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

DAILY DISCUSSION AND CLIMATE SUMMARY
WEDNESDAY, JUNE 20, 2018  
ALL TIMES ARE IN EASTERN STANDARD TIME

TEMPERATURES QUICKLY RISE AFTER WIND SHIFT BRINGS
WIND FROM THE SOUTH-SOUTHWEST... 

The morning began comfortably with light wind, low 
humidity and seasonable temperatures. The overnight 
low of 58F is 1 degree below the daily normal of 59F. 
The wind shifted just before 7:00 A.M. from northwest 
to south-southwest and temperatures quickly began to 
rise. So far today we reached a max temperature of 81F 
by 1:00 P.M. This is 5 degrees above the daily normal 
of 76F. The visibility was best at the 7:00 A.M. 
observation with 80 miles. Commonly when we have wind 
from the south a haze is observed, today it only slightly 
obscured visibility with 70 miles at each other 
observation. The cloud cover and wind increased throughout 
the day today due to the falling pressure which began
to fall just after 7:00 A.M.

Today's Observations:

7 A.M.
Weather: Scattered altocumulus  
Temperature: 68F; Dew Point: 48F; Wind: S at 3 kts,
Wind: Light
Sea-level pressure: 29.94 ins. Hg, rising, then more rapidly  
Visibility: 80 miles
6-hr Max temp: 68F
6-hr Min temp: 58F
24-hr Precip: 0.00 ins.
BHO SA 1155 160 SCT 80 140/68/48/1703/994/ WND LGT/ 8/030 
53015 10068 20058

10 A.M.
Weather: Scattered altocumulus, scattered cirrus, few 
distant cumulus SSE-S
Temperature: 76F; Dew Point: 50F; Wind: S at 8G13 kts
Sea-level pressure: 29.90 ins. Hg, falling, then more rapidly 
Visibility: 70 miles, thin distant haze in all directions
3-hr Precip: 0.00 ins
BHO SA 1455 160 SCT 250 SCT 70 125/76/50/1908G13/990/ 
FEW CU DSNT SSE-S THN DSNT HZ ALQDS/ 8/132 58015 

1 P.M.
Weather: Scattered altocumulus, broken cirrus, few 
distant cumulus E-SSW
Temperature: 79F; Dew Point: 50F; Wind: WSW at 11G16 kts
Sea-level pressure: 29.84 ins. Hg, rising, then falling
Visibility: 70 miles, thin distant haze in all directions
6-hr Max temp: 81F
6-hr Min temp: 68F
6-hr precip: 0.00 ins.
BHO SA 1755 160 SCT 250 BKN 70 104/79/50/2511G16/984/ FEW 
CU DSNT E-SSW THN DSNT HZ ALQDS/ 8/132 58021 10081 20068 

SUMMARY FOR TUESDAY, JUNE 19, 2018

TEMPERATURE (DEGREES F)
MAX.....81   NORMAL.....76
MIN.....64   NORMAL.....58
MEAN....73   NORMAL.....67

DEPARTURE FROM 30-YEAR NORMAL.........................+6
TOTAL DEPARTURE FOR THE MONTH.........................-5 [-0.5 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY..............0   DEPARTURE...........-2
TOTAL HEATING UNITS FOR THE MONTH.............62   DEPARTURE............0
TOTAL HEATING UNITS FOR THE SEASON..........5909   DEPARTURE.........-456
TOTAL HEATING UNITS LAST SEASON TO DATE.....5724   DIFFERENCE........+185

COOLING DEGREE DAYS (SEASON JAN TO DEC)
TOTAL COOLING UNITS FOR YESTERDAY...............8   DEPARTURE..........+4
TOTAL COOLING UNITS FOR THE MONTH..............48   DEPARTURE..........-3
TOTAL COOLING UNITS FOR THE SEASON............110   DEPARTURE.........+35
TOTAL COOLING UNITS LAST SEASON TO DATE.......130   DEPARTURE.........-20

PEAK GUST AND AVERAGE WIND SPEED (MPH) 
PEAK WIND GUST FOR YESTERDAY....................31 WSW AT 12:27 A.M.
                   AERO.........................32 WSW AT 12:27 A.M. 
                   ASOS.........................33 SW  AT 12:27 A.M.
                   DAVIS........................35 M   AT 12:27 A.M.** RMY 32
FASTEST MILE FOR YESTERDAY......................22 NW  AT 10:36 A.M.
MAXIMUM 2-MINUTE ASOS AVERAGE...................21 NW  AT 10:38 A.M.  
MAXIMUM 2-MINUTE DAVIS AVERAGE..................22 M   AT 12:30 A.M.**
AVERAGE WIND SPEED AND DIRECTION..............12.7 NW
                   ASOS.......................12.2
                   DAVIS......................11.8
**Davis direction malfunctioning 

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.00  DEPARTURE......-0.15
                         ASOS..............0.00
TOTAL PRECIPITATION FOR THE MONTH..........1.13  DEPARTURE......-1.88
                         ASOS..............1.15  
TOTAL PRECIPITATION FOR THE YEAR..........28.45  DEPARTURE......+2.96
                         ASOS.............30.02

PRELIMINARY CLIMATE SUMMARY FOR JUNE CALENDAR DAY DATA
DATE: MAX/MIN/MEAN/DEP/PRECIP/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

6/01 78/62/70/+8/T/009/01            21 S   AERO 21 S   RMY N/A
6/02 79/54/67/+5/T/353/39            26 ENE AERO 25 ENE RMY 27
6/03 59/45/52/-10/0.00/816/90        28 ENE AERO 25 ENE RMY N/A  
6/04 52/45/49/-14/0.82/000/00        29 ENE AERO 26 ENE RMY 29
6/05 64/47/56/-7/0.19/173/19         24 N   AERO 21 N   RMY 23  TSTM  
6/06 66/50/58/-5/0.00/373/41         23 S   AERO 21 S   RMY 22
6/07 69/50/60/-4/0.00/282/31         25 S   AERO 25 S   RMY 27 
6/08 79/52/66/+2/0.00/.../..         20 SW  AERO 17 SW  RMY 18
6/09 79/58/69/+5/0.00/.../..         22 W   AERO 21 W   RMY 22
6/10 72/56/64/-1/0.00/.../..         20 S   AERO 18 S   RMY 17
6/11 68/51/60/-5/0.00/.../..         21 ENE AERO 20 SSW RMY N/A
6/12 77/49/63/-2/0.00/.../..         37 SW  AERO 37 SW  RMY 39
6/13 74/56/65/0/T/.../..             35 SW  AERO 36 SW  RMY 36
6/14 77/61/69/+3/0.00/.../..         35 W   AERO 36 WNW RMY 37
6/15 68/53/61/-5/0.01/.../..         17 NNW AERO 16 WNW RMY 19
6/16 83/54/69/+3/0.00/.../..         25 NNW AERO 24 NNW RMY 25
6/17 86/63/75/+8/0.00/.../..         23 S   AERO 22 S   RMY N/A
6/18 86/64/75/+8/0.10/.../..         37 SSW AERO 37 SSW RMY 40  TSTM
6/19 81/64/73/+6/0.01/.../..         31 WSW AERO 32 WSW RMY 32 

6/20 Low temp since midnight is 58F; normal low is now 59F

DAILY RECORDS FOR JUNE 2018

None so far.

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

RECORDS FOR JUNE 20
HIGH 94F IN 1953
LOW 41F IN 1918
PRECIP 2.62 INS 1945
PEAK GUST 63 MPH NE IN 1967, SSW IN 2010 

RECORDS FOR JUNE 21
HIGH 94F IN 2012
LOW 42F IN 1940
PRECIP 1.40 INS 1903
PEAK GUST 51 MPH SSW IN 2000

TODAY'S REPORT PREPARED BY: Kaitlin Geagan