Friday, July 30, 2021
BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
FRIDAY, JULY 30, 2021
ALL TIMES ARE IN EASTERN STANDARD TIME
SUNRISE: 0435E
SUNSET: 1906E
A PLEASANT DAY ATOP GREAT BLUE HILL…
Main story today is falling dew points. 62F was the recorded
reading at 7E, yet by early afternoon we saw values
slipping to the upper-50sF! The air is becoming more
comfortable, and is being accompanied by increasing visibility.
We began around 30 miles increasing to 45 miles at the
last observation.
Winds are to thank for the aforementioned dew point drop
and visibility increase. Winds are gradually picking up out
of the WNW as a cold front approaches. The peak so far today
is 29 MPH.
With the end of the month a day away, let’s dive into
precipitation. Overnight rainfall deposited 0.18 inches raising
the monthly total to 11.59″. This is only 0.09″ from breaking
the all-time wettest July on record here. The only foreseeable
opportunity to surpass this milestone prior to closing out the
month is a very slim chance of a passing shower this afternoon.
BHO Wettest Julys, inches (1885-2021)
1) 11.67 in 1938
2) 10.68 in 1988
3) 10.43 in 1921
4) 9.52 in 1915
5) 8.47 in 1889
6) 7.62 in 2009
7) 7.55 in 1916
The high so far today is 78F, 4 degrees below the daily
normal maximum of 82F. The low so far today is 61F, which
is 3 degrees below the daily normal minimum of 64F.
———————————————–
Today’s Observations:
7 A.M.
Weather: Clear, Few Altocumulus N
Temperature: 65F; Dew Point: 62F; Relative Humidity: 91%
Wind: NW @ 10G17 kts
Sea-level pressure: 29.71 in. Hg; Rising, then rising more rapidly
Visibility: 35 miles, thin fog
6-hr Max temp: 67F
6-hr Min temp: 61F
24-hr Precip: 0.18 ins.
BHO SA 1155 CLR 35 060/65/62/3110G17/971/ FEW AC N THN F ALQDS/
8/050 53019 70018 10067 20061
10 A.M.
Weather: Scattered Cumulus
Temperature: 73F; Dew Point: 62F; Relative Humidity: 68%
Wind: NW @ 7G17 kts
Sea-level pressure: 29.72in Hg; falling, then rising
Visibility: 30 miles, hazy
3-hr Precip: 0.00 ins.
BHO SA 1455 30 SCT 30 063/73/62/3107G17/972/ HAZY/ 8/100 53003
1 P.M.
Weather: Scattered Cumulus (virga NW-NE)
Temperature: 75F, Dew point: 58F; Relative Humidity: 56%
Wind: WNW @ 9G23 kts
Sea-level pressure: 29.72 in Hg; rising, then falling
Visibility: 45 miles, hazy
6-hr Max temp: 78F
6-hr Min temp: 65F
6-hr Precip: 0.00 ins.
BHO SA 1755 30 SCT 45 064/75/58/2909G23/972/ VIRGA NW-NE HAZY/ 8/100 50001 10078 20065
SUMMARY FOR THURSDAY, JULY 29, 2021
TEMPERATURE (DEGREES F)
MAX…….77 NORMAL…..82
MIN…….61 NORMAL…..64
MEAN……69 NORMAL…..73
DEPARTURE FROM 30-YEAR (1991-2020) NORMAL……….-4
TOTAL DEPARTURE FOR THE MONTH…………………-98 [-3.6 DEGREES/DAY]
HEATING DEGREE DAYS (SEASON: JUL 2021 THRU JUN 2022)
TOTAL HEATING UNITS FOR YESTERDAY…………….0 DEPARTURE…….. 0
TOTAL HEATING UNITS FOR THE MONTH……………26 DEPARTURE…….+20
TOTAL HEATING UNITS FOR THE SEASON…………..26 DEPARTURE…….+20
TOTAL HEATING UNITS LAST SEASON TO DATE……….1 DEPARTURE…….+25
COOLING DEGREE DAYS (SEASON: JAN 2021 THRU DEC 2021)
TOTAL COOLING UNITS FOR YESTERDAY…………….4 DEPARTURE……..-4
TOTAL COOLING UNITS FOR THE MONTH…………..150 DEPARTURE…….-81
TOTAL COOLING UNITS FOR THE SEASON………….376 DEPARTURE……..+6
TOTAL COOLING UNITS LAST SEASON TO DATE……..460 DEPARTURE…….-84
PEAK WIND GUST (MPH):
Official……………….39 S @ 7:07 P.M.
AEROVANE (south tower)…..40 S @ 10:58 P.M.
VECTOR #2 (south tower)….43 @ 7:08 P.M.
DAVIS #2 (south tower)…..46 S @ 7:01 P.M.
ASOS………..OUT OF SERVICE D/T RENOVATIONS
VECTOR #1……OUT OF SERVICE D/T RENOVATIONS
DAVIS #1…….OUT OF SERVICE D/T RENOVATIONS
RMY…………OUT OF SERVICE D/T RENOVATIONS
MERLIN………OUT OF SERVICE D/T RENOVATIONS
FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………32 S @ 8:15 P.M.
MAXIMUM 2-MINUTE VECTOR #2 AVERAGE…………..30 @ 8:15 P.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………35 S @ 8:15 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE…….OUT OF SERVICE D/T RENOVATIONS
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE…OUT OF SERVICE D/T RENOVATIONS
MAXIMUM 2-MINUTE VECTOR #1 AVERAGE..OUT OF SERVICE D/T RENOVATIONS
MAXIMUM 2-MINUTE RMY AVERAGE……..OUT OF SERVICE D/T RENOVATIONS
AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL……15.8 S [378 total miles] VECTOR #2…………….16.4
DAVIS #2……………..16.4 SSW
RMY……………..OUT OF SERVICE D/T RENOVATIONS
ASOS…………….OUT OF SERVICE D/T RENOVATIONS
VECTOR #1………..OUT OF SERVICE D/T RENOVATIONS
DAVIS #1…………OUT OF SERVICE D/T RENOVATIONS
PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M…….0.18 DEPARTURE….+0.06
TOTAL PRECIPITATION FOR THE MONTH…………11.59 DEPARTURE….+8.36
TOTAL PRECIPITATION FOR THE YEAR………….34.97 DEPARTURE….+4.77
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 80/65/73/+2/0.74/155/17 22 W AERO 20 WSW RMY 21
07/02 65/55/60/-11/1.49/000/00 37 NE AERO 36 NE RMY 39
07/03 56/54/55/-17/1.98/000/00 41 NE AERO 44 NE RMY 45 TSTM
07/04 66/54/60/-12/0.16/191/21 26 ENE AERO 23 ENE RMY 26
07/05 74/53/64/-8/0.01/546/60 26 SSW AERO 28 SSW RMY 27
07/06 87/66/77/+5/0.26/255/28 37 W AERO 48 W RMY 38 TSTM
07/07 88/88/77/+5/0.77/699/77 63 NW AERO 75 NW RMY 70 TSTM
07/08 67/59/63/-9/0.38/109/12 46 W AERO 46 W RMY 51 TSTM
07/09 73/62/68/-5/3.02/163/18 40 WNW AERO 44 WNW RMY 43
07/10 71/63/67/-6/0.07/109/12 23 NE AERO 21 NNE RMY 22
07/11 81/61/71/-2/T/325/36 21 SW AERO 19 S RMY N/A
07/12 67/61/64/-9/1.01/000/00 31 ENE AERO 31 ENE RMY N/A
07/13 66/60/63/-10/0.02/000/00 19 E AERO 18 E RMY N/A
07/14 80/62/71/-2/0.01/216/24 19 S AERO 18 S RMY N/A
07/15 88/67/78/+5/0.00/844/94 19 WSW AERO 18 SSW RMY N/A
07/16 90/70/80/+7/0.04/609/68 36 NNW AERO 39 NNW RMY N/A TSTM
07/17 78/64/71/-2/0.34/394/44 26 ENE AERO 25 ENE RMY N/A TSTM
07/18 74/63/69/-4/0.15/000/00 22 NE AERO 22 NE RMY N/A TSTM
07/19 71/63/67/-6/0.07/027/03 17 ENE AERO 17 ENE RMY N/A
07/20 83/64/74/+1/0.00/730/82 23 NW AERO 23 NW RMY N/A
07/21 79/62/71/-2/0.16/577/65 26 NNW AERO 23 NNW RMY N/A TSTM
07/22 79/58/69/-4/T/656/74 20 WNW AERO 20 WNW RMY N/A
07/23 79/62/71/-2/0.00/708/80 22 S AERO 21 S RMY N/A TSTM
07/24 78/59/69/-4/0.00/830/94 19 S AERO 18 S RMY N/A
07/25 71/64/68/-5/0.08/009/01 40 SSW AERO 41 SSW RMY N/A
07/26 87/67/77/+4/0.01/765/87 27 WSW AERO 25 WNW RMY N/A
07/27 87/65/76/+3/…./…/.. 55 NW AERO 58 NW RMY N/A
07/28 72/61/67/-6/…./…/.. 18 NNE AERO 18 NNE RMY N/A
07/29 77/61/69/-4/…./…/… 39 S AERO 40 S RMY N/A
07/30 The low since midnight is 61F, the daily normal low is 64F
RECORDS FOR JULY:
JULY 2: Record daily precipitation of 1.49″,
Surpasses previous record of 1.42″ set in 1986
JULY 3: Record daily precipitation of 1.98″,
Surpasses previous record of 1.36″ set in 1985
JULY 7: Record peak gust of 63 MPH,
Surpasses previous record of 55 MPH set in 1989
DAILY EXTREMES
Temperature and precipitation records back to 1885, and
wind records back to 1940 (e = estimated)
RECORDS FOR JULY 30
HIGH 99F IN 1949
LOW 51F IN 1956
PRECIP 1.84 INS IN 1976
PEAK GUST 70e MPH SW 1944
RECORDS FOR JULY 31
HIGH 95F IN 1917
LOW 50F IN 1895
PRECIP 1.34 INS IN 1892
PEAK GUST 43e MPH WNW SW IN 1953, 43 SW IN 1971
TODAY’S REPORT PREPARED BY: Andrew Swanson
