Tuesday, December 29, 2015

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

DAILY DISCUSSION AND CLIMATE SUMMARY
TUESDAY, DECEMBER 29, 2015
ALL TIMES ARE IN EASTERN STANDARD TIME

FIRST MEASURABLE SNOW OF THE SEASON THIS MORNING,
1.3 INCHES OF NEW SNOW- TIES DATE FOR THIRD LATEST
MEASURABLE SNOWFALL ON RECORD

Snow began late last evening, dropping just a trace
of new snow before midnight. By 7:00 AM EST this morning
snow had transitioned to ice pellets (sleet), accumulating
to 1.0 inches of new frozen precipitation and 0.44 inches
of liquid equivalent. It is possible, given the high snow to
water equivalent that some snow and ice pellets were compressed
by the time of measurement this morning.

By 9:15 AM EST rain and ice pellets transitioned to just
rain. At the 10:00 AM EST observation an additional 0.3 inches
of ice pellets had a fallen, with a liquid equivalent of
0.29 inches (rain included as well).

By the 1:00 PM EST observation rain continued, falling
moderately at times with fog. Liquid precipitation since
7:00 AM total 0.50 inches, and nearly 1 inch since midnight.

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)
December 29, 2015  (1.3 inches)
5) December 22, 1998  (0.6 inches)
6) December 16, 1973  (0.4 inches)
7) December 15, 1891  (0.3 inches)

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.)

Today’s Observations:

7 A.M.
Weather: Fog, light ice pellets
Temperature: 30F; Dew Point: 29F; Wind: E @ 14G22 kts
Sea-level pressure: 30.35 ins. Hg, falling, then more slowly
Visibility: 3/4 of a mile, ice pellets and fog
6-hr Max temp: 30F
6-hr Min temp: 27F
24-hr precip: 0.44 ins.
24-hr snowfall: 1.0 ins.
BHO SA 1155 W4 X 3/4IP-F 278/30/29/0914G22/035/
NEW SNW PST 24 HRS 1.0 INS/ 8//// 56027
ASOS 60044 70044 MANUAL 70044 10030 20027

10 A.M.
Weather: Light rain, fog, ice pellets end 9:15 AM EST
Temperature: 33F; Dew Point: 33F; Wind: E @ 16G24 kts,
Sea-level pressure: 30.19 ins. Hg, falling rapidly
Visibility: 3 miles, light rain, fog
3-hr precip: 0.29 ins.
3-hr snowfall: 0.3 ins.
BHO SA 1455 W4 X 3R-F 223/33/33/1016G24/019/
NEW SNW PST 3 HRS 0.3 INS PRESFR/ 8//// 56055
ASOS 60030 MANUAL 60029

1 P.M.
Weather: Light rain, fog
Temperature: 37F; Dew Point: 37F; Wind: ENE @ 18G29 kts
Peak Wind: 29 knots ENE at 12:53 PM EST
Sea-level pressure: 30.01 ins. Hg, falling rapidly
Visibility: 1/2 of a mile, light rain, fog
6-hr Max temp: 37F
6-hr Min temp: 30F
6-hr precip: 0.50 ins.
BHO SA 1755 W3 X 1/2R-F 164/37/37/0618G29/001/ PRESFR
PK WND 0629/53/ 8//// 58059 ASOS 60052 MANUAL 60050 10037 20030

SUMMARY FOR MONDAY, DECEMBER 28, 2015

TEMPERATURE (DEGREES F)
MAX…..35   NORMAL…..36
MIN…..27   NORMAL…..20
MEAN….31   NORMAL…..28

DEPARTURE FROM 30-YEAR NORMAL………………….+3
TOTAL DEPARTURE FOR THE MONTH………………..+371  [+13.2 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY…………..34   DEPARTURE……….-3
TOTAL HEATING UNITS FOR THE MONTH………….556   DEPARTURE……..-374
TOTAL HEATING UNITS FOR THE SEASON………..1558   DEPARTURE……..-633
TOTAL HEATING UNITS LAST SEASON TO DATE……1942   DIFFERENCE…….-384

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY……………….33  NW  AT  2:03 A.M.
ASOS……………………36  NW  AT  2:04 A.M.
DAVIS…………………..33  N   AT  2:03 A.M. RMY 33
FASTEST MILE FOR YESTERDAY…………………26  N   AT  7:36 A.M.
MAXIMUM 2-MINUTE ASOS AVERAGE………………25  N   AT  7:37 A.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE……………..23  N   AT  7:36 A.M.
AVERAGE WIND SPEED AND DIRECTION…………..11.9 N
ASOS…………………..12.4
DAVIS………………….10.0 N [011 Deg.]

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M…..0.44  DEPARTURE……+0.29
ASOS……………0.44
TOTAL PRECIPITATION FOR THE MONTH………..3.51  DEPARTURE……-0.96
ASOS……………3.53
TOTAL PRECIPITATION FOR THE YEAR………..42.93  DEPARTURE…..-10.08
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……….1.0  DEPARTURE…….+0.4
TOTAL SNOWFALL FOR THE MONTH…………….1.0  DEPARTURE……-10.8
TOTAL SNOWFALL FOR THE SEASON……………1.0  DEPARTURE……-13.4

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 52/35/44/+16/…./0.0/000/00          36 NW  RMY 33
12/28 35/27/31/+3/T/T/…/..                33 NW  RMY 33

12/29 low since midnight is 27F; 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 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)

RECORDS FOR DECEMBER 30
HIGH 60 IN 1984
LOW -18 IN 1933
PRECIP 1.48 INS. IN 1891
SNOWFALL 7.5 INS. IN 1956
PEAK GUST 81 MPH WNW IN 1962

TODAY’S REPORT PREPARED BY: Brian Fitzgerald