Sunday, May 24, 2020

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

DAILY DISCUSSION AND CLIMATE SUMMARY
SUNDAY, MAY 24, 2020
ALL TIMES ARE IN EASTERN STANDARD TIME

BRILLIANT SUNSHINE, BUT COOL TEMPERATURES TODAY…

The onshore flow continues today keeping temperatures
below normal despite an abundance of late May sunshine.
Dry air relative for this time of year is also being
observed with dew points holding in the upper 30s all
day so far.

Visibility has been gradually increasing from a low of
30 miles this morning up to 60 miles early this
afternoon. The “hazy” appearance and reduction to the
visibility is once again due to high pollen counts
across the region.

The high so far today is 57F, this is 12 degrees below
the daily normal high of 69F. The low since midnight is
43F, which is 7 degrees below the daily normal low of
50F.

Today’s Observations:

7 A.M.
Weather: Thin scattered cirrus, few stratocumulus distant
southeast through southwest
Temperature: 50F; Dew Point: 38F; Relative Humidity: 63%
Wind: NE at 10G18 kts
Sea-level pressure: 30.33 ins. Hg: rising, then more slowly
Visibility: 30 miles, hazy
6-hr Max temp: 50F
6-hr Min temp: 43F
24-hr Precip:  0.00 ins.
24-hr Snowfall: 0.0 ins.
BHO SA 1155 250 –SCT 30 271/50/38/0510G18/033/ FEW SC DSNT
SE-SW HAZY/ 8/501 51012 10050 20043

10 A.M.
Weather: Thin scattered cirrus, few stratocumulus distant
east through south
Temperature: 54F; Dew Point: 37F; Relative Humidity: 53%
Wind: NE at 12G20 kts
Sea-level pressure: 30.36 ins. Hg: rising, then more slowly
Visibility: 40 miles, hazy
3-hr Precip:  0.00 ins.
3-hr Snowfall: 0.0 ins.
BHO SA 1455 250 –SCT 40 281/54/37/0512G20/036/ FEW SC DSNT E-S
HAZY/ 8/501 51010

1 P.M.
Weather: Thin broken cirrus, few stratocumulus distant
east-northeast through south
Temperature: 55F; Dew Point: 37F; Relative Humidity: 50%
Wind: NE at 8G15 kts
Sea-level pressure: 30.35 ins. Hg: rising then falling
Visibility: 60 miles
6-hr Max temp: 57F
6-hr Min temp: 50F
6-hr Precip:  0.00 ins.
6-hr Snowfall: 0.0 ins.
BHO SA 1755 250 –BKN 60 277/55/37/0508G15/035/ FEW SC DSNT
ENE-S/ 8/501 58004 10057 20050

SUMMARY FOR SATURDAY, MAY 23, 2020

TEMPERATURE (DEGREES F)
MAX…..67   NORMAL…..68
MIN…..44   NORMAL…..50
MEAN….56   NORMAL…..59

DEPARTURE FROM 30-YEAR NORMAL………………-3
TOTAL DEPARTURE FOR THE MONTH………………-49 [-2.3 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY…………….9  DEPARTURE……..+2
TOTAL HEATING UNITS FOR THE MONTH…………..259  DEPARTURE…….+37
TOTAL HEATING UNITS FOR THE SEASON…………5780  DEPARTURE……-476
TOTAL HEATING UNITS LAST SEASON TO DATE…….6166  DEPARTURE……-386

COOLING DEGREE DAYS (SEASON JAN TO DEC)
TOTAL COOLING UNITS FOR YESTERDAY…………….0  DEPARTURE……..-1
TOTAL COOLING UNITS FOR THE MONTH…………….3  DEPARTURE……..-9
TOTAL COOLING UNITS FOR THE SEASON……………3  DEPARTURE…….-11
TOTAL COOLING UNITS LAST SEASON TO DATE……….4  DEPARTURE……..-1

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY………………..42 ENE AT  9:21 A.M.
AERO…………………….43 ENE AT  9:21 A.M.
ASOS…………………….42 ENE AT  9:20 A.M.
DAVIS……………………41 ENE AT  9:20 A.M. RMY 40
FASTEST MILE FOR YESTERDAY………………….33 ENE AT  9:32 A.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………….31 ENE AT  9:49 A.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE………………32 E   AT  9:49 A.M.
AVERAGE WIND SPEED AND DIRECTION…………….14.3 ENE
ASOS…………………….13.5
DAVIS……………………14.6 ENE [076 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……….2.57  DEPARTURE……-0.33
ASOS…………..2.55
TOTAL PRECIPITATION FOR THE YEAR……….19.61  DEPARTURE……-1.84
ASOS………….20.15

SNOWFALL (INCHES) THROUGH THIS MORNING (EST)
TOTAL SNOWFALL 24 HRS ENDING 7 A.M……….0.0  DEPARTURE……..0.0
TOTAL SNOWFALL FOR THE MONTH…………..Trace  DEPARTURE……..0.0
TOTAL SNOWFALL FOR THE SEASON…………..31.9  DEPARTURE……-30.8

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  64/52/58/+5/…./0.0/000/00         46 SSE  AERO 44 SSE RMY N/A
05/02  70/42/56/+3/…./0.0/729/86         41 NW   AERO 40 NW  RMY N/A
05/03  78/55/67/+14/0.00/0.0/613/72        35 SSW  AERO 35 SSW RMY 36
05/04  72/45/59/+5/T/0.0/247/29            37 NW   AERO 40 WNW RMY 39
05/05  60/40/50/-4/0.00/0.0/821/96         31 NW   AERO 32 NW  RMY N/A
05/06  57/38/48/-6/T/0.0/498/58            24 ESE  AERO 22 ENE RMY 22
05/07  63/37/50/-5/0.00/0.0/576/67         30 WSW  AERO 29 WSW RMY N/A
05/08  57/40/49/-6/…./0.0/328/38         31 W    AERO 32 W   RMY N/A
05/09  44/32/38/-17/…./T/484/56          52 W    AERO 53 W   RMY 54
05/10  59/31/45/-10/0.00/0.0/763/88        46 W    AERO 46 W   RMY 49
05/11  65/43/54/-2/0.22/0.0/…/..         39 S    AERO 43 S   RMY 41
05/12  55/37/46/-10/0.00/0.0/…/..        37 W    AERO 37 W   RMY 37
05/13  59/32/46/-10/0.00/0.0/…/..        37 WNW  AERO 37 WNW RMY 38
05/14  70/40/55/-2/0.00/0.0/…/..         29 W    AERO 26 W   RMY 27
05/15  78/50/64/+7/…./0.0/…/..         40 WSW  AERO 40 WSW RMY 43
05/16  69/47/58/+1/…./0.0/…/..         31 NW   AERO 31 NW  RMY 32
05/17  67/47/57/0/0.00/0.0/…/..          22 SSW  AERO N/A    RMY 21
05/18  60/47/54/-4/T/0.0/…/..            24 W    AERO 22 ENE RMY N/A
05/19  56/45/51/-7/0.00/0.0/…/..         35 ENE  AERO 34 ENE RMY 32
05/20  63/43/53/-5/0.00/0.0/…/..         22 ESE  AERO 20 SE  RMY 19
05/21  76/42/59/0/0.00/0.0/…/..          26 S    AERO 25 S   RMY 25
05/22  82/50/66/+7/0.00/0.0/…/..         29 W    AERO 29 W   RMY 28
05/23  67/44/56/-3/0.02/0.0/…/..         42 ENE  AERO 43 ENE RMY 40

05/24 The low since midnight is 43F, the daily normal low is 50F

DAILY RECORDS FOR MAY 2020

5/13/2020: NEW RECORD LOW OF 32F, REPLACING 35F SET IN
1914 AND 2005

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

RECORDS FOR MAY 24
HIGH 92F IN 1964
LOW 35F IN 1956
PRECIP 2.13 INS IN 1951
PEAK GUST 54 MPH NNE IN 2005

RECORDS FOR MAY 25
HIGH 91F IN 2007
LOW 37F IN 1967
PRECIP 3.73 INS IN 1967
PEAK GUST 83 MPH NE IN 1967 (RECORD FOR MAY)

TODAY’S REPORT PREPARED BY: Matt Douglas