Wednesday, January 6, 2016

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

DAILY DISCUSSION AND CLIMATE SUMMARY
WEDNESDAY, JANUARY 6, 2016
ALL TIMES ARE IN EASTERN STANDARD TIME

TEMPERATURES BEGIN TO MODERATE AFTER ANOTHER CHILLY OVERNIGHT

Yesterday’s average temperature of 14F provided the coldest
day of the winter thus far, with a temperature departure
of 12 degrees below normal and a minimum temperature of 4F.

Completely clear skies were present at this morning’s 7:00 AM EST
observation, with a thermal inversion present below the summit.
By today’s 1:00 PM EST observation skies remained clear with
only a few thin cirrus fibratus distant to the S and WSW-NE.
Temperatures had reached a maximum of 42F by that time as well.

DECEMBER FINISHES AS THE WARMEST ON RECORD…NEARLY FIVE
DEGREES WARMER THAN PREVIOUS RECORD FOR THE MONTH…
THIRD RECORD WARM MONTH IN 2015…GREATEST POSITIVE TEMPERATURE
DEPARTURE FOR ANY MONTH…DECEMBER ALSO AMONG CLOUDIEST ON RECORD…

BHO Warmest Decembers (24-hour Mean), deg F (1885-2015)

1) 42.9 in 2015
2) 38.1 in 2006
3) 37.5 in 2011
4) 37.3 in 2001
5) 37.2 in 1891
6) 36.9 in 1998
7) 36.7 in 1990

BHO Largest Monthly 24-Hour Mean Temperature Departure from the Long-Term
Mean, deg F (1885-2015):

1)+13.1 in December 2015
2) +9.9 in January 1913
3) +9.3 in January 1932
4) +9.1 in March 1946
5) +9.0 in March 2012
6) +8.9 in January 1937
7) +8.5 in February 1984

BHO Lowest December Sunshine, hours (1885-2015):

1) 72.9 in 1972  [27%] 2) 81.0 in 1982  [29%] 3) 87.2 in 1933  [32%] 4) 88.2 in 1996  [32%] 5) 89.0 in 1922  [32%] 6) 89.5 in 1981  [33%] 7) 91.1 in 1906  [33%] 8) 92.0 in 2012  [34%] 9) 92.9 in 2013  [34%] 10) 93.3 in 2015 [34%]

PRELIMINARY STATS FOR DECEMBER 2015

TEMPERATURE, Deg. F
Avg. Max. 50.5 [+11.4] Avg. Min. 36.9 [+13.3] Mean      43.7 [+12.4] 24-hour Corrected Mean: 42.9 [+13.1] Max. for month: 67 on 24th
Min. for month: 23 on 29th, 30th

HEATING DEGREE DAYS
Total cooling units: 654 [-389] Total for the season: 1656 [-649] Total for last season: 2060

PRECIPITATION, Inches
Total: 4.27 [-0.49] Greatest in 24 hrs: N/A
Snowfall: 1.3 [-12.1] Greatest in 24 hrs: 1.3 ins. on the 29th

WIND, mph
Avg. uncorrected wind speed: 11.3
Avg. corrected wind speed: 11.8
Prevailing wind direction: W @ 12%
Peak gust and direction: 48 W on the 15th

SUNSHINE:
Campbell-Stokes card minutes: 5598 mins. of possible 16470 or 34%
Astronomical total minutes:   5786 mins. of possible 17002 or 34%
Long-term average for December is 46%

Today’s Observations:

7 A.M.
Weather: Sky clear
Temperature: 21F; Dew Point: 0F; Wind: WSW at 11 kts
Sea-level pressure: 30.51 ins. Hg, falling, then more slowly
Visibility: 75 miles
6-hr Max temp: 22F
6-hr Min temp: 17F
24-hr precip: 0.00 ins.
24-hr snowfall: 0.0 ins.
Snow depth: Trace
BHO SA 1155 CLR 75 331/21/0/2511/051/ SKC INVSN PRSNT BLO SMT ESTMD
TOP 2 HND FT/ 8/000 50000 10022 20017

10 A.M.
Weather: Clear, few cirrus distant SW and WNW-NNE
Temperature: 29F; Dew Point: 3F; Wind: SW at 8 kts
Sea-level pressure: 30.51 ins. Hg, steady, then rising
Visibility: 80 miles
BHO SA 1455 CLR 80 333/29/3/2309/051/ FEW CI DSNT SW AND WNW-NNE/
8/001 53002

1 P.M.
Weather: Clear, few cirrus distant S and WSW-NE
Temperature: 42F; Dew Point: -4F; Wind: SW at 11G18 kts
Sea-level pressure: 30.44 ins. Hg, rising, then falling and lower
Visibility: 80 miles
6-hr Max temp: 42F
6-hr Min temp: 20F
BHO SA 1755 CLR 80 308/42/-4/2311G18/044/ FEW CI DSNT S AND WSW-NE/
8/001 58025 10042 20020

SUMMARY FOR TUESDAY, JANUARY 5, 2016

TEMPERATURE (DEGREES F)
MAX…..23   NORMAL…..34
MIN……4   NORMAL…..18
MEAN….14   NORMAL…..26

DEPARTURE FROM 30-YEAR NORMAL………………….-12
TOTAL DEPARTURE FOR THE MONTH…………………..+1 [+0.0 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY…………..51   DEPARTURE………+12
TOTAL HEATING UNITS FOR THE MONTH………….192   DEPARTURE……….-1
TOTAL HEATING UNITS FOR THE SEASON………..1848   DEPARTURE……..-649
TOTAL HEATING UNITS LAST SEASON TO DATE……2228   DIFFERENCE…….-380

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY……………….28  NNW AT  1:31 A.M.*
ASOS……………………28  NNW AT  1:28 A.M.
DAVIS…………………..24  N   AT  1:38 A.M. RMY N/A
FASTEST MILE FOR YESTERDAY…………………19  NNW AT  1:39 A.M.
MAXIMUM 2-MINUTE ASOS AVERAGE………………20  NNW AT  1:39 A.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE……………..17  NNW AT  1:39 A.M.
AVERAGE WIND SPEED AND DIRECTION………….11.0 N
ASOS………………….11.0
DAVIS………………….9.5 NNW [327 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………TRACE  DEPARTURE……-0.72
ASOS…………..0.00
TOTAL PRECIPITATION FOR THE YEAR……….TRACE  DEPARTURE……-0.72
ASOS…………..0.00

SNOWFALL (INCHES) THROUGH THIS MORNING (EST)
TOTAL SNOWFALL 24 HRS ENDING 7 A.M……….0.0  DEPARTURE…….-0.5
TOTAL SNOWFALL FOR THE MONTH…………….0.2  DEPARTURE…….-2.6
TOTAL SNOWFALL FOR THE SEASON……………1.5  DEPARTURE……-17.3

PRELIMINARY CLIMATE SUMMARY FOR DECEMBER/JANUARY CALENDAR DAY DATA
DATA REPORTED:
DATE: MAX/MIN/MEAN/DEP/PRECIP/SUN(MIN.)/SUN(%)/ PEAK GUST/RMY 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

12/1  42/30/36/-1/0.16/0.0/000/00           19 NNE RMY 19
12/2  53/37/45/+9/0.20/0.0/000/00           25 SSE RMY 25
12/3  53/37/45/+9/0.01/0.0/162/29           43 WNW RMY 42
12/4  47/32/40/+5/0.00/0.0/444/80           32 NW  RMY 32
12/5  50/33/42/+7/0.00/0.0/548/99           21 W   RMY N/A
12/6  57/35/46/+11/0.00/0.0/531/96          22 SW  RMY N/A
12/7  54/37/46/+12/0.00/0.0/353/64          31 NE  RMY N/A
12/8  42/35/39/+5/0.01/0.0/000/00           32 NE  RMY 31
12/9  44/34/39/+5/0.00/0.0/044/08           28 SSE RMY N/A
12/10 57/41/49/+16/T/0.0/209/38             29 SE  RMY N/A
12/11 56/44/50/+17/0.00/0.0/049/09          28 SSW RMY 28
12/12 59/46/53/+20/0.00/0.0/367/67          23 W   RMY N/A
12/13 54/44/49/+17/0.00/0.0/000/00          18 ESE RMY 19
12/14 60/43/52/+20/0.45/0.0/000/00          32 S   RMY N/A
12/15 61/45/53/+21/0.17/0.0/371/68          48 W   RMY 51
12/16 45/34/40/+9/0.00/0.0/415/76           25 N   RMY N/A
12/17 53/36/45/+14/0.50/0.0/000/00          29 SE  RMY 28
12/18 50/35/43/+12/0.10/0.0/000/00          29 NW  RMY 30
12/19 38/30/34/+4/0.00/0.0/480/88           39 W   RMY 40
12/20 40/28/34/+4/0.00/0.0/491/90           24 W   RMY N/A
12/21 51/31/41/+11/T/0.0/000/00             38 SSW RMY 42
12/22 57/49/53/+24/0.28/0.0/000/00          35 SW  RMY 35
12/23 54/47/51/+22/0.61/0.0/000/00          30 E   RMY 27
12/24 67/48/58/+29/0.31/0.0/033/06          37 SSW RMY 39
12/25 64/52/58/+30/…./0.0/240/44          23 N   RMY N/A
12/26 53/40/47/+19/…./0.0/436/80          26 NNW RMY N/A
12/27 52/35/44/+16/…./0.0/000/00          36 NW  RMY 33
12/28 35/27/31/+3/T/T/355/65                33 NW  RMY 33
12/29 38/23/31/+4/…./1.3/000/00           35 ENE RMY 35
12/30 34/23/29/+2/…./T/000/00             17 SSE RMY N/A
12/31 44/32/38/+11/…./0.0/258/47          25 WNW RMY 25

1/1   37/29/33/+6/0.00/0.0/…/..           29 W   RMY 29
1/2   37/27/32/+5/0.00/0.0/…/..           31 W   RMY N/A
1/3   41/27/34/+8/0.00/0.0/…/..           28 W   RMY 29
1/4   30/10/20/-6/T/T/000/00                29 NNW RMY 29
1/5   23/4/14/-12/0.00/0.0/…/..           28 NNW RMY N/A

1/6 low since midnight is 17F; normal low is now 18F

DAILY RECORDS FOR DECEMBER 2015

**12/13/2015- NEW DAILY RECORD HIGH MINIMUM TEMPERATURE OF 44F,
BREAKS PREVIOUS RECORD OF 43F SET IN 1919, TIED 1983
**12/24/2015- NEW DAILY RECORD MAXIMUM TEMPERATURE OF 67F,
BREAKS PREVIOUS RECORD OF 61F SET IN 2014
**12/24/2015- NEW DAILY RECORD HIGH MINIMUM TEMPERATURE OF 48F,
BREAKS PREVIOUS RECORD OF 46F SET IN 1900
**12/25/2015- NEW DAILY RECORD MAXIMUM TEMPERATURE OF 64F,
BREAKS PREVIOUS RECORD OF 62F SET IN 1889
**12/25/2015- NEW DAILY RECORD HIGH MINIMUM TEMPERATURE OF 52F,
BREAKS PREVIOUS RECORD OF 46F SET IN 1964

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

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

RECORDS FOR JANUARY 7
HIGH 60F IN 1930
LOW -7F IN 1896
PRECIP 1.97 INS. IN 1977
SNOWFALL 16.0 INS. IN 1977
PEAK GUST 74 MPH NW IN 1968

TODAY’S REPORT PREPARED BY: Brian Fitzgerald