Sunday, May 6, 2018

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

DAILY DISCUSSION AND CLIMATE SUMMARY
SUNDAY, MAY 6, 2018
ALL TIMES ARE IN EASTERN STANDARD TIME

CLOUDY DAY ON GREAT BLUE HILL…

After back to back days of broken records, temperatures
returned to being closer to average.

Cloudy skies have kept temperatures in the low 60s for
the day with very light winds that have gone calm for
several short time periods.

Despite low humidity, visibility is around 40 miles with
a distant haze in all directions.

PRELIMINARY STATS FOR APRIL 2018

TEMPERATURE, Deg. F
Avg. Max. 52.4 [-3.3] Avg. Min. 34.9 [-2.8] Mean      43.7 [-3.0] 24-hour corrected mean: 43.1
Max. for month:  73F on 28th
Min. for month:  24F on  9th

HEATING DEGREE DAYS
Total heating units:    635  [+84] Total for the season:  5693 [-342] Total for last season: 5333

PRECIPITATION, Inches
Total: 6.51 [+1.93] Greatest in 24 hrs: 2.85 on the 15-16th

SNOWFALL, Inches
Total: 2.6 [-0.4] Greatest in 24 hrs: 1.6 in. on 2nd

WIND, mph
Avg. uncorrected wind speed: 12.2
Avg. corrected wind speed: 12.6
Prevailing wind direction: WNW at 16%
Peak gust and direction: 56 NW on the 4th

SUNSHINE:
Campbell-Stokes card minutes:N/A
Astronomical total minutes: N/A

Today’s Observations:

7 A.M.
Weather: Overcast Altostratus Undulatus Asperatus
Temperature: 59F; Dew Point: 47F; Wind: S at 06 kts
Wind: Light
Sea-level pressure: 30.05 ins. Hg, rising then falling
Visibility: 40 miles
6-hr Max temp: 63F
6-hr Min temp: 59F
24-hr precip:  0.00 ins.
24-hr snowfall: 0.0 ins.
Snow depth: 0 ins.
BHO SA 1155 E90 OVC 40 177/59/47/1706/005/
LGT DSNT HZ WND LGT/ 8/02/ 58000 10063 20059

10 A.M.
Weather: Overcast Altostratus Undulatus Asperatus
Temperature: 63F; Dew Point: 47F; Wind: Calm
Sea-level pressure: 30.05 ins. Hg, decreasing then steady
Visibility: 40 miles
3-hr precip: 0.00 ins.
3-hr snowfall: 0.0 ins.
BHO SA 1455 E90 OVC 40 175/63/47/0000/005/
LGT DSNT HZ WND CALM/ 8/02/ 56002

1 P.M.
Weather:  Broken Altocumulus, Overcast Altostratus
Temperature: 63F; Dew Point: 48F; Wind: E at 09 kts
Sea-level pressure: 29.97 ins. Hg, steady then decreasing
Visibility: 30 miles
6-hr Max temp: 65F
6-hr Min temp: 63F
6-hr precip:   0.00 ins
6-hr snowfall: 0.0 ins.
Snow depth: 0 ins.
BHO SA 1755 E8 BKN 11 OVC 30 150/63/48/1009/997/ LGT
DSNT HZ/ 8/09/ 58025 10065 20063

SUMMARY FOR SATURDAY, MAY 5, 2018

TEMPERATURE (DEGREES F)
MAX…..73   NORMAL…..63
MIN…..54   NORMAL…..44
MEAN….64   NORMAL…..54

DEPARTURE FROM 30-YEAR NORMAL…………………….+10
TOTAL DEPARTURE FOR THE MONTH…………………….+76 [+15.4 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY…………..1   DEPARTURE………-11
TOTAL HEATING UNITS FOR THE MONTH………….14   DEPARTURE………-46
TOTAL HEATING UNITS FOR THE SEASON……….5707   DEPARTURE……..-388
TOTAL HEATING UNITS LAST SEASON TO DATE…..5403   DIFFERENCE…….+304

COOLING DEGREE DAYS (SEASON JAN TO DEC)
TOTAL COOLING UNITS FOR YESTERDAY……………0   DEPARTURE………..0
TOTAL COOLING UNITS FOR THE MONTH…………..32   DEPARTURE………+31
TOTAL COOLING UNITS FOR THE SEASON………….32   DEPARTURE………+29
TOTAL COOLING UNITS LAST SEASON TO DATE……..20   DEPARTURE………+12

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY……………….56 W  AT  1:11 A.M.
AERO……………………55 W  AT 12:59 A.M.
ASOS……………………54 W  AT  1:10 A.M.
DAVIS…………………..55 M  AT 12:52 A.M.** RMY N/A
FASTEST MILE FOR YESTERDAY…………………37 W  AT  1:08 A.M.
MAXIMUM 2-MINUTE ASOS AVERAGE………………39 W  AT  1:11 A.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE……………..35 M  AT  2:39 A.M.**
AVERAGE WIND SPEED AND DIRECTION………….14.7 W
ASOS………………….14.1
DAVIS…………………13.3 M**

** Davis direction malfunctioning

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M….0.00  DEPARTURE……-0.13
ASOS…………..0.00
TOTAL PRECIPITATION FOR THE MONTH……….0.18  DEPARTURE……-0.44
ASOS…………..0.17
TOTAL PRECIPITATION FOR THE YEAR……….25.49  DEPARTURE……+6.47
ASOS………….27.09

SNOWFALL (INCHES) THROUGH THIS MORNING (EST)
TOTAL SNOWFALL 24 HRS ENDING 7 A.M……….0.0  DEPARTURE………0.0
TOTAL SNOWFALL FOR THE MONTH…………….0.0  DEPARTURE………0.0
TOTAL SNOWFALL FOR THE SEASON…………..92.8  DEPARTURE…….+30.0

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
*   : Estimated data

4/01 58/33/46/+5/0.00/0.0/336/44   45 SSW AERO 43 SSW RMY N/A
4/02 38/30/34/-7/0.13/1.6/077/10   20 SSW AERO 15 SSW RMY 17
4/03 48/30/39/-3/0.54/0.0/238/31   28 SSE AERO 25 SSE RMY 25
4/04 54/36/45/+3/0.21/0.0/000/00   56 WNW AERO 56 WNW RMY 54
4/05 40/27/34/-9/0.00/0.0/760/98   53 WNW AERO 53 WNW RMY 52
4/06 41/25/33/-10/0.25/1.0/156/20  37 S   AERO 36 S   RMY 38
4/07 46/32/35/-4/0.00/0.0/312/40   32 WNW*AERO 35 WNW RMY 34
4/08 41/29/35/-9/0.00/0.0/290/37   35 WNW*AERO 31 WNW RMY 34
4/09 45/24/35/-9/0.00/0.0/715/01   28 WNW AERO 25 WNW RMY 29
4/10 39/31/35/-10/T/T/000/00       14 SSW AERO 13 SSW RMY N/A
4/11 48/29/39/-6/T/0.0/364/46      24 SSE AERO 23 SSE RMY 25
4/12 61/33/47/+2/0.03/0.0/500/63   39 SSW AERO 38 SSW RMY 41
4/13 65/47/56/+10/T/0.0/096/12     37 SSW AERO 37 SSW RMY N/A
4/14 51/36/44/-2/0.00/0.0/328/41   33 ENE AERO 31 ENE RMY N/A
4/15 36/30/33/-14/0.32/T/000/00    39 ENE AERO 39 ENE RMY N/A
4/16 55/32/44/-3/2.63/000/00       41 ENE AERO 43 ENE RMY 41
4/17 48/36/42/-5/0.00/0.0/210/26   37 W   AERO 33 W   RMY 37
4/18 53/32/43/-5/0.00/0.0/633/78   35 W   AERO 31 W   RMY 34
4/19 41/34/38/-10/0.22/T/000/00    28 WNW AERO 25 WNW RMY N/A
4/20 52/31/42/-7/0.00/0.0/522/64   34 NW  AERO 33 NW  RMY 36
4/21 60/33/47/-2/0.00/0.0/811/99   28 NW  AERO 26 NW  RMY 29
4/22 61/36/49/0/0.00/0.0/821/100   25 NW  AERO 24 NW  RMY 26
4/23 62/40/51/+1/0.00/0.0/816/99   25 S   AERO 25 S   RMY 26
4/24 67/39/53/+3/0.00/0.0/645/78   31 S   AERO 29 S   RMY 32
4/25 57/47/52/+2/…./0.0/000/00   32 SE  AERO 32 SE  RMY 33
4/26 66/48/57/+6/…./0.0/308/37   36 WNW AERO 35 WNW RMY 37
4/27 60/45/53/+2/…./0.0/…/..   18 W   AERO 15 W   RMY N/A
4/28 73/47/60/+8/0.00/0.0/…/..   25 S   AERO 21 S   RMY 25
4/29 59/38/49/-3/0.04/0.0/…/..   32 SW  AERO 26 SW  RMY 31
4/30 46/36/41/-11/0.37/0.0/…/..  23 WSW AERO 16 WSW RMY N/A

DAILY RECORDS FOR APRIL 2018

4/16/18: NEW DAILY RECORD MAXIMUM PRECIPITATION OF 2.63 INS.
PREVIOUS RECORD WAS 2.45 INS. SET IN 1929

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

5/1 65/39/52/-1/0.00/0.0/…/..    25 WNW AERO 21 WNW RMY 25
5/2 88/59/74/+21/0.00/0.0/…/..   37 WSW AERO 29 WSW RMY 35
5/3 90/67/70/+26/…./0.0/…/..   36 SW  AERO 32 WSW RMY 36
5/4 84/67/74/+20/…./0.0/…/..   39 SSW AERO 37 SSW RMY N/A
5/5 73/54/64/+10/0.00/0.0/…/..   56 W   AERO 55 W   RMY N/A

5/6  Low temp since midnight is 58F; normal low is now 45F

DAILY RECORDS FOR MAY 2018

5/03/18: DAILY RECORD HIGH MINIMUM TEMPERATURE OF 67F,
BREAKS PREVIOUS RECORD OF 66F SET IN 2001

5/04/18: DAILY RECORD HIGH MINIMUM TEMPERATURE OF 67F,
BREAKS PREVIOUS RECORD OF 66F SET IN 2001

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

RECORDS FOR MAY 6
HIGH 90F IN 1930
LOW 29F IN 1891
PRECIP 1.04 INCHES IN 1890
SNOWFALL TRACE IN 1917,1996
PEAK GUST 65 MPH SSE IN 1989

RECORDS FOR MAY 7
HIGH 93F IN 1930
LOW 33F IN 1970
PRECIP 1.19 INCHES IN 2005
SNOWFALL TRACE IN 1967
PEAK GUST 66e MPH WNW IN 1940

TODAY’S REPORT PREPARED BY: Robert Millette