Monday, September 24, 2018

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

DAILY DISCUSSION AND CLIMATE SUMMARY
MONDAY, SEPTEMBER 24, 2018
ALL TIMES ARE IN EASTERN STANDARD TIME

A COOL AND OVERCAST FALL DAY WITH A MODERATE NORTHEASTERLY
WIND….

Due to overcast skies and a 15 mph wind coming from the
northeast, temperatures have risen to only 54F so far
today. That is 15 degrees below our daily normal maximum
of 69F. It has been breezy on Great Blue hill, with frequent
gusts over 20 mph. The highest gust so far today is 37 mph at
6 A.M. Visibility increased from 20 miles this morning to 70
miles at the 1 P.M. observation.

Today’s Observations:

7 A.M.
Weather: Overcast stratus
Temperature: 52F; Dew Point: 46F; Wind: ENE at 16G28 kts,
Peak Wind: 32 kts (37 MPH) ENE at 6:21 P.M.
Sea-level pressure: 30.51 ins. Hg, rising, then more rapidly
Visibility: 20 miles, distant haze in all directions
6-hr Max temp: 55F
6-hr Min temp: 51F
24-hr Precip: 0.00 ins.
BHO SA 1155 E25 OVC 20 333/52/46/0616G28/051/ DSNT HZ ALQDS
PK WND 0632/21/ 8/6// 53030 10055 20051

10 A.M.
Weather: Overcast stratus
Temperature: 52F; Dew Point: 43F; Wind: NE at 15G20 kts
Sea-level pressure: 30.59 ins. Hg, rising steadily
Visibility: 40 miles, distant haze in all directions
3-hr Precip: 0.00 ins.
BHO SA 1455 E30 OVC 40 358/52/43/0515G20/059/ DSNT HZ ALQDS/
8/6// 51025

1 P.M.
Weather: Overcast stratus
Temperature: 53F; Dew Point: 44F; Wind: NE at 13G22 kts
Sea-level pressure: 30.58 ins. Hg, steady then falling
Visibility: 70 miles
6-hr Max temp: 54F
6-hr Min temp: 52F
6-hr Precip: 0.00 ins.
BHO SA 1755 E30 OVC 70 357/53/44/0513G22/058/ 8/6// 58001 10054 20052

SUMMARY FOR SUNDAY, SEPTEMBER 23, 2018

TEMPERATURE (DEGREES F)
MAX…..60   NORMAL…..69
MIN…..47   NORMAL…..52
MEAN….54   NORMAL…..60

DEPARTURE FROM 30-YEAR NORMAL…………………..-6
TOTAL DEPARTURE FOR THE MONTH………………….+70 [+2.8 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY…………..11   DEPARTURE………+5
TOTAL HEATING UNITS FOR THE MONTH…………..44   DEPARTURE……..-24
TOTAL HEATING UNITS FOR THE SEASON………….44   DEPARTURE……..-49
TOTAL HEATING UNITS LAST SEASON TO DATE……..68   DIFFERENCE…….-24

COOLING DEGREE DAYS (SEASON JAN TO DEC)
TOTAL COOLING UNITS FOR YESTERDAY……………0  DEPARTURE……….-1
TOTAL COOLING UNITS FOR THE MONTH………….102  DEPARTURE………+48
TOTAL COOLING UNITS FOR THE SEASON…………855  DEPARTURE……..+265
TOTAL COOLING UNITS LAST SEASON TO DATE…….667  DIFFERENCE…….+188

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY…………………14 N   AT 12:07 A.M.
AERO……………………..13 N   AT 12:07 A.M.
ASOS……………………..14 N   AT 12:07 A.M.
DAVIS…………………….14 N   AT 12:06 A.M. RMY N/A
FASTEST MILE FOR YESTERDAY…………………..11 N   AT 12:08 A.M.
MAXIMUM 2-MINUTE ASOS AVERAGE………………..12 N   AT  6:07 A.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE……………….12 N   AT 12:08 A.M.
AVERAGE WIND SPEED AND DIRECTION……………6.5 NNW
ASOS……………………7.1
DAVIS…………………..7.1 NNW [324 deg.]

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M….0.00  DEPARTURE……-0.14
ASOS…………..0.00
TOTAL PRECIPITATION FOR THE MONTH……….6.46  DEPARTURE……+3.44
ASOS…………..6.53
TOTAL PRECIPITATION FOR THE YEAR……….44.41  DEPARTURE……+6.55
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 Low temp since midnight is 51F; normal low is now 52F

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 24
HIGH 87F IN 1959
LOW 33F IN 1885,1950,1963
PRECIP 1.19 INCHES IN 1955
PEAK GUST 54e MPH SW IN 1940

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

TODAY’S REPORT PREPARED BY: Benjamin Turner