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

DAILY DISCUSSION AND CLIMATE SUMMARY
MONDAY, APRIL 16, 2018  
ALL TIMES ARE IN EASTERN STANDARD TIME

ANOTHER WINDY, BELOW SEASONABLE DAY WITH RAIN, 
HEAVY AT TIMES... 

Temperatures continued to be below seasonable 
today with a max of 46F by 1:00 P.M. This is 
10 degrees below the normal of 56F. Wind was
moderate today with strong gust over 40 MPH. 
We also has frequent gust of 25 MPH throughout 
the day. The wind slowly veered from the ENE to 
the SE today. 
Rain was continuous and heavy at times today. So
far we measured 1.28 ins since 1:00 P.M. 
yesterday. Today humidity was constant at 100%.
This limited visibility to from 2 miles to 
1/2 miles by 10:00 A.M. 

Today's Observations:

7 A.M.
Weather: Heavy rain and fog, overcast nimbostratus  
Temperature: 36F; Dew Point: 36F; Wind: ENE at 20G30 kts,
Peak Wind: 36 kts (41 MPH) ENE at 6:14 A.M.
Sea-level pressure: 30.17 ins. Hg, falling, then more slowly     
Visibility: 1 miles, except 2 miles NNE-SSE 
6-hr Max temp: 36F
6-hr Min temp: 32F
24-hr precip: 0.67 ins. 
24-hr snowfall: Trace  
Snow depth: 0 ins.
BHO SA 1155 E7 OVC 1R+F 217/36/36/0720G30/017/ NEW SNW PST 24 
HRS TRACE VSBY NNE-SSE 2 PK WND 0736/14/ 8/6// 56021 MANUAL 
70067 ASOS 70057 10036 20032 

10 A.M.
Weather: Rain and fog, overcast nimbostratus
Temperature: 40F; Dew Point: 40F; Wind: ENE at 23G34 kts,
Peak Wind: 36 kts (41 MPH) ENE at 9:03 A.M.
Sea-level pressure: 30.49 ins. Hg, falling, then more rapidly 
Visibility: 1/2 mile
3-hr precip: 0.16 ins. 
3-hr snowfall: 0.0 ins. 
BHO SA 1455 E4 OVC 1/2RF 158/40/40/0723G34/000/ PK WND 
0736/03/ 8/6// 58059 MANUAL 6016/ ASOS 60024

1 P.M.
Weather: Light rain and fog, overcast nimbostatus 
Temperature: 46F; Dew Point: 46F; Wind: E at 21G32 kts,
Peak Wind: 32 kts (37 MPH) ENE at 12:54 P.M.
Sea-level pressure: 29.83 ins. Hg, falling, then more rapidly
Visibility: 1/2 mile 
6-hr Max temp: 46F
6-hr Min temp: 36F
6-hr precip: 0.60 ins. 
6-hr snowfall: 0.0 ins.  
Snow depth: 0 ins.
BHO SA 1755 E4 OVC 1/2RF 101/46/46/0821G32/983/ PRESFR PK WND 
0832/54/ 8/6// 58057 MANUAL 6060/ ASOS 60071 10046 10036

SUMMARY FOR SUNDAY, APRIL 15, 2018

TEMPERATURE (DEGREES F)
MAX.....36   NORMAL.....56
MIN.....30   NORMAL.....38
MEAN....33   NORMAL.....47

DEPARTURE FROM 30-YEAR NORMAL..........................-14
TOTAL DEPARTURE FOR THE MONTH..........................-63 [-4.4 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY.............32   DEPARTURE.........+14
TOTAL HEATING UNITS FOR THE MONTH............381   DEPARTURE.........+63
TOTAL HEATING UNITS FOR THE SEASON..........5439   DEPARTURE........-363
TOTAL HEATING UNITS LAST SEASON TO DATE.....5156   DIFFERENCE.......+283

PEAK GUST AND AVERAGE WIND SPEED (MPH) 
PEAK WIND GUST FOR YESTERDAY...................39 ENE AT  8:37 A.M.  
                   AERO........................39 ENE AT  8:37 A.M.
                   ASOS........................42 ENE AT  8:37 A.M.
                   DAVIS.......................38 M   AT  8:36 A.M ** RMY N/A
FASTEST MILE FOR YESTERDAY.....................29 ENE AT  8:36 A.M.
MAXIMUM 2-MINUTE ASOS AVERAGE..................29 E   AT  9:58 P.M.  
MAXIMUM 2-MINUTE DAVIS AVERAGE.................26 M   AT  8:28 A.M.**
AVERAGE WIND SPEED AND DIRECTION.............18.2 ENE
                   ASOS......................19.4
                   DAVIS.....................12.8 M**
** Davis direction malfunctioning 

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.67  DEPARTURE......-0.16
                         ASOS..............0.57
TOTAL PRECIPITATION FOR THE MONTH..........1.83  DEPARTURE......-0.68
                         ASOS..............1.72  
TOTAL PRECIPITATION FOR THE YEAR..........20.63  DEPARTURE......+4.30
                         ASOS.............21.96

SNOWFALL (INCHES) THROUGH THIS MORNING (EST)
TOTAL SNOWFALL 24 HRS ENDING 7 A.M..........0.0  DEPARTURE........-0.1
TOTAL SNOWFALL FOR THE MONTH................2.6  DEPARTURE........+0.4
TOTAL SNOWFALL FOR THE SEASON..............92.8  DEPARTURE.......+30.8

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

4/01 58/33/46/+5/..../0.0/336/44   45 SSW AERO 43 SSW RMY N/A  
4/02 38/30/34/-7/..../1.6/077/10   20 SSW AERO 15 SSW RMY 17
4/03 48/30/39/-3/..../0.0/.../..   28 SSE AERO 25 SSE RMY 25
4/04 54/36/45/+3/..../0.0/.../..   56 WNW AERO 56 WNW RMY 54
4/05 40/27/34/-9/0.00/0.0/.../..   53 WNW AERO 53 WNW RMY 52 
4/06 41/25/33/-10/0.25/1.0/.../..  37 S   AERO 36 S   RMY 38
4/07 46/32/35/-4/0.00/0.0/.../..   32 WNW AERO 35 WNW RMY 34<
4/08 41/29/35/-9/0.00/0.0/.../..   35 WNW*AERO 31 WNW RMY 34
4/09 45/24/35/-9/0.00/0.0/.../..   28 WNW*AERO 25 WNW RMY 29
4/10 39/31/35/-10/T/T/.../..       14 SSW AERO 13 SSW RMY N/A
4/11 48/29/39/-6/T/0.0/.../..      24 SSE AERO 23 SSE RMY 25 
4/12 61/33/47/+2/..../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/..../0.0/.../..   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 Low temp since midnight is 32F; normal low is now 38F

*Estimated

DAILY EXTREMES
Temperature and precipitation records back to 1885, and
wind records back to 1940 (e = estimated):    

RECORDS FOR APRIL 16
HIGH 89 IN 2012
LOW 23 IN 1943
PRECIP 2.45 IN. IN 1929
SNOWFALL 2.0 IN. IN 1904, 1962
PEAK GUST 73 MPH E IN 2007

RECORDS FOR APRIL 17
HIGH 93 IN 2002
LOW 21 IN 1908
PRECIP 1.68 IN 1954
SNOWFALL 1.0 IN. IN 1899
PEAK GUST 63 MPH ESE IN 2011

TODAY'S REPORT PREPARED BY: K.A. Geagan