Friday, September 25, 2020

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

FRIDAY, SEPTEMBER 25, 2020
ALL TIMES ARE IN EASTERN STANDARD TIME

CLEAR, WARM, BUT VERY HAZY ATOP GREAT BLUE HILL…

Clear skies have dominated overhead today accompanied
by an increasing smoke layer. Wildfire smoke from the
West Coast has once again found its way nearly 2,500
miles eastward to New England. Forecast models suggest
the smoke layer will gradually thicken as we head toward
sunset, so expect a filtered setting sun around 5:35 EST.

Dew points have been hovering in the mid-50s. A far
difference from earlier in the week when dew points
were in the crisp mid-30s! The moistened air has dampened
(no pun intended!) the visibility to at most 30
miles today – the Boston skyline taking on a hazy
appearance. Temperatures have been warm since the
start of the day with the mercury reading 60 degrees
at 7AM and expanding to a max of 77 degrees by early afternoon.

Aside from the present weather, today marked the 14th
consecutive day without measurable precipitation.
The entire state of MA has deepened its drought conditions
since 1 week ago. It is worth mentioning that while the
departures range from 5 inches to as much as 13 inches
across the Commonwealth, the Quabbin and the Wachusett
Reservoirs remain in very healthy condition. For perspective,
93% is the current capacity at the Quabbin which fully serves
32 communities in Eastern MA plus an additional 16
municipalities for partial supply. Wachusett Reservoir sits
right behind at 91% capacity. The last significant drought
in MA occurred during the last half of 2016 into early 2017
where the Quabbin and Wachusett Reservoirs measured 79% and
89% respectively- both readings safely above warning criteria.

The high so far today is 77F, 9 degrees above the daily
normal max of 68F. The low since midnight is 57F, which
is 6 degrees above the normal low of 51F.

Today’s Observations:

7 A.M.
Weather: Clear; Thin Smoke Layer Aloft
Temperature: 60F; Dew Point: 55F; Relative Humidity: 83%
Wind: NW at 9 kts
Sea-level pressure: 30.10 ins. Hg: rising unsteadily
Visibility: 15 miles (thin fog)
6-hr Max temp: 60F
6-hr Min temp: 57F
24-hr Precip: 0.00 ins.
BHO SA 1155 CLR 15 192/60/55/3109/010/ THN K LYR ALF
THN F ALQDS/ 8/000 52019 10060 20057

10 A.M.
Weather: Clear; Few Cirrus Distant SE-SW; Thin Smoke Layer Aloft
Temperature: 72F; Dew Point: 57F; Relative Humidity: 59%
Wind: NW at 4 kts (wind light)
Sea-level pressure: 30.14 ins. Hg: rising, then rising more rapidly
Visibility: 20 miles (hazy)
3-hr Precip: 0.00 ins.
BHO SA 1455 CLR 20 208/72/57/3104/014/ FEW CI DSNT SE-SW
THN K LYR ALF HAZY WND LGT/ 8/001 51016

1 P.M.
Weather: Clear; Few Cumulus All-Quads; Few Cirrus Distant SE-SW;
Thin Smoke Layer Aloft
Temperature: 75F; Dew Point: 57F; Relative Humidity: 54%
Wind: WNW at 8 kts
Sea-level pressure: 30.11 ins. Hg: falling, then falling more rapidly
Visibility: 30 miles (hazy)
6-hr Max temp: 77F
6-hr Min temp: 60F
6-hr Precip: 0.00 ins.
BHO SA 1755 CLR 30 197/75/57/3008/011/ FEW CU ALQDS
FEW CI DSNT SE-SW THN K LYR ALF HAZY/ 8/101 58011 10077 20060

SUMMARY FOR THURSDAY, SEPTEMBER 24, 2020

TEMPERATURE (DEGREES F)
MAX…..76 NORMAL…..69
MIN…..57 NORMAL…..52
MEAN….67 NORMAL…..60

DEPARTURE FROM 30-YEAR NORMAL……………. +7
TOTAL DEPARTURE FOR THE MONTH…………….-25 [-1.2 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY…………..0 DEPARTURE……-6
TOTAL HEATING UNITS FOR THE MONTH………….94 DEPARTURE…..+20
TOTAL HEATING UNITS FOR THE SEASON…………97 DEPARTURE……-2
TOTAL HEATING UNITS LAST SEASON TO DATE…….76 DEPARTURE…..+21

COOLING DEGREE DAYS (SEASON JAN TO DEC)
TOTAL COOLING UNITS FOR YESTERDAY…………..2 DEPARTURE……+1
TOTAL COOLING UNITS FOR THE MONTH………… 52 DEPARTURE….. -3
TOTAL COOLING UNITS FOR THE SEASON………..809 DEPARTURE….+217
TOTAL COOLING UNITS LAST SEASON TO DATE……676 DEPARTURE….+133

PEAK WIND GUST FOR YESTERDAY (MPH)
420C/Official…………….20 SW AT 11:01 A.M.
AERO…………………….18 WSW AT 4:39 P.M.
ASOS…………………….19 WSW AT 4:49 P.M.
DAVIS……………………19 W AT 12:11 A.M.
RMY 19 MERLIN 19
FASTEST MILE FOR YESTERDAY………………….14 WSW AT 11:48 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………….14 WSW AT 11:59 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE………………15 WSW AT 11:45 P.M.
AVERAGE WIND SPEED AND DIRECTION……………9.5 WNW (228 total miles)
ASOS……………………9.8
DAVIS………………….10.0 W [268 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……….0.51 DEPARTURE….-2.66
ASOS…………..0.51
TOTAL PRECIPITATION FOR THE YEAR……….33.32 DEPARTURE….-4.87
ASOS………….34.09

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

09/01 76/59/68/0/0.00/698/88 22 SSE AERO 21 SE RMY 20
09/02 69/59/64/-4/0.18/102/13 23 SSE AERO 23 SSE RMY 24
09/03 75/66/71/+4/0.04/000/00 22 SSW AERO 21 SSW RMY N/A
09/04 82/62/72/+5/0.00/763/98 26 WNW AERO 26 WNW RMY 25
09/05 76/55/66/-1/0.00/760/98 25 W AERO 25 W RMY 24
09/06 78/58/68/+1/0.00/356/46 24 W AERO 24 W RMY N/A
09/07 79/61/70/+4/0.00/632/82 27 SSE AERO 30 SSE RMY 28
09/08 82/61/72/+6/0.00/545/71 17 S AERO 16 S RMY 17
09/09 80/62/71/+5/0.00/214/28 16 S AERO 15 S RMY 16
09/10 81/69/75/+10/0.28/015/02 21 SSW AERO 21 SSW RMY N/A
09/11 72/55/64/-1/0.01/152/20 25 N AERO 25 N RMY N/A
09/12 68/51/60/-5/0.00/666/88 21 ENE AERO 21 ENE RMY 21
09/13 74/53/64/0/0.00/611/81 26 SSW AERO 26 SSW RMY 26
09/14 74/50/62/-2/0.00/511/68 29 NNW AERO 33 NNW RMY 30
09/15 64/44/54/-10/0.00/…/.. 18 S AERO 18 S RMY N/A
09/16 72/49/61/-2/0.00/…/.. 31 SSW AERO 31 SSW RMY 31
09/17 76/57/67/+4/0.00/…/.. 26 WSW AERO 28 W RMY N/A
09/18 64/48/56/-6/0.00/…/.. 28 NE AERO 30 NNW RMY N/A
09/19 59/42/51/-11/0.00/…/.. 23 N AERO 23 N RMY N/A
09/20 58/40/49/-13/0.00/…/.. 25 NE AERO 25 NE RMY 27
09/21 61/41/51/-10/0.00/…/.. 29 NE AERO 27 NE RMY 29
09/22 63/39/51/-10/0.00/…/.. 28 NNW AERO 30 NNW RMY 29
09/23 78/50/64/+4/0.00/…/.. 31 NW AERO 32 WNW RMY 32
09/24 76/57/67/+7/0.00/…/.. 20 SW AERO 18 WSW RMY 19