BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA

DAILY DISCUSSION AND CLIMATE SUMMARY
SUNDAY, APRIL 22, 2018  
ALL TIMES ARE IN EASTERN STANDARD TIME

VERY SUNNY AND SEASONABLE TODAY...

The low temperature of the day so far of 36F was
two degrees cooler than the normal minimum temperature
for this date. By early afternoon, the temperature had
climbed to the upper 50s, which is very close to the
normal high for this time of year. The sky was completely
free of clouds until the early afternoon, and remained very sunny
all day with only a few cirrostratus forming later in the
afternoon. The dew point dropped from the low 20's to
the middle teens during the day as high pressure moved into
the area.  Visibility has been very good at 75 miles all day. 


Today's Observations:

7 A.M.
Weather: Clear (SKC), no clouds 
Temperature: 44F; Dew Point: 21F; Wind: NW at 8 kts,
Sea-level pressure: 30.34 ins. Hg, rising, then more slowly     
Visibility: 75 miles
6-hr Max temp: 44F
6-hr Min temp: 36F
24-hr precip: 0.00 ins. 
24-hr snowfall: 0.0 ins.  
Snow depth: 0 ins. 
BHO SA 1155 CLR 75 273/44/21/3108/034/ SKC/ 8/000 51011 10044 20036

10 A.M.
Weather: Clear (SKC), no clouds 
Temperature: 55F; Dew Point: 17F; Wind: W at 5G15 kts,
Wind: Light
Sea-level pressure: 30.34 ins. Hg, rising then falling 
Visibility: 75 miles
3-hr precip: 0.00 ins. 
3-hr snowfall: 0.0 ins. 
BHO SA 1455 CLR 75 274/55/17/2805G15/034/SKC WND LGT/8/000 50001 

1 P.M.
Weather: Clear, few cirrostratus S-SSW
Temperature: 58F; Dew Point: 13F; Wind: NW at 9G16 kts,
Sea-level pressure: 30.32 ins. Hg, steady then decreasing 
Visibility: 75 miles 
6-hr Max temp: 58F
6-hr Min temp: 44F
6-hr precip: 0.00 ins. 
6-hr snowfall: 0.00 ins.   
Snow depth: 0 ins.
BHO SA 1755 CLR 75 267/58/13/3309G16/032/ FEW CS S-SSW/ 8/008 58009 \
10058 20044
    

SUMMARY FOR SATURDAY, APRIL 21, 2018

TEMPERATURE (DEGREES F)
MAX.....60   NORMAL.....58
MIN.....33   NORMAL.....40
MEAN....47   NORMAL.....49

DEPARTURE FROM 30-YEAR NORMAL...........................-2
TOTAL DEPARTURE FOR THE MONTH..........................-95 [-5.0 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY.............18   DEPARTURE..........+2
TOTAL HEATING UNITS FOR THE MONTH............515   DEPARTURE.........+94
TOTAL HEATING UNITS FOR THE SEASON..........5573   DEPARTURE........-332
TOTAL HEATING UNITS LAST SEASON TO DATE.....5237   DIFFERENCE.......+336

PEAK GUST AND AVERAGE WIND SPEED (MPH) 
PEAK WIND GUST FOR YESTERDAY...................28 NW AT  8:57 A.M.  
                   AERO........................26 NW AT  8:57 A.M. 
                   ASOS........................28 NW AT  8:58 A.M.
                   DAVIS.......................30 M      8:57 A.M ** RMY 29
FASTEST MILE FOR YESTERDAY.....................18 NW AT 12:01 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE..................20 NW AT 11:40 A.M.  
MAXIMUM 2-MINUTE DAVIS AVERAGE.................20 M  AT  9:46 A.M.**
AVERAGE WIND SPEED AND DIRECTION.............11.3 NW
                   ASOS......................10.8
                   DAVIS.....................10.7 M **
** Davis direction malfunctioning 

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..........4.32  DEPARTURE......+0.97
                         ASOS..............4.48  
TOTAL PRECIPITATION FOR THE YEAR..........23.12  DEPARTURE......+5.95
                         ASOS.............24.72

SNOWFALL (INCHES) THROUGH THIS MORNING (EST)
TOTAL SNOWFALL 24 HRS ENDING 7 A.M..........0.0  DEPARTURE.........0.0
TOTAL SNOWFALL FOR THE MONTH................2.6  DEPARTURE........-0.1
TOTAL SNOWFALL FOR THE SEASON..............92.8  DEPARTURE.......+30.3

PRELIMINARY CLIMATE SUMMARY FOR APRIL CALENDAR DAY DATA
DATE: MAX/MIN/MEAN/DEP/PRECIP/SNOW/SUN(MIN.)/SUN(%)/PEAK GUST/AERO/RMY GUST
AERO: Aerovane wind recording system gust
RMY : R.M. Young wind gust recording system
TSTM: Thunderstorm day (thunder heard some time during day)
....: Data not yet available, records not finalized
M   : Missing data
*   : Estimated data 

4/01 58/33/46/+5/0.00/0.0/336/44   45 SSW AERO 43 SSW RMY N/A  
4/02 38/30/34/-7/0.13/1.6/077/10   20 SSW AERO 15 SSW RMY 17
4/03 48/30/39/-3/..../0.0/238/31   28 SSE AERO 25 SSE RMY 25
4/04 54/36/45/+3/..../0.0/000/00   56 WNW AERO 56 WNW RMY 54
4/05 40/27/34/-9/0.00/0.0/760/98   53 WNW AERO 53 WNW RMY 52 
4/06 41/25/33/-10/0.25/1.0/156/20  37 S   AERO 36 S   RMY 38
4/07 46/32/35/-4/0.00/0.0/312/40   32 WNW AERO 35 WNW RMY 34
4/08 41/29/35/-9/0.00/0.0/290/37   35 WNW*AERO 31 WNW RMY 34
4/09 45/24/35/-9/0.00/0.0/715/01   28 WNW*AERO 25 WNW RMY 29
4/10 39/31/35/-10/T/T/000/00       14 SSW AERO 13 SSW RMY N/A
4/11 48/29/39/-6/T/0.0/364/46      24 SSE AERO 23 SSE RMY 25 
4/12 61/33/47/+2/0.03/0.0/.../..   39 SSW AERO 38 SSW RMY 41 
4/13 65/47/56/+10/T/0.0/.../..     37 SSW AERO 37 SSW RMY N/A
4/14 51/36/44/-2/0.00/0.0/.../..   33 ENE AERO 31 ENE RMY N/A
4/15 36/30/33/-14/..../T/.../..    39 ENE AERO 39 ENE RMY N/A
4/16 55/32/44/-3/..../.../..       41 ENE AERO 43 ENE RMY 41
4/17 48/36/42/-5/0.00/0.0/.../..   37 W   AERO 33 W   RMY 37
4/18 53/32/43/-5/..../0.0/.../..   35 W   AERO 31 W   RMY 34
4/19 41/34/38/-10/0.22/T/.../..    28 WNW AERO 25 WNW RMY N/A 
4/20 52/31/42/-7/0.00/0.0/.../..   34 NW  AERO 33 NW  RMY 36
4/21 60/33/47/-2/0.00/0.0/.../..   28 NW  AERO 26 NW  RMY 29

4/22 Low temp since midnight is 36F; normal low is now 40F

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, 2007 
LOW 25 IN 1933,1989
PRECIP 1.99 IN. IN 2012
SNOWFALL 2.0 IN. IN 2012
PEAK GUST 64 MPH WNW IN 1962

TODAY'S REPORT PREPARED BY: Robert Millette