
sunshine has boosted the temperature to the mid-50's from 
33 degrees early this morning. The air is very dry with the 
dewpoint in the mid to upper teens the relative humidity is
dropping to near 20% early this afternoon.
 
Today will average a couple degrees cooler than normal. 
Our maximum temperature was very close to normal in 
the middle 50's but the minimum of 33 is 4 degrees 
below the normal for the date. 
 
Today's observations:
 
8 A.M. EDT
Weather: Clear  
Temperature: 37F, Dew point: 21F  Wind: NW at 10 kts
Sea-level pressure: 30.14 inches Hg, rising
Visibility: 75 miles
6-hour min temp: 33F
24-hour precipitation: none 
BHO SA 1155 CLR 75 208/37/21/3110/014/ VRY THN K ALG HRZNS/ 
53018 10037 20033  
 
11 A.M. EDT
Weather: Clear   
Temperature: 51F, Dew point: 16F, Wind: NW at 7 kts 
Sea-level pressure: 30.16 inches Hg, falling
Visibility: 70 miles  
BHO SA 1455 CLR 70 215/51/16/3107/016/ WND 26V36/ 50007 
  
2 P.M. EDT
Weather: Clear  
Temperature: 54F, Dew point: 17F, Wind: WNW at 4 kts 
Wind: Light and variable, gust to 21 kts past hour
Sea-level pressure: 30.12 inches Hg, falling
Visibility: 80 miles 
6-hourly max.temp: 56F  
BHO SA 1755 CLR 80 199/54/17/3004/012/ GST TO 21 KTS PST HR 
WND L/V/ 56016 10056 20037
 
WEATHER SUMMARY FOR MONDAY, APRIL 14
 
TEMPERATURE (DEGREES F)
MAX.....53    NORMAL.....55
MIN.....30    NORMAL.....37
MEAN....42    NORMAL.....46
DEPARTURE FROM 30-YEAR NORMAL..........- 4 
TOTAL DEPARTURE FOR THE MONTH..........+13 [+0.7 DEGREES/DAY]
 
HEATING DEGREE DAYS
TOTAL HEATING UNITS FOR YESTERDAY............23  DEPARTURE....... +4
TOTAL HEATING UNITS FOR THE MONTH...........288  DEPARTURE.......-13 
TOTAL HEATING UNITS FOR THE SEASON.........5425  DEPARTURE......-340
TOTAL HEATING UNITS LAST SEASON TO DATE....5382  DIFFERENCE......+43  
 
PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY............29 NW   AT  8:02 A.M.*  
                   AEROVANE.............29 NW   AT  8:02 A.M.*  
                   ASOS.................26 NW   AT  8:02 A.M.   
                   DAVIS................29 WNW  AT  7:41 A.M.    
FASTEST MILE FOR YESTERDAY............. 20 WNW  AT  7:59 A.M.   
MAXIMUM 2-MINUTE ASOS AVERAGE...........20 WNW  AT  7:59 A.M.  
MAXIMUM 2-MINUTE DAVIS AVERAGE..........21 WNW  AT  7:53 A.M.   
AVERAGE WIND SPEED AND DIRECTION......11.4 WNW  
                   ASOS...............11.2    
                   DAVIS..............12.0 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..........1.52   DEPARTURE......-0.58
                         ASOS..............1.66 
TOTAL PRECIPITATION FOR THE YEAR..........19.12   DEPARTURE......+3.39
                         ASOS.............21.54 #
# Includes erroneous ASOS precipitation data on 2/13/08.
 
SNOWFALL (INCHES) THROUGH THIS MORNING (EST)
TOTAL SNOWFALL 24 HRS ENDING 7 A.M.........0.0    DEPARTURE......-0.1
TOTAL SNOWFALL FOR APRIL...................0.0    DEPARTURE......-1.5
TOTAL SNOWFALL FOR THE SEASON.............66.5    DEPARTURE......+8.0
 
PRELIMINARY CLIMATE SUMMARY FOR APRIL 2008 CALENDAR DAY DATA
DATA REPORTED:
DATE: MAX/MIN/MEAN/DEP/PRECIP/SNOW/SUN(MIN.)/SUN(%)/ PEAK GUST/AERO GUST
AERO: Aerovane recording wind system when significant
TSTM: Thunderstorm day
....: Data not yet available, records not finalized
 
4/1  59/50/55/+14/0.20/0/000/00    54 S    Aero 58 MPH SSW
4/2  47/31/39/-3/0/0/745/97        52 W    Aero 51 MPH W
4/3  52/27/40/-2/0/0/648/84        37 SSW 
4/4  43/34/39/-3/0.71/0/000/00     35 E
4/5  51/37/44/+1/0.06/0/093/12 *   21 W
4/6  40/36/38/-5/0.09/0/000/00 *   36 NE 
4/7  39/34/37/-6/0/0/172/22        35 NE    Aero 36 MPH NE
4/8  47/30/39/-5/0/0/627/80        22 NE
4/9  59/33/47/+3/0/0/150/19        29 S    
4/10 71/44/58/+14/T/0/624/79       34 W
4/11 54/40/47/+2/0.03/096/13       24 SE 
4/12 70/43/57/+12/0.43/0/.../..    40 WNW   Aero 42 WNW
4/13 47/34/41/-4/T/0/.../..        30 NW 
4/14 53/30/42/-4/0/0/.../..        29 NW 
 
4/15 morning low temp. 33F; our normal low is now 37F
 
* DAILY SUNSHINE CORRECTIONS....
corrections have been made; the data for the 5th and 6th 
have been reversed from previous reports. The 5th is corrected to 
read 93 mins. and 12% sunshine and the 6th has been 
corrected to zero minutes and zero percent.
 
NEW DAILY RECORDS FOR APRIL 2008
None to date.
 
DAILY EXTREMES
Temperature and precipitation records back to 1885, and
wind records back to 1940 (e = estimated):
 
RECORDS FOR APRIL 15
HIGH 81 IN 1896
LOW 23 IN 1943
PRECIP 1.75 IN. IN 2007
SNOWFALL 1.0 IN. IN 1916, 1962
PEAK GUST 66 MPH E IN 2007      
 
RECORDS FOR APRIL 16
HIGH 87 IN 1896
LOW 23 IN 1943
PRECIP 2.45 IN. IN 1929
SNOWFALL 2.0 IN. IN 1904, 1962
PEAK GUST 73 MPH E IN 2007
 
TODAY'S REPORT PREPARED By: Robert Skilling