Sunday, May 16, 2021
BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
SUNDAY, MAY 16, 2021
ALL TIMES ARE IN EASTERN STANDARD TIME
SUNRISE: 0422E
SUNSET: 1900E
WARM AND BREEZY AT TIMES WITH SCATTERED SHOWERS AND
THUNDERSTORMS IN THE VICINITY…
Variable amounts of cloud cover have been the theme today,
but we’ve seen enough sun to get temperatures into the
upper 70s through 1 P.M.
With the warmth, convection has been developing late this
morning into early this afternoon. A cluster of showers
and storms have so far passed to the south and north of
Blue Hill. We even observed a cloud to ground lightning
strike from the storm that passed to the south between
11 A.M. and 12 P.M.
The wind has been getting busy at times out of the west-
southwest gusting in the 20-25 mph range, however most of
the time the wind is generally light. The average speed
since 7 A.M. is only around 8 mph.
The high so far today is 78F, which is 12 degrees
above the normal high of 66F. The low since midnight
is 54F, which is 6 degrees above the daily normal low
of 48F.
Today’s Observations:
7 A.M.
Weather: Scattered altocumulus castellanus, broken altocumulus,
broken cirrus
Temperature: 62F; Dew Point: 37F; Relative Humidity: 39%
Wind: WNW at 9 kts
Sea-level pressure: 30.25 in. Hg; rising, then more rapidly
Visibility: 70 miles
6-hr Max temp: 62F
6-hr Min temp: 54F
24-hr Precip: 0.01 ins.
24-hr Snow: 0.0 ins.
Snow Depth: 0.0 ins.
BHO SA 1155 70 SCT E130 BKN 250 BKN 70 243/62/37/2909/025/
VIRGA DSNT W-N-NNE/ 8/082 53016 70001 10062 20054
10 A.M.
Weather: Scattered cumulus, scattered altocumulus/castellanus,
broken cirrus
Temperature: 72F; Dew Point: 33F; Relative Humidity: 23%
Wind: W @ 7G14 kts
Sea-level pressure: 30.24 in Hg; rising, then falling
Visibility: 65 miles
3-hr Precip: 0.00 ins.
3-hr Snow: 0.0 ins.
BHO SA 1455 60 SCT 120 SCT E250 BKN 65 240/72/33/2607G14/024/
FEW MDT CU SSW AND DSNT W-NW/ 8/282 58003
1 P.M.
Weather: Broken cumulus, broken altocumulus, broken cirrus,
cumulonimbus all quadrants, virga all quadrants
Temperature: 77F, Dew point: 34F; Relative Humidity: 21%
Wind: W @ 8 kts
Sea-level pressure: 30.19 in Hg; falling, then more slowly
Visibility: 50 miles
6-hr Max temp: 78F
6-hr Min temp: 62F
6-hr Precip: 0.00 ins.
6-hr Snow: 0.0 ins.
Snow Depth: 0 ins.
BHO SA 1755 E55 BKN 120 BKN 250 BKN 50 224/77/34/2708/019/
CB ALQDS VIRGA ALQDS/ 8/363 56016 10078 20062
SUMMARY FOR SATURDAY, MAY 15, 2021
TEMPERATURE (DEGREES F)
MAX…….75 NORMAL…..66
MIN…….55 NORMAL…..48
MEAN……65 NORMAL…..57
DEPARTURE FROM 30-YEAR (1981-2010) NORMAL……. +8
TOTAL DEPARTURE FOR THE MONTH………………. -7 [-0.7 DEGREES/DAY]
HEATING DEGREE DAYS (SEASON JUL THRU JUN)
TOTAL HEATING UNITS FOR YESTERDAY…………… 0 DEPARTURE…….-9
TOTAL HEATING UNITS FOR THE MONTH…………..159 DEPARTURE…… -1
TOTAL HEATING UNITS FOR THE SEASON…………5500 DEPARTURE…..-695
TOTAL HEATING UNITS LAST SEASON TO DATE…….5713 DEPARTURE…..-213
COOLING DEGREE DAYS (SEASON JAN THRU DEC)
TOTAL COOLING UNITS FOR YESTERDAY…………… 0 DEPARTURE…….-1
TOTAL COOLING UNITS FOR THE MONTH…………… 0 DEPARTURE…….-5
TOTAL COOLING UNITS FOR THE SEASON………….. 0 DEPARTURE…….-7
TOTAL COOLING UNITS LAST SEASON TO DATE……… 2 DEPARTURE…….-2
PEAK WIND GUST (MPH):
420C/Official…………..24 SSE @ 5:56 P.M.
AEROVANE (south tower)…..26 SSE @ 4:22 P.M.
ASOS…………………..24 S @ 5:56 P.M.
DAVIS #1……………….26 S @ 5:44 P.M.
DAVIS #2 (south tower)…..30 SSE @ 4:35 P.M.
RMY……………………26 @ 2:32 P.M.
VECTOR…………………28 @ 5:54 P.M.
MERLIN…………………24
FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………17 SSE @ 6:03 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………….18 S @ 5:56 P.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………18 W @ 5:45 P.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………22 S @ 5:56 P.M.
MAXIMUM 2-MINUTE RMY AVERAGE………………..18 S @ 5:54 P.M.
MAXIMUM 2-MINUTE VECTOR AVERAGE……………..18 @ 5:42 P.M.
AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL…… 9.5 SSE [229 total miles]
ASOS………………… 9.6
DAVIS #1…………….. 9.9 SSW
DAVIS #2……………..10.6 S
RMY…………………. 9.4 SSW
VECTOR……………….10.0
PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M…….0.01 DEPARTURE….-0.11
ASOS………….0.01
TOTAL PRECIPITATION FOR THE MONTH………….1.79 DEPARTURE….-0.04
ASOS………….1.74
TOTAL PRECIPITATION FOR THE YEAR………….16.85 DEPARTURE….-3.53
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/-8/0.45/0.0/000/00 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 The low since midnight is 54F, the daily normal low is 48F
DAILY EXTREMES
Temperature and precipitation records back to 1885, and
wind records back to 1940 (e = estimated)
RECORDS FOR MAY 16
HIGH 90F IN 1951
LOW 30F IN 1936
PRECIP 2.63 INCHES IN 1954
PEAK GUST 56e MPH NW IN 1952
RECORDS FOR MAY 17
HIGH 90F IN 2017
LOW 34F IN 1956, 1957
PRECIP 2.07 INS IN 1916
PEAK GUST 52 MPH SW IN 1967, W IN 1974
TODAY’S REPORT PREPARED BY: Matt Douglas
