Thursday, January 7, 2016

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

DAILY DISCUSSION AND CLIMATE SUMMARY
THURSDAY, JANUARY 7, 2016
ALL TIMES ARE IN EASTERN STANDARD TIME

TEMPS RETURN TO ABOVE NORMAL WARMTH- THIN ICE FREEZE OVER
ON BOTH HOUGHTON’S AND PONKAPOAG PONDS AS OF WEDNESDAY 1/6/16

Thin, glassy ice covered the entirety of both Houghton’s
and Ponkapoag ponds, making Wednesday the first freeze over
of the season for both ponds. Wednesday’s date was nearly
one month later than the mean date for freeze over our 130
year record of both ponds, and only 12 days before the latest
freeze on record for both ponds on January 18th, 2007. The warmest
December on record at Blue Hill Observatory was likely one
of the main factors for this year’s late freeze date.

Another thermal inversion set up below the hill this morning,
trapping hazy and foggy cold air below. Following an overnight
low temperature of 26F, temperatures have climbed into the
40s for the second consecutive day, reaching 43F by the 1:00 PM
EST observation.

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: 1.04 ins. on the 28th-29th
Snowfall: 1.3 [-12.1] Greatest in 24 hrs: 1.3 ins. on the 28th-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: Clear, few cirrus fibratus in all directions,
few cirrostratus distant E-SW, inversion present below
the summit in all directions, light distant haze
below the inversion in all directions.
Temperature: 26F; Dew Point: 10F; Wind: W at 11 kts
Sea-level pressure: 30.33 ins. Hg, falling, then rising and higher
Visibility: 60 miles, light distant haze
6-hr Max temp: 30F
6-hr Min temp: 26F
24-hr precip: 0.00 ins.
24-hr snowfall: 0.0 ins.
Snow depth: Trace
BHO SA 1155 CLR 60 271/26/10/2811/033/ FEW CI ALQDS
FEW CS DSNT E-SW INVSN PRSNT BLO SMT ALQDS LGT DSNT HZ
BLO INVSN ALQDS/ 8/001 50006 10030 20026

10 A.M.
Weather: Thin broken cirrus, light smoke layer along the
horizon
Temperature: 35F; Dew Point: 8F; Wind: estimated N at 6 kts
Wind Speed: Light
Sea-level pressure: 30.35 ins. Hg, rising, then more quickly
Visibility: 70 miles, light distant haze and smoke layer
BHO SA 1455 E250- BKN 70 276/35/8/E3506/035/ LGT DSNT HZ ALQDS
LGT K LYR ALQDS ALNG HRZN WND LGT/ 8/001 53005

1 P.M.
Weather: Thin brokn cirrus, light smoke layer along the
horizon in all directions
Temperature: 43F; Dew Point: 2F; Wind: estimated NNE at 3 kts
Wind Speed: Light
Sea-level pressure: 30.27 ins. Hg, falling, then more slowly
Visibility: 65 miles, think smoke layer, light distant haze
6-hr Max temp: 43F
6-hr Min temp: 25F
BHO SA 1755 E250- BKN 65 249/43/2/E0303/027/ THN K LYR ALQDS
ALNG HRZN LGT DSNT HZ ALQDS WND LGT/ 8/001 56027 10043 20025

SUMMARY FOR WEDNESDAY, JANUARY 6, 2016

TEMPERATURE (DEGREES F)
MAX…..43   NORMAL…..34
MIN…..17   NORMAL…..18
MEAN….30   NORMAL…..26

DEPARTURE FROM 30-YEAR NORMAL…………………..+4
TOTAL DEPARTURE FOR THE MONTH…………………..+5 [+0.6 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY…………..35   DEPARTURE……….-4
TOTAL HEATING UNITS FOR THE MONTH………….227   DEPARTURE……….-5
TOTAL HEATING UNITS FOR THE SEASON………..1883   DEPARTURE……..-653
TOTAL HEATING UNITS LAST SEASON TO DATE……2280   DIFFERENCE…….-397

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY……………….24  SW  AT  7:59 P.M.
ASOS……………………24  SW  AT  7:59 P.M.
DAVIS…………………..22  SW  AT  7:58 P.M. RMY 24
FASTEST MILE FOR YESTERDAY…………………19  W   AT  5:03 A.M.
MAXIMUM 2-MINUTE ASOS AVERAGE………………20  W   AT  5:08 A.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE……………..16  SW  AT  9:08 P.M.
AVERAGE WIND SPEED AND DIRECTION………….13.1 W
ASOS………………….13.2
DAVIS…………………11.9 WSW [249 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……-0.86
ASOS…………..0.00
TOTAL PRECIPITATION FOR THE YEAR……….TRACE  DEPARTURE……-0.86
ASOS…………..0.00

SNOWFALL (INCHES) THROUGH THIS MORNING (EST)
TOTAL SNOWFALL 24 HRS ENDING 7 A.M……….0.0  DEPARTURE…….-0.6
TOTAL SNOWFALL FOR THE MONTH…………….0.2  DEPARTURE…….-3.2
TOTAL SNOWFALL FOR THE SEASON……………1.5  DEPARTURE……-17.9

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/T/0.0/240/44             23 N   RMY N/A
12/26 53/40/47/+19/0.00/0.0/436/80          26 NNW RMY N/A
12/27 52/35/44/+16/0.27/0.0/000/00          36 NW  RMY 33
12/28 35/27/31/+3/T/T/355/65                33 NW  RMY 33
12/29 38/23/31/+4/1.04/1.3/000/00           35 ENE RMY 35
12/30 34/23/29/+2/0.05/T/000/00             17 SSE RMY N/A
12/31 44/32/38/+11/0.11/0.0/258/47          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   43/17/30/+4/0.00/0.0/…/..           24 SW  RMY 24

1/7 low since midnight is 26F; 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 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

RECORDS FOR JANUARY 8
HIGH 65F IN 2008
LOW -8F IN 1968
PRECIP 1.70 INS. IN 1958,1979
SNOWFALL 12.5 INS. IN 1996
PEAK GUST 77 MPH NNW IN 1958

TODAY’S REPORT PREPARED BY: Brian Fitzgerald