Sunday, December 29, 2013

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

DAILY DISCUSSION AND CLIMATE SUMMARY
SUNDAY, DECEMBER 29, 2013
ALL TIMES ARE IN EASTERN STANDARD TIME

OVERCAST DAY WITH RAIN BEGINNING EARLY THIS AFTERNOON

Today has been predominately overcast, with only a few breaks in the clouds
observed right around sunrise.  Temperatures are running above normal today,
with a warm morning low of 36F.  The afternoon high so far has only come
up to 42F, but that is also well above average.  The wind has been steady at
around 10-15 mph out of the S and SSW.  Rain was seen moving in from the
south and west during the late morning and early afternoon, and some light
rain began falling on the summit around 12:30 PM.  This rain is associated
with a storm moving up from the south which is expected to strengthen as
it passes near or just east of us.  The barometer has been steadily falling
from late morning into the afternoon, signaling the storm’s approach.

Today is setting up to be the 12th day of this very cloudy month with no
sunshine observed.  Despite the excess of clouds, precipitation has actually
been below average so far, by almost half an inch.  The expected rainfall
today and tonight is likely to wipe out this deficit, however.

Today’s Observations:

7 A.M.
Weather: Overcast altostratus, few altocumulus distant E-SE
Temperature: 37F; Dew Point: 27F; Wind: S at 9 kts
Sea-level pressure: 30.01 ins. Hg, falling then steady
Visibility: 25 miles, hazy
6-hr. min temp: 36F
BHO SA 1155 E140 OVC 25 163/37/27/1909/001/ FEW AC DSNT E-SE HAZY/
8/07/ 56007 10039 20036

10 A.M.
Weather: Overcast altostratus, thin smoke layer along horizon all quadrants
Temperature: 39F; Dew Point: 29F; Wind: SSW at 9 kts
Sea-level pressure: 30.02 ins. Hg, rising slightly
Visibility: 45 miles, distant haze
BHO SA 1455 E130 OVC 45 165/39/29/2009/002/ DSNT HZ THN K LYR ALG HRZN ALQDS/
8/57/ 50002

1 P.M.
Weather: Light rain, overcast nimbostratus, thin smoke layer along horizon
WNW-NE, light rain began at 12:28 P.M.
Temperature: 40F; Dew Point: 34F; Wind: S at 12 kts
Sea-level pressure: 29.90 ins. Hg, falling then falling more slowly
Visibility: 20 miles
6-hr precip: Trace
6-hr max temp: 42F
BHO SA 1755 E70 OVC 20R- 126/40/34/1912/990/ THN K LYR ALG HRZN WNW-NE R-B28/
8/02/ 56039 6000/ 10042 20036

WEATHER SUMMARY FOR SATURDAY, DECEMBER 28, 2013

TEMPERATURE (DEGREES F)
MAX…..46    NORMAL…..36
MIN…..25    NORMAL…..20
MEAN….36    NORMAL…..28

DEPARTURE FROM 30-YEAR NORMAL………………….+8
TOTAL DEPARTURE FOR THE MONTH…………………-14 [-0.7 DEGREE/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY…………..29  DEPARTURE………-8
TOTAL HEATING UNITS FOR THE MONTH………….942  DEPARTURE……..+12
TOTAL HEATING UNITS FOR THE SEASON………..2166  DEPARTURE……..-25
TOTAL HEATING UNITS LAST SEASON TO DATE……1910  DIFFERENCE……+256

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY………………30 WSW  AT 12:41 P.M.
AERO…………………..32 SW   AT 11:28 A.M.
ASOS…………………..32 SSW  AT 11:14 A.M.
DAVIS………………….32 SSW  AT 11:12 A.M. RMY 32
FASTEST MILE FOR YESTERDAY………………..24 SW   AT 11:17 A.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………..24 WSW  AT 12:42 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE…………….23 SSW  AT 11:19 A.M.
AVERAGE WIND SPEED AND DIRECTION…………14.5 SSW
ASOS…………………14.3
DAVIS………………..13.3 SW [225 deg.]

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M….0.00  DEPARTURE………….-0.15
ASOS…………..0.00
TOTAL PRECIPITATION FOR THE MONTH……….4.04  DEPARTURE………….-0.43
ASOS…………..4.02
TOTAL PRECIPITATION FOR THE YEAR……….50.64  DEPARTURE………….-2.36
ASOS…………..N/A**
** ASOS malfunctioned during storm on 2/8-9, leading to erroneous totals

SNOWFALL (INCHES) THROUGH THIS MORNING (EST)
TOTAL SNOWFALL 24 HRS ENDING 7 A.M…….0.0     DEPARTURE………….-0.6
TOTAL SNOWFALL FOR THE MONTH…………15.4     DEPARTURE………….+3.6
TOTAL SNOWFALL FOR THE SEASON………..15.6     DEPARTURE………….+1.2

PRELIMINARY CLIMATE SUMMARY FOR DECEMBER 2013 CALENDAR DAY DATA
DATA REPORTED:
DATE: MAX/MIN/MEAN/DEP/PRECIP/SNOW/SUN(MIN.)/SUN(%)/ PEAK GUST/AERO GUST
AERO: Aerovane wind recording system gust
RMY:  RMY = R.M. Young wind gust recording system added 8/9/2011
TSTM: Thunderstorm day (thunder heard some time during day)
….: Data not yet available, records not finalized

12/1  45/30/38/+1/0.28/T/000/00           22 SSE AERO 23 MPH SSE RMY 23
12/2  38/34/36/0/T/0.0/000/00             15 NW  AERO 15 MPH NW  RMY 16
12/3  45/32/39/+3/0.00/0.0/284/51         18 NNW AERO 18 MPH NNW RMY 20
12/4  43/29/36/+1/0.00/0.0/389/70         21 WNW AERO 21 MPH WNW RMY 21
12/5  53/38/46/+11/0.02/0.0/000/00        36 S   AERO 40 MPH S   RMY 39
12/6  55/33/44/+9/0.38/T/000/00           25 SSW AERO 28 MPH SSW RMY N/A
12/7  40/26/33/-1/0.12/T/287/52           23 NW  AERO 25 MPH NW  RMY N/A
12/8  30/22/26/-8/T/T/039/07              25 NW  AERO 27 MPH NW  RMY N/A
12/9  41/25/33/-1/0.35/0.6/000/00         28 E   AERO 28 MPH E   RMY 24
12/10 33/21/27/-6/0.14/2.1/000/00         28 W   AERO 28 MPH W   RMY 28
12/11 28/19/24/-9/0.00/0.0/345/63         27 SW  AERO 28 MPH SW  RMY 27
12/12 23/14/19/-14/0.00/0.0/542/99        28 WNW AERO 31 MPH NW  RMY 30
12/13 28/14/21/-11/0.00/0.0/405/74        31 W   AERO 32 MPH W   RMY 33
12/14 28/9/19/-13/0.45/4.8/000/00         30 E   AERO 26 MPH E   RMY N/A
12/15 36/21/29/-3/0.98/2.0/000/00         48 NE  AERO 50 MPH NE  RMY 51
12/16 27/14/21/-10/0.00/0.0/529/97        36 W   AERO 37 MPH W   RMY N/A
12/17 23/7/15/-16/0.53/5.5/104/19         28 N   AERO 30 MPH N   RMY 28
12/18 32/15/24/-7/0.00/0.0/436/80         29 WNW AERO 30 MPH NW  RMY 29
12/19 42/22/32/+2/0.00/0.0/425/78         38 SW  AERO 44 MPH SW  RMY 42
12/20 52/34/43/+13/0.00/0.0/332/61        26 SSW AERO 29 MPH SSW RMY 29
12/21 58/42/50/+20/0.00/0.0/082/15        28 SSW AERO 29 MPH SSW RMY 30
12/22 63/35/49/+20/…./0.0/000/00        37 SW  AERO 41 MPH SW  RMY 41
12/23 37/32/35/+6/…./0.0/000/00         24 NW  AERO 25 MPH NW  RMY 25
12/24 36/25/31/+2/T/T/142/26              25 NW  AERO
12/25 25/13/19/-9/0.00/0.0/480/88         29 NW  AERO 30 MPH WNW RMY 30
12/26 35/19/27/-1/0.05/0.4/000/00         24 W   AERO 25 MPH W   RMY 25
12/27 32/22/27/-1/0.00/0.0/…/..         25 W   AERO 25 MPH W   RMY 26
12/28 46/25/36/+8/0.00/0.0/…/..         30 WSW AERO 32 MPH SW  RMY 32

12/29 morning low temp: 36F; the normal low is now 20F

DAILY RECORDS FOR DECEMBER 2013
12/22- NEW DAILY RECORD MAXIMUM TEMPERATURE OF 63F;
surpasses previous record of 62F set in 1994
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: Jonathan O’Brien