BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
 
DAILY DISCUSSION AND CLIMATE SUMMARY
THURSDAY, APRIL 25, 2013
ALL TIMES ARE IN EASTERN STANDARD TIME
 
WINDS GUST TO 36 MPH SSW AHEAD OF COLD FRONT
PEAK WIND GUST TO 38 MPH WNW BEHIND THE FRONT 
LIGHT SHOWERS PRECEDE COLD FRONTAL PASSAGE
 
Yesterday's high temperature of 72 degrees made a 3-way tie
for the warmest it has been so far during this month.  Temp-
eratures remained mild overnight.  The low of 47 degrees
occurred during the late evening followed by temperatures
rising into the low 50's during the rest of the night.
 
Increasing S-SSW winds during the night reached a peak gust
of 36 MPH occurred at 12:36 A.M. EDT just after midnight.
Early this morning the passage of a cold front brought a
wind shift to WNW with a peak gust to 38 MPH occurring at
6:07 A.M. Temperatures dropped into the mid 40's with the
low this morning of 44F registered at 8:43 A.M. EDT.
 
Light rain showers preceded the frontal passage and left
a total of just 0.05 inch.
 
Today's observations:
 
7 A.M.
Weather: Overcast altocumulus, few stratocumulus distant SW-NW,
line of clearing WSW-NNW moving east, line of virga SW-NW-NE
moving east, a break in overcast exists along line of clearing 
Temperature: 46F; Dew Point: 36F; Wind: WNW at 14 kts,
Wind: Peak wind from NW at 28 kts at 6:28 A.M. EST
Wind: Direction variable W-NNW
Sea-level pressure: 30.04 ins. Hg, rising then more slowly 
Visibility: 60 miles, except 30 miles E-SE in precipitation,
75 miles to the W-NW 
24-hr precip: 0.05 inch
6-hr precip: 0.05 inch
6-hour min. temp: 46F
BHO SA 1155 E75 OVC 60 173/46/36/3014/004/ BINOVC/LINE OF CLRG
XTDNG WSW-NNW LINE OF VIRGA SW-NW-NE MOVG E FEW SC DSNT SW-N
VSBY E-SE 30 W-NW 75 PK WND 3128/20/ WND 26V34/ 8/57/ 51047
ASOS 60004 MANUAL 6005/ ASOS 70004 MANUAL 70005 10053 20046
 
10 A.M. 
Weather: Scattered altocumulus, altocumulus castellanus and
castellanus with virga, layer NNE-E-S receding, few patches dense
cirrus distant W-NW  
Temperature: 53F; Dew Point: 33F; Wind: W at 14G20 kts,
Wind: Direction variable W-NW
Sea-level pressure: 30.09 ins. Hg, rising then more slowly 
Visibility: 60 miles, except 30 miles E-SE, hazy, 70 miles NW,
light distant haze
3-hour precip: trace
BHO SA 1455 110 SCT 200 SCT 60 189/53/33/2814G20/009/ SKY CLRG
AC/ACC/ACC VIRGA NNE-S LYR MOVG E FEW PTCHS DNS CI DSNT W-NW
VSBY NW 70 LGT DSNT HZ WND 26V32/ 8/082 51016 MANUAL 600/
 
Office closed 12 noon EDT today
 
WEATHER SUMMARY FOR WEDNESDAY, APRIL 24
 
TEMPERATURE (DEGREES F)
MAX.....72     NORMAL.....59
MIN.....40     NORMAL.....41                         
MEAN....56     NORMAL.....50             
 
DEPARTURE FROM 30-YEAR NORMAL....................+6
TOTAL DEPARTURE FOR THE MONTH...................+26 [+0.9 DEGREES/DAY]
 
HEATING DEGREE DAYS 
TOTAL HEATING UNITS FOR YESTERDAY.............9   DEPARTURE..........-6
TOTAL HEATING UNITS FOR THE MONTH...........441   DEPARTURE.........-27
TOTAL HEATING UNITS FOR THE SEASON.........5461   DEPARTURE........-491
TOTAL HEATING UNITS LAST SEASON TO DATE....4612   DIFFERENCE.......+849
 
PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY...............36 SSW AT 11:31 P.M. 
                   AERO....................33 SSW AT 10:56 P.M. 
                   ASOS....................36 SSW AT 11:31 P.M.
                   DAVIS...................N/A                  RMY: N/A
THE FASTEST MILE FOR YESTERDAY............ 29 SSW AT 11:23 A.M.
MAXIMUM 2-MINUTE ASOS AVERAGE..............29 SSW AT 11:32 P.M. 
MAXIMUM 2-MINUTE DAVIS AVERAGE.............28 S   AT  9:05 P.M. 
AVERAGE WIND SPEED AND DIRECTION.........15.6 S      
                   ASOS..................15.0
                   DAVIS.................13.8 WSW [250 deg]
*last of several occurrences.
 
PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.05  DEPARTURE...........-0.08
                         ASOS..............0.04
TOTAL PRECIPITATION FOR THE MONTH..........2.29  DEPARTURE...........-1.46
                         ASOS..............2.23
TOTAL PRECIPITATION FOR THE YEAR..........16.38  DEPARTURE...........-1.37
                         ASOS..............N/A*
*ASOS malfunctioned during storm on 2/8-9, leading to erroneous totals
                       
SNOWFALL (INCHES) THROUGH THIS MORNING (EST)
TOTAL SNOWFALL 24 HRS ENDING 7 A.M.........0.0   DEPARTURE............ 0.0
TOTAL SNOWFALL FOR THE MONTH.............Trace   DEPARTURE............-2.9
TOTAL SNOWFALL FOR THE SEASON.............99.0   DEPARTURE...........+36.4
 
PRELIMINARY CLIMATE SUMMARY FOR APRIL 2013 CALENDAR DAY DATA
DATA REPORTED:
DATE: MAX/MIN/MEAN/DEP/PRECIP/SUN(MIN.)/SUN(%)/ PEAK GUST/AERO GUST
AERO: Aerovane wind recording system gust
RMY:  RMY = R.M. Young wind gust recording system added 8/9/2011
TSTM: Thunderstorm day (thunder heard some time during day)
....: Data not yet available, records not finalized
 
4/1  61/31/46/+5/0.34/0.0/458/60     40 W   AERO 44 MPH WNW RMY 46  TSTM
4/2  40/27/34/-7/T/T/460/60          45 W   AERO 42 MPH W   RMY 47
4/3  45/27/36/-6/0.00/0.0/755/98     44 W   AERO 43 MPH W   RMY 47
4/4  55/26/41/-1/0.00/0.0/719/93     30 WSW AERO 27 MPH WSW RMY 31
4/5  59/36/48/+5/0.00/0.0/403/52     33 NNW AERO 28 MPH NNW RMY 38
4/6  47/30/39/-4/0.00/0.0/747/96     38 NW  AERO 35 MPH NW  RMY 40 
4/7  52/31/42/-1/0.00/0.0/391/50     51 S   AERO 46 MPH S   RMY 50
4/8  65/43/54/+10/T/0.0/494/63       29 SSW AERO 22 MPH SSW RMY N/A
4/9  72/44/58/+14/T/0.0/456/58       35 WNW AERO 35 MPH WNW RMY 39  TSTM
4/10 64/43/54/+9/0.13/0.0/426/54     23 SE  AERO 20 MPH SE  RMY 25
4/11 52/40/46/+1/0.09/0.0/063/08     18 ENE AERO 14 MPH ENE RMY N/A
4/12 40/34/37/-8/0.58/T/000/00       38 E   AERO 32 MPH E   RMY 41
4/13 52/34/43/-3/0.04/0.0/128/16     31 NNE AERO 27 MPH NNE RMY 21
4/14 52/36/44/-2/0.00/0.0/216/27     31 WNW AERO 27 MPH WNW RMY 32
4/15 55/35/45/-2/0.00/0.0/514/64     21 ESE AERO 15 MPH S   RMY N/A
4/16 62/38/50/+3/T/0.0/540/67        44 S   AERO 40 MPH S   RMY 45
4/17 67/48/58/+11/T/0.0/769/95       29 SSW AERO 25 MPH SSW RMY N/A
4/18 65/43/54/+6/0.00/0.0/503/62     30 S   AERO 25 MPH S   RMY N/A
4/19 72/50/61/+13/0.07/0.0/195/24    47 SSW AERO 48 MPH SSW RMY 50
4/20 62/39/51/+2/0.48/0.0/147/18     43 SSW AERO 41 MPH SSW RMY N/A
4/21 53/31/42/-7/0.00/0.0/819/100    31 WNW AERO 25 MPH WNW RMY N/A
4/22 49/35/42/-7/0.00/0.0/.../..     32 E   AERO 28 MPH E   RMY 33
4/23 40/38/39/-11/0.50/0.0./000/00   35 NNE AERO 30 MPH NNE RMY 35
4/24 72/40/56/+6/0.01/0.0/.../..     36 SSW AERO 33 MPH SSW RMY N/A
 
4/25  morning low temp: 44F at 7:37 A.M.; the normal low is now 41F
 
DAILY RECORDS FOR APRIL 2013
None so far.
 
DAILY EXTREMES
Temperature and precipitation records back to 1885, and
wind records back to 1940 (e = estimated):
 
RECORDS FOR APRIL 25
HIGH 83 IN 2009
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 88 IN 2009
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 PREPARED BY: Robert Skilling