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

DAILY DISCUSSION AND CLIMATE SUMMARY
WEDNESDAY, APRIL 22, 2020
ALL TIMES ARE IN EASTERN STANDARD TIME

A STRONG WESTERLY WIND KEEPS TEMPERATURES
LOW AS THE SKY BECOMES OVERCAST IN THE
AFTERNOON HOURS...

The day started off with partly cloudy skies and chilly
temperatures in the low 30s. However clouds quickly 
increased by mid to late morning with some snow flurries
between the 10 A.M. and 1 P.M. observations. We observed 
only a trace of snow during that time. Visibility has 
remained good, being 70 miles on average.

A west wind has been increasing steadily into early this 
afternoon with frequent gusts over 40 mph and a peak gust
thus far of 47 mph at 11:50 P.M.

Despite intermittent sunshine, temperatures are lower
than seasonal averages. This is due to significant 
cold air advection from the west. Our high temperature 
so far today is 41F, which is 17 degrees below our daily 
normal high temperature of 58F. The low since midnight 
is 30F, which is 10 degrees below the daily normal low 
of 40F. 


Today's Observations:

7 A.M.
Weather: Scattered cumulus
Temperature: 32F; Dew Point: 14F; Relative Humidity: 46%
Wind: S at 23G39 kts, peak wind W 45 MPH at 6:50 A.M.
Sea-level pressure: 29.68 ins. Hg: rising steadily
Visibility: 75 miles
6-hr Max temp: 32F
6-hr Min temp: 30F
24-hr Precip:  0.34 ins.
24-hr Snowfall: 0.0 ins.
BHO SA 1155 50 SCT 75 051/32/14/2823G39/968/ PK WND 2739/50/ 
8/100 70034 53020 10032 20030

10 A.M.
Weather: Broken altostratus
Temperature: 36F; Dew Point: 18F; Relative Humidity: 48%
Wind: W at 21G33 kts, peak wind W 42 MPH at 9:19 A.M.
Sea-level pressure: 29.69 ins. Hg: falling then rising
Visibility: 75 miles
3-hr Precip:   0.00 ins.
3-hr Snowfall: 0.0 ins.
BHO SA 1455 E70 BKN 75 056/36/18/2721G33/969/ PK WND 2836/19/ 
8/020 600// 50005

1 P.M.
Weather: Broken stratocumulus
Temperature: 40F; Dew Point: 17F; Relative Humidity: 39%
Wind: W at 17G37 kts, peak wind W 47 MPH at 11:41 A.M. 
Sea-level pressure: 29.69 ins. Hg: rising unsteadily
Visibility: 65 miles
6-hr Max temp: 41F
6-hr Min temp: 32F
6-hr Precip:   Trace
6-hr Snowfall: Trace
BHO SA 1755 E50 BKN 65 057/40/17/2717G37/969/ NEW SNOW PST 6 HRS TRACE PK 
WND 2843/1641/ 8/800 600// 52001 10041 20032


SUMMARY FOR TUESDAY, APRIL 21, 2020 

TEMPERATURE (DEGREES F)
MAX.....53   NORMAL.....58
MIN.....33   NORMAL.....40
MEAN....43   NORMAL.....49

DEPARTURE FROM 30-YEAR NORMAL................... -6
TOTAL DEPARTURE FOR THE MONTH...................-27 [-1.5 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY...............22  DEPARTURE....... +6
TOTAL HEATING UNITS FOR THE MONTH..............447  DEPARTURE.......+26
TOTAL HEATING UNITS FOR THE SEASON............5320  DEPARTURE......-585
TOTAL HEATING UNITS LAST SEASON TO DATE.......5748  DEPARTURE......-428

PEAK GUST AND AVERAGE WIND SPEED (MPH) 
PEAK WIND GUST FOR YESTERDAY....................52 S   AT 12:23 P.M.  
                   AERO.........................52 S   AT 12:59 P.M  
                   ASOS.........................52 S   AT 12:24 P.M. 
                   DAVIS........................53 S   AT 12:24 P.M. RMY 52
FASTEST MILE FOR YESTERDAY......................38 S   AT 12:38 P.M. 
MAXIMUM 2-MINUTE ASOS AVERAGE...................36 S   AT 12:25 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE..................37 S   AT 12:25 P.M.
AVERAGE WIND SPEED AND DIRECTION................18.8 S               
                   ASOS.........................18.0
                   DAVIS........................18.2 SSW [209 deg.]

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.34  DEPARTURE......+0.21
                         ASOS..............0.35
TOTAL PRECIPITATION FOR THE MONTH..........6.00  DEPARTURE......+2.66
                         ASOS..............6.19
TOTAL PRECIPITATION FOR THE YEAR..........15.33  DEPARTURE......-2.22
                         ASOS.............15.92

SNOWFALL (INCHES) THROUGH THIS MORNING (EST)
TOTAL SNOWFALL 24 HRS ENDING 7 A.M..........0.0  DEPARTURE....... 0.0
TOTAL SNOWFALL FOR THE MONTH................4.3  DEPARTURE.......+1.6
TOTAL SNOWFALL FOR THE SEASON..............31.9  DEPARTURE......-30.5

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

04/01  42/28/35/-6/0.00/0.0/008/01         28 NE  AERO 28 NE  RMY 30
04/02  46/35/41/0/.../0.0/000/00           39 NW  AER0 40 NW  RMY 41
04/03  42/38/40/-2/..../0.0/000/00         48 NE  AERO 53 NE  RMY 49
04/04  46/36/41/-1/..../0.0/278/36         38 NE  AERO 38 NE  RMY N/A
04/05  55/36/46/+3/T/0.0/039/05            22 S   AERO 21 S   RMY 21
04/06  61/40/51/+8/0.00/0.0/732/94         29 NW  AERO 30 NW  RMY 29
04/07  63/42/53/+10/0.00/0.0/649/83        29 W   AERO 30 W   RMY 28
04/08  50/41/46/+2/..../.../047/06         23 S   AERO 22 S   RMY 22 
04/09  47/37/42/-2/..../.../000/00         58 W   AERO 58 W   RMY 56
04/10  47/35/41/-4/0.02/T/324/41           48 W   AERO 50 W   RMY 53 
04/11  51/33/42/-3/0.00/0.0/730/92         38 WNW AERO 39 WNW RMY 40
04/12  60/33/47/+2/0.00/0.0/326/41         38 S   AERO 40 S   RMY N/A
04/13  59/50/55/+9/1.42/0.0/000/00         79 S   AERO 83 S   RMY 78
04/14  57/41/49/+3/0.00/0.0/.../..         41 W   AERO 40 W   RMY N/A
04/15  52/36/44/-3/0.02/0.0/.../..         37 W   AERO 36 W   RMY 37
04/16  47/32/40/-7/T/T/.../..              33 WNW AERO 33 WNW RMY 32
04/17  49/29/39/-8/..../0.0/.../..         41 W   AERO 39 W   RMY 41
04/18  37/31/34/-14/..../4.3/.../..        29 NE  AERO 25 NE  RMY 25
04/19  60/31/46/-2/0.00/0.0/.../..         40 SSW AERO 40 SSW RMY 41
04/20  49/37/43/-6/0.00/0.0/.../..         25 ENE AERO 22 W   RMY N/A
04/21  53/33/43/-6/..../.../.../..         52 S   AERO 52 S   RMY 52

04/22 The low since midnight is 30F, daily normal minimum is 40F 

DAILY RECORDS FOR APRIL 2020

4/13/2020
NEW PEAK GUST OF 79 MPH S, REPLACING THE OLD
RECORD OF 59 MPH SSW IN 1995

4/18/2020
NEW RECORD SNOWFALL OF 4.3 INS, REPLACING THE OLD
RECORD OF 3.7 INS IN 1965

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: Benjamin Turner