Saturday, July 7, 2018

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

DAILY DISCUSSION AND CLIMATE SUMMARY
SATURDAY, JULY 7, 2018
ALL TIMES ARE IN EASTERN STANDARD TIME

CLEAR AND COMFORTABLE DAY ON TOP OF GREAT BLUE HILL…

We observed a wind shift yesterday just before 5:00 P.M.
from the SSW to the NNW bringing cooler and less humid
air into the area. Temperatures dropped overnight to a
54F which is 8 degrees below the normal of 62F. So far
high temperatures have also been below normal with a
high of 75F so far today. This is 5 degrees below the
daily normal of 80F. The also allowed for dew points
to be in the 40’s and the relative humidity to return
to drier more comfortable level. With this dry air we
had excellent visibility at 80 miles all day.
The wind was strong overnight with an official peak gust
yesterday of 37 MPH (32 kts) just after 9:00 P.M. but
so far today the wind has been fairly light. Becoming
lighter and more variable midday.

PRELIMINARY STATS FOR JUNE 2018

TEMPERATURE, Deg. F
Avg. Max. 75.1 [+0.1] Avg. Min. 56.2 [-0.9] Mean      65.7 [-0.5] 24-hour corrected mean: 65.7
Max. for month: 90F on  30th
Min. for month: 45F on  3rd and 4th

HEATING DEGREE DAYS
Total heating units:   69   [-4] Total for the season:  5916 [-460] Total for last season: 5725

COOLING DEGREE DAYS
Total cooling units:    97 [-8] Total for the season:  159 [+30] Total for last season: 201

PRECIPITATION, Inches
Total: 2.85 [-1.46] Greatest in 24 hrs: 1.29 in on 27th-28th

WIND, mph
Avg. uncorrected wind speed: 10.3
Avg. corrected wind speed: 10.8
Prevailing wind direction: SSW at 30%
Peak gust and direction: 37 SW on 12th

SUNSHINE:
Campbell-Stokes card minutes: 13404 minutes of possible 26376 or 51%
Astronomical total minutes: 13945 minutes of possible 27417 or 51%

Today’s Observations:

7 A.M.
Weather: Clear, few cirrostratus along the horizon ENE-SSW
Temperature: 61F; Dew Point: 48F; Wind: NW at 8 kts
Sea-level pressure: 30.32 ins. Hg, rising, then more rapidly
Visibility: 80 miles
6-hr Max temp: 61F
6-hr Min temp: 54F
24-hr Precip: 0.56 ins.
BHO SA 1155 CLR 80 266/61/48/3208/032/ FEW CS ALNG HRZN
ENE-SSW/ 8/005 53015 10061 20054 MANUAL 70056

10 A.M.
Weather: Clear, few cumulus distant WSW-N, few cirrostratus
along the horizon ENE-SSW
Temperature: 69F; Dew Point: 42F; Wind: NNW at 5 kts,
Wind: Light
Sea-level pressure: 30.33 ins. Hg, rising, then more slowly
Visibility: 80 miles
3-hr Precip: 0.00 ins.
BHO SA 1455 CLR 80 272/69/42/3305/033/ FEW CU DSNT
WSW-N FEW CS ALNG HRZN ENE-SSW WND LGT/ 8/105 51006

1 P.M.
Weather: Clear, few cumulus distant S-N, few cirrostratus
along the horizon ENE-SSW
Temperature: 75F; Dew Point: 46F; Wind: NW at 5 kts,
Wind: Light
Sea-level pressure: 30.31 ins. Hg, falling, then more rapidly
Visibility: 80 miles
6-hr Max temp: 75F
6-hr Min temp: 61F
6-hr precip: 0.00 ins.
BHO SA 1755 CLR 80 265/75/46/3105/031/ FEW CU DSNT S-N FEW
CS ALNG HRZN ENE-SSW WND LGT/ 8/105 58007 10075 20061

SUMMARY FOR FRIDAY, JULY 6, 2018

TEMPERATURE (DEGREES F)
MAX…..80   NORMAL…..80
MIN…..59   NORMAL…..62
MEAN….70   NORMAL…..71

DEPARTURE FROM 30-YEAR NORMAL…………………….-1
TOTAL DEPARTURE FOR THE MONTH……………………+53 [+8.6 DEGREES/DAY]

COOLING DEGREE DAYS (SEASON JAN TO DEC)
TOTAL COOLING UNITS FOR YESTERDAY……………5   DEPARTURE……….-2
TOTAL COOLING UNITS FOR THE MONTH…………..87   DEPARTURE………+50
TOTAL COOLING UNITS FOR THE SEASON…………246   DEPARTURE………+80
TOTAL COOLING UNITS LAST SEASON TO DATE…….257   DEPARTURE………-11

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY………………..37 NNW AT 9:10 P.M.
AERO…………………….36 NNW AT 9:08 P.M.
ASOS……………………..M ***
DAVIS……………………35 M ***    RMY 40
FASTEST MILE FOR YESTERDAY………………….27 SW  AT 5:47 A.M.
MAXIMUM 2-MINUTE ASOS AVERAGE………………..M ***
MAXIMUM 2-MINUTE DAVIS AVERAGE……………….M ***
AVERAGE WIND SPEED AND DIRECTION…………..15.6 SW
ASOS……………………..M ***
DAVIS………………….15.9

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M….0.56  DEPARTURE……+0.45
ASOS…………..0.00***
TOTAL PRECIPITATION FOR THE MONTH……….0.56  DEPARTURE……-0.09
ASOS…………..0.00***
TOTAL PRECIPITATION FOR THE YEAR……….30.73  DEPARTURE……+3.29
ASOS………….31.73***

***ASOS and parts of Davis systems down due to lightning storm

PRELIMINARY CLIMATE SUMMARY FOR JUNE 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

6/01 78/62/70/+8/T/009/01            21 S   AERO 21 S   RMY N/A
6/02 79/54/67/+5/T/353/39            26 ENE AERO 25 ENE RMY 27
6/03 59/45/52/-10/0.00/816/90        28 ENE AERO 25 ENE RMY N/A
6/04 52/45/49/-14/0.82/000/00        29 ENE AERO 26 ENE RMY 29
6/05 64/47/56/-7/0.19/173/19         24 N   AERO 21 N   RMY 23  TSTM
6/06 66/50/58/-5/0.00/373/41         23 S   AERO 21 S   RMY 22
6/07 69/50/60/-4/0.00/282/31         25 S   AERO 25 S   RMY 27
6/08 79/52/66/+2/0.00/684/75         20 SW  AERO 17 SW  RMY 18
6/09 79/58/69/+5/0.00/767/84         22 W   AERO 21 W   RMY 22
6/10 72/56/64/-1/0.00/593/65         20 S   AERO 18 S   RMY 17
6/11 68/51/60/-5/0.00/594/65         21 ENE AERO 20 SSW RMY N/A
6/12 77/49/63/-2/0.00/814/89         37 SW  AERO 37 SW  RMY 39
6/13 74/56/65/0/T/284/31             35 SW  AERO 36 SW  RMY 36
6/14 77/61/69/+3/0.00/495/54         35 W   AERO 36 WNW RMY 37
6/15 68/53/61/-5/0.01/266/29         17 NNW AERO 16 WNW RMY 19
6/16 83/54/69/+3/0.00/761/83         25 NNW AERO 24 NNW RMY 25
6/17 86/63/75/+8/0.00/807/88         23 S   AERO 22 S   RMY N/A
6/18 86/64/75/+8/0.10/284/31         37 SSW AERO 37 SSW RMY 40  TSTM
6/19 81/64/73/+6/0.01/789/86         31 WSW AERO 32 WSW RMY 32
6/20 81/58/70/+2/0.00/459/50         22 W   AERO 21 W   RMY 23
6/21 81/62/72/+4/0.00/706/77         22 E   AERO 18 E   RMY 21
6/22 75/56/66/-2/0.00/688/75         24 ESE AERO 22 ESE RMY 24
6/23 65/55/60/-8/0.03/000/00         22 ENE AERO 21 NE  RMY 22
6/24 78/56/67/-2/0.26/009/01         21 SSW AERO 20 SSW RMY N/A
6/25 70/56/63/-6/0.14/449/49         30 N   AERO 29 N   RMY 31  TSTM
6/26 79/53/66/-3/0.00/824/90         24 SSW AERO 24 SSW RMY 25
6/27 78/59/69/0/0.13/156/17          26 S   AERO 28 S   RMY N/A
6/28 71/63/67/-3/1.16/000/00         28 S   AERO 26 S   RMY N/A TSTM
6/29 87/66/77/+7/0.00/824/90         18 W   AERO 16 W   RMY 18
6/30 90/69/80/+10/0.00/686/75        21 SSW AERO 20 SSW RMY 21

PRELIMINARY CLIMATE SUMMARY FOR JULY 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

7/01 94/72/83/+13/0.00/…/..       21 ESE AERO 18 ESE RMY 19
7/02 90/68/79/+9/0.00/…/..        21 S   AERO 21 S   RMY 22
7/03 94/69/82/+11/0.00/…/..       20 SSW AERO 18 SW  RMY 19 TSTM
7/04 89/73/81/+10/0.00/…/..       17 NE  AERO 15 NE  RMY 16
7/05 91/73/82/+11/0.00/…/..       29 SSW AERO 28 SSW RMY N/A
7/06 80/59/70/-1/0.56/…/..        37 NNW AERO 38 SW  RMY 40 TSTM

7/07 Low temp since midnight is 54F; normal low is now 62F

DAILY RECORDS FOR JULY 2018

07/01/18: DAILY RECORD HIGH MINIMUM TEMPERATURE OF 72F,
TIES PREVIOUS RECORD OF 72F SET IN 1968

DAILY EXTREMES
Temperature and precipitation records back to 1885, and
wind records back to 1940 (e = estimated):

RECORDS FOR JULY 7
HIGH 97F IN 1908,1993
LOW 48F IN 1902
PRECIP 2.11 INS IN 1966
PEAK GUST 55 MPH NW IN 1989

RECORDS FOR JULY 8
HIGH 95F IN 1981
LOW 50F IN 1919
PRECIP 1.74 INS IN 1916
PEAK GUST 46e SSW IN 1941

TODAY’S REPORT PREPARED BY: K. Geagan