Thursday, December 28, 2017

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

DAILY DISCUSSION AND CLIMATE SUMMARY
THURSDAY, DECEMBER 28, 2017
ALL TIMES ARE IN EASTERN STANDARD TIME

DRY AND CLEAR SKIES WITH BITTER TEMPERATURES
CONTINUE….

Temperatures have been well below seasonable today
and yesterday. Yesterday we had a maximum temp of
19F. This is 17 degrees below the normal daily
max of 36F. Overnight temperatures dipped down
to 1 degree, which is 19 degrees below the normal
daily minimum temp of 20F. This is the coldest
temperature in over a year. The last time we recorded
a minimum temp of 1 degree was December 16, 2016.
This min is only 3 degrees above the daily record
of -2F set in 1933. We can beat this daily record
if temperatures drop to -2 or below before midnight.
So far today we have had a high of 10F. This is
26 degrees below the normal of 36F.
Winds continue to be strong from the W/WNW. The
strong gust made the air feel much colder today
with a windchill at times of -19F. So far today
we have had a peak gust of 32 kts (37 MPH) from
the WNW. Skies remained dry and clear today with
a few stratocumulus along the horizon during each
observation.

Today’s Observations:

7 A.M.
Weather: Clear, few distant stratocumulus along the
horizon NNE-SSW
Temperature: 2F; Dew Point: -10F; Wind: WNW at 9 kts
Wind chill: -17F
Sea-level pressure: 30.41 ins. Hg, steady then rising
Visibility: 40 miles, distant haze
6-hr Max temp: 6F
6-hr Min temp: 1F
24-hr precip: 0.00 ins.
24-hr snowfall: 0.0 ins.
Snow depth: 2 ins.
BHO SA 1155 CLR 40 298/2/M10/2909/041/ FEW SC DSNT ALG
HRZN NNE-SSW DSNT HZ WND CHILL –17F/ 8/400 4/002 53010
10006 20001

10 A.M.
Weather: Clear, few distant stratocumulus along the
horizon NNE-SSE
Temperature: 5F; Dew Point: -14F; Wind: WNW at 16G26 kts,
Peak Wind: 26 kts (30 MPH) WNW at 9:17 A.M.
Wind chill: -18F
Sea-level pressure: 30.40 ins. Hg, rising then falling
Visibility: 70 miles
3-hr precip: 0.00 ins.
BHO SA 1455 CLR 70 296/5/M14/2916G26/040/ FEW SC DSNT ALG
HRZN NNE-SSE PK WND 2926/17 WND CHILL –18F/ 8/400 55002

1 P.M.
Weather: Clear, few distant stratocumulus and cumulus NNE-E
and SSE-S
Temperature: 10F; Dew Point: -14F; Wind: W at 18G29 kts,
Peak wind: 32 kts (37 MPH) WNW at 12:03 P.M.
Sea-level pressure: 30.26 ins. Hg, falling, then more slowly
Visibility: 75 miles
6-hr Max temp: 10F
6-hr Min temp: 1F
6-hr precip: 0.00 ins.
Snow depth: 2 ins.
BHO SA 1755 CLR 75 263/10/M14/2818G29/031/ FEW SC/CU DSNT
ALG HRZN NNE-E AND SSE-S PK WND 2932/03/ 8/600 4/002 56033
10010 20001

SUMMARY FOR WEDNESDAY, DECEMBER 27, 2017

TEMPERATURE (DEGREES F)
MAX…..19   NORMAL…..36
MIN……6   NORMAL…..20
MEAN….13   NORMAL…..28

DEPARTURE FROM 30-YEAR NORMAL……………………..-15
TOTAL DEPARTURE FOR THE MONTH……………………..-26 [-1.2 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY………….52  DEPARTURE………+15
TOTAL HEATING UNITS FOR THE MONTH…………917  DEPARTURE………+25
TOTAL HEATING UNITS FOR THE SEASON……….1886  DEPARTURE……..-268
TOTAL HEATING UNITS LAST SEASON TO DATE…..1905  DIFFERENCE……..-19

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY……………….28 WNW AT 2:41 P.M.
AERO……………………25 WNW AT 2:39 P.M.
ASOS……………………26 W   AT 2:40 P.M.
DAVIS…………………..26 WNW AT 2:04 P.M. RMY N/A
FASTEST MILE FOR YESTERDAY…………………20 W   AT 1:34 A.M.
MAXIMUM 2-MINUTE ASOS AVERAGE………………21 W   AT 2:42 P.M
MAXIMUM 2-MINUTE DAVIS AVERAGE……………..20 W   AT 1:34 A.M.
AVERAGE WIND SPEED AND DIRECTION………….12.4 W
ASOS………………….12.6
DAVIS…………………12.0 WNW [291 DEG.]

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M….0.00  DEPARTURE……-0.14
ASOS…………..0.00
TOTAL PRECIPITATION FOR THE MONTH……….2.95  DEPARTURE……-1.37
ASOS…………..3.20
TOTAL PRECIPITATION FOR THE YEAR……….52.79  DEPARTURE……-0.06
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…….-0.5
TOTAL SNOWFALL FOR THE MONTH…………….8.9  DEPARTURE…….-2.3
TOTAL SNOWFALL FOR THE SEASON……………8.9  DEPARTURE…….-4.9

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/+6/0.04/0.0/262/47          28 NW  AERO 29 NW  RMY 30
12/02 42/29/36/0/0.00/0.0/033/06           20 NNW AERO 18 NNW RMY N/A
12/03 42/32/37/+1/0.00/0.0/172/31          14 N   AERO 10 N   RMY N/A
12/04 43/32/38/+3/0.00/0.0/522/94          16 E   AERO 14 E   RMY N/A
12/05 58/34/46/+11/0.18/0.0/000/00         62 S   AERO 66 S   RMY 65
12/06 56/32/44/+9/0.54/0.0/160/29          52 S   AERO 55 S   RMY N/A
12/07 44/30/37/+3/0.00/0.0/540/98          25 WSW AERO 24 WSW RMY 25
12/08 38/28/33/-1/0.00/0.0/116/21          21 W   AERO 18 W   RMY 20
12/09 34/28/31/-3./0.70/…/000/00         23 NNW AERO 23 NNW RMY 23
12/10 35/27/31/-2/0.02/…/384/70          30 W   AERO 30 W   RMY 27
12/11 38/29/34/+1/0.00/0.0/301/55          23 W   AERO 21 W   RMY 22
12/12 43/31/37/+4/0.06/0.0/000/00          35 W   AERO 31 W   RMY N/A
12/13 31/18/25/-7/0.00/0.0/312/57          44 W   AERO 44 W   RMY 44
12/14 27/14/21/-11/T/T/…/..              35 WSW AERO 33 W   RMY 34
12/15 24/12/18/-14/T/…/…/..            25 W   AERO 23 W   RMY N/A
12/16 32/17/25/-6/0.00/0.0/…/..          33 W   AERO 35 W   RMY 36
12/17 27/14/21/-10/0.00/0.0/…/..         21 NW  AERO 21 NW  RMY 20
12/18 35/20/28/-3/T/…/…/..             20 SSE AERO 16 SSE RMY 20
12/19 49/34/42/+12/T/…/…/..            36 WNW AERO 35 SW  RMY 38
12/20 42/26/34/+4/T/…/…/..             41 W   AERO 40 W   RMY 45
12/21 32/23/28/-2/0.00/0.0/…/..          26 NW  AERO 24 NW  RMY 27
12/22 32/21/27/-2/…./…/…/..          18 E   AERO 17 E   RMY N/A
12/23 36/24/30/+1/…./…/…/..          31 WSW AERO 28 WSW RMY 31
12/24 35/29/32/+3/…./…/…/..          30 ENE AERO 25 ENE RMY N/A
12/25 35/21/28/0/…./…/…/..           50 W   AERO 54 W   RMY 47
12/26 24/13/19/-9/0.00/0.0/…./..         39 W   AERO 39 W   RMY 41
12/27 19/6/13/-15/0.00/0.0/…./..         28 WNW AERO 25 WNW RMY N/A

12/28 Low temp since midnight is 1F; normal low is now 20F

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

RECORDS FOR DECEMBER 28
HIGH 60 IN 1982
LOW -2 IN 1933
PRECIP 2.16 INS. IN 1967
SNOWFALL 9.5 INS. IN 1967
PEAK GUST 89 MPH SSE IN 1983

RECORDS FOR DECEMBER 29
HIGH 72 IN 1984
LOW -19 IN 1933 (RECORD FOR DECEMBER)
PRECIP 1.91 INS. IN 1945
SNOWFALL 18.4 INS. IN 1945
PEAK GUST 95 MPH S IN 1966 (RECORD FOR DECEMBER)

TODAY’S REPORT PREPARED BY: Kaitlin Geagan