Friday, July 31, 2020

| July 31, 2020 | Reply

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

FRIDAY, JULY 31, 2020
ALL TIMES ARE IN EASTERN STANDARD TIME

COOLER, SUNNIER CONDITIONS RETURN TO GREAT
BLUE HILL…

After a week featuring several 90+ degree heat
and muggy conditions, we have returned to more
normal temperatures atop the hill. As of the 1PM
observation, we have achieved “only” 83 degrees
for the daily high. Dew points began in the low-
60s slipping to the upper-50s by early afternoon.
The refreshing temperatures were accompanied by
gradually clearing skies and excellent visibility
around 80 miles.

As we round out July, a review of 90+ degree days
so far this year indicates a total of 7. Per our
Chief Scientist, Mike Iacono, “the full record mean
(1885-2019) number of days is 6 for the year, but
the most recent 30-year average is 9 for the year,
so it’s increasing”. The most ever recorded during
the year was 23 back in 1949 and in 2002.

The high so far today is 83 degrees. This is 2
degrees above the daily normal high of 81F. The
low since midnight is 69F, which is 6 degrees
above the daily normal low of 63F

Today’s Observations:

7 A.M.
Weather: Broken Altocumulus/Altostratus, few stratus
distant SE-S, FEW CI SW-NE
Temperature: 70F; Dew Point: 61F; Relative Humidity: 73%
Wind: NW at 5 kts (wind light)
Sea-level pressure: 29.84 ins. Hg: rising, then more rapidly
Visibility: 80 miles (30 SE-S)
6-hr Max temp: 72F
6-hr Min temp: 69F
24-hr Precip: 0.00 ins.
BHO SA 1155 E130 BKN 80 106/70/61/3205/984/ FEW ST DSNT
SE-S FEW CI SW-NE VSBY 30 SE-S WND LGT/ 8/752 53009
10072 20069

10 A.M.
Weather: Scattered Altocumulus/Altostratus, few stratus
SE-SW, few cumulus W-N, few cirrus SW-NE
Temperature: 77F; Dew Point: 62F; Relative Humidity: 61%
Wind: NW at 4 kts (wind light)
Sea-level pressure: 29.85 ins. Hg: falling, then rising
Visibility: 80 miles
3-hr Precip: 0.00 ins.
BHO SA 1455 140 SCT 80 107/77/62/3204/985/ FEW ST SE-SW
FEW CU W-N FEW CI SW-NE WND LGT/ 8/252 50001

1 P.M.
Weather: Scattered Cumulus, Scattered Altocumulus/Altostratus,
few cirrus E-W
Temperature: 83F; Dew Point: 59F; Relative Humidity: 45%
Wind: N at 6 kts (wind light)
Sea-level pressure: 29.81 ins. Hg: falling, then more rapidly
Visibility: 75 miles
6-hr Max temp: 83F
6-hr Min temp: 70F
6-hr Precip: 0.00 ins.
BHO SA 1755 45 SCT 140 SCT 75 096/83/59/3506/981/ FEW CI E-W
WND LGT/ 8/252 58011 10083 20070

SUMMARY FOR THURSDAY, JULY 30, 2020

TEMPERATURE (DEGREES F)
MAX…..88   NORMAL…..81
MIN…..71   NORMAL…..63
MEAN….80   NORMAL…..72

DEPARTURE FROM 30-YEAR NORMAL………………+8
TOTAL DEPARTURE FOR THE MONTH……………..+92 [+2.9 DEGREES/DAY]

COOLING DEGREE DAYS (SEASON JAN TO DEC)
TOTAL COOLING UNITS FOR YESTERDAY……………15  DEPARTURE…….+8
TOTAL COOLING UNITS FOR THE MONTH…………..291  DEPARTURE……+76
TOTAL COOLING UNITS FOR THE SEASON………….475  DEPARTURE…..+131
TOTAL COOLING UNITS LAST SEASON TO DATE……..397  DEPARTURE……+78

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY………………..29  W AT 1:56 P.M.
AERO…………………….28  W AT 1:56 P.M.
ASOS…………………….29  W AT 1:56 P.M.
DAVIS……………………29  W AT 1:56 P.M
RMY 29  MERLIN 26
FASTEST MILE FOR YESTERDAY………………….20  W AT 1:24 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………….21  W AT 1:22 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE………………21  W AT 1:22 P.M.
AVERAGE WIND SPEED AND DIRECTION……………9.0 WSW
ASOS……………………9.2
DAVIS…………………..9.3 WSW [255 deg.]

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M……0.00  DEPARTURE……-0.15
ASOS…………….0.00
TOTAL PRECIPITATION FOR THE MONTH…………1.72  DEPARTURE……-2.15
ASOS…………….1.80
TOTAL PRECIPITATION FOR THE YEAR…………29.07  DEPARTURE……-1.77
ASOS……………29.81

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

07/01  76/63/70/0/0.00/228/25              16 E    AERO 14 E    RMY 14  TSTM
07/02  86/61/74/4/0.00/803/88              30 WSW  AERO 25 WSW  RMY 33
07/03  73/60/67/-4/0.00/091/10             30 NE   AERO 28 NE   RMY 30
07/04  79/60/70/-1/0.00/565/62             16 S    AERO 16 S    RMY 16
07/05  83/63/73/+2/0.54/373/41             24 NW   AERO 30 NW   RMY 26  TSTM
07/06  73/60/67/-4/0.00/482/53             20 ENE  AERO 16 NNE  RMY 18
07/07  78/60/69/-2/0.00/454/50             25 S    AERO 25 S    RMY 26
07/08  83/64/74/+2/0.00/227/25             32 SSW  AERO 32 SSW  RMY 32
07/09  89/70/80/+8/0.00/834/92             24 S    AERO 23 S    RMY 22
07/10  83/70/77/+5/0.05/109/12             30 SSE  AERO 32 SSE  RMY N/A
07/11  85/70/78/+6/0.00/614/68             39 S    AERO 39 S    RMY 38
07/12  86/70/78/+6/0.00/830/92             28 WSW  AERO 28 WSW  RMY 29
07/13  82/69/76/+4/0.23/306/34             30 SSE  AERO 31 SSE  RMY 30  TSTM
07/14  78/63/71/-1/0.00/369/41             26 ENE  AERO 25 ENE  RMY 26
07/15  72/59/66/-6/0.00/539/60             21 NE   AERO 21 NE   RMY N/A
07/16  73/57/65/-7/0.00/815/91             21 E    AERO 21 E    RMY 19
07/17  71/57/64/-8/0.19/027/03             24 SSW  AERO 24 SSW  RMY 25
07/18  89/66/78/+6/0.00/822/92             18 W    AERO 17 W    RMY 19
07/19  92/69/81/+9/0.00/…/..             28 S    AERO 28 S    RMY 26
07/20  91/72/82/+10/T/…/..               25 SSW  AERO 25 SSW  RMY N/A
07/21  88/68/78/+6/0.00/…/..             25 W    AERO 25 W    RMY 24
07/22  80/67/74/+2/…./…/..             16 ENE  AERO M  M    RMY 16
07/23  88/68/78/+6/0.48/…/..             31 N    AERO 32 N    RMY 31 TSTM
07/24  81/68/75/+3/0.00/…/..             15 ENE  AERO 15 ENE  RMY 16
07/25  88/67/78/+6/0.00/…/..             18 W    AERO 18 WNW  RMY N/A
07/26  89/70/80/+8/0.00/…/..             27 W    AERO 28 W    RMY 27
07/27  94/72/83/+11/0.00/…/..            23 SW   AERO 25 SW   RMY N/A
07/28  95/74/85/+13/0.01/…/..            28 WSW  AERO 25 WSW  RMY 25
07/29  90/68/79/+7/0.00/…/..             23 SSW  AERO 25 SSW  RMY 24
07/30  88/71/80/+8/0.00/…/..             29 W    AERO 28 W    RMY 29

07/31 The low since midnight is 69F, the daily normal low is 63F

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

RECORDS FOR JULY 31
HIGH 95F IN 1917
LOW 50F IN 1895,1918
PRECIP 1.34 INS IN 1892
PEAK GUST 43e MPH WNW SW IN 1953, 43 SW IN 1971

RECORDS FOR AUGUST 1
HIGH 97F IN 1917
LOW 49F IN 1891
PRECIP 3.61 INCHES IN 1927
PEAK GUST 41 MPH NNW IN 1985

TODAY’S REPORT PREPARED BY: Andrew Swanson

Category: Daily Discussions

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