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

DAILY DISCUSSION AND CLIMATE SUMMARY
FRIDAY, JANUARY 5, 2018  
ALL TIMES ARE IN EASTERN STANDARD TIME

INTENSE COLD RETURNS FOLLOWING POWERFUL STORM
BLIZZARD CONDITIONS CONFIRMED ON BLUE HILL

Skies have cleared today following a major snowstorm, which hit New England
yesterday.  Here at Blue Hill, 16.5 inches of snow fell, breaking the daily
record for Jan 4 of 8.6 inches set in 1923 and tied in 1941.  A liquid 
equivalent total of 1.66 inches was recorded, for a nearly exact 10:1 snow-liquid
ratio.  A peak wind gust of 54mph from the NNW was recorded at 2:45 P.M.
A minimum sea level pressure of 976.9mb (28.85 ins. Hg) was observed.  This was 
the lowest sea level pressure since the Valentine's blizzard of 2/14/15, and the 
lowest January pressure since the all time January record low pressure of 
28.60 ins. Hg in 1987.

In addition, it was confirmed that Blue Hill met blizzard criteria from
approximately 1:30 to 4:45 P.M. yesterday.  Moderate to heavy snow with
visibilities under a quarter mile was observed in that period.  Sustained winds
did not reach 35mph for three hours, but gusts to 35mph or greater were almost
continuous during this period, fulfilling blizzard requirements.

Arctic air has been advecting into the region today on strong westerly winds
behind the storm.  A morning low of 8F was observed, and the temperature has
barely risen during the day, staying slightly above 10F.  A peak wind gust
for today of 51mph has been recorded so far, with sustained winds well in
excess of 20mph.  Significant blowing and drifting of snow has been observed.

Today's Observations:

7 A.M.
Weather: Overcast altocumulus, few breaks E-S
Temperature: 10F; Dew Point: 2F; Wind: W at 20G30 kts,
Peak wind: 33 kts (38 mph) W at 6:19 A.M.
Sea-level pressure: 29.38 ins. Hg, rising 
Visibility: 30 miles
6-hr Max temp: 18F
6-hr Min temp: 10F
24-hr precip: 1.66 ins.
24-hr snowfall: 16.5 ins.
Snow depth: 17 ins.
BHO SA 1155 E85 OVC 30 950/10/2/2720G30/938/ FEW BINOVC E-S 
NEW SNW PST 24 HRS 16.5 INS PK WND 2733/19/ 8/05/ 4/017 52033 
MANUAL 70166 ASOS 70196 10018 20010

10 A.M.
Weather: Clear, few stratocumulus distant NE-SE, few altocumulus all
quadrants (dissipating)
Temperature: 9F; Dew Point: -3F; Wind: W at 24G32 kts,
Peak wind: 35 kts (40 mph) W at 9:08 A.M.
Sea-level pressure: 29.44 ins. Hg, rising
Visibility: 55 miles, blowing snow
3-hr precip: 0.00 ins. 
BHO SA 1455 CLR 55BS 971/9/-3/2724G32/944/ FEW SC DSNT NE-SE 
FEW AC ALQDS DSPTG PK WND 2735/08/ 8/550 52021

1 P.M.
Weather: Clear, few stratocumulus mostly distant NE-E, few patches of
cirrus distant SW-NW
Temperature: 11F; Dew Point: -4F; Wind: W at 26G42 kts,
Peak wind: 42kts (48 mph) W at 12:49 P.M.
Sea-level pressure: 29.44 ins. Hg, rising then falling 
Visibility: 60 miles, blowing snow
6-hr Max temp: 13F
6-hr Min temp: 8F
6-hr precip: 0.00 ins.
6-hr snowfall: 0.0 ins.
Snow depth: 17 ins.
BHO SA 1755 CLR 60BS 971/11/-4/2626G42/944/ FEW SC MSTLY DSNT NE-E 
FEW PTCHS CI DSNT SW-NW PK WND 2642/49/ 8/501 4/017 58000 10013 20008

SUMMARY FOR THURSDAY, JANUARY 4, 2017

TEMPERATURE (DEGREES F)
MAX.....28   NORMAL.....34
MIN.....18   NORMAL.....18
MEAN....23   NORMAL.....26

DEPARTURE FROM 30-YEAR NORMAL...........................-3
TOTAL DEPARTURE FOR THE MONTH..........................-53 [-13.4 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY.............42  DEPARTURE..........+3
TOTAL HEATING UNITS FOR THE MONTH............207  DEPARTURE.........+53
TOTAL HEATING UNITS FOR THE SEASON..........2329  DEPARTURE........-129
TOTAL HEATING UNITS LAST SEASON TO DATE.....2146  DIFFERENCE.......+183

PEAK GUST AND AVERAGE WIND SPEED (MPH) 
PEAK WIND GUST FOR YESTERDAY...................54  NNW  AT  2:45 P.M.
                   AERO........................60  NNW  AT  2:45 P.M.
                   ASOS........................N/A*
                   DAVIS.......................N/A*                    RMY 64
FASTEST MILE FOR YESTERDAY.....................40  WNW  AT  7:45 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE..................N/A
MAXIMUM 2-MINUTE DAVIS AVERAGE.................N/A
AVERAGE WIND SPEED AND DIRECTION.............23.5  N
                   ASOS......................N/A 
                   DAVIS.....................N/A
*ASOS and Davis anemometers malfunctioning

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....1.66  DEPARTURE......+1.52
                         ASOS..............1.96
TOTAL PRECIPITATION FOR THE MONTH..........1.66  DEPARTURE......+1.08
                         ASOS..............1.96
TOTAL PRECIPITATION FOR THE YEAR...........1.66  DEPARTURE......+1.08
                         ASOS..............1.96

SNOWFALL (INCHES) THROUGH THIS MORNING (EST)
TOTAL SNOWFALL 24 HRS ENDING 7 A.M.........16.5  DEPARTURE.......+15.9
TOTAL SNOWFALL FOR THE MONTH...............16.5  DEPARTURE.......+14.2
TOTAL SNOWFALL FOR THE SEASON..............25.9  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

12/01 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./0.70/5.5/000/00       23 NNW AERO 23 NNW RMY 23 
12/10 35/27/31/-2/0.02/0.1/384/70        30 W   AERO 30 W   RMY 27 
12/11 38/29/34/+1/T/T/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/-7/0.00/0.0/372/68        44 W   AERO 44 W   RMY 44
12/14 27/14/21/-11/T/T/257/47            35 WSW AERO 33 W   RMY 34 
12/15 24/12/18/-14/0.00/0.0/011/02       25 W   AERO 23 W   RMY N/A
12/16 32/17/25/-6/0.00/0.0/382/70        33 W   AERO 35 W   RMY 36
12/17 27/14/21/-10/0.00/0.0/425/78       21 NW  AERO 21 NW  RMY 20
12/18 35/20/28/-3/T/T/011/02             20 SSE AERO 16 SSE RMY 20
12/19 49/34/42/+12/0.00/0.0/185/34       36 WNW AERO 35 SW  RMY 38  
12/20 42/26/34/+4/T/T/447/82             41 W   AERO 40 W   RMY 45 
12/21 32/23/28/-2/0.00/0.0/533/98        26 NW  AERO 24 NW  RMY 27
12/22 32/21/27/-2/..../.../000/00        18 E   AERO 17 E   RMY N/A
12/23 36/24/30/+1/..../.../000/00        31 WSW AERO 28 WSW RMY 31
12/24 35/29/32/+3/..../.../191/35        30 ENE AERO 25 ENE RMY N/A
12/25 35/21/28/0/..../.../098/18         50 W   AERO 54 W   RMY 47
12/26 24/13/19/-9/0.00/0.0/529/97        39 W   AERO 39 W   RMY 41     
12/27 19/6/13/-15/0.00/0.0/530/97        28 WNW AERO 25 WNW RMY N/A
12/28 10/1/6/-22/0.00/0.0/..../..        37 WNW AERO 44 WNW RMY 43          
12/29 13/-3/5/-22/0.00/0.0/.../..        25 W   AERO 25 W   RMY 27
12/30 14/1/8/-19/0.03/0.5/.../..         21 W   AERO 18 W   RMY 24
12/31 10/0/5/-22/0.00/0.0/.../..         32 WNW AERO 32 WNW RMY 35

PRELIMINARY CLIMATE SUMMARY FOR JANUARY 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

1/1 11/-5/3/-24/0.00/0.0/.../..         30 NW  AERO 30 NW  RMY 31
1/2 15/-2/7/-20/0.00/0.0/.../..         26 W   AERO 25 W   RMY 26  
1/3 28/11/20/-6/0.00/0.0/.../..         23 WSW AERO 20 WSW RMY N/A
1/4 28/18/23/-3/1.66/16.5/000/00        54 NNW AERO 60 NNW RMY 64

1/5 Low temp since midnight is 8F; normal low is now 18F

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

RECORDS FOR JANUARY 5
HIGH 61F IN 2007
LOW -9F IN 1981
PRECIP 0.98 INS. IN 1993
SNOW 4.5 INS. IN 1891
PEAK GUST 70 MPH WNW IN 1959

RECORDS FOR JANUARY 6
HIGH 66F IN 2007
LOW -14F IN 1896
PRECIP 3.10 INS. IN 1889 [RECORD FOR MONTH]
SNOWFALL 7.5 INS. IN 1893
PEAK GUST 70 MPH WNW IN 1959

TODAY'S REPORT PREPARED BY: Jonathan O'Brien