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

DAILY DISCUSSION AND CLIMATE SUMMARY
TUESDAY, SEPTEMBER 26, 2017  
ALL TIMES ARE IN EASTERN STANDARD TIME

ABOVE NORMAL TEMPERATURES AND HUMID CONDITIONS CONTINUE

Thick fog covered the top of Great Blue Hill this morning making
visibility just 1/8 mile.  Skies had scattered cumulus fractus
from the clearing fog and broken cirrus at the 10:00AM observation.
The foggy and cloudy conditions in the morning helped to keep temps.
slightly lower than the previous two days, reaching a maximum of 82F
by 1:00PM.  Visibility increased to 60 miles in the afternoon, but hazy
conditions still persisted in the northwest limiting visibility to 30
miles in that direction.

Today's Observations:

7 A.M.
Weather: Sky obscurement due to fog
Temperature: 66F; Dew Point: 66F; Wind: estimated W at 2 kts,
Wind: Light and variable
Sea-level pressure: 30.06 ins. Hg, rising unsteadily
Visibility: 1/8 mile
6-hr Max temp: 66F
6-hr Min temp: 66F
24-hr precip: 0.00 in.
BHO SA 1155 W2 X 1/8F 181/66/66/E2702/006/ WND L/V/ 8//// 52010 
10066 20066

10 A.M.
Weather: Scattered cumulus fractus, broken cirrus
Temperature: 72F; Dew Point: 69F; Wind: estimated S at 3 kts,
Wind speed: Light
Sea-level pressure: 30.06 ins. Hg, falling then rising
Visibility: 20 miles, distant haze in all directions
BHO SA 1455 19 SCT E250 BKN 20 181/72/69/E1903/006/ DSNT HZ ALQDS/ 
8/701 55000

1 P.M. 
Weather: Few cumulus E-SW, broken cirrus
Temperature: 82F; Dew Point: 66F; Wind: estimated W at 2 kts,
Wind: Light and variable
Sea-level pressure: 30.03 ins. Hg, falling, then more quickly
Visibility: 60 miles, except 30 miles W-NE, distant haze W-NE
6-hr Max temp: 82F 
6-hr Min temp: 66F
BHO SA 1755 E250 BKN 60 168/82/66/E2702/003/ FEW CU E-SW VSBY 
W-NE 30 DSNT HZ W-NE WND L/V/ 8/101 58013 10082 20066


SUMMARY FOR MONDAY, SEPTEMBER 25, 2017
 
TEMPERATURE (DEGREES F)
MAX.....86   NORMAL.....68
MIN.....66   NORMAL.....51
MEAN....76   NORMAL.....60

DEPARTURE FROM 30-YEAR NORMAL........................+16
TOTAL DEPARTURE FOR THE MONTH........................+56 [+2.0 DEGREES/DAY]

COOLING DEGREE DAYS (SEASON JAN TO DEC)
TOTAL COOLING UNITS FOR YESTERDAY..............11   DEPARTURE.........+10
TOTAL COOLING UNITS FOR THE MONTH..............80   DEPARTURE.........+24
TOTAL COOLING UNITS FOR THE SEASON............687   DEPARTURE.........+94
TOTAL COOLING UNITS LAST SEASON TO DATE.......894   DEPARTURE........-207

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY...............0   DEPARTURE..........-6
TOTAL HEATING UNITS FOR THE MONTH..............42   DEPARTURE.........-38
TOTAL HEATING UNITS FOR THE SEASON.............68   DEPARTURE.........-37
TOTAL HEATING UNITS LAST SEASON TO DATE........35   DEPARTURE.........+33

PEAK GUST AND AVERAGE WIND SPEED (MPH) 
PEAK WIND GUST FOR YESTERDAY...................15 ESE AT 5:54 P.M.*
                   AERO........................13 ESE AT 5:56 P.M.
                   ASOS........................15 ESE AT 5:54 P.M.
                   DAVIS.......................12 ENE AT 1:39 P.M. RMY 14
FASTEST MILE FOR YESTERDAY.....................11 ESE AT 5:53 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE..................13 ESE AT 5:55 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE.................10 ESE AT 5:55 P.M.
AVERAGE WIND SPEED AND DIRECTION..............5.2  E
                   ASOS.......................5.7
                   DAVIS......................3.8  E [091 DEG.]
*last of multiple occurrences

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..........3.17  DEPARTURE......-0.15
                         ASOS..............3.24
TOTAL PRECIPITATION FOR THE YEAR..........39.53  DEPARTURE......+1.19
                         ASOS...............N/A ***
*** ASOS annual total not available due to erroneous readings


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

9/1  68/47/58/-10/0.00/749/95              26 WNW AERO 28 WNW RMY 31
9/2  72/46/59/-9/0.00/542/69               18 NNW AERO 18 NNW RMY 21
9/3  63/52/58/-9/0.24/000/00               33 W   AERO 33 W   RMY 37
9/4  79/55/67/0/0.00/702/90                29 SSW AERO 28 SSW RMY N/A
9/5  84/62/73/+6/0.00/583/75               36 S   AERO 32 S   RMY 38
9/6  76/59/68/+1/0.49/070/09               28 S   AERO 28 S   RMY 30 TSTM
9/7  74/58/66/0/0.79/417/54                24*WSW AERO 23 WSW RMY 24 
9/8  74/53/64/-2/0.00/577/75               21 WSW AERO 18 WSW RMY 22
9/9  68/51/60/-5/T/620/81                  18 ENE AERO 16 ENE RMY 18
9/10 71/51/61/-4/0.00/694/91               18 NW  AERO 16 NW  RMY N/A
9/11 78/50/64/-1/0.00/692/91               20 NNW AERO 17 NNW RMY 20
9/12 84/58/71/+6/0.00/690/91               22 WSW AERO 18 WSW RMY 23
9/13 84/59/72/+8/T/680/90                  18 WSW AERO 15 WSW RMY 20 TSTM
9/14 82/66/74/+10/0.00/233/31              23 SW  AERO 23 WSW RMY 25 TSTM
9/15 83/66/75/+11/0.05/300/40              18 WNW AERO 15 WNW RMY 18
9/16 78/65/72/+9/T/261/35                  14 E   AERO  9 E   RMY 12
9/17 79/61/70/+7/T/334/45                  15 SSE AERO 14 SSE RMY 15
9/18 67/62/65/+3/0.02/000/00               21 NE  AERO 18 NE  RMY N/A
9/19 63/61/62/0/0.13/000/00                28 NE* AERO 25 NNE RMY N/A
9/20 68/62/65/+3/0.37/000/00               41 NNE AERO 44 NNE RMY 45
9/21 69/60/65/+4/0.00/242/33               47 NNE AERO 44 NNE RMY 50
9/22 60/54/57/-4/..../.../..               40 NNE AERO 38 NNE RMY N/A
9/23 74/59/67/+7/..../.../..               29 NNE AERO 29 NNE RMY N/A
9/24 85/63/74/+14/0.00/.../..              16 N   AERO 14 N*  RMY N/A
9/25 86/66/76/+16/0.00/.../..              15 ESE*AERO 13 ESE RMY 14

9/26 Low temp since midnight is 66F; normal low is now 51F

DAILY RECORDS FOR SEPTEMBER

9/1/17: DAILY RECORD LOW MINIMUM TEMPERATURE OF 47F,
        TIES PREVIOUS RECORD SET IN 1975

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

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

RECORDS FOR SEPTEMBER 27
HIGH 84F IN 1998,2014
LOW 32F IN 1947
PRECIP 2.26 INCHES IN 1962
PEAK GUST 100 MPH SSE IN 1985 (HURRICANE GLORIA)

TODAY'S REPORT PREPARED BY: Cecilia Borries-Strigle