Friday, September 10, 2021

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

FRIDAY, SEPTEMBER 10, 2021
ALL TIMES ARE IN EASTERN STANDARD TIME
SUNRISE: 05189E
SUNSET:  1802E
 
PLEASANT FALL WEATHER RETURNS TO THE SUMMIT…

Wet and gray conditions were the theme here yesterday. Storm
total was 0.94″. This was yet another delivery of rainfall
to an already saturated ground. In fact, we are currently just
shy of a 10″ surplus on the year!

Brilliant sunshine and decorative cumulus are thankfully the
central focus of today’s weather. Temperatures are reaching the
low- to mid- 70s with dew points slowly easing into the low 60s.
Winds have been steady around 10 MPH from the NW with a peak gust
clocking in at 31 MPH. A few moderate cumulus are developing thanks
to upper-level stability – some producing raindrops. A brief sprinkle
was felt here around 1:30 PM as the summit clipped the shoulder
of a downpour to the north.

The high so far today is 74F, this is 1 degree below the
daily normal maximum of 75F. The low so far today is 61F, which is
2 degrees above the daily normal minimum of 58F.


PRELIMINARY STATS FOR AUGUST 2021

TEMPERATURE, Deg. F
Avg. Max. 81.6 [+1.4]
Avg. Min. 65.4 [+2.8]
Mean      73.5 [+2.1]
24-hour corrected mean: 72.6
Max. for month: 92F on the 13th
Min. for month: 58F on the 1st

HEATING DEGREE DAYS
Total heating units:      0 [-11]
Total for the season:    28 [+25]
Total for last season:    3

COOLING DEGREE DAYS
Total cooling units:     271 [+62]
Total for the season:    650 [+54]
Total for last season:   757

PRECIPITATION, Inches
Total: 5.37 [+1.46]
Greatest in 24 hrs: N/A

WIND, mph
Avg. uncorrected wind speed:  8.8 mph
Avg. corrected wind speed:    9.5 mph
Prevailing wind direction:   SSW [14%]
Peak gust and direction:     47 ESE on the 22nd

SUNSHINE:
Campbell-Stokes card minutes: 12612 minutes of a possible 24780, or 51%
Astronomical total minutes: 13116 minutes of a possible 25728, or 51%

Today’s Observations:

7 A.M.
Weather: Clear (few cumulus, few cirrus)
Temperature: 64F; Dew Point: 64F; Relative Humidity: 64%
Wind: NW @ 12G15 kts
Sea-level pressure: 1008.6 mb; 29.78 in. Hg; rising, then rising more rapidly
Visibility: 50 miles (thin fog)
6-hr Max temp: 64F
6-hr Min temp: 61F
24-hr Precip: 0.89 ins.
BHO SA 1155 CLR 50 086/64/64/3112G15/978/ FEW STFRA ALQDS FEW CI DSNT NE-SE THN F ALQDS/ 8/101 70089 53016 10064 20061

10 A.M.
Weather: Scattered Cumulus
Temperature: 71F; Dew Point: 62F; Relative Humidity: 74%
Wind: NW @ 12G14 kts
Sea-level pressure: 1009.3 mb; 29.80 in Hg; rising, then rising more rapidly
Visibility: 80 miles
3-hr Precip: 0.00 ins.
BHO SA 1455 25 SCT 80 093/71/62/3112G14/980/ 8/100 53007

1 P.M.
Weather: Scattered Cumulus (few moderate cumulus W-N)
Temperature: 72F, Dew point: 60F; Relative Humidity: 66%
Wind: NNW @ 7G13 kts
Sea-level pressure: 1009.4 mb; 29.81 in Hg; falling, then rising
Visibility: 85 miles
6-hr Max temp: 74F
6-hr Min temp: 64F
6-hr Precip: 0.00 ins.
BHO SA 1755 35 SCT 85 094/72/60/330713/981/ FEW MDT CU ALQDS VIRGA DSNT W-N/ 8/200 53001 10074 20064

SUMMARY FOR THURSDAY, SEPTEMBER 9, 2021

TEMPERATURE (DEGREES F)
MAX…….71     NORMAL…..75
MIN…….64     NORMAL…..58
MEAN……68     NORMAL…..67

DEPARTURE FROM 30-YEAR (1991-2020) NORMAL………….+1
TOTAL DEPARTURE FOR THE MONTH……………………-14 [-1.8 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON: JUL 2021 THRU JUN 2022)
TOTAL HEATING UNITS FOR YESTERDAY…………….0  DEPARTURE……..-2
TOTAL HEATING UNITS FOR THE MONTH…………….8  DEPARTURE……..-3
TOTAL HEATING UNITS FOR THE SEASON…………..36  DEPARTURE……..+7
TOTAL HEATING UNITS LAST SEASON TO DATE……….4  DEPARTURE…….+32

COOLING DEGREE DAYS (SEASON: JAN 2021 THRU DEC 2021)
TOTAL COOLING UNITS FOR YESTERDAY…………….3  DEPARTURE………0
TOTAL COOLING UNITS FOR THE MONTH……………20  DEPARTURE…….-17
TOTAL COOLING UNITS FOR THE SEASON………….670  DEPARTURE…….+38
TOTAL COOLING UNITS LAST SEASON TO DATE……..795  DEPARTURE……-125

PEAK WIND GUST (MPH):
                     Official……………….33 S   @ 12:18 A.M.
                     AEROVANE (south tower)…..36 S   @ 12:19 A.M.
                     VECTOR #2 (south tower)….34     @ 12:05 A.M.
                     DAVIS #2 (south tower)…..36 S   @  2:41 A.M.
                     ASOS………..OUT OF SERVICE D/T RENOVATIONS
                     VECTOR #1……OUT OF SERVICE D/T RENOVATIONS
                     DAVIS #1…….OUT OF SERVICE D/T RENOVATIONS
                     RMY…………OUT OF SERVICE D/T RENOVATIONS  
                     MERLIN………OUT OF SERVICE D/T RENOVATIONS

FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………26 S   @ 12:48 A.M.
MAXIMUM 2-MINUTE VECTOR #2 AVERAGE…………..24     @ 12:47 A.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………26 S   @ 12:48 A.M.
MAXIMUM 2-MINUTE ASOS AVERAGE…….OUT OF SERVICE D/T RENOVATIONS
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE…OUT OF SERVICE D/T RENOVATIONS
MAXIMUM 2-MINUTE VECTOR #1 AVERAGE..OUT OF SERVICE D/T RENOVATIONS
MAXIMUM 2-MINUTE RMY AVERAGE……..OUT OF SERVICE D/T RENOVATIONS

AVERAGE WIND SPEED AND DIRECTION:
                     CONTACTING/OFFICIAL…….9.5 S  [228 total miles]
                     VECTOR #2……………..10.3
                     DAVIS #2………………10.1 SSW
                     RMY……………..OUT OF SERVICE D/T RENOVATIONS
                     ASOS…………….OUT OF SERVICE D/T RENOVATIONS
                     VECTOR #1………..OUT OF SERVICE D/T RENOVATIONS
                     DAVIS #1…………OUT OF SERVICE D/T RENOVATIONS   

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M…….0.89  DEPARTURE….+0.76
TOTAL PRECIPITATION FOR THE MONTH………….4.98  DEPARTURE….+3.92
TOTAL PRECIPITATION FOR THE YEAR………….45.32  DEPARTURE….+9.91

PRELIMINARY CLIMATE SUMMARY FOR AUGUST 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

08/01   77/58/68/-5/T/589/68             23 SSW AERO 24 SSW RMY N/A
08/02   78/61/70/-3/T/821/95             28 WNW AERO 28 WNW RMY N/A
08/03   76/60/68/-5/0.00/302/35          15 N   AERO 16 N   RMY N/A
08/04   75/61/68/-5/0.71/077/09          21 ESE AERO 21 ESE RMY N/A
08/05   68/61/65/-8/1.68/000/00          28 NE  AERO 28 NE  RMY N/A
08/06   85/62/74/+1/0.00/727/85          19 S   AERO 20 WSW RMY N/A
08/07   88/66/77/+4/0.00/520/61          23 SW  AERO 23 SW  RMY N/A
08/08   80/67/74/+2/T/128/15             16 SW  AERO 16 WNW RMY N/A
08/09   75/64/70/-2/0.25/076/09          22 ENE AERO 21 NE  RMY N/A
08/10   78/63/71/-1/0.12/203/24          19 S   AERO 20 S   RMY N/A
08/11   89/70/80/+8/0.00/667/79          29 SSW AERO 28 SSW RMY N/A
08/12   91/71/81/+9/T/580/69             36 WSW AERO 37 WSW RMY N/A TSTM
08/13   92/73/83/+11/0.00/696/83         18 WSW AERO 18 WSW RMY N/A
08/14   87/69/78/+6/T/601/72             25 W   AERO 25 NNW RMY N/A
08/15   80/62/71/-1/0.00/800/96          19 NNW AERO 20 NNW RMY N/A
08/16   78/59/69/-3/0.00/564/68          15 S   AERO 15 S   RMY N/A
08/17   82/63/73/1/0.00/555/67           22 SSW AERO 23 SSW RMY N/A
08/18   86/66/76/+5/0.00/338/41          21 SSW AERO 22 SSW RMY N/A
08/19   81/69/75/+4/0.62/222/27          41 S   AERO 43 S   RMY N/A
08/20   78/70/74/+3/0.01/066/08          21 WSW AERO N/A    RMY N/A
08/21   86/69/78/+7/0.00/581/71          17 S   AERO 17 S   RMY N/A
08/22   74/66/70/-1/0.78/000/00          47 ESE AERO 48 ESE RMY N/A
08/23   83/68/76/+5/1.17/333/41          25 SSE AERO 26 SSE RMY N/A TSTM
08/24   86/67/77/+6/0.01/567/70          21 NNW AERO 21 NNW RMY N/A
08/25   89/70/80/+10/0.00/783/97         17 SW  AERO 18 SW  RMY N/A
08/26   92/72/82/+12/0.00/765/95         19 WSW AERO 18 WSW RMY N/A
08/27   89/70/80/+10/T/626/78            30 ENE AERO 30 ENE RMY N/A
08/28   70/59/65/-5/0.02/296/37          34 ENE AERO 34 ENE RMY N/A
08/29   72/59/66/-4/T/016/02             20 S   AERO 21 S   RMY N/A
08/30   84/67/76/+7/0.00/246/31          25 SW  AERO 26 SW  RMY N/A
08/31   80/65/73/+4/0.00/371/47          27 WNW AERO 28 WNW RMY N/A

RECORDS FOR THE MONTH

08/22 NEW PEAK GUST RECORD OF 47 MPH,
      BEATING THE OLD RECORD OF 44 MPH IN 1987

PRELIMINARY CLIMATE SUMMARY FOR SEPTEMBER 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

09/01   68/56/62/-7/1.47/…/..          34 NNE AERO 37 NNE RMY N/A    
09/02   71/55/63/-6/2.53/…/..          49 ENE AERO 52 ENE RMY N/A
09/03   72/52/62/-6/0.00/…/..          23 NW  AERO 23 NW  RMY N/A
09/04   76/55/66/-2/0.00/…/..          22 WNW AERO 21 WNW RMY N/A
09/05   72/60/66/-2/0.04/…/..          27 S   AERO 29 S   RMY N/A
09/06   80/61/71/+3/0.00/…/..          24 WNW AERO 25 WNW RMY N/A
09/07   78/57/68/+1/0.00/…/..          23 WSW AERO 22 WSW RMY N/A
09/08   81/61/71/+4/…./…/..          43 S   AERO 45 S   RMY N/A
09/09   71/64/68/+1/…./…/..          33 S   AERO 36 S   RMY N/A

09/10  The low since midnight is 61F, the daily normal low is 58F

DAILY EXTREMES

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

RECORDS FOR SEPTEMBER 10
HIGH 90F IN 1931,1989
LOW 41F IN 1956
PRECIP 5.60 INCHES IN 1999 (DAILY RECORD FOR SEPTEMBER)
PEAK GUST 48 MPH NW IN 1972

RECORDS FOR SEPTEMBER 11
HIGH 93F IN 1983, 2013
LOW 37F IN 1917
PRECIP 5.23 INCHES IN 1954 (HURRICANE EDNA)
PEAK GUST 101 MPH NW IN 1954 (HURRICANE EDNA)

TODAY’S REPORT PREPARED BY: Andrew Swanson