Saturday, December 2, 2017

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

DAILY DISCUSSION AND CLIMATE SUMMARY
SATURDAY, DECEMBER 2, 2017
ALL TIMES ARE IN EASTERN STANDARD TIME

PARTIAL SUNSHINE THIS MORNING FADES AS CLOUDS
MOVE IN THIS AFTERNOON…FALL 2017 WAS THE
WARMEST ON RECORD…

The day began with a middle level deck of altocumulus
and an advancing overcast of thin cirrostratus. As the
morning continued, the high cloud layer became more
opaque and lower clouds moved in as well. The temperature
as been much cooler than yesterday with a low of 29F
before sunrise, and this has only climbed into the lower
40s by 1 PM. The visibility has been very good today
near 70-75 miles, though it is starting to decrease
this afternoon.

The mean temperature for the three Fall months, September
to November, was the warmest ever recorded at the Observatory.

PRELIMINARY STATS FOR NOVEMBER 2017

TEMPERATURE, Deg. F
Avg. Max. 49.8 [-0.2] Avg. Min. 32.9 [-0.6] Mean      41.4 [-0.3] 24-hour corrected mean: 41.7
Max. for month: 74F on 3rd
Min. for month: 18F on 11th

HEATING DEGREE DAYS
Total heating units: 701 [+3] Total for the season: 969 [-292] Total for last season: 1030

PRECIPITATION, Inches
Total: 2.04 [-2.72] Greatest in 24 hrs: 0.87 in. on the 22nd

WIND, mph
Avg. uncorrected wind speed: 12.7
Avg. corrected wind speed: 13.0
Prevailing wind direction: WNW at 12%
Peak gust and direction: 50 W on 19th

SUNSHINE:
Campbell-Stokes card minutes: 9,108 minutes of possible 17,010 or 54%
Astronomical total minutes: 9,431 minutes of possible 17,610 or 54%

BHO Warmest Fall (Sep-Nov) 24-hour Corrected Mean Temperature, deg F (1885-2017):

1) 55.3 in 2017
2) 55.1 in 2011
3) 54.8 in 1931
54.8 in 2015
5) 54.3 in 1946
54.3 in 2001

Today’s Observations:

7 A.M.
Weather: Scattered stratocumulus, thin overcast altostratus,
few stratocumulus distant NE-SE, few altocumulus lenticularis
SE-SW, breaks in overcast S-W
Temperature: 30F; Dew Point: 24F; Wind: NNW at 9 kts
Sea-level pressure: 30.31 ins. Hg, rising, then more rapidly
Visibility: 75 miles
6-hr Max temp: 33F
6-hr Min temp: 29F
24-hr precip: 0.00 ins.
BHO SA 1155 120 SCT E160 –OVC 75 264/30/24/3309/031/
FEW SC DSNT NE-SE FEW ACSL SE-SW BINOVC S-W/ 8/57/
53013 10033 20029

10 A.M.
Weather: Broken stratocumulus, overcast cirrostratus,
few lower stratocumulus distant SE, breaks in overcast overhead,
thin spots in overcast in all directions
Temperature: 38F; Dew Point: 27F; Wind: N at 6 kts
Sea-level pressure: 30.32 ins. Hg, rising, then more slowly
Visibility: 70 miles
3-hr precip: 0.00 ins.
BHO SA 1455 E30 BKN 200 OVC 70 267/38/27/3506/032/
FEW LWR SC DSNT SE BINOVC OVHD THN SPTS IOVC ALQDS WND LGT/
8/505 51003

1 P.M.
Weather: Broken stratocumulus, overcast cirrostratus, few lower
distant stratocumulus E
Temperature: 42F; Dew Point: 29F; Wind: NE at 2 kts (estimated)
Sea-level pressure: 30.25 ins. Hg, falling, then more rapidly
Visibility: 70 miles
6-hr Max temp: 42F
6-hr Min temp: 30F
6-hr precip: 0.00 ins.
BHO SA 1755 E30 BKN 200 OVC 70 244/42/29/E0502/025/
FEW LWR SC DSNT E WND LGT/ 8/506/ 58023 10042 20030

SUMMARY FOR FRIDAY, DECEMBER 1, 2017

TEMPERATURE (DEGREES F)
MAX…..50   NORMAL…..44
MIN…..35   NORMAL…..29
MEAN….43   NORMAL…..37

DEPARTURE FROM 30-YEAR NORMAL………………………+6
TOTAL DEPARTURE FOR THE MONTH………………………+6 [+5.8 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY…………22  DEPARTURE……….-7
TOTAL HEATING UNITS FOR THE MONTH…………22  DEPARTURE……….-7
TOTAL HEATING UNITS FOR THE SEASON……….991  DEPARTURE……..-299
TOTAL HEATING UNITS LAST SEASON TO DATE….1048  DIFFERENCE……..-57

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY……………….28 NW  AT 10:37 A.M.*
AERO……………………29 NW  AT 10:36 A.M.
ASOS……………………29 NW  AT 10:39 A.M.
DAVIS…………………..27 NW  AT 10:27 A.M. RMY 30
FASTEST MILE FOR YESTERDAY…………………20 NW  AT 11:09 A.M.
MAXIMUM 2-MINUTE ASOS AVERAGE………………21 NW  AT 11:10 A.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE……………..20 NW  AT 11:10 A.M.
AVERAGE WIND SPEED AND DIRECTION………….12.0 NW
ASOS………………….11.7
DAVIS…………………10.8 NW [320 DEG.] * Last of several occurrences

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M….0.00  DEPARTURE……-0.16
ASOS…………..0.00
TOTAL PRECIPITATION FOR THE MONTH……….0.04  DEPARTURE……-0.12
ASOS…………..0.04
TOTAL PRECIPITATION FOR THE YEAR……….49.88  DEPARTURE……+1.19
ASOS……………N/A **
** ASOS annual total not available due to erroneous readings

SNOWFALL (INCHES) THROUGH THIS MORNING (EST)
TOTAL SNOWFALL 24 HRS ENDING 7 A.M……….0.0  DEPARTURE…….-0.2
TOTAL SNOWFALL FOR THE MONTH…………….0.0  DEPARTURE…….-0.2
TOTAL SNOWFALL FOR THE SEASON……………0.0  DEPARTURE…….-2.8

PRELIMINARY CLIMATE SUMMARY FOR NOVEMBER 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

11/01 53/39/46/0/0.00/167/27           25 SE  AERO 24 SE  RMY 25
11/02 71/49/60/+14/0.00/000/00         28 SSE AERO 25 SSE RMY 27
11/03 74/47/61/+15/T/350/57            35 WNW AERO 35 WNW RMY 38
11/04 54/39/47/+2/0.00/545/89          31 NW  AERO 31 NW  RMY N/A
11/05 61/46/54/+9/0.01/006/01          26 S   AERO 24 S   RMY N/A
11/06 64/47/56/+11/0.05/000/00         32 S   AERO 28 SSW RMY 35
11/07 46/35/41/-4/0.11/145/24          26 NNW AERO 23 N   RMY 26
11/08 3/34/39/-5/0.08/295/49           26 N   AERO 23 N   RMY 27
11/09 50/31/41/-3/0.01/480/80          25 S   AERO 23 S   RMY N/A
11/10 45/20/33/-11/0.00/586/98         46 WNW AER0 44 WNW RMY 46
11/11 36/18/27/-16/0.00/589/99         28 WNW AERO 26 WNW RMY 28
11/12 44/27/36/-7/0.00/302/51          13 E   AERO  9 S   RMY 14
11/13 40/35/38/-5/0.26/000/00          20 NNW AERO 17 NNW RMY 20
11/14 40/33/37/-5/T/000/00             18 N   AERO 15 N   RMY 18
11/15 43/31/37/-5/0.00/417/71          20 NE  AERO 15 NE  RMY N/A
11/16 51/37/44/+2/0.21/012/02          32 SE  AERO 32 SE  RMY N/A TSTM
11/17 42/30/36/-5/0.00/565/97          41 WNW AERO 43 WNW RMY 47
11/18 49/26/38/-3/0.08/168/29          35 SSW AERO 35 SSW RMY 39
11/19 58/34/46/+5/0.36/231/40          50 W   AERO 50 W   RMY 54
11/20 39/31/35/-5/0.00/462/80          48 WNW AERO 50 WNW RMY 44
11/21 57/35/46/+6/0.00/506/88          46 SSW AERO 46 SSW RMY 48
11/22 53/35/44/+4/0.87/000/00          37 NW  AERO 38 NW  RMY 41
11/23 40/26/33/-6/0.00/571/100         26 NW  AERO 25 NW  RMY N/A
11/24 49/29/39/0/0.00/558/98           28 SSW AERO 26 SSW RMY 29
11/25 57/38/48/+9/0.00/523/92          29 SSW AERO 28 SSW RMY 31
11/26 46/33/40/+2/0.00/509/90          39 WNW AERO 41 WNW RMY 41
11/27 44/24/34/-4/0.00/254/45          37 W   AERO 39 W   RMY 36
11/28 45/19/32/-6/0.00/557/99          35 S   AERO 37 S   RMY N/A
11/29 58/34/46/+9/0.00/370/66          46 W   AERO 47 W   RMY 46
11/30 43/26/37/-2/0.00/263/47          25 SSE AERO 25 NNW RMY 25

PRELIMINARY CLIMATE SUMMARY FOR DECEMBER 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

12/01 50/35/43/+6/0.00/…/..          28 NW  AERO 29 NW  RMY 30

12/02 Low temp since midnight is 29F; normal low is now 28F

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

RECORDS FOR DECEMBER 2
HIGH 61 IN 1998
LOW 3 IN 1890
PRECIP 2.09 INS. IN 1974
SNOWFALL 5.0 INS. IN 1894, 1929
PEAK GUST 89e MPH SSE IN 1942

RECORDS FOR DECEMBER 3
HIGH 67 IN 2009
LOW  -1 IN 1890
PRECIP 2.10 INS. IN 1986
SNOWFALL 6.0 INS. IN 1963
PEAK GUST 73e MPH W IN 1942

TODAY’S REPORT PREPARED BY: Afshin Pourmokhtarian/Michael Iacono