Saturday, May 22, 2021
BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
SATURDAY MAY 22, 2021
ALL TIMES ARE IN EASTERN STANDARD TIME
SUNRISE: 0416E
SUNSET: 1905E
HOT WITH LIMITED VISIBILITY AND A COOL OPTICAL
FEATURE EARLIER ON….
Today was mostly cloudy with skies being obscured
by smoke. Visibility was limited to only 20 miles
due to a smoke layer moving in from southern
Canada and Vermont’s wildfires. There is not much
to speak of as far as wind, but it has shifted from
south to west as the day went on. The max gust
so far today is 15 mph.
A full solar halo was witnessed between 11 A.M. and
12 P.M., which could also be due in part to the
layer of smoke.
The high so far today is 87F, which is 19 degrees
above the normal high of 68F. The low since midnight
is 56F, which is 6 degrees above the daily normal low
of 50F.
Today’s Observations:
7 A.M.
Weather: Scattered altocumulus, broken cirrus
Temperature: 59F; Dew Point: 53F; Relative Humidity: 81%
Wind: SW @ 10 kts
Sea-level pressure: 30.22 in. Hg; falling steadily
Visibility: 25 miles, smoke layer
6-hr Max temp: 59F
6-hr Min temp: 56F
24-hr Precip: 0.00 ins.
BHO SA 1155 100 SCT 250 BKN 25 232/59/53/2110/022/ FEW CU
ALQDS K LYR ALG HRZN/ 8/171 70000 58007 10059 20056
10 A.M.
Weather: Scattered altocumulus, broken cirrus
Temperature: 75F; Dew Point: 59F; Relative Humidity: 58%
Wind: SSW @ 7 kts
Sea-level pressure: 30.16 in Hg; falling steadily
Visibility: 25 miles, smoke layer
3-hr Precip: 0.00 ins.
BHO SA 1455 100 SCT 250 BKN 25 214/75/59/2007/016/ FEW CU
ALQDS K LYR ALG HRZN/ 8/171 58018
1 P.M.
Weather: Scattered altocumulus, broken cirrus
Temperature: 86F, Dew point: 59F; Relative Humidity: 40%
Wind: W @ 7 kts
Sea-level pressure: 30.14 in Hg; falling steadily
Visibility: 20 miles, smoke
6-hr Max temp: 87F
6-hr Min temp: 59F
6-hr Precip: 0.00 ins.
BHO SA 1755 140 SCT 250 20 207/86/59/2607/014/ K LYR ALG HRZN/
8/051 58007 10087 20059
SUMMARY FOR FRIDAY, MAY 21, 2021
TEMPERATURE (DEGREES F)
MAX…….78 NORMAL…..68
MIN…….50 NORMAL…..49
MEAN……64 NORMAL…..59
DEPARTURE FROM 30-YEAR (1981-2010) NORMAL…….+5
TOTAL DEPARTURE FOR THE MONTH……………….+38 [+1.6 DEGREES/DAY]
HEATING DEGREE DAYS (SEASON JUL THRU JUN)
TOTAL HEATING UNITS FOR YESTERDAY…………… 1 DEPARTURE…….-6
TOTAL HEATING UNITS FOR THE MONTH…………..161 DEPARTURE……-47
TOTAL HEATING UNITS FOR THE SEASON…………5502 DEPARTURE…..-740
TOTAL HEATING UNITS LAST SEASON TO DATE…….5771 DEPARTURE…..-269
COOLING DEGREE DAYS (SEASON JAN THRU DEC)
TOTAL COOLING UNITS FOR YESTERDAY…………… 0 DEPARTURE…….-1
TOTAL COOLING UNITS FOR THE MONTH…………… 4 DEPARTURE…….-7
TOTAL COOLING UNITS FOR THE SEASON………….. 4 DEPARTURE…….-9
TOTAL COOLING UNITS LAST SEASON TO DATE……… 3 DEPARTURE…….+3
PEAK WIND GUST (MPH):
420C/Official…………..23 S @ 8:15 P.M.
AEROVANE (south tower)…..22 S @ 5:23 P.M.
ASOS…………………..24 S @ 8:15 P.M.
DAVIS #1……………….28 SSE @ 7:27 P.M.
DAVIS #2 (south tower)…..28 SSE @ 7:27 P.M.
RMY……………………26 @ 8:15 P.M.
VECTOR…………………26 @ 8:14 P.M.
MERLIN…………………23
FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………20 SSW @ 9:46 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………….18 SSW @ 9:46 P.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………20 S @ 3:37 P.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………20 S @ 3:37 P.M.
MAXIMUM 2-MINUTE RMY AVERAGE………………..18 SSW @ 11:30 P.M.
MAXIMUM 2-MINUTE VECTOR AVERAGE……………..18 @ 11:29 P.M.
AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL…..11.4 SSW [273 total miles] ASOS………………..11.8
DAVIS #1…………….12.1 SSW
DAVIS #2…………….12.1 SSW
RMY…………………11.4 SSW
VECTOR………………11.8
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………….1.80 DEPARTURE….-0.81
ASOS………….1.74
TOTAL PRECIPITATION FOR THE YEAR………….16.86 DEPARTURE….-4.30
ASOS………..17.02
PRELIMINARY CLIMATE SUMMARY FOR MAY CALENDAR DAY DATA
DATE: MAX/MIN/MEAN/DEP/PRECIP/SNOW/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
05/01 62/38/50/-3/0.06/0.0/659/78 31 WNW AERO 35 WNW RMY 40
05/02 76/48/62/+9/0.01/0.0/220/26 41 SW AERO 41 SW RMY 46
05/03 67/48/58/+5/0.07/0.0/400/47 21 E AERO 20 E RMY 20
05/04 50/44/47/-7/0.78/0.0/000/00 36 NNE AERO 32 NNE RMY 37
05/05 48/44/46/-8/0.47/0.0/000/00 18 ESE AERO 14 ESE RMY 17
05/06 64/45/55/+1/0.00/0.0/780/91 33 NW AERO 38 NNW RMY 39
05/07 61/43/52/-3/0.00/0.0/516/60 28 ESE AERO 22 ESE RMY 26
05/08 54/40/47/-8/0.00/0.0/069/08 24 SSW AERO 23 SSW RMY 25
05/09 66/42/54/-1/T/0.0/579/67 30 SW AERO 29 SW RMY 34
05/10 60/45/53/-2/0.39/0.0/…/.. 21 W AERO 20 W RMY 20
05/11 63/45/54/-2/0.00/0.0/…/.. 38 WNW AERO 41 WNW RMY 41
05/12 65/41/53/-3/0.00/0.0/…/.. 28 NW AERO M M RMY 31
05/13 69/45/57/+1/0.00/0.0/…/.. 22 WNW AERO 21 WNW RMY 21
05/14 76/49/63/+8/0.00/0.0/…/.. 23 WNW AERO 23 WNW RMY 25
05/15 75/55/65/+8/0.01/0.0/…/.. 24 SSE AERO 26 SSE RMY 26
05/16 78/54/66/+9/0.01/0.0/…/.. 36 W AERO 37 W RMY 42
05/17 77/52/65/+8/0.00/0.0/…/.. 20 SSW AERO 21 SSW RMY 21
05/18 81/54/68/+10/T/0.0/…/.. 32 W AERO 30 W RMY 32
05/19 75/55/65/+7/0.00/0.0/…/.. 25 NE AERO 23 NNE RMY 27
05/20 75/52/64/+6/0.00/0.0/…/.. 18 ESE AERO 18 ESE RMY 19
05/21 78/50/64/+5/T/0.0/…/.. 23 S AERO 22 S RMY 26
05/22 The low since midnight is 56F, the daily normal low is 50F
DAILY EXTREMES
Temperature and precipitation records back to 1885, and
wind records back to 1940 (e = estimated)
RECORDS FOR MAY 22
HIGH 93F IN 1911
LOW 35F IN 1907
PRECIP 3.75 INCHES IN 1920
PEAK GUST 49e MPH SSW IN 1947
RECORDS FOR MAY 23
HIGH 92F IN 1964,1992
LOW 38F IN 1976
PRECIP 1.60 INS IN 1919
PEAK GUST 49e MPH W IN 1945
TODAY’S REPORT PREPARED BY: Benjamin Turner
