Monday, September 17, 2018

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

DAILY DISCUSSION AND CLIMATE SUMMARY
MONDAY, SEPTEMBER 17, 2018
ALL TIMES ARE IN EASTERN STANDARD TIME

A WARM FALL DAY STARTING FOGGY AND ENDING OVERCAST….

Today began with a layer of fog obscuring visibility to
10 miles. The sun broke through the clouds around 8 A.M.
The temperature increased by 10 degrees between the 7 A.M.
and the 10 A.M. observations. Pressure has been decreasing
since this morning, dropping a total of 3 millibars by
noontime. The high so far today is 82F, 11 degrees above
the daily normal of 71F. The low since midnight is 64F,
10 degrees above the normal minimum of 54F.

Today’s Observations:

7 A.M.
Weather: Overcast stratus
Temperature: 65F; Dew Point: 65F; Wind: SSW at 9G15 kts
Sea-level pressure: 30.17 ins. Hg, rising, then falling
Visibility: 10 miles, fog
6-hr Max temp: 65F
6-hr Min temp: 64F
24-hr Precip: 0.01 ins.
BHO SA 1155 E9 OVC 10F 217/65/65/2109G15/017/ FOG/ 8/6// 58000
70001 10065 20064

10 A.M.
Weather: Scattered cirrus, few cumulus in all directions
Temperature: 75F; Dew Point: 65F; Wind: SW at 9G12 kts
Sea-level pressure: 30.15 ins. Hg, falling, then more rapidly
Visibility: 30 miles, distant haze in all directions
BHO SA 1455 E250 SCT 30 209/75/65/2209G12/015/ FEW CU ALQDS
DSNT HZ ALQDS/ 8/108 58008

1 P.M.
Weather: Broken cirrostratus, few cumulus in all directions
Temperature: 81F; Dew Point: 62F; Wind: SW at 11G14 kts
Sea-level pressure: 30.12 ins. Hg, falling, then more rapidly
Visibility: 70 miles
6-hr Max temp: 82F
6-hr Min temp: 65F
BHO SA 1755 E250 BKN 70 201/81/62/2211G14/012/ FEW CU ALQDS/
8/108 58022 10082 20065

SUMMARY FOR SUNDAY, SEPTEMBER 16, 2018

TEMPERATURE (DEGREES F)
MAX…..84   NORMAL…..72
MIN…..61   NORMAL…..55
MEAN….73   NORMAL…..63

DEPARTURE FROM 30-YEAR NORMAL………………….+10
TOTAL DEPARTURE FOR THE MONTH………………….+58 [+3.4 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………-17
TOTAL HEATING UNITS FOR THE SEASON………….18   DEPARTURE………-42
TOTAL HEATING UNITS LAST SEASON TO DATE……..57   DIFFERENCE……..-39

COOLING DEGREE DAYS (SEASON JAN TO DEC)
TOTAL COOLING UNITS FOR YESTERDAY……………8  DEPARTURE……….+6
TOTAL COOLING UNITS FOR THE MONTH…………..88  DEPARTURE………+43
TOTAL COOLING UNITS FOR THE SEASON…………841  DEPARTURE……..+259
TOTAL COOLING UNITS LAST SEASON TO DATE…….660  DIFFERENCE…….+181

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY…………………15 S  AT 7:00 P.M.
AERO……………………..14 S  AT 6:58 P.M.
ASOS……………………..15 S  AT 7:23 P.M.
DAVIS…………………….14 SE AT 6:59 P.M. RMY N/A
FASTEST MILE FOR YESTERDAY…………………..11 S  AT 7:00 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE………………..12 S  AT 7:00 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE……………….14 SE AT 6:59 P.M.
AVERAGE WIND SPEED AND DIRECTION…………….5.6 S
ASOS…………………….5.8
DAVIS……………………6.1 **
**Davis direction malfunctioning

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M….0.00  DEPARTURE……-0.13
ASOS…………..0.00
TOTAL PRECIPITATION FOR THE MONTH……….2.96  DEPARTURE……+0.94
ASOS…………..2.95
TOTAL PRECIPITATION FOR THE YEAR……….40.91  DEPARTURE……+4.05
ASOS………….42.47

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 Low temp since midnight is 65F; normal low is now 53F

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 17
HIGH 87F IN 2015
LOW 38F IN 1959
PRECIP 2.73 INCHES IN 1933
PEAK GUST 60 MPH WNW IN 1999

RECORDS FOR SEPTEMBER 18
HIGH 88F IN 1906
LOW 36F IN 1919
PRECIP 4.25 INCHES IN 1996
PEAK GUST 77e MPH WNW IN 1948

TODAY’S REPORT PREPARED BY: Benjamin Turner