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

DAILY DISCUSSION AND CLIMATE SUMMARY
WEDNESDAY, APRIL 19, 2017  
ALL TIMES ARE IN EASTERN STANDARD TIME

AFTERNOON WINDS INCREASE AND LOW CLOUDS BEGIN TO CLEAR

This morning began with light winds out of the south-
southeast and skies mostly cloudy with stratocumulus
and altostratus. Low clouds cleared to just a few
cumulus by the 1:00PM EST observation, but skies were
still mostly cloudy with a layer of scattered alto-
cumulus and a layer of broken cirrus.

Wind speeds increased into early afternoon with gusts
over 25 MPH. Visibility decreased since yesterday 
back down to 40 miles at each observation.


Today's Observations:

7 A.M.
Weather: Broken stratocumulus, broken altostratus
Temperature: 40F; Dew Point: 30F; Wind: SSE at 7 kts
Sea-level pressure: 30.58 ins. Hg, rising unsteadily
Visibility: 40 miles, distant fog in all directions
6-hr Max temp: 40F
6-hr Min temp: 34F
24-hr precip: 0.00 in.
24-hr snowfall: 0.0 in.
BHO SA 1155 E20 BKN 230 BKN 40 354/40/30/1507/058/ DSNT FG ALQDS/
8/510 52003 10040 20034

10 A.M.
Weather: Broken cumulus, broken cirrus
Temperature: 47F; Dew Point: 31F; Wind: S at 9G14 kts
Sea-level pressure: 30.50 ins. Hg, falling, then more quickly
Visibility: 40 miles
BHO SA 1455 E24 BKN 250 BKN 40 330/47/31/1709G14/050/ 8/101 58024

1 P.M.
Weather: Few cumulus in all directions, scattered altocumulus,
broken cirrus
Temperature: 54F; Dew Point: 29F; Wind: S at 16G22 kts
Sea-level pressure: 30.43 ins. Hg, falling, then more quickly
Visibility: 40 miles
6-hr Max temp: 54F
6-hr Min temp: 40F
BHO SA 1755 140 SCT E250 BKN 40 306/54/29/1816G22/043/ FEW CU ALQDS/
8/131 56024 10054 20040


SUMMARY FOR TUESDAY, APRIL 18, 2017
 
TEMPERATURE (DEGREES F)
MAX.....52   NORMAL.....57
MIN.....35   NORMAL.....39
MEAN....44   NORMAL.....48

DEPARTURE FROM 30-YEAR NORMAL.........................-4
TOTAL DEPARTURE FOR THE MONTH.......................+102 [+5.5 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY..............21   DEPARTURE..........+4
TOTAL HEATING UNITS FOR THE MONTH.............278   DEPARTURE.........-94
TOTAL HEATING UNITS FOR THE SEASON...........5180   DEPARTURE........-675
TOTAL HEATING UNITS LAST SEASON TO DATE......4823   DIFFERENCE.......+357

COOLING DEGREE DAYS (SEASON JAN TO DEC)
TOTAL HEATING UNITS FOR YESTERDAY...............0   DEPARTURE...........0
TOTAL HEATING UNITS FOR THE MONTH...............9   DEPARTURE..........+9
TOTAL HEATING UNITS FOR THE SEASON..............9   DEPARTURE..........+9
TOTAL HEATING UNITS LAST SEASON TO DATE.........0   DIFFERENCE.........+9

PEAK GUST AND AVERAGE WIND SPEED (MPH) 
PEAK WIND GUST FOR YESTERDAY...................25 ENE AT 6:03 P.M.
                   AERO........................23 ENE AT 3:14 P.M.
                   ASOS........................27 ENE AT 4:32 P.M.
                   DAVIS.......................24  E  AT 4:31 P.M. RMY 25
FASTEST MILE FOR YESTERDAY.....................18  E  AT 5:58 P.M.*
MAXIMUM 2-MINUTE ASOS AVERAGE..................20  E  AT 4:21 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE.................17  E  AT 4:21 P.M.
AVERAGE WIND SPEED AND DIRECTION.............11.1 ENE
                   ASOS......................11.0
                   DAVIS......................9.5 ENE [070 deg.]
*LAST OF MULTIPLE 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..........4.28  DEPARTURE......+1.34
                         ASOS..............4.29
TOTAL PRECIPITATION FOR THE YEAR..........18.40  DEPARTURE......+1.46
                         ASOS...............N/A ***
*** ASOS annual total not available due to erroneous readings

SNOWFALL (INCHES) THROUGH THIS MORNING (EST)
TOTAL SNOWFALL 24 HRS ENDING 7 A.M..........0.0  DEPARTURE.......-0.1
TOTAL SNOWFALL FOR THE MONTH................2.7  DEPARTURE.......+0.2
TOTAL SNOWFALL FOR THE SEASON..............66.4  DEPARTURE.......+4.2


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

4/1  35/31/33/-8/2.21/2.7/000/00           40 ENE AERO 41 ENE RMY 41
4/2  53/30/42/+1/0.00/0.0/.../..           32 NW  AERO 33 NW  RMY 34
4/3  60/35/48/+6/0.00/0.0/.../..           21 W*  AERO 20 NW  RMY N/A
4/4  42/35/39/-3/0.78/0.0/.../..           41 ESE AERO 43 ESE RMY 42
4/5  41/35/38/-5/0.00/0.0/000/00           21 NNW AERO 20 NNW RMY N/A
4/6  55/35/45/+2/1.27/0.0/000/00           35 SSE AERO 37 S   RMY 37  TSTM
4/7  53/38/46/+3/0.00/0.0/.../..           43 SSW AERO 47 SSW RMY 48
4/8  50/34/42/-2/0.00/0.0/.../..           37 WNW AERO 40 WNW RMY 39
4/9  65/34/50/+6/0.00/0.0/.../..           23 W   AERO 23 W   RMY N/A
4/10 77/45/61/+16/0.00/0.0/.../..          37 S   AERO 37 S   RMY 39
4/11 85/50/68/+23/0.00/0.0/.../..          28 S   AERO 28 S   RMY 30
4/12 68/47/58/+13/0.01/0.0/.../..          26 WNW AERO 28 WNW RMY N/A
4/13 58/39/49/+3/0.00/0.0/.../..           28 WNW AERO 31 NW  RMY 30 
4/14 62/40/51/+5/0.00/0.0/.../..           22 NNW AERO 22 NNW RMY 24
4/15 68/40/54/+7/0.01/0.0/.../..           40 SSW AERO 45 SSW RMY 45
4/16 86/55/71/+24/T/0.0/.../..             38 W*  AERO 39 SW  RMY 42
4/17 75/48/62/+15/0.00/0.0/.../..          37 W   AERO 37 W   RMY 43
4/18 52/35/44/-4/0.00/0.0/.../..           25 ENE AERO 23 ENE RMY 25

4/19 Low temp since midnight is 34F; normal low is now 39F


DAILY RECORDS FOR APRIL 2017

4/11/17: DAILY RECORD MAXIMUM TEMPERATURE OF 85F,
         BREAKS PREVIOUS RECORD OF 78F SET IN 1945

4/11/17: DAILY RECORD HIGH MINIMUM TEMPERATURE OF 50F,
         TIES WITH PREVIOUS RECORD SET IN 1955


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

RECORDS FOR APRIL 19
HIGH 94 IN 1976 [RECORD FOR MONTH]
LOW 21 IN 1890
PRECIP 1.71 IN 1969
SNOWFALL 6.0 IN. IN 1887
PEAK GUST 66 MPH E IN 1984

RECORDS FOR APRIL 20
HIGH 88 IN 1927
LOW 18 IN 1897
PRECIP 1.14 IN 1972
SNOWFALL 2.5 IN. IN 1904, 1972
PEAK GUST 76 MPH WNW IN 1963

TODAY'S REPORT PREPARED BY: Cecilia Borries-Strigle