Monday, June 29, 2020

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

MONDAY, JUNE 29, 2020
ALL TIMES ARE IN EASTERN STANDARD TIME

RECORD RAIN IN THUNDERSTORMS YESTERDAY, MORE HEAVY RAIN
IN THUNDERSTORMS TODAY….

After receiving record rainfall yesterday, thunderstorms
have once again dropped heavy rain on the hill today.
1.42″ of rain was measured at 1 P.M. after a thunderstorm
moved through the area between 11 A.M. and 12:30 P.M.
Multiple cloud to ground lightning strikes were observed
near the hill. Fog has rolled in after the storm with
visibility down to only 1/16 of a mile.

The high so far today is 71 degrees, this is 8 degrees
below the daily normal high of 79F. The low since midnight
is 63F, which is 2 degrees above the daily normal low of
61F.

Yesterday’s thunderstorm brought 3.27″ of rain to the hill.
This was a record amount for the day beating the old
record of 2.09″ set in 1938. The heavy rainfall brought
the monthly total to 6.08″ (not including today’s rain),
which has now set a surplus for the month of 1.98″. The
yearly deficit also took a big hit, dropping from near 4
inches to only 0.89″.

Per our Chief Scientist, Mike Iacono, yesterday’s rainfall
ranked 7th for most on a calendar day in June. Here is a
list of rankings…

BHO Wettest June Calendar Days, inches (1885-2020):

1) 6.07 on 13 June 1998
2) 4.01 on 7 June 2006
3) 3.92 on 19 June 1922
4) 3.61 on 6 June 2000
5) 3.36 on 18 June 1998
6) 3.28 on 7 June 2013
7) 3.27 on 28 June 2020
8) 3.15 on 6 June 1986
9) 3.04 on 30 June 1921

Today’s Observations:

7 A.M.
Weather: Broken stratus fractus, broken altocumulus/altocumulus
castellanous, few breaks in overcast overhead
Temperature: 67F; Dew Point: 67F; Relative Humidity: 100%
Wind: NNE at 5 kts, wind light
Sea-level pressure: 29.82 ins. Hg: rising unsteadily
Visibility: 3 miles, fog; visibility 1 mile NW-NE, 6 SE-S
6-hr Max temp: 67F
6-hr Min temp: 63F
24-hr Precip: 3.27 ins.
24-hr Frozen:  0.0 ins.
BHO SA 1155 E1 BKN 45 OVC 3F 097/67/67/0205/982/ STFRA OCCLY
DRFTG OVR SMT FEW BINOVC OVHD SUN DMLY VSBL VSBY 1 NW-NE 6 SE-S
WND LGT/ 8/57/ 52016 70327 10067 20063

10 A.M.
Weather: Broken cumulus, broken moderate cumulus, thunderstorm
with light rain showers
Temperature: 69F; Dew Point: 67F; Relative Humidity: 93%
Wind: ENE at 4 kts, wind light
Sea-level pressure: 29.83 ins. Hg: falling, then rising
Visibility: 10 miles, 4 miles E-SE
3-hr Precip: Trace
3-hr Frozen:   0.0 ins.
BHO SA 1455 E10 BKN 35 OVC 10TRW- 100/69/67/0604/983/
RW OVHD-ENE MVNG SE PCPN VRY LGT VSBY 4 E-SE WND LGT
TB45 RB55/ 8/2// 53003 6000/

1 P.M.
Weather: Vertical visibility 100 ft, sky obscured
Temperature: 65F; Dew Point: 65F; Relative Humidity: 100%
Wind: ENE at 7G14 kts
Sea-level pressure: 29.82 ins. Hg: rising then falling
Visibility: 1/16 mile, fog
6-hr Max temp: 71F
6-hr Min temp: 65F
6-hr Precip:  1.42 ins.
6-hr Frozen:   0.0 ins.
BHO SA 1755 W1 X 1/16F 098/65/65/0607G14/982/ TE30 REUKN/
8//// 58002 6142/ 10071 20065

SUMMARY FOR SUNDAY, JUNE 28, 2020

TEMPERATURE (DEGREES F)
MAX…..84   NORMAL…..79
MIN…..62   NORMAL…..61
MEAN….73   NORMAL…..70

DEPARTURE FROM 30-YEAR NORMAL…………….. +3
TOTAL DEPARTURE FOR THE MONTH……………..+87 [+2.9 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY…………….0  DEPARTURE……. -1
TOTAL HEATING UNITS FOR THE MONTH……………40  DEPARTURE…….-33
TOTAL HEATING UNITS FOR THE SEASON…………5852  DEPARTURE……-523
TOTAL HEATING UNITS LAST SEASON TO DATE…….6254  DEPARTURE……-402

COOLING DEGREE DAYS (SEASON JAN TO DEC)
TOTAL COOLING UNITS FOR YESTERDAY……………. 8  DEPARTURE……. +3
TOTAL COOLING UNITS FOR THE MONTH……………151  DEPARTURE…….+58
TOTAL COOLING UNITS FOR THE SEASON…………..183  DEPARTURE…….+66
TOTAL COOLING UNITS LAST SEASON TO DATE……….79  DEPARTURE……+104

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY………………..35 W   AT  3:52 P.M.
AERO…………………….33 N   AT  1:00 P.M.
ASOS…………………….34 W   AT  3:52 P.M.
DAVIS……………………37 W   AT  3:51 P.M RMY 37
FASTEST MILE FOR YESTERDAY………………….26 W   AT  3:54 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………….23 W   AT  3:54 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE………………24 W   AT  3:54 P.M.
AVERAGE WIND SPEED AND DIRECTION……………8.5 WSW
ASOS………………….. 9.3
DAVIS…………………. 8.8 WSW [242 deg.]

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M….3.27  DEPARTURE……+3.15
ASOS…………..3.40
TOTAL PRECIPITATION FOR THE MONTH……….6.08  DEPARTURE……+1.98
ASOS…………..6.21
TOTAL PRECIPITATION FOR THE YEAR……….25.87  DEPARTURE……-0.89
ASOS………….26.52

PRELIMINARY CLIMATE SUMMARY FOR JUNE CALENDAR DAY DATA
DATE: MAX/MIN/MEAN/DEP/PRECIP/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

06/01  64/42/53/-9/T/0.0/…/..            28 WNW  AERO 29 WNW RMY 28
06/02  72/45/59/-3/…./0.0/…/..         28 W    AERO 27 W   RMY 28
06/03  79/55/67/+5/T/0.0/…/..            29 W    AERO 28 W   RMY 26
06/04  87/62/75/+12/…./0.0/…/..        26 W    AERO 25 S   RMY N/A
06/05  80/65/73/+10/…./0.0/…/..        28 SSW  AERO 28 SSW RMY N/A TSTM
06/06  86/57/72/+9/…./0.0/…/..         55 SW   AERO 59 SW  RMY 59  TSTM
06/07  68/54/61/-3/0.00/0.0/…/..         24 NW   AERO 24 NW  RMY N/A
06/08  77/51/64/0/0.00/0.0/…/..          25 W    AERO 24 W   RMY 25
06/09  77/60/69/+5/T/0.0/…/..            23 E    AERO 21 E   RMY N/A
06/10  70/58/64/-1/T/0.0/…/..            25 E    AERO 24 E   RMY N/A
06/11  71/64/68/+3/0.62/0.0/…/..         40 S    AERO 40 S   RMY 42
06/12  82/63/73/+8/0.00/0.0/…/..         26 W    AERO 25 W   RMY 27
06/13  71/53/62/-3/0.00/0.0/…/..         21 WNW  AERO 20 WNW RMY N/A
06/14  67/49/58/-8/0.00/0.0/…/..         21 E    AERO 21 ENE RMY 21
06/15  67/53/60/-6/5/0/0.0/…/..          21 NE   AERO 16 ENE RMY 20
06/16  73/54/64/-2/0.00/0.0/…/..         18 E    AERO 18 E   RMY 18
06/17  78/57/68/+1/0.00/0.0/…/..         20 S    AERO 20 S   RMY 20
06/18  86/59/73/+6/0.00/0.0/…/..         22 S    AERO 22 SSW RMY 22
06/19  86/66/76/+9/0.00/0.0/…/..         22 S    AERO 22 S   RMY 21
06/20  90/65/78/+10/0.00/0.0/…/..        22 S    AERO 21 S   RMY 21
06/21  90/66/78/+10/0.83/0.0/…/..        33 ESE  AERO 35 ESE RMY 33  TSTM
06/22  77/65/71/+3/0.00/0.0/…/..         15 E    AERO 17 S   RMY 14
06/23  85/65/75/+7/0.00/0.0/…/..         27 S    AERO 24 S   RMY 26
06/24  84/66/75/+6/0.00/0.0/…/..         25 S    AERO 24 S   RMY 25
06/25  84/63/74/+5/0.00/0.0/…/..         29 W    AERO 29 W   RMY 29
06/26  83/65/74/+5/0.02/0.0/…/..         25 S    AERO 25 S   RMY 27
06/27  82/65/74/+5/0.05/0.0/…/..         21 S    AERO 20 S   RMY 20
06/28  84/62/73/+3/3.27/0.0/…/..         35 W    AERO 33 N   RMY 37  TSTM

06/29  The low since midnight is 63F, the daily normal low is 61F

Record rainfall on the 28th of 3.27″. Old record 2.09″ in 1938

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

RECORDS FOR JUNE 29
HIGH 93F IN 1933
LOW 42F IN 1919
PRECIP 1.60 INS IN 1889
PEAK GUST 49 MPH S IN 1957

RECORDS FOR JUNE 30
HIGH 94F IN 1964
LOW 47F IN 1919
PRECIP 3.04 INS IN 1921
PEAK GUST 51 MPH WNW IN 1957

TODAY’S REPORT PREPARED BY: Matt Douglas