Wednesday, September 12, 2018

| September 12, 2018 | Reply

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

DAILY DISCUSSION AND CLIMATE SUMMARY
WEDNESDAY, SEPTEMBER 12, 2018
ALL TIMES ARE IN EASTERN STANDARD TIME

OVERCAST DAY WITH INTERMITTENT SHOWERS AND BELOW NORMAL
HIGH TEMPERATURE…

The high temperatures of 67F so far today is 6 degrees
below normal. There was not much divergence in temperature
varying between 66-63F during today’s observations. The
humidity remained between 99-100% all day making for thick
air and dense foggy conditions on top of Great Blue Hill.
The wind was light and variable for most of the day yesterday
but has been moderate and from the NE today. Skies remained
overcast all day with a constant drizzle and multiple heavier
rain showers. So far we have measured 0.05 ins overnight and
an additional 0.13 ins. by 1:00 P.M. A few of thunderstorms
have moved over the hill in the past 24 hrs. The first was
south of the observatory yesterday afternoon around 3:00 P.M.
EST. Another two storms passed by this afternoon ending before
2:00 P.M.
The month of September so far is still running above normal
for both temperatures and precipitation.

Today’s Observations:

7 A.M.
Weather: Very light drizzle and fog, overcast nimbostratus
Temperature: 66F; Dew Point: 66F; Wind: ENE at 10G15 kts
Sea-level pressure: 30.27 ins. Hg, rising, then more slowly
Visibility: 1/8 mile, fog
6-hr Max temp: 69F
6-hr Min temp: 66F
24-hr Precip: 0.05 ins.
BHO SA 1155 W3 X 1/8L-F 249/66/66/0610G15/027/ PCPN VRY LGT/
8//// 51011 MANUAL 70005 ASOS 70005 10069 20066

10 A.M.
Weather: Light rain and fog, overcast nimbostratus
Temperature: 65F; Dew Point: 65F; Wind: ENE at 10G17 kts
Sea-level pressure: 30.16 ins. Hg, rising, then more rapidly
Visibility: 3/4 mile, fog
3-hr Precip: 0.05 ins.
BHO SA 1455 E4 OVC 3/4R-F 261/65/65/0710G17/030/ 8/02/
53021 MANUAL 70005 ASOS 70006

1 P.M.
Weather: Light rain and fog, overcast nimbostratus
Temperature: 63F; Dew Point: 63F; Wind: NE at 8G14 kts
Sea-level pressure: 30.30 ins. Hg, falling then steady
Visibility: 1/2 mile, fog
6-hr Max temp: 67F
6-hr Min temp: 63F
6-hr Precip: 0.13 ins.
BHO SA 1755 E6 OVC 1/2R-F 261/63/63/0408G14/030/
TSE45/ 8/02/ 51000 MANUAL 6013/ ASOS 60013 10067 20063

SUMMARY FOR TUESDAY, SEPTEMBER 11, 2018

TEMPERATURE (DEGREES F)
MAX…..75   NORMAL…..73
MIN…..61   NORMAL…..56
MEAN….68   NORMAL…..65

DEPARTURE FROM 30-YEAR NORMAL…………………..+3
TOTAL DEPARTURE FOR THE MONTH………………….+37 [+3.2 DEGREES/DAY]

COOLING DEGREE DAYS (SEASON JAN TO DEC)
TOTAL COOLING UNITS FOR YESTERDAY……………0  DEPARTURE……….-2
TOTAL COOLING UNITS FOR THE MONTH…………..69  DEPARTURE………+34
TOTAL COOLING UNITS FOR THE SEASON…………822  DEPARTURE……..+250
TOTAL COOLING UNITS LAST SEASON TO DATE…….621  DEPARTURE……..+201

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY……………3   DEPARTURE………..0
TOTAL HEATING UNITS FOR THE MONTH…………..21   DEPARTURE………..2
TOTAL HEATING UNITS FOR THE SEASON………….21   DEPARTURE………-23
TOTAL HEATING UNITS LAST SEASON TO DATE……..44   DEPARTURE………+57

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY…………………23 E   AT 12:04 A.M.
AERO……………………..21 E   AT 12:04 A.M.
ASOS……………………..22 E   AT 12:04 A.M.
DAVIS…………………….22 ENE AT 12:04 A.M. RMY N/A
FASTEST MILE FOR YESTERDAY…………………..16 E   AT 12:05 A.M.
MAXIMUM 2-MINUTE ASOS AVERAGE………………..17 E   AT 12:08 A.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE……………….17 E   AT 12:05 A.M.
AVERAGE WIND SPEED AND DIRECTION…………….4.5 E
ASOS…………………….4.6
DAVIS……………………4.9 S [DEG 190]

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M….0.05  DEPARTURE……-0.08
ASOS…………..0.05
TOTAL PRECIPITATION FOR THE MONTH……….1.99  DEPARTURE……+0.64
ASOS…………..1.98
TOTAL PRECIPITATION FOR THE YEAR……….39.94  DEPARTURE……+3.75
ASOS………….41.50

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/…/..        17 NE  AERO 15 NE  RMY 16
9/02 83/61/72/+4/0.00/…/..        20 SSW AERO 18 SSW RMY N/A
9/03 92/68/80/+13/0.00/…/..       24 WSW AERO 22 WSW RMY 25
9/04 88/70/79/+12/0.00/…/..       17 W   AERO 16 W   RMY 17
9/05 89/67/78/+11/0.00/…/..       23 SSW AERO 23 SSW RMY 25
9/06 92/70/81/+14/0.56/…/..       29 NNW AERO 29 NNW RMY N/A
9/07 70/63/67/+1/0.01/…/..        24 NE  AERO 22 NE  RMY N/A
9/08 68/54/61/-5/0.00/…/..        22 NE  AERO 18 NE  RMY 21
9/09 61/53/57/-9/0.00/…/..        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 Low temp since midnight is 63F; normal low is now 56F

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 12
HIGH 92F IN 1961
LOW 42F IN 1958,1967,1985
PRECIP 2.79 INCHES IN 1960 (HURRICANE DONNA)
PEAK GUST 140 MPH SSE IN 1960 (HURRICANE DONNA)

RECORDS FOR SEPTEMBER 13
HIGH 91F IN 1957
LOW 40F IN 1985
PRECIP 3.10 INCHES IN 1987
PEAK GUST 44 MPH WNW IN 1986

TODAY’S REPORT PREPARED BY: Kaitlin Geagan

 

Category: Daily Discussions

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