BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS 02186
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
 
DAILY DISCUSSION AND CLIMATE SUMMARY
SUNDAY, APRIL 22, 2007   
ALL TIMES ARE IN EASTERN STANDARD TIME
 
A SECOND SPECTACULAR WEEKEND WEATHER DAY TODAY
TEMPERATURE HIT 74 DEGREES YESTERDAY...HIGHEST SINCE 78 OCTOBER 9TH
VERY DRY CONDITIONS WITH RELATIVE HUMDITY DOWN TO 13%
 
Both days this weekend are having spectacular weather with temperatures
again today expected to reach the 70's.  Yesterday's high of 74 degrees
occurred during the early afternoon.  Later a feeble seabreeze resulted
in slowly falling temperatures into the 60's by late afternoon. 
The warm temperatures were accompanied by very dry air with a dewpoint
of 20 degrees giving an early afternoon very low humidity of 13%.
 
A temperature inversion overnight left our morning low this morning 
at a very mild 52 degrees while Norwood Airport dropped to 40 degrees
and other surrounding locations had 30-degree readings this morning. 
 
The extended period of overcast weather during the prolonged mid-April
nor'easter left the monthly sunshine at only 31% of possible through 
last Thursday, April 19th, but 100% of the possible sunshine on Friday
and probably close to that yesterday and today will raise the percentage
for the month up ten points. 
 
 
Today's observations:
 
7 A.M.   
Weather: High thin scattered cirrocumulus/cirrus
Temperature: 54F, Dew point: 29F, Wind: NNW at 7 kts
Sea-level pressure: 30.20 ins. Hg, rising
Visibility: 60 miles 
6-hour min. 52 deg.   
BHO SA 1155 250 –SCT 300 –SCT 60 228/54/29/3407/020/ THN CC/CI/ 8/009 
51019 10056 20052 
 
10 A.M.
Weather: High thin broken cirrus clouds   
Temperature: 66F, Dew point: 25F, Wind: W at 5 kts
Sea-level pressure: 30.23 inches Hg, steady 
Visibility: 60-70 miles 
BHO SA 1455 250 –SCT 300 –BKN 60 236/66/25/2805/023/ VSBY NW 70/ 8/001 
51008 

   
WEATHER SUMMARY FOR SATURDAY, APRIL 21
 
TEMPERATURE (DEGREES F)
MAX.....74    NORMAL.....58 
MIN.....45    NORMAL.....39
MEAN....60    NORMAL.....48
 
DEPARTURE FROM 30-YEAR NORMAL..........+12
TOTAL DEPARTURE FOR THE MONTH.........-105 (-5.2 DEGREES/DAY) 
 
HEATING DEGREE DAYS
TOTAL HEATING UNITS FOR YESTERDAY...........5   DEPARTURE........-12
TOTAL HEATING UNITS FOR THE MONTH.........531   DEPARTURE.......+104 
TOTAL HEATING UNITS FOR THE SEASON.......5525   DEPARTURE.......-366
TOTAL HEATING UNITS LAST SEASON TO DATE..5262   DIFFERENCE......+263
 
PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY............24 NW AT 12:52 P.M. *    
                   AEROVANE.............24 NW AT 12:52 P.M.   
                   ASOS.................22 NW AT 12:52 P.M.   
                   DAVIS................25 NW AT 12:52 P.M.  
FASTEST MILE FOR YESTERDAY..............17 WNW AT 11:26 A.M.       
MAXIMUM 2-MINUTE ASOS AVERAGE...........17 WNW AT 12:40 P.M.     
MAXIMUM 2-MINUTE DAVIS AVERAGE..........19 W   AT 11:27 A.M.    
AVERAGE WIND SPEED AND DIRECTION........ 8.5 WNW
                    ASOS................ 8.8   
                    DAVIS............... 9.1 WNW [300 deg]
* last of several occurrences
 
PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.00  DEPARTURE.....-0.14
                         ASOS..............0.00
TOTAL PRECIPITATION FOR THE MONTH..........7.18  DEPARTURE.....+4.08  
                         ASOS..............6.85    
TOTAL PRECIPITATION FOR THE YEAR..........18.92  DEPARTURE.....+2.19
                         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......-2.0 
TOTAL SNOWFALL FOR THE SEASON..............27.6  DEPARTURE.....-31.5  
    
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 morning low temp. 52 deg; normal low now 39 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.       
 
DAILY EXTREMES
Temperature and precipitation records back to 1885, and
wind records back to 1940 (e = estimated):
 
RECORDS FOR APRIL 22
HIGH 85 IN 1977, 2001
LOW 26 IN 1981
PRECIP 1.85 IN. IN 2000
SNOWFALL 3.0 IN. IN 1940
PEAK GUST 68e MPH NW IN 1945
 
RECORDS FOR APRIL 23
HIGH 85 IN 1908
LOW 25 IN 1933,1989
PRECIP 1.51 IN. IN 1998
SNOWFALL 0.5 IN. IN 1911, 1956
PEAK GUST 64 MPH WNW IN 1962
 
TODAY'S REPORT By: Robert Skilling