Sunday, December 8, 2013

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

DAILY DISCUSSION AND CLIMATE SUMMARY
SUNDAY, DECEMBER 8, 2013
ALL TIMES ARE IN EASTERN STANDARD TIME

PARTLY CLOUDY SKY TURNS OVERCAST AS NEXT WEATHER SYSTEM APPROACHES
BELOW AVERAGE TEMPERATURES AND LIGHT WINDS

The day began with partly cloudy skies allowing for a nice view of the
sunrise, but clouds have been on the increase today.  By mid-late morning,
the sky was almost completely overcast.  The increase in clouds heralds the
arrival of our next weather system which will provide some precipitation to
the area tonight and tomorrow.  The temperature fell to 22F this morning,
easily the coldest reading of the month so far after the month’s first
six days were 4.0 degrees above average.  The temperature has struggled
to increase much through early afternoon thanks to the cloud cover.  The
high temperature so far is only 30F, and today’s high temperature will
almost certainly be the lowest maximum temperature of the month so far.

Winds have been very light since 7AM this morning, not gusting over 12mph
since then.  The wind has been coming in mostly from the NW.  The barometric
pressure has been high today, as an area of high pressure has been over the
region.  Sea level pressure has been over 30.50 ins. Hg.  The visibility
has been good today, up to 80 miles.  Through yesterday, four of December’s
first seven days have had no sunshine at all observed, and it is possible
tomorrow may also go without any sunshine.

Today’s Observations:

7 A.M.
Weather: Broken cirrostratus, broken thin cirrus, stratocumulus mostly
distant offshore NE-SE, altocumulus distant SE-SW
Temperature: 22F; Dew Point: 14F; Wind: NW at 7 kts
Sea-level pressure: 30.55 ins. Hg, rising
Visibility: 55 miles, distant haze
24-hr precip: Trace
24-hr snowfall: Trace
6-hr min temp: 22F
BHO SA 1155 E200 BKN 270 –BKN 55 345/22/14/3107/055/ SC MSTLY DSNT OFFSHR
NE-SE AC DSNT SE-SW DSNT HZ/ 8/571 52026 MANUAL 7000/ 10025 20022

10 A.M.
Weather: Overcast cirrostratus, stratocumulus mostly distant offshore NE-SE,
break in overcast distant NE, Sun visible
Temperature: 28F; Dew Point: 16F; Wind: NW at 6 kts,
Wind: Direction variable W-N
Sea-level pressure: 30.59 ins. Hg, rising then rising more rapidly
Visibility: 70 miles, light distant haze
BHO SA 1455 E200 OVC 70 358/28/16/3106/059/ SC MSTLY DSNT OFFSHR NE-SE
BINOVC DSNT NE SUN VSBL LGT DSNT HZ WND 28V35/ 8/507 53013

1 P.M.
Weather: Overcast altostratus, few stratocumulus distant WNW-NW and distant
offshore NE-SE
Temperature: 28F; Dew Point: 15F; Wind: Estimated NNW at 5 kts,
Wind: Light and variable
Sea-level pressure: 30.54 ins. Hg, rising then falling
Visibility: 80 miles
6-hr. max temp. 30F
BHO SA 1755 E150 OVC 80 343/28/15/E3405/054/ FEW SC DSNT WNW-NW AND
DSNT OFFSHR NE-SE WND LGT AND VRB 8/52/ 58015 10030 20022

WEATHER SUMMARY FOR SATURDAY, DECEMBER 7, 2013

TEMPERATURE (DEGREES F)
MAX…..40    NORMAL…..42
MIN…..26    NORMAL…..27
MEAN….33    NORMAL…..34

DEPARTURE FROM 30-YEAR NORMAL………………….-1
TOTAL DEPARTURE FOR THE MONTH…………………+24 [+3.2 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY…………..32  DEPARTURE………+1
TOTAL HEATING UNITS FOR THE MONTH………….183  DEPARTURE……..-24
TOTAL HEATING UNITS FOR THE SEASON………..1407  DEPARTURE……..-62
TOTAL HEATING UNITS LAST SEASON TO DATE……1323  DIFFERENCE…….+84

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY………………23 NW  AT  3:03 P.M. *
AERO…………………..25 NW  AT  3:02 P.M. *
ASOS…………………..26 NW  AT  2:47 P.M.
DAVIS………………….24 WNW AT 11:20 A.M. RMY N/A
FASTEST MILE FOR YESTERDAY………………..18 NW  AT  2:53 P.M. *
MAXIMUM 2-MINUTE ASOS AVERAGE……………..21 NW  AT  2:52 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE…………….19 WNW AT  2:52 P.M.
AVERAGE WIND SPEED AND DIRECTION…………10.0 NW
ASOS…………………10.4
DAVIS………………..8.2  NW  [316 degrees] * last of several occurrences…

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M…Trace  DEPARTURE………….-0.17
ASOS…………..0.00
TOTAL PRECIPITATION FOR THE MONTH……….0.80  DEPARTURE………….-0.35
ASOS…………..0.76
TOTAL PRECIPITATION FOR THE YEAR……….47.40  DEPARTURE………….-2.28
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…..Trace     DEPARTURE………….-0.4
TOTAL SNOWFALL FOR THE MONTH………..Trace     DEPARTURE………….-2.1
TOTAL SNOWFALL FOR THE SEASON…………0.2     DEPARTURE………….-4.5

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 N/A
12/3  45/32/39/+3/0.00/0.0/…/..         18 NNW AERO 18 MPH NNW RMY 20
12/4  43/29/36/+1/0.00/0.0/…/..         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/…./../000/00          25 SSW AERO 28 MPH SSW RMY N/A
12/7  40/26/33/-1/…./../…/..          23 NW  AERO 25 MPH NW  RMY N/A

12/8 morning low temp: 22F; the normal low is now 26F

DAILY RECORDS FOR DECEMBER 2013
None so far.

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

RECORDS FOR DECEMBER 8
HIGH 62 IN 1966
LOW -4 IN 1906
PRECIP 1.54 INS. IN 1969
SNOWFALL 2.5 INS. IN 2001
PEAK GUST 78e W IN 1979

RECORDS FOR DECEMBER 9
HIGH 68 IN 1966
LOW -14 IN 1902
PRECIP 1.52 INS. IN 1956
SNOWFALL 10.8 INS. IN 2005
PEAK GUST 66 SE IN 1973

TODAY’S REPORT PREPARED BY: Jonathan O’Brien