BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS 02186
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
 
DAILY DISCUSSION AND CLIMATE SUMMARY
WEDNESDAY, APRIL 25, 2007   
ALL TIMES ARE IN EASTERN STANDARD TIME
 
CLOUDY SKIES AND MUCH COOLER TEMPERATURES TODAY
 
The sky clouded over early this morning and continues 
heavily overcast around noon with the temperature only in the 
mid-50's to upper 50's as compared to the 70's yesterday. 
 
Today's observations:
 
7 A.M.   
Weather: High thin overcast  
Temperature: 52F, Dew point: 29F, Wind: estimated from NNE @ 02 kts
Sea-level pressure: 30.10 ins. Hg, rising 
Visibility: 55 miles, light haze, visibility NE 25  
6-hour min. 47 deg.   
BHO SA 1155 300 –OVC 55 194/52/29/E0302/010/ AC DSNT WSW-NNW/
FEW LWR CI THN K ALG HRZN NNE VSBY NE-E 20 HAZY/
8/037 52011 10053 20047
 
10 A.M.
Weather: Overcast altocumulus    
Temperature: 55F, Dew point: 28F, Wind: Calm
Sea-level pressure: 30.09 inches Hg, falling 
Visibility: 60 miles  
BHO SA 1455 E95 OVC 60 191/55/28/0000/009/ 8/07/ 58003
 
1 P.M.
Weather: Overcast  
Temperature: 58F, Dew point: 29F, Wind: W @ 05 KTS [light and variable]
Sea-level pressure: 29.  inches Hg, falling 
Visibility: 50 miles, 30 miles W-NW PCPN PRSNT  
6-hourly max. temp. 58 deg.   0
BHO SA 1755 SCT 100 E150 OVC 50 175/58/29/2605/005/
VIRGA BRGHT SPTS IOVC VSBY W-NW 30 PCPN PRSNT WND L/V 8/07/
56016 10058 20051
 
WEATHER SUMMARY FOR TUESDAY, APRIL 24
 
TEMPERATURE (DEGREES F)
MAX.....73    NORMAL.....59 
MIN.....50    NORMAL.....40
MEAN....62    NORMAL.....49
DEPARTURE FROM 30-YEAR NORMAL..........+13
TOTAL DEPARTURE FOR THE MONTH.........- 60 (-2.7 DEGREES/DAY) 
 
HEATING DEGREE DAYS
TOTAL HEATING UNITS FOR YESTERDAY.......... 3   DEPARTURE........-13
TOTAL HEATING UNITS FOR THE MONTH.........536   DEPARTURE.......+ 61 
TOTAL HEATING UNITS FOR THE SEASON.......5530   DEPARTURE.......-409
TOTAL HEATING UNITS LAST SEASON TO DATE..5324   DIFFERENCE......+206
 
PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY............39  W   AT 8:08 A.M.   
                   AEROVANE.............41  WNW AT 8.00 A.M.    
                   ASOS.................38  WNW AT 8:02 A.M.
                   DAVIS................40  W   AT 8:06 A.M.    
FASTEST MILE FOR YESTERDAY..............30  W   AT 8:10 A.M. *  
MAXIMUM 2-MINUTE ASOS AVERAGE...........30  W   AT 8:10 A.M.        
MAXIMUM 2-MINUTE DAVIS AVERAGE..........30  W   AT 8:10 A.M.      
AVERAGE WIND SPEED AND DIRECTION........14.0 WNW  
                    ASOS................13.2    
                    DAVIS...............N/A
* last of several occurrences...
 
PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.00  DEPARTURE.....-0.14
                         ASOS..............0.00
TOTAL PRECIPITATION FOR THE MONTH..........7.18  DEPARTURE.....+3.66  
                         ASOS..............6.85    
TOTAL PRECIPITATION FOR THE YEAR..........18.92  DEPARTURE.....+1.77
                         ASOS.............18.49   

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......-2.3 
TOTAL SNOWFALL FOR THE SEASON..............27.6  DEPARTURE.....-31.8  
    
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      Aero 42 MPH 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 51/28/40/-5/0/0/712/90          22 SSE
4/12 39/32/36/-9/0.89/T/000/00       42 E      Aero 40 MPH E
4/13 47/31/39/-6/0/0/096/12          41 W      Aero 42 MPH W
4/14 52/35/44/-2/0/0/392/49          37 W
4/15 44/35/40/-6/1.75/T/000/00       66 E      Aero 64 MPH E  
4/16 50/40/45/-1/1.56/0/000/00       73 E      Aero 73 MPH E 
4/17 40/35/38/-9/0.69/T/000/00       54 NNE    Aero 53 MPH NNE
4/18 39/36/38/-9/0.37/0/000/00       43 N
4/19 49/36/43/-4/0.02/T/285/35       38 NE     Aero 35 MPH NE 
4/20 57/36/47/-1/0/0/815/100         31 N
4/21 74/45/60/+12/0/0/753/92         24 NW
4/22 75/50/63/+14/0/0/779/95         31 SSE     
4/23 85/49/67/+18/0/0/675/82         42 S      Davis 45 MPH S 
4/24 73/50/62/+13/0/0/586/71         39 W      Aero  41 MPH W
 
4/25 morning low temp. 47 deg; normal low now 40 deg.

NEW DAILY RECORDS FOR APRIL SO FAR....
 
4/15 - NEW RECORD HIGH PEAK WIND GUST FOR THIS DATE OF 66 MPH E; the previous   
record was 59 mph estimated from the S in 1946 and measured from the S in 1980.   
NEW RECORD DAILY RAINFALL OF 1.75 INS.; previous record 1.29 ins. in 1990.
 
4/16 - NEW RECORD HIGH PEAK WIND GUST OF 73 MPH E; the previous record for this  
date was 63 mph SSE in 1996.       
 
4/23 - EQUALED RECORD HIGH MAXIMUM TEMPERATURE OF 85 DEGREES set in 1908.
 
DAILY EXTREMES
Temperature and precipitation records back to 1885, and
wind records back to 1940 (e = estimated):
 
RECORDS FOR APRIL 25
HIGH 80 IN 1942
LOW 24 IN 1892
PRECIP 1.38 IN. IN 1901
SNOWFALL 0.7 IN. IN 2002.
PEAK GUST 66 MPH SE IN 1968
 
RECORDS FOR APRIL 26
HIGH 83 IN 1908
LOW 23 IN 1919
PRECIP 1.64 IN. IN 1931
SNOWFALL 1.0 IN. IN 2000
PEAK GUST 53 MPH SSW IN 1996
 
TODAY'S REPORT By: Robert Skilling