Sunday, May 30, 2021

| May 30, 2021 | Reply

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

SUNDAY MAY 30, 2021
ALL TIMES ARE IN EASTERN STANDARD TIME
SUNRISE: 0411E
SUNSET:  1910E

RAINY AND RAW WITH SOME REALLY CHILLY
TEMPERATURES….

Today had almost no temperature variation, with temps between
45F and 46F. Overnight rain totaled 0.33 inches, with an
additional 0.22 inches between 7 A.M. and 1 P.M. Visibility
is very low due to fog, being a 1/2 mile on average.

It is quite windy at the summit, with a max gust of 38 mph
occurring this morning. The average wind speed is 15 mph
from the northeast with frequent gusts above 25 mph!

Yesterday’s max temperature of 46F was the 3rd coldest
On record for the date, and it was the first below 50F on
May 29th in over a hundred years. This was also the coldest
maximum temperature this late in the season since 46F was
observed as the high temperature on June 2nd, 1946.

BHO Coldest May 29 Daily Maximum Temperature, deg F (1885-2021):

1) 45 in 1887
   45 in 1917
3) 46 in 2021!!!
4) 51 in 2017
   51 in 2019
6) 52 in 1946
7) 53 in 1891

Credit: BHO Chief Scientist Michael Iacono

The high so far today is 46F, which is 24 degrees below
the normal high of 70F. The low since midnight is 45F,
which is 6 degrees below the daily normal low of 51F.


Today’s Observations:

7 A.M.
Weather: Overcast stratus, light rain
Temperature: 46F; Dew Point: 46F; Relative Humidity: 100%
Wind: NE @ 19G22 kts, peak of 35 mph NE at 6:23 A.M.
Sea-level pressure: 30.25 in. Hg; falling, then rising
Visibility: 4 miles, fog
6-hr Max temp: 46F
6-hr Min temp: 45F
24-hr Precip: 0.33 ins.
BHO SA 1155 15 OVC 4R-F 245/46/46/0614G22/025/ L-BCMG R-5 PK
WND 0631/23/ 8/6// 70033 50009 10046 20045

10 A.M.
Weather: Light rain
Temperature: 46F; Dew Point: 46F; Relative Humidity: 100%
Wind: NE @ 15G29 kts, peak of 38 mph NE at 9:25 A.M.
Sea-level pressure: 30.26 in Hg; falling then rising
Visibility: 1/2 mile, fog
3-hr Precip: 0.05 ins.
BHO SA 1455 X W3 1/2R-F 247/46/46/0615G29/026/ PK WND 0633/25/
8//// 6005/ 50002

1 P.M.
Weather: Light rain
Temperature: 45F, Dew point: 45F; Relative Humidity: 100%
Wind: NE @ 11G25 kts, peak of 38 mph NE at 12:18 P.M.
Sea-level pressure: 30.25 in Hg; falling steadily
Visibility: 1/16 miles, fog
6-hr Max temp: 46F
6-hr Min temp: 45F
6-hr Precip: 0.22 ins.
BHO SA 1755 X W3 1/16R-F 244/45/45/0611G25/025/ PK WND
0633/18/ 8//// 58003 6022/ 10046 20045

SUMMARY FOR SATURDAY, MAY 29, 2021

TEMPERATURE (DEGREES F)
MAX…….46     NORMAL…..70
MIN…….42     NORMAL…..52
MEAN……44     NORMAL…..61

DEPARTURE FROM 30-YEAR (1981-2010) NORMAL…….-17
TOTAL DEPARTURE FOR THE MONTH……………….+60 [+1.9 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL THRU JUN)
TOTAL HEATING UNITS FOR YESTERDAY……………21  DEPARTURE……+15
TOTAL HEATING UNITS FOR THE MONTH…………..205  DEPARTURE……-53
TOTAL HEATING UNITS FOR THE SEASON…………5546  DEPARTURE…..-746
TOTAL HEATING UNITS LAST SEASON TO DATE…….5803  DEPARTURE…..-257

COOLING DEGREE DAYS (SEASON JAN THRU DEC)
TOTAL COOLING UNITS FOR YESTERDAY…………… 0  DEPARTURE…….-1
TOTAL COOLING UNITS FOR THE MONTH……………29  DEPARTURE……+10
TOTAL COOLING UNITS FOR THE SEASON…………..29  DEPARTURE…….+8
TOTAL COOLING UNITS LAST SEASON TO DATE………26  DEPARTURE…….+3

PEAK WIND GUST (MPH):
                     420C/Official…………..44 ENE @  5:02 A.M.
                     AEROVANE (south tower)…..47 ENE @  5:02 A.M.
                     ASOS…………………..42 ENE @  5:02 A.M.
                     DAVIS #1……………….47 ENE @  5:01 A.M.
                     DAVIS #2 (south tower)…..46 ENE @  5:01 A.M.
                     RMY……………………50     @  5:01 A.M.
                     VECTOR…………………48     @  5:01 A.M.
                     MERLIN…………………N/A

FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………30 ENE @  2:06 A.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………….30 ENE @  2:06 A.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………31 E   @  2:06 A.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………30 ENE @  6:45 A.M.
MAXIMUM 2-MINUTE RMY AVERAGE………………..28 ENE @  2:03 A.M.
MAXIMUM 2-MINUTE VECTOR AVERAGE……………..28     @  2:02 A.M.

AVERAGE WIND SPEED AND DIRECTION:
                     CONTACTING/OFFICIAL…….18.3 NE [439 total miles]
                     ASOS………………….17.8
                     DAVIS #1………………18.3 ENE
                     DAVIS #2………………18.3 ENE
                     RMY…………………..16.7 E
                     VECTOR………………..17.3


PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M…….0.33  DEPARTURE….+0.19
                             ASOS………….0.36
TOTAL PRECIPITATION FOR THE MONTH………….4.55  DEPARTURE….+0.75
                             ASOS………….4.50
TOTAL PRECIPITATION FOR THE YEAR………….19.61  DEPARTURE….-2.74
                              ASOS………..19.78


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/-2/0.39/0.0/078/09       21 W    AERO 20 W    RMY 20
05/11   63/45/54/-2/0.00/0.0/764/88       38 WNW  AERO 41 WNW  RMY 41
05/12   65/41/53/-3/0.00/0.0/722/83       28 NW   AERO M  M    RMY 31
05/13   69/45/57/+1/0.00/0.0/759/87       22 WNW  AERO 21 WNW  RMY 21
05/14   76/49/63/+8/0.00/0.0/725/83       23 WNW  AERO 23 WNW  RMY 25
05/15   75/55/65/+8/0.01/0.0/569/65       24 SSE  AERO 26 SSE  RMY 26
05/16   78/54/66/+9/0.01/0.0/483/55       36 W    AERO 37 W    RMY 42
05/17   77/52/65/+8/0.00/0.0/722/82       20 SSW  AERO 21 SSW  RMY 21
05/18   81/54/68/+10/T/0.0/600/68         32 W    AERO 30 W    RMY 32
05/19   75/55/65/+7/0.00/0.0/778/88       25 NE   AERO 23 NNE  RMY 27
05/20   75/52/64/+6/0.00/0.0/842/95       18 ESE  AERO 18 ESE  RMY 19
05/21   78/50/64/+5/T/0.0/524/59          23 S    AERO 22 S    RMY 26
05/22   87/56/72/+13/T/0.0/285/32         25 WNW  AERO 21 WNW  RMY 24
05/23   87/58/73/+14/T/0.0/687/77         38 NNW  AERO 37 NNW  RMY 40
05/24   70/49/60/+1/0.00/0.0/…/..       30 S    AERO 35 S    RMY 33
05/25   75/47/61/+1/0.00/0.0/…/..       31 SW   AERO 35 SW   RMY 34
05/26   86/57/72/+12/…./0.0/…/..      30 S    AERO 36 S    RMY 35 TSTM
05/27   79/57/68/+8/…/0.0/…/..        25 N    AERO 25 WNW  RMY 27
05/28   58/43/51/-10/…./0.0/…/..      28 ENE  AERO 32 ENE  RMY 27
05/29   46/42/44/-17/…./0.0/…/..      44 ENE  AERO 47 ENE  RMY 50

05/30   The low since midnight is 42F, the daily normal low is 52F
 

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

RECORDS FOR MAY 30
HIGH 93F IN 1929
LOW 39F IN 1949,1961
PRECIP 1.28 INS 1948
PEAK GUST 61e MPH NW IN 1945

RECORDS FOR MAY 31
HIGH 92F IN 1944,1987,2013
LOW 35F IN 1961
PRECIP 5.02 INS 1984 (RECORD FOR MAY)
PEAK GUST 54e MPH WNW IN 1945

TODAY’S REPORT PREPARED BY: Benjamin Turner

Category: Daily Discussions

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