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

DAILY DISCUSSION AND CLIMATE SUMMARY
TUESDAY, SEPTEMBER 25, 2018 
ALL TIMES ARE IN EASTERN STANDARD TIME

STEADY RAIN ARRIVING AS A WARM FRONT APPROACHES THE REGION.... 

High Pressure lingering offshore is contributing 
to increased windspeed and ESE winds ushering in greater moisture 
from the ocean. Combined with a low pressure system pressing in 
to our north, we observe steady rain as the storm's warm sector 
enters the region. Rainfall began this morning around 8 A.M., 
amounting to 0.12 inches by 1 P.M. Winds have shifted from NE to SE 
overnight with speeds at or exceeding 20 mph past noontime. The 
high so far today is 59F, 9 degrees below the normal maximum of 68F.
The low since midnight is 51, the same as the daily normal. 

Today's Observations:

7 A.M.
Weather: Overcast altostratus, few cumulus NW-E 
Temperature: 54F; Dew Point: 50F; Wind: ESE at 12G18 kts  
Sea-level pressure: 30.52 ins. Hg, falling, then more rapidly        
Visibility: 20 miles, distant fog in all directions
6-hr Max temp: 54F
6-hr Min temp: 51F
24-hr Precip: 0.00 ins.   
BHO SA 1155 E140 OVC 20 335/54/50/1012G18/052/ 
FEW CU NW-E DSNT FG ALQDS/ 8/110 58005 10054 20051

10 A.M.
Weather: Overcast nimbostratus, few cumulus in all
directions, light rain becoming light drizzle
Temperature: 58F; Dew Point: 56F; Wind: E at 13G18 kts  
Sea-level pressure: 30.48 ins. Hg, falling, then more rapidly
Visibility: 20 miles, distant fog in all directions 
3-hr Precip: 0.01 ins.
BHO SA 1455 E140 OVC 20L- 322/58/56/0913G18/048/ 
DSNT FG ALQDS FEW CU ALQDS R-BCMG L-UNK/ 8/120 6001/ 58013

1 P.M.
Weather: Overcast nimbostratus, few stratus fractus in all 
directions, moderate rain
Temperature: 59F; Dew Point: 58F; Wind: ESE at 16G26 kts, 
Peak wind: 26 kts (30 mph) ESE at 12:47 P.M.
Sea-level pressure: 30.37 ins. Hg, falling, then more rapidly     
Visibility: 10 miles, distant fog in all directions 
6-hr Max temp: 59F
6-hr Min temp: 54F 
6-hr Precip: 0.12 ins.
BHO SA 1755 E85 OVC 10R 286/59/58/1116G26/037/ DSNT FG ALQDS 
FEW STFA ALQDS R CTD PK WND 1126/47/ 8/72/ 6012/ 58036 10059 20054 
  
SUMMARY FOR MONDAY, SEPTEMBER 24, 2018 

TEMPERATURE (DEGREES F)
MAX.....55   NORMAL.....69
MIN.....50   NORMAL.....52
MEAN....53   NORMAL.....60

DEPARTURE FROM 30-YEAR NORMAL.......................-7
TOTAL DEPARTURE FOR THE MONTH......................+63 [+2.4 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY..............12   DEPARTURE.........+6
TOTAL HEATING UNITS FOR THE MONTH..............56   DEPARTURE........-18
TOTAL HEATING UNITS FOR THE SEASON.............56   DEPARTURE........-43
TOTAL HEATING UNITS LAST SEASON TO DATE........68   DIFFERENCE.......-12

COOLING DEGREE DAYS (SEASON JAN TO DEC)
TOTAL COOLING UNITS FOR YESTERDAY...............0  DEPARTURE..........-1
TOTAL COOLING UNITS FOR THE MONTH.............102  DEPARTURE.........+47
TOTAL COOLING UNITS FOR THE SEASON............855  DEPARTURE........+263
TOTAL COOLING UNITS LAST SEASON TO DATE.......676  DIFFERENCE.......+179

PEAK GUST AND AVERAGE WIND SPEED (MPH) 
PEAK WIND GUST FOR YESTERDAY.....................37 ENE AT 6:21 A.M.
                   AERO..........................35 ENE AT 6:20 A.M.
                   ASOS..........................38 ENE AT 6:21 A.M.
                   DAVIS.........................37 ENE AT 6:21 A.M. RMY 35
FASTEST MILE FOR YESTERDAY.......................26 ENE AT 6:22 A.M. 
MAXIMUM 2-MINUTE ASOS AVERAGE....................25 ENE AT 6:22 A.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE...................27 ENE AT 6:22 A.M.
AVERAGE WIND SPEED AND DIRECTION..............13.6 ENE
                   ASOS.......................13.8
                   DAVIS......................14.0 ENE [72 deg.]   

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..........6.46  DEPARTURE......+3.29
                         ASOS..............6.53 
TOTAL PRECIPITATION FOR THE YEAR..........44.41  DEPARTURE......+6.40
                         ASOS.............46.05 

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 Low temp since midnight is 51F; normal low is now 51F

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 25
HIGH 87F IN 1970
LOW 31F IN 1950
PRECIP 2.68 INCHES IN 1961
PEAK GUST 63 MPH SSW IN 1991

RECORDS FOR SEPTEMBER 26
HIGH 91F IN 2007
LOW 36F IN 1905,1922,1978
PRECIP 3.84 INCHES IN 1888
PEAK GUST 54e MPH S IN 1977

TODAY'S REPORT PREPARED BY: Benjamin Turner and Nate Iannuccillo