Saturday, December 31, 2016

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

DAILY DISCUSSION AND CLIMATE SUMMARY
SATURDAY, DECEMBER 31, 2016
ALL TIMES ARE IN EASTERN STANDARD TIME

2016 ENDS CALMLY WITH MOSTLY CLOUDY SKIES
YEAR WILL GO DOWN AS WARMER AND DRIER THAN NORMAL

Sky conditions changed quickly at the Observatory this morning, with
mostly clear skies at sunrise quickly replaced by a mid-level overcast
by mid-morning.  This is associated with a weak weather system moving in
from the west that may bring some showers tonight.  We reached a low of
23F this morning, and have climbed slowly to 32F by 1:00 P.M.  Winds have
calmed down significantly today as we have exited the influence of a
powerful storm which developed in the area on Thursday and moved northward.
Winds yesterday averaged over 20mph.  That average has dropped closer to
10mph by this afternoon, with winds gradually backing west to south.

Despite almost an inch of precipitation and 1.8 inches of snow from the
most recent storm, December will go down as solidly drier and less snowy
than normal, and slightly warmer than normal.  That wraps up a year that
has seen many months of above normal temperatures and below normal
precipitation.

Happy New Year from all of us at the Blue Hill Observatory!

7 A.M.
Weather: Clear, stratocumulus distant NE-SSW, patches of altocumulus S-WNW,
few cirrus all quadrants
Temperature: 23F; Dew Point: 15F; Wind: SW at 10 kts
Sea-level pressure: 30.08 ins. Hg, rising, then more quickly
Visibility: 40 miles
6-hr Max temp: 25F
6-hr Min temp: 23F
24-hr precip: Trace
24-hr snowfall: Trace
Snow depth: 1 inch
BHO SA 1155 CLR 40 186/23/15/2310/008/ SC DSNT NE-SSW PTCHS AC S-WNW
FEW CI ALQDS/ 8/531 4/001 53037 MANUAL 7000/ 10025 20023

10 A.M.
Weather: Scattered altocumulus, broken altostratus, broken cirrus,
few stratocumulus distant NE-S, Sun dimly visible
Temperature: 29F; Dew Point: 19F; Wind: SW at 9 kts
Sea-level pressure: 30.14 ins. Hg, rising then falling
Visibility: 70 miles
BHO SA 1455 100 SCT E150 BKN 250 BKN 70 205/29/19/2209/014/
FEW SC DSNT NE-S SUN DMLY VSBL/ 8/571 51019

1 P.M.
Weather: Overcast altostratus, few stratocumulus distant NE-E, few
altocumulus and altocumulus lenticularis mostly SE-S, break in overcast S,
Sun dimly visible
Temperature: 32F; Dew Point: 17F; Wind: S at 11 kts
Sea-level pressure: 30.07 ins. Hg, falling then more rapidly
Visibility: 60 miles
6-hr Max temp: 32F
6-hr Min temp: 23F
BHO SA 1755 E180 OVC 60 182/32/17/1911/007/ FEW SC DSNT NE-E
FEW AC/ACSL MSTLY SE-S BINOVC S SUN DMLY VSBL/ 8/57/ 58023 10032 20023

SUMMARY FOR FRIDAY, DECEMBER 30, 2016

TEMPERATURE (DEGREES F)
MAX…..37   NORMAL…..35
MIN…..26   NORMAL…..19
MEAN….32   NORMAL…..27

DEPARTURE FROM 30-YEAR NORMAL……………………+5
TOTAL DEPARTURE FOR THE MONTH…………………..+34 [+0.9 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY…………..33   DEPARTURE……….-5
TOTAL HEATING UNITS FOR THE MONTH………….969   DEPARTURE………-36
TOTAL HEATING UNITS FOR THE SEASON………..1999   DEPARTURE……..-268
TOTAL HEATING UNITS LAST SEASON TO DATE……1629   DIFFERENCE…….+370

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY……………….46 WSW AT 1:46 P.M.*
ASOS……………………53 WSW AT 1:46 P.M.
DAVIS…………………..48 WSW AT 1:47 P.M. RMY 50
FASTEST MILE FOR YESTERDAY…………………34 W   AT 4:49 P.M.*
MAXIMUM 2-MINUTE ASOS AVERAGE………………32 W   AT 5:57 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE……………..31 WSW AT 1:47 P.M.
AVERAGE WIND SPEED AND DIRECTION………….21.2 W
ASOS………………….20.7
DAVIS…………………18.2 W [270 Deg.] *Last of several occurrences

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M…Trace  DEPARTURE……-0.14
ASOS…………..0.00
TOTAL PRECIPITATION FOR THE MONTH……….2.77  DEPARTURE……-1.98
ASOS…………..3.12
TOTAL PRECIPITATION FOR THE YEAR……….39.74  DEPARTURE…..-13.54
ASOS………….40.55

SNOWFALL (INCHES) THROUGH THIS MORNING (EST)
TOTAL SNOWFALL 24 HRS ENDING 7 A.M……..Trace  DEPARTURE…….-0.5
TOTAL SNOWFALL FOR THE MONTH…………….7.8  DEPARTURE…….-5.0
TOTAL SNOWFALL FOR THE SEASON……………7.8  DEPARTURE…….-7.6

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

12/1  55/39/47/+10/0.20/0.0/385/69          36 W   AERO 37 W   RMY 36
12/2  48/34/41/+5/0.00/0.0/535/96           32 W   AERO 32 W   RMY N/A
13/3  44/31/38/+2/0.00/0.0/445/80           37 WNW AERO 39 WNW RMY 40
12/4  39/27/33/-2/0.00/0.0/355/64           25 NW  AERO 25 NW  RMY N/A
12/5  36/27/32/-3/0.13/0.4/000/00           26 W   AERO 25 W   RMY 29
12/6  42/30/36/+1/0.00/0.0/392/71           22 W   AERO 21 W   RMY N/A
12/7  39/34/37/+3/0.10/0.0/000/00           21 E   AERO 21 E   RMY N/A
12/8  40/29/35/+1/0.00/0.0/033/06           30 W   AERO 31 W   RMY 33
12/9  35/21/28/-6/0.00/0.0/549/100          35 W   AERO 36 WNW RMY 34
12/10 27/17/22/-11/0.00/0.0/544/99          26 WNW AERO 27 WNW RMY 29
12/11 33/16/25/-8/0.06/0.4/411/75           17 SSW AERO 15 SW  RMY N/A
12/12 41/27/34/+1/0.35/0.9/038/07           29 ESE AERO 29 SE  RMY 30
12/13 41/30/36/+4/0.00/0.0/427/78           25 WSW AERO 25 W   RMY 27
12/14 40/26/33/+1/0.00/0.0/530/97           30 WNW AERO 31 WNW RMY N/A
12/15 29/13/21/-11/T/T/420/77               50 W   AERO 62 W   RMY 56
12/16 18/01/10/-21/0.00/0.0/485/89          39 WNW AERO 51 WNW RMY N/A
12/17 36/18/27/-4/0.60/4.3/000/00           25 SSW AERO 28 SSW RMY N/A
12/18 55/30/43/+12/0.05/0.0/000/00          47 WSW AERO 53 S   RMY 53
12/19 30/17/24/-6/0.00/0.0/273/50           26 WNW*AERO 28 NW  RMY 26
12/20 32/13/23/-7/0.00/0.0/359/66           28 SSE AERO 29 SSW RMY N/A
12/21 40/25/33/+3/0.00/0.0/354/65           28 SSE AERO 28 SSW RMY 30
12/22 38/29/34/+5/T/T/033/06                28 SSE AERO 29 S   RMY 30
12/23 44/29/37/+8/0.00/0.0/512/94           25 WNW AERO 25 WNW RMY N/A
12/24 41/34/38/+9/0.39/0.0/033/06           30 SSW AERO 31 SSW RMY 30
12/25 43/25/34/+6/0.00/0.0/545/100          35 NW  AERO 37 NW  RMY 36
12/26 46/20/33/+5/…./0.0/425/78           39 S   AERO 40 S   RMY N/A
12/27 56/35/46/+18/…./0.0/…/..          51 SW  AERO 55 SW  RMY N/A
12/28 40/29/35/+7/0.00/0.0/…/..           31 W   AERO 32 W   RMY 26
12/29 40/28/34/+7/…./…/000/00           38 NW  AERO 44 NW  RMY 42
12/30 37/26/32/+5/…./…/…/..           46 W   AERO 55 WSW RMY 50

12/31 Low temp since midnight is 23F; normal low is now 19F

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

RECORDS FOR DECEMBER 31
HIGH 62 IN 1965
LOW -12 IN 1917
PRECIP 0.96 INS. IN 1906
SNOWFALL 7.5 INS. IN 2008
PEAK GUST 78 MPH NW IN 1990

RECORDS FOR JANUARY 1
HIGH 58F IN 1966
LOW -6F IN 1918
PRECIP 1.45 INS. IN 1982
SNOWFALL 7.2 INS. IN 1938
PEAK GUST 90e MPH S IN 1945

TODAY’S REPORT PREPARED BY: Jonathan O’Brien