Friday, April 10, 2020

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

DAILY DISCUSSION AND CLIMATE SUMMARY
FRIDAY, APRIL 10, 2020
ALL TIMES ARE IN EASTERN STANDARD TIME

A BUSY WESTERLY WIND WITH INCREASING CLOUDINESS…

Mostly clear skies gave way to broken cumulus and strato-
cumulus clouds by early afternoon. Visibility remained
very good around 80 miles for much of the day. We began noting
some scattered virga off in the distance around noontime, but no
precipitation here on the hill so far. We did, however, record
a beneficial 0.66 ins. of rain by 7 A.M. today to help chip away
at the annual deficient.

Also to note, a southerly wind switched to the west early
yesterday evening and has remained westerly. This frontal
passage yielded our peak gust for the day at 58 MPH! Max
gust so far today is 47 MPH.

Our high temperature so far today is 45F, which is 8
degrees below our daily normal high temperature of 53F.
The low since midnight is 35F, which is 1 degree below
the daily normal low of 36F.

PRELIMINARY STATS FOR MARCH 2020

TEMPERATURE, Deg. F
Avg. Max. 49.8 [+5.5] Avg. Min. 32.3 [+5.7] Mean      41.1 [+5.6] 24-hour corrected mean: 40.5
Max. for month: 72F on the 9th
Min. for month: 15F on the 1st

HEATING DEGREE DAYS
Total heating units:    733 [-183] Total for the season:  4873 [-611] Total for last season: 5432

PRECIPITATION, Inches
Total: 4.67 [-0.91] Greatest in 24 hrs: N/A

SNOWFALL, Inches
Total: 2.8 [-9.9] Greatest in 24 hrs: N/A

WIND, mph
Avg. uncorrected wind speed: 12.6 mph
Avg. corrected wind speed:   12.9 mph
Prevailing wind direction:   W [12%] Peak gust and direction:     56 W on the 4th

SUNSHINE:
Campbell-Stokes card minutes: 11298 minutes of possible 21516 or 53%
Astronomical total minutes: 11708 minutes of possible 22287 or 53%

Today’s Observations:

7 A.M.
Weather: Clear; few cumulus, few altocumulus/altostratus SW-NE
Temperature: 38F; Dew Point: 23F; Relative Humidity: 54%
Wind: W at 19G29 kts
Peak Wind: 43 MPH (37 kts) W at 6:19 A.M.
Sea-level pressure: 29.16 ins. Hg: rising, then falling
Visibility: 80 miles
6-hr Max temp: 38F
6-hr Min temp: 35F
24-hr Precip:  0.66 ins.
24-hr Snowfall: 0.0 ins.
BHO SA 1155 CLR 80 876/38/23/2719G29/916/ FEW CU ALQDS
FEW AC/AS DSNT SW-NE PK WND 2737/19/ 8/170 70066 50000
10038 20035

10 A.M.
Weather: Broken Cumulus
Temperature: 42F; Dew Point: 24F; Relative Humidity: 48%
Wind: W at 23G36 kts
Peak wind: 47 MPH (41 kts) W at 8:50 A.M.
Sea-level pressure: 29.16 ins. Hg: falling, then rising
Visibility: 85 miles
3-hr Precip:  0.00 ins.
3-hr Snowfall: 0.0 ins.
BHO SA 1455 E50 BKN 85 874/42/24/2723G36/916/
PK WND 2741/1350/ 8/100 55002

1 P.M.
Weather: Broken Cumulus & Stratocumulus (distant virga)
Temperature: 44F; Dew Point: 24F; Relative Humidity: 44%
Wind: W at 13G28 kts
Peak wind: 43 MPH (37 kts) W at 12:30 P.M.
Sea-level pressure: 29.16 ins. Hg: steady, then rising
Visibility: 75 miles
6-hr Max temp: 45F
6-hr Min temp: 38F
6-hr Precip:  0.00 ins.
6-hr Snowfall: 0.0 ins.
BHO SA 1755 E65 BKN 75 876/44/24/2813G28/916/ VIRGA DSNT
ALDQS PK WND 2837/30/ 8/800 53002 10045 20038

SUMMARY FOR THURSDAY, APRIL 9, 2020

TEMPERATURE (DEGREES F)
MAX…..47   NORMAL…..53
MIN…..37   NORMAL…..35
MEAN….42   NORMAL…..44

DEPARTURE FROM 30-YEAR NORMAL………………..-2
TOTAL DEPARTURE FOR THE MONTH………………..+12 [+1.1 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY……………23  DEPARTURE……..+2
TOTAL HEATING UNITS FOR THE MONTH…………..190  DEPARTURE…….-12
TOTAL HEATING UNITS FOR THE SEASON…………5063  DEPARTURE……-622
TOTAL HEATING UNITS LAST SEASON TO DATE…….5606  DEPARTURE……-543

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY………………..58 W   AT  6:08 P.M.
AERO…………………….58 W   AT  6:19 P.M
ASOS…………………….60 W   AT  6:08 P.M.
DAVIS……………………57 W   AT  6:07 P.M. RMY 56
FASTEST MILE FOR YESTERDAY………………….43 W   AT  6:09 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………….39 W   AT  6:09 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE………………43 W   AT  6:09 P.M.
AVERAGE WIND SPEED AND DIRECTION………….. 17.8 S
ASOS………………….. 17.7
DAVIS…………………..17.5 SW [222 deg.]

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M….0.66  DEPARTURE……+0.48
ASOS…………..0.68
TOTAL PRECIPITATION FOR THE MONTH……….3.46  DEPARTURE……+1.94
ASOS…………..3.57
TOTAL PRECIPITATION FOR THE YEAR……….12.79  DEPARTURE……-2.73
ASOS………….13.30

SNOWFALL (INCHES) THROUGH THIS MORNING (EST)
TOTAL SNOWFALL 24 HRS ENDING 7 A.M……….0.0  DEPARTURE…….-0.1
TOTAL SNOWFALL FOR THE MONTH…………….0.0  DEPARTURE…….-1.5
TOTAL SNOWFALL FOR THE SEASON…………..27.6  DEPARTURE……-33.6

PRELIMINARY CLIMATE SUMMARY FOR MARCH 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

03/01  33/15/24/-7/0.00/0.0/676/100        28 WNW AERO 28 WNW RMY 27
03/02  52/24/38/+7/T/T/482/71              40 S   AERO 39 S   RMY 41
03/03  64/45/55/+23/…./0.0/361/53        30 S   AERO 30 S   RMY N/A
03/04  50/38/44/+12/…./0.0/561/82        56 W   AERO 56 W   RMY 58
03/05  51/32/42/+10/0.00/0.0/666/97        31 W   AERO 31 NW  RMY 32
03/06  47/30/39/+7/…./…/283/41         46 NE  AERO 45 NE  RMY 46
03/07  43/26/35/+2/…./…/534/77         42 N   AERO 43 N   RMY 44
03/08  53/26/40/+7/0.00/0.0/508/73         31 W   AERO 30 W   RMY 28
03/09  72/40/56/+23/0.00/0.0/685/98        32 SW  AERO 32 SW  RMY 31
03/10  68/49/59/+26/0.00/0.0/246/35        48 WSW AERO 46 WSW RMY 49
03/11  56/37/47/+13/0.00/0.0/501/71        31 WNW AERO M  M   RMY 21
03/12  46/31/39/+5/…./0.0/156/22         21 SE  AERO 18 SE  RMY N/A
03/13  59/38/49/+15/…./0.0/000/00        46 WNW AERO 44 WNW RMY 46
03/14  51/35/43/+8/0.00/0.0/613/86         37 W   AERO 36 W   RMY 35
03/15  47/28/38/+3/0.00/0.0/680/95         28 NW  AERO 28 NW  RMY N/A
03/16  36/22/29/-6/0.00/0.0/618/86         21 NE  AERO 21 ESE RMY 21
03/17  43/28/36/0/…./0.4/000/00          29 W   AERO 30 W   RMY 29
03/18  54/31/43/+7/…./0.0/609/84         26 S   AERO 26 S   RMY 26
03/19  43/37/40/+4/…./0.0/000/00         36 E   AERO 35 E   RMY 34
03/20  66/37/52/+15/…./0.0/000/00        48 W   AERO 48 W   RMY 46
03/21  55/29/42/+5/0.00/0.0/535/73         45 W   AERO 48 W   RMY N/A
03/22  36/23/30/-7/0.00/0.0/692/94         23 NE  AERO 24 NE  RMY 23
03/23  40/25/33/-5/…./1.6/037/05         38 NNE AERO 39 NNE RMY 38
03/24  48/33/41/+3/…./…/148/20         37 NNW AERO 37 NNW RMY N/A
03/25  41/35/38/0/0.03/0.0/000/00          28 ENE AERO 28 ENE RMY 27
03/26  51/30/41/+2/…./0.0/613/82         25 SSE AERO 26 SSW RMY N/A
03/27  61/41/51/+12/…./0.0/…/..        32 NW  AERO M  M   RMY 33
03/28  56/36/46/+7/…./0.0/…/..         22 S   AERO 21 E   RMY N/A
03/29  43/37/40/0/…./0.0/…/..          32 NE  AERO 33 NE  RMY 33
03/30  40/34/37/-3/…./0.0/…/..         33 NE  AERO 33 NE  RMY 33
03/31  40/29/35/-6/…./0.0/…/..         28 ENE AERO 26 ENE RMY N/A

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  42/28/35/-6/0.00/0.0/…/..         28 NE  AERO 28 NE  RMY 30
04/02  46/35/41/0/…/0.0/…/..           39 NW  AER0 40 NW  RMY 41
04/03  42/38/40/-2/…./0.0/…/..         48 NE  AERO 53 NE  RMY 49
04/04  46/36/41/-1/…./0.0/…/..         38 NE  AERO 38 NE  RMY N/A
04/05  55/36/46/+3/T/0.0/…/..            22 S   AERO 21 S   RMY 21
04/06  61/40/51/+8/0.00/0.0/…/..         29 NW  AERO 30 NW  RMY 29
04/07  63/42/53/+10/0.00/0.0/…/..        29 W   AERO 30 W   RMY 28
04/08  50/41/46/+2/…./…/…/..         23 S   AERO 22 S   RMY 22
04/09  47/37/42/-2/…./…/…/..         58 W   AERO 58 W   RMY 56

04/10 The low since midnight is 35F, daily normal minimum is 36F

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

RECORDS FOR APRIL 10
HIGH 83 IN 1922
LOW 20 IN 1985
PRECIP 2.40 IN. IN 1935
SNOWFALL 10.1 IN. IN 1996
PEAK GUST 66 MPH WNW IN 1967

RECORDS FOR APRIL 11
HIGH 85 IN 2017
LOW 19 IN 1909
PRECIP 1.72 IN. IN 2003
SNOWFALL 9.5 IN. IN 1958
PEAK GUST 65 MPH NW IN 1963

TODAY’S REPORT PREPARED BY: Andrew Swanson