Monday, September 25, 2017

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

DAILY DISCUSSION AND CLIMATE SUMMARY
MONDAY, SEPTEMBER 25, 2017
ALL TIMES ARE IN EASTERN STANDARD TIME

WARM AND HUMID DAY FOR LATE SEPTEMBER

Temperatures remain well above normal for this time of year.  The
max. by 1:00PM was 86F which is just 1F shy of tying the record
high.  Temps. were on the decline after noon and had fallen to 82F
at 1:00PM.  Dew points measured in the upper 60s, and haze continued
to limit visibility today between 15 and 35 miles.  Winds were light
and variable for much of the morning but had begun to pick up in the
early afternoon.

Today’s Observations:

7 A.M.
Weather: Few cirrus NNE-NE
Temperature: 73F; Dew Point: 67F; Wind: ENE at 4 kts,
Wind speed: Light
Sea-level pressure: 30.09 ins. Hg, rising, then more slowly
Visibility: 15 miles, hazy
6-hr Max temp: 73F
6-hr Min temp: 67F
24-hr precip: 0.00 in.
BHO SA 1155 CLR 15 190/73/67/0604/009/ FEW CI NNE-NE HAZY WND LGT/
8/001 51014 10073 20067

10 A.M.
Weather: Sky clear
Temperature: 81F; Dew Point: 65F; Wind: estimated E at 3 kts,
Wind: Light and variable
Sea-level pressure: 30.11 ins. Hg, rising then falling
Visibility: 20 miles, except 30 miles E-SSW, distant haze in all directions
BHO SA 1455 CLR 20 195/81/65/E1003/011/ SKC VSBY E-SSW 30 DSNT HZ ALQDS
WND L/V/ 50005

1 P.M.
Weather: Broken cumulus and stratocumulus
Temperature: 82F; Dew Point: 67F; Wind: ENE at 7 kts
Sea-level pressure: 30.09 ins. Hg, falling then steady
Visibility: 35 miles, distant haze in all directions
6-hr Max temp: 86F
6-hr Min temp: 73F
BHO SA 1755 E45 BKN 35 191/82/67/0707/009/ DSNT HZ ALQDS/
8/400 58004 10086 20073

SUMMARY FOR SUNDAY, SEPTEMBER 24, 2017

TEMPERATURE (DEGREES F)
MAX…..85   NORMAL…..69
MIN…..63   NORMAL…..52
MEAN….74   NORMAL…..60

DEPARTURE FROM 30-YEAR NORMAL……………………+14
TOTAL DEPARTURE FOR THE MONTH……………………+40 [+1.5 DEGREES/DAY]

COOLING DEGREE DAYS (SEASON JAN TO DEC)
TOTAL COOLING UNITS FOR YESTERDAY……………9   DEPARTURE……….+8
TOTAL COOLING UNITS FOR THE MONTH…………..69   DEPARTURE………+14
TOTAL COOLING UNITS FOR THE SEASON…………676   DEPARTURE………+84
TOTAL COOLING UNITS LAST SEASON TO DATE…….894   DEPARTURE……..-218

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY……………0   DEPARTURE……….-6
TOTAL HEATING UNITS FOR THE MONTH…………..42   DEPARTURE………-32
TOTAL HEATING UNITS FOR THE SEASON………….68   DEPARTURE………-31
TOTAL HEATING UNITS LAST SEASON TO DATE……..25   DEPARTURE………+43

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY……………….16 N AT 6:18 A.M.
AERO……………………14 N AT 5:30 A.M.*
ASOS……………………17 N AT 5:27 A.M.
DAVIS…………………..15 N AT 5:29 A.M. RMY N/A
FASTEST MILE FOR YESTERDAY…………………13 N AT 5:13 A.M.
MAXIMUM 2-MINUTE ASOS AVERAGE………………14 N AT 5:29 A.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE……………..12 N AT 5:13 A.M.
AVERAGE WIND SPEED AND DIRECTION…………..6.6 N
ASOS…………………..7.1
DAVIS………………….4.9 N [356 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……+0.00
ASOS…………..3.24
TOTAL PRECIPITATION FOR THE YEAR……….39.53  DEPARTURE……+1.34
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/…/..                  14 E   AERO  9 E   RMY 12
9/17 79/61/70/+7/T/…/..                  15 SSE AERO 14 SSE RMY 15
9/18 67/62/65/+3/…./…/..               21 NE  AERO 18 NE  RMY N/A
9/19 63/61/62/0/…./…/..                28 NE* AERO 25 NNE RMY N/A
9/20 68/62/65/+3/…./…/..               41 NNE AERO 44 NNE RMY 45
9/21 69/60/65/+4/…./…/..               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 Low temp since midnight is 67F; 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 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: Cecilia Borries-Strigle