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

DAILY DISCUSSION AND CLIMATE SUMMARY
THURSDAY, SEPTEMBER 27, 2018 
ALL TIMES ARE IN EASTERN STANDARD TIME

A FAIR AUTUMN DAY WITH GREAT VISIBILITY ATOP GREAT BLUE HILL.... 

Temperatures have reached 66F so far today, 3 degrees below
the daily normal of 67F. The low since midnight is 57F, 7 degrees
above the normal minimum temperature of 50F. Winds have remained 
from the northeast, blowing at or above 10 mph. Humidity dropped 
from 90% this morning to 56% at the 1 P.M. observation. Visibility
stayed excellent throughout the day at 80 miles. We measured 0.55 
inches of rain this morning from the last night's storms.  

Today's Observations:

7 A.M.
Weather: Broken altocumulus, broken cirrocumulus, few
stratocumulus in all directions 
Temperature: 57F; Dew Point: 55F; Wind: N at 11G16 kts  
Sea-level pressure: 30.09 ins. Hg, rising, then more slowly        
Visibility: 80 miles
6-hr Max temp: 66F
6-hr Min temp: 57F
24-hr Precip: 0.56 ins.   
BHO SA 1155 E160 BKN E250 BKN 80 191/57/55/3511G16/009/ FEW SC ALQDS/ 
8/479 70056 51029 10066 20057

10 A.M.
Weather: Broken altocumulus, broken cirrocumulus, few
cumulus in all directions
Temperature: 65F; Dew Point: 51F; Wind: NNE at 14G24 kts  
Sea-level pressure: 30.04 ins. Hg, rising steadily
Visibility: 80 miles 
3-hr Precip: 0.00 ins.
BHO SA 1455 E160 SCT E250 BKN 80 173/65/51/0314G24/004/ FEW CU ALQDS/ 
8/179 51018

1 P.M.
Weather: Scattered cirrus, few cumulus NE-N
Temperature: 66F; Dew Point: 50F; Wind: NE at 12G18 kts
Sea-level pressure: 30.03 ins. Hg, falling steadily     
Visibility: 80 miles 
6-hr Max temp: 66F
6-hr Min temp: 57F 
6-hr Precip: 0.00 ins.
BHO SA 1755 250 SCT 80 169/66/50/0412G18/003/ FEW CU NE-N/ 8/102 
58004 10066 20057 
  
SUMMARY FOR WEDNESDAY, SEPTEMBER 26, 2018 

TEMPERATURE (DEGREES F)
MAX.....79   NORMAL.....68
MIN.....66   NORMAL.....51
MEAN....73   NORMAL.....59

DEPARTURE FROM 30-YEAR NORMAL......................+14
TOTAL DEPARTURE FOR THE MONTH......................+77 [+2.8 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY...............0   DEPARTURE.........-7
TOTAL HEATING UNITS FOR THE MONTH..............61   DEPARTURE........-26
TOTAL HEATING UNITS FOR THE SEASON.............61   DEPARTURE........-51
TOTAL HEATING UNITS LAST SEASON TO DATE........68   DIFFERENCE........-7

COOLING DEGREE DAYS (SEASON JAN TO DEC)
TOTAL COOLING UNITS FOR YESTERDAY...............8  DEPARTURE..........+7
TOTAL COOLING UNITS FOR THE MONTH.............110  DEPARTURE.........+53
TOTAL COOLING UNITS FOR THE SEASON............863  DEPARTURE........+269
TOTAL COOLING UNITS LAST SEASON TO DATE.......697  DIFFERENCE.......+166

PEAK GUST AND AVERAGE WIND SPEED (MPH) 
PEAK WIND GUST FOR YESTERDAY.....................35 SSW AT 12:02 P.M.
                   AERO..........................37 SSW AT 12:00 P.M.
                   ASOS..........................37 S   AT 12:03 P.M.
                   DAVIS.........................36 SSW AT 12:07 P.M. RMY 37
FASTEST MILE FOR YESTERDAY.......................26 SSW AT 12:03 P.M. 
MAXIMUM 2-MINUTE ASOS AVERAGE....................26 SSW AT 12:07 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE...................26 SSW AT 12:08 P.M.
AVERAGE WIND SPEED AND DIRECTION..............16.6 SSW
                   ASOS.......................16.6
                   DAVIS......................15.5 SSW [215 deg.]   

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.56  DEPARTURE......+0.41
                         ASOS..............0.56
TOTAL PRECIPITATION FOR THE MONTH..........8.64  DEPARTURE......+5.17
                         ASOS..............8.90 
TOTAL PRECIPITATION FOR THE YEAR..........46.59  DEPARTURE......+8.28
                         ASOS.............48.42 

PRELIMINARY CLIMATE SUMMARY FOR SEPTEMBER 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

9/01 75/58/67/-1/0.00/521/66        17 NE  AERO 15 NE  RMY 16 
9/02 83/61/72/+4/0.00/684/87        20 SSW AERO 18 SSW RMY N/A 
9/03 92/68/80/+13/0.00/650/83       24 WSW AERO 22 WSW RMY 25
9/04 88/70/79/+12/0.00/695/89       17 W   AERO 16 W   RMY 17 
9/05 89/67/78/+11/0.00/638/82       23 SSW AERO 23 SSW RMY 25 
9/06 92/70/81/+14/0.56/488/63       29 NNW AERO 29 NNW RMY N/A TSTM
9/07 70/63/67/+1/0.01/000/00        24 NE  AERO 22 NE  RMY N/A 
9/08 68/54/61/-5/0.00/031/04        22 NE  AERO 18 NE  RMY 21
9/09 61/53/57/-9/0.00/000/00        23 NE  AERO 21 NE  RMY N/A
9/10 62/56/59/-6/..../.../..        30 E   AERO 28 E   RMY 28
9/11 75/61/68/+3/..../.../..        23 E   AERO 21 E   RMY N/A TSTM 
9/12 69/63/66/+1/..../.../..        21 ENE AERO 21 ENE RMY 21  TSTM 
9/13 68/62/65/+1/..../.../..        21 NE  AERO 21 NE  RMY N/A TSTM 
9/14 75/61/68/+4/..../.../..        13 NE  AERO 12 ENE RMY 12 
9/15 76/62/69/+5/0.01/.../..        14 SW  AERO 13 SW  RMY 13
9/16 84/61/73/+10/..../.../..       15 S   AERO 14 S   RMY N/A
9/17 82/64/73/+10/..../.../..       22 SSW AERO 22 SSW RMY N/A
9/18 74/67/71/+9/..../.../..        31 SSW AERO 30 SSW RMY N/A TSTM
9/19 66/57/62/0/..../.../..         28 NE  AERO 25 NE  RMY 26
9/20 63/55/59/-3/..../.../..        22 NE  AERO 21 NE  RMY 19
9/21 70/55/63/+2/..../.../..        37 SSW AERO 37 SSW RMY 41
9/22 70/51/61/0/..../.../..         37 SW  AERO 36 SW  RMY 30
9/23 60/47/54/-6/..../.../..        14 N   AERO 13 N   RMY N/A 
9/24 55/50/53/-7/..../.../..        37 ENE AERO 35 ENE RMY 35
9/25 68/51/60/0/..../.../..         36 SE  AERO 37 SE  RMY 38
9/26 79/66/73/+14/..../.../..       35 SSW AERO 37 SSW RMY 37

9/27 Low temp since midnight is 57F; normal low is now 50F

DAILY RECORDS FOR SEPTEMBER

09/04/18: DAILY RECORD HIGH MINIMUM TEMPERATURE OF 70F,
          BREAKS PREVIOUS RECORD OF 68F SET IN 1937 AND 1959

09/06/18: DAILY RECORD HIGH MAXIMUM TEMPERATURE OF 92F,
          TIES PREVIOUS RECORD OF 92F SET IN 1900 

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

RECORDS FOR SEPTEMBER 27
HIGH 86F IN 2017
LOW 32F IN 1947
PRECIP 2.26 INCHES IN 1962
PEAK GUST 100 MPH SSE IN 1985 (HURRICANE GLORIA)

RECORDS FOR SEPTEMBER 28
HIGH 86F IN 2014
LOW 33F IN 1897,1947
PRECIP 2.46 INCHES IN 2004
PEAK GUST 69 MPH NE IN 1962

TODAY'S REPORT PREPARED BY: Benjamin Turner