Thursday, May 6, 2021

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

THURSDAY, MAY 6, 2021
ALL TIMES ARE IN EASTERN STANDARD TIME
SUNRISE: 0433E
SUNSET: 1849E

FAIR WEATHER DAY WITH A STILL-PREVALENT
COOL BREEZE….

Yesterday we experienced more rainfall with an overnight
total of 0.24 inches. Visibility was much better today,
being 75 miles on average. Skies are partly cloudy with
a cool northwesterly breeze. There are frequent gusts of
20 mph, with the highest one being 34 mph so far.

The high so far today is 61F, this is 3 degrees below the
normal high of 64F. The low since midnight is 45F, which
is a degree above the daily normal low of 44F.

Today’s Observations:

7 A.M.
Weather: Scattered stratocumulus
Temperature: 49F; Dew Point: 46F; Relative Humidity: 90%
Wind: WNW at 14G20 kts
Sea-level pressure: 29.81 in Hg, rising steadily
Visibility: 75 miles
6-hr Max temp: 49F
6-hr Min temp: 46F
24-hr Precip: 0.24 ins.
24-hr Snow: 0.0 ins.
Snow Depth: 0.0 ins.
BHO SA 1155 50 SCT 75 095/49/46/3014G20/981/ 8/800 53019
70024 10049 20046

10 A.M.
Weather: Broken stratocumulus
Temperature: 55F; Dew Point: 36F; Relative Humidity: 148%
Wind: WNW @ 13G24 kts
Sea-level pressure: 29.85 in Hg; rising steadily
Visibility: 75 miles
3-hr Precip: 0.00 ins.
3-hr Snow: 0.0 ins.
BHO SA 1455 50 BKN 75 108/55/36/3013G24/985/ 8/800 51013

1 P.M.
Weather: Clear, few cumulus
Temperature: 60F, Dew point: 36F; Relative Humidity: 40%
Wind: NW @ 14G22 kts, peak of 33 mph WNW at 12:14 P.M.
Sea-level pressure: 29.85 in Hg; rising then steady
Visibility: 75 miles
6-hr Max temp: 61F
6-hr Min temp: 49F
6-hr Precip: 0.00 ins.
6-hr Snow: 0.0 ins.
Snow Depth: 0 ins.
BHO SA 1755 CLR 75 109/60/36/3314G22/985/ FEW CU ALQDS PK
WND 3028/14/ 8/100 53001 10061 20049

SUMMARY FOR WEDNESDAY, MAY 5, 2021

TEMPERATURE (DEGREES F)
MAX…….48 NORMAL…..63
MIN…….44 NORMAL…..45
MEAN……46 NORMAL…..54

DEPARTURE FROM 30-YEAR (1981-2010) NORMAL…….. -8
TOTAL DEPARTURE FOR THE MONTH…………………-4 [-1.0 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL THRU JUN)
TOTAL HEATING UNITS FOR YESTERDAY……………19 DEPARTURE…….+8
TOTAL HEATING UNITS FOR THE MONTH……………62 DEPARTURE…….+2
TOTAL HEATING UNITS FOR THE SEASON…………5403 DEPARTURE…..-692
TOTAL HEATING UNITS LAST SEASON TO DATE…….5558 DEPARTURE…..-155

COOLING DEGREE DAYS (SEASON JAN THRU DEC)
TOTAL COOLING UNITS FOR YESTERDAY…………… 0 DEPARTURE……. 0
TOTAL COOLING UNITS FOR THE MONTH…………… 0 DEPARTURE…….-1
TOTAL COOLING UNITS FOR THE SEASON………….. 0 DEPARTURE…….-3
TOTAL COOLING UNITS LAST SEASON TO DATE……… 2 DEPARTURE…….-2

PEAK WIND GUST (MPH):
420C/Official…………..18 ESE @ 12:44 A.M.
AEROVANE (south tower)…..14 ESE @ 12:46 A.M.
ASOS…………………..16 NNE @ 2:01 P.M.
DAVIS #1……………….17 NNE @ 12:43 A.M.
DAVIS #2 (south tower)…..16 E @ 2:05 P.M.
RMY……………………17 @ 2:00 P.M.
VECTOR…………………18 @ 1:59 P.M.
MERLIN…………………N/A

FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………11 NNE @ 2:02 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………….12 N @ 6:54 P.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………12 ESE @ 12:43 A.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………12 NNW @ 1:59 P.M.
MAXIMUM 2-MINUTE RMY AVERAGE………………..12 SE @ 12:36 A.M.
MAXIMUM 2-MINUTE VECTOR AVERAGE……………..12 @ 12:37 A.M.

AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL…… 6.0 NE [144 total miles]ASOS………………… 5.7
DAVIS #1…………….. 6.2 NE
DAVIS #2…………….. 6.1 NE
RMY…………………. 6.0 ENE
VECTOR………………. 6.4

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M…….0.24 DEPARTURE….+0.11
ASOS………….0.24
TOTAL PRECIPITATION FOR THE MONTH………….1.39 DEPARTURE….+0.77
ASOS………….1.35
TOTAL PRECIPITATION FOR THE YEAR………….16.45 DEPARTURE….-2.72
ASOS………..16.63

PRELIMINARY CLIMATE SUMMARY FOR APRIL 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

04/01 56/30/43/+2/0.89/T/000/00 44 NW AERO 51 NW RMY 49
04/02 37/24/31/-10/0.00/0.0/614/80 28 NW AERO 32 NNW RMY 30
04/03 48/23/36/-6/0.00/0.0/755/98 24 NW AERO 25 NW RMY 26
04/04 58/33/46/+4/0.00/0.0/734/95 38 NNW AERO 41 NNW RMY 41
04/05 57/41/49/+6/T/T/031/04 41 NNW AERO 48 NNW RMY 50
04/06 61/40/51/+8/0.00/0.0/412/53 26 NNW AERO 25 NNW RMY 31
04/07 57/41/49/+6/0.00/0.0/391/50 23 ENE AERO 21 ENE RMY 22
04/08 59/43/51/+7/0.00/0.0/745/95 22 ENE AERO 22 ENE RMY 24
04/09 69/42/56/+12/0.00/0.0/707/90 24 S AERO M M RMY 26
04/10 75/43/59/+14/0.00/0.0/576/73 26 SSW AERO 28 SSW RMY 30
04/11 53/40/47/+2/T/0.0/000/00 33 ENE AERO 33 ENE RMY 34
04/12 46/37/42/-3/0.05/0.0/000/00 36 ENE AERO 37 ENE RMY 41
04/13 56/37/47/+1/T/0.0/415/52 31 NE AERO 30 NE RMY 33
04/14 56/42/49/+3/0.00/0.0/729/91 22 ESE AERO 23 ESE RMY 22
04/15 51/37/44/-3/0.30/0.0/016/02 26 ESE AERO 25 ESE RMY 28
04/16 39/31/35/-12/2.22/3.6/000/00 48 NNW AERO 58 NNW RMY 58
04/17 45/34/40/-7/0.07/T/040/05 27 NNW AERO 30 NNW RMY 29
04/18 60/38/49/+1/0.00/0.0/666/82 28 NW AERO 28 NW RMY 31
04/19 66/44/55/+7/T/0.0/…/.. 22 SSW AERO 25 SSW RMY 28
04/20 72/45/59/+10/0.00/0.0/…/.. 38 SW AERO 37 WSW RMY 40
04/21 68/32/50/+1/0.48/*T/…/.. 45 S AERO 51 S RMY 51 TSTM
04/22 44/28/36/-13/T/T/…/.. 54 W AERO 55 W RMY 59
04/23 58/32/45/-5/0.00/0.0/…/.. 47 W AERO 48 W RMY 52
04/24 70/44/57/+7/0.00/0.0/…/.. 33 WNW AERO 37 WNW RMY 55
04/25 54/44/49/-1/0.20/0.0/…/.. 23 NNE AERO 20 SSW RMY 24
04/26 55/40/48/-3/0.00/0.0/…/.. 39 NW AERO 40 NW RMY 43
04/27 67/38/53/+2/T/0.0/…/.. 26 W AERO 28 WNW RMY 28
04/28 63/46/55/+3/0.18/0.0/…/.. 18 ENE AERO 21 WNW RMY 20
04/29 54/44/48/-4/0.42/0.0/…/.. 18 ENE AERO 20 NNE RMY 19
04/30 62/41/52/0/0.08/0.0/…/.. 58 WNW AERO 60 WNW RMY 65

*Trace of frozen on 04/21 was hail, 1/8″ diameter, this does not
count as snowfall.

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/…/.. 31 WNW AERO 35 WNW RMY 40
05/02 76/48/62/+9/0.01/0.0/…/.. 41 SW AERO 41 SW RMY 46
05/03 67/48/58/+5/0.07/0.0/…/.. 21 E AERO 20 E RMY 20
05/04 50/44/47/-7/…./0.0/…/.. 36 NNE AERO 32 NNE RMY 37
05/05 48/44/46/-8/…./0.0/…/.. 18 ESE AERO 14 ESE RMY 17

05/06 The low since midnight is 46F, the daily normal low is 45F

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

RECORDS FOR MAY 6
HIGH 90F IN 1930
LOW 29F IN 1891
PRECIP 1.04 INCHES IN 1890
SNOWFALL TRACE IN 1917, 1952, 1996
PEAK GUST 65 MPH SSE IN 1989

RECORDS FOR MAY 7
HIGH 93F IN 1930
LOW 33F IN 1970
PRECIP 1.19 INCHES IN 2005
SNOWFALL TRACE IN 1967
PEAK GUST 66e MPH WNW IN 1940

TODAY’S REPORT PREPARED BY: Benjamin Turner