Wednesday, September 19, 2018

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

DAILY DISCUSSION AND CLIMATE SUMMARY
WEDNESDAY, SEPTEMBER 19, 2018
ALL TIMES ARE IN EASTERN STANDARD TIME

DRIZZLY, FOGGY AND COOL FOLLOWING YESTERDAY’S RAIN….

We measured approximately 3.32 inches from yesterday’s
rainfall, with another 0.11 inches falling today.
Cool temperatures were accompanied by a thick fog
this morning, reducing visibility to 1/16 mile.
The fog had cleared slightly by 1 P.M., allowing the
visibility to reach 2 miles. The high so far today is
61F, 10 degrees below the daily normal of 71F. The low
since midnight is 59F, 5 degrees above the normal
minimum of 54F.

Today’s Observations:

7 A.M.
Weather: Moderate drizzle and dense fog
Temperature: 59F; Dew Point: 59F; Wind: NE at 10G20 kts
Sea-level pressure: 29.88 ins. Hg, rising, then more slowly
Visibility: 1/16 mile, fog
6-hr Max temp: 66F
6-hr Min temp: 59F
24-hr Precip: 3.32 ins.
BHO SA 1155 W3 X 1/16LF 120/59/59/0510G20/988/ L CTD/ 8////
70332 51024 10066 20059

10 A.M.
Weather: Moderate drizzle and dense fog
Temperature: 60F; Dew Point: 60F; Wind: NE at 13G20 kts
Sea-level pressure: 29.95 ins. Hg, rising, then more rapidly
Visibility: 1/16 mile, fog
3-hr Precip: 0.04 ins.
BHO SA 1455 W3 X 1/16LF 142/60/60/0513G20/995/ L CTD/ 8////
6004/ 52024

1 P.M.
Weather: Overcast stratus, very light drizzle, sky partly obscured
in fog
Temperature: 60F; Dew Point: 59F; Wind: ENE at 10G16 kts
Sea-level pressure: 29.96 ins. Hg, rising steadily
Visibility: 2 miles, fog
6-hr Max temp: 61F
6-hr Min temp: 59F
6-hr Precip: 0.04 ins.
BHO SA 1755 –X E9 OVC 2L-F 147/60/59/0610G16/996/ F2 L- CTD PCPN
VRY LGT/ 8/6// 6004/ 53005 10061 20059

SUMMARY FOR TUESDAY, SEPTEMBER 18, 2018

TEMPERATURE (DEGREES F)
MAX…..74   NORMAL…..71
MIN…..67   NORMAL…..54
MEAN….71   NORMAL…..62

DEPARTURE FROM 30-YEAR NORMAL…………………..+9
TOTAL DEPARTURE FOR THE MONTH………………….+77 [+4.1 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY……………0   DEPARTURE………-4
TOTAL HEATING UNITS FOR THE MONTH…………..18   DEPARTURE……..-25
TOTAL HEATING UNITS FOR THE SEASON………….18   DEPARTURE……..-50
TOTAL HEATING UNITS LAST SEASON TO DATE……..57   DIFFERENCE…….-39

COOLING DEGREE DAYS (SEASON JAN TO DEC)
TOTAL COOLING UNITS FOR YESTERDAY……………6  DEPARTURE……….+4
TOTAL COOLING UNITS FOR THE MONTH………….102  DEPARTURE………+54
TOTAL COOLING UNITS FOR THE SEASON…………855  DEPARTURE……..+270
TOTAL COOLING UNITS LAST SEASON TO DATE…….665  DIFFERENCE…….+190

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY…………………31 SSW AT 9:42 A.M.
AERO……………………..30 SSW AT 9:42 A.M.
ASOS……………………..33 SSW AT 9:46 A.M.
DAVIS…………………….38 M   AT 9:44 A.M.** RMY 32
FASTEST MILE FOR YESTERDAY…………………..22 SSW AT 9:50 A.M.
MAXIMUM 2-MINUTE ASOS AVERAGE………………..22 SSW AT 9:49 A.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE……………….26 M   AT 9:45 A.M.**
AVERAGE WIND SPEED AND DIRECTION……………..9.0 W
ASOS……………………..9.3
DAVIS…………………….9.0 **

**Davis direction malfunctioning

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M….3.32  DEPARTURE……+3.18
ASOS…………..3.39
TOTAL PRECIPITATION FOR THE MONTH……….6.35  DEPARTURE……+4.05
ASOS…………..6.41
TOTAL PRECIPITATION FOR THE YEAR……….44.30  DEPARTURE……+7.16
ASOS………….45.93

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 Low temp since midnight is 59F; normal low is now 54F

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 19
HIGH 87F IN 1906,1983
LOW 37F IN 1929
PRECIP 3.69 INCHES IN 1936
PEAK GUST 55 MPH S IN 2012

RECORDS FOR SEPTEMBER 20
HIGH 90 IN 1983
LOW 34 IN 1979
PRECIP 4.57 INS IN 1899
PEAK GUST 44 MPH NE IN 1972

TODAY’S REPORT PREPARED BY: Benjamin Turner