Sunday, December 27, 2015

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

DAILY DISCUSSION AND CLIMATE SUMMARY
SUNDAY, DECEMBER 27, 2015
ALL TIMES ARE IN EASTERN STANDARD TIME

FOG, LIGHT RAIN, AND CONTINUED MILD TEMPERATURES TODAY

Light rain began at the summit in the overnight hours, and had added up to
0.16 ins. of rain by the 7:00 observation. Light rain and drizzle continued
for most of the morning, adding an additional 0.03 ins. of rain. Temperatures
have again been well above normal, rising slowly from a low of 42F to a high
so far of 48F, and this will mark the 26th day in a row of above normal
temperatures.  Very dense fog has limited to visibility to only 1/16th of
a mile for much of the day.

It was a record breaking Christmas holiday here at Blue Hill and
throughout the Northeast, with exceptionally warm temperatures making it
feel more like early October than late December.  December 24th and 25th
both set new records for daily maximum and high minimum temperatures.  The
67F reading on December 24th broke last year’s record of 61F, and the
Christmas day maximum of 64F broke a record of 62F set in 1889.  The
minimum temperature of 52F on the 25th broke the previous high minimum
record by six degrees (46F in 1964).  Six days this month have had a
temperature departure of +20F or greater, including three in a row, both
of which are records for December.  The +30F departure yesterday was the
second largest on record for December.  Also impressive have been the dew
points, which exceeded 60F for much of the day on the 24th.  The temperature
departure for December now sits at over +13F, and we are well on our way to
the warmest December on record.

BHO Largest December Daily Temperature Departure, deg F (1885-2015):

1) +35 on 29 Dec 1984 (72/51/62)
2) +30 on 25 Dec 2015 (64/52/58)
3) +29 on 23 Dec 1990 (62/53/58)
+29 on 24 Dec 2015 (67/48/58)
5) +27 on 31 Dec 1965 (62/45/54)
+27 on 22 Dec 1990 (58/53/56)
7) +26 on 27 Dec 1949 (57/51/54)
+26 on 9 Dec 1966 (68/52/60)
+26 on 6 Dec 2001 (70/52/61)

(Thanks to Mike Iacono for compiling these statistics.)

So far this season, there has been no measurable snow on Blue Hill.
This season is now the fourth latest on record for the first
occurrence of measurable snowfall.

BHO Latest First Measurable Snowfall, (1885-2014)

1) January  13, 2000  (7.0 inches)
2) January   1, 1954  (0.8 inches)
3) December 29, 1941  (0.4 inches)
4) December 22, 1998  (0.6 inches)
5) December 16, 1973  (0.4 inches)
6) December 15, 1891  (0.3 inches)

Today’s Observations:

7 A.M.
Weather: Sky obscured by dense fog, light rain
Temperature: 43F; Dew Point: 43F; Wind: WNW @ 7 kts
Sea-level pressure: 30.01 ins. Hg, falling then falling more slowly
Visibility: 1/16 mile
6-hr Max temp: 43F
6-hr Min temp: 42F
24-hr precip: 0.16 ins.
BHO SA 1155 W2 X 1/16R-F 162/43/43/3007/001/ 8//// 56032 ASOS 60016
ASOS 70016 MANUAL 70016 10043 20042

10 A.M.
Weather: Sky obscured by dense fog, light drizzle
Temperature: 44F; Dew Point: 44F; Wind: estimated NW @ 5 kts,
Wind: Light
Sea-level pressure: 29.91 ins. Hg, falling then falling more slowly
Visibility: 1/16 mile
3-hr precip: 0.03 ins.
BHO SA 1455 W2 X 1/16L-F 130/44/44/E3105/991/ WND LGT/ 8//// 56032
ASOS 60003 MANUAL 60003

1 P.M.
Weather: Sky obscured by dense fog
Temperature: 48F; Dew Point: 48F; Wind: WNW @ 9 kts
Sea-level pressure: 29.78 ins. Hg, falling then falling more slowly
Visibility: 1/16 mile
6-hr Max temp: 48F
6-hr Min temp: 42F
6-hr precip: 0.03 ins.
BHO SA 1755 W3 X 1/16F 084/48/48/2609/978/ 8//// 56046
ASOS 60003 MANUAL 60003 10048 20042

SUMMARY FOR SATURDAY, DECEMBER 26, 2015

TEMPERATURE (DEGREES F)
MAX…..53   NORMAL…..36
MIN…..40   NORMAL…..20
MEAN….47   NORMAL…..28

DEPARTURE FROM 30-YEAR NORMAL…………………+19
TOTAL DEPARTURE FOR THE MONTH………………..+352  [+13.3 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY…………..18   DEPARTURE………-30
TOTAL HEATING UNITS FOR THE MONTH………….501   DEPARTURE……..-354
TOTAL HEATING UNITS FOR THE SEASON………..1503   DEPARTURE……..-614
TOTAL HEATING UNITS LAST SEASON TO DATE……1897   DIFFERENCE…….-394

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY……………….26  NNW  AT 3:53 A.M.
ASOS……………………27  NNW  AT 3:53 A.M.
DAVIS…………………..24  N    AT 1:41 A.M. RMY N/A
FASTEST MILE FOR YESTERDAY…………………18  NNW  AT 3:55 A.M.
MAXIMUM 2-MINUTE ASOS AVERAGE………………17  NNW  AT 3:56 A.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE……………..15  N    AT 1:13 A.M.
AVERAGE WIND SPEED AND DIRECTION…………..8.3  N
ASOS…………………..8.9
DAVIS………………….7.3  NE [046 Deg.]

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M…..0.16  DEPARTURE…….0.00
ASOS……………0.16
TOTAL PRECIPITATION FOR THE MONTH………..2.96  DEPARTURE……-1.22
ASOS……………2.99
TOTAL PRECIPITATION FOR THE YEAR………..42.38  DEPARTURE…..-10.34
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…………….0.0  DEPARTURE……-10.7
TOTAL SNOWFALL FOR THE SEASON………….TRACE  DEPARTURE……-13.3

PRELIMINARY CLIMATE SUMMARY FOR DECEMBER 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/…./0.0/000/00           19 NNE RMY 19
12/2  53/37/45/+9/…./0.0/000/00           25 SSE RMY 25
12/3  53/37/45/+9/…./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/…./0.0/044/08           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/…./0.0/000/00          32 S   RMY N/A
12/15 61/45/53/+21/…./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/…./0.0/000/00          29 SE  RMY 28
12/18 50/35/43/+12/…./0.0/000/00          29 NW  RMY 30
12/19 38/30/34/+4/0.00/0.0/…/..           39 W   RMY 40
12/20 40/28/34/+4/0.00/0.0/…/..           24 W   RMY N/A
12/21 51/31/41/+11/T/0.0/…/..             38 SSW RMY 42
12/22 57/49/53/+24/0.28/0.0/000/00          35 SW  RMY 35
12/23 56/47/52/+23/…./0.0/…/..          30 E   RMY 27
12/24 67/48/58/+29/…./0.0/…/..          37 SSW RMY 39
12/25 64/52/58/+30/…./0.0/…/..          23 N   RMY N/A
12/26 53/40/47/+19/…./0.0/…/..          26 NNW RMY N/A

12/27 low since midnight is 42F; normal low is now 20F

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 DECEMBER 27
HIGH 57 IN 1895,1949
LOW -4 IN 1903
PRECIP 2.43 INS. IN 1969
SNOWFALL 11.2 INS. IN 1947
PEAK GUST 73 S IN 2011

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

TODAY’S REPORT PREPARED BY: Jonathan O’Brien