BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS 02186
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
 
DAILY DISCUSSION AND CLIMATE SUMMARY
TUESDAY, APRIL 24, 2007   
ALL TIMES ARE IN EASTERN STANDARD TIME
 
COLD FRONTAL PASSAGE AROUND 9 A.M. BRINGS RAPIDLY INCREASING
WEST TO WEST-NORTHWEST WINDS FOR A SHORT PERIOD
 
MAXIMUM TEMPERATURE YESTERDAY OF 85 DEGREES EQUALED THE RECORD FOR 
THE DATE SET ON APRIL 23, 1908
 
West to west-northwest winds began increasing rapidly just after 
9 a.m. this morning as a dry cold front passed by. Peak gust were
in the 40 to 46 MPH range, but this lasted less than a half hour.
 
Several weather observing stations in southern New England established
new record high temperatures for April 23 but here at the Obsevatory 
it was a tie with 1908.  Very warm nighttime temperatures prevailed 
last night with our low of 60 degrees running 20 degrees warmer than 
normal. The very dry airmass of the past several days has been replaced
by a more moist one with dewpoint temperatures rising from the 30's of 
yesterday to around 50 degrees this morning. 
 
Today's observations:
 
7 A.M.   
Weather: High overcast with thin spots, hazy 
Temperature: 64F, Dew point: 50F, Wind: WSW at 15 kts
Sea-level pressure: 29.80 ins. Hg, rising 
Visibility: 20 miles, hazy 
6-hour min. 60 deg.   
BHO SA 1155 220 SCT E250 OVC 20 090/64/50/2415/980/
MDT CU/SC W-NW PTCHS DENSE CI OVC PTLY THN HAZY/
8/202 51014 10064 20060
 
10 A.M.
Weather:  Scattered cumulus and thin broken cirrus  
Temperature: 70F, Dew point: 46F, Wind: W at 14G24 kts
Sea-level pressure: 29.84 inches Hg, rising 
Visibility: 40 miles  
BHO SA 1455 50 SCT 220 SCT 250 SCT 300 –BKN 40 106/70/46/2814G24/984/   
CI/CS LYR CLRG E-S VSBY W-N 55/ 8/408 50002 
 
1 P.M.
Weather: Thin overcast cirrus
Temperature: 72F, Dew point: 40F, Wind: WNW at 10G20 kts 
Sea-level pressure: 29.85 inches Hg, rising 
Visibility: 75 miles   
6-hourly max. temp. 73 deg.  
BHO SA 1755 250 SCT 300 –OVC 75 109/72/40/3010G20/985/ 
FEW SML CU BINOVC WND 26V33/ 8/107 50002 10073 20064
 
WEATHER SUMMARY FOR MONDAY, APRIL 23
 
TEMPERATURE (DEGREES F)
MAX.....85    NORMAL.....58 
MIN.....49    NORMAL.....39
MEAN....67    NORMAL.....49
DEPARTURE FROM 30-YEAR NORMAL..........+18
TOTAL DEPARTURE FOR THE MONTH.........- 73 (-3.4 DEGREES/DAY) 
 
HEATING DEGREE DAYS
TOTAL HEATING UNITS FOR YESTERDAY.......... 0   DEPARTURE........-16
TOTAL HEATING UNITS FOR THE MONTH.........533   DEPARTURE.......+ 74 
TOTAL HEATING UNITS FOR THE SEASON.......5527   DEPARTURE.......-396
TOTAL HEATING UNITS LAST SEASON TO DATE..5303   DIFFERENCE......+224
 
PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY............42  S AT 3:54 P.M.     
                   AEROVANE.............41  S AT 3:31 P.M. *  
                   ASOS.................39  S AT 3:31 P.M.    
                   DAVIS................45  S AT 3:55 P.M.   
FASTEST MILE FOR YESTERDAY..............34  S AT 3:55 P.M.  
MAXIMUM 2-MINUTE ASOS AVERAGE...........35  S AT 3:56 P.M.       
MAXIMUM 2-MINUTE DAVIS AVERAGE..........31  S AT 3:31 P.M.     
AVERAGE WIND SPEED AND DIRECTION........19.3 S   
                    ASOS................19.1    
                    DAVIS...............18.7 S [190 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.....+3.80  
                         ASOS..............6.85    
TOTAL PRECIPITATION FOR THE YEAR..........18.92  DEPARTURE.....+1.91
                         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......-2.2 
TOTAL SNOWFALL FOR THE SEASON..............27.6  DEPARTURE.....-31.7  
    
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      Aero 41 MPH S
 
4/24 morning low temp. 60 deg; normal 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 24
HIGH 82 IN 2001
LOW 22 IN 1930
PRECIP 2.51 INS IN 1898
SNOWFALL 1.2 INS IN 1967
PEAK GUST 59 MPH NW IN 1962
 
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
 
TODAY'S REPORT By: Robert Skilling