Wednesday, December 4, 2013

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

DAILY DISCUSSION AND CLIMATE SUMMARY
WEDNESDAY, DECEMBER 4, 2013
ALL TIMES ARE IN EASTERN STANDARD TIME

SUNSHINE RETURNS YESTERDAY AFTER TWO OVERCAST DAYS
SUNSHINE CONTINUES TODAY DESPITE SOME HIGH CLOUDINESS
HEAVY EARLY MORNING FROST TODAY

The sun made another appearance today after first appearing
yesterday by mid-day, this after being overcast for the first
two days of December. The sunshine was continuing despite
high cirrus clouds. A heavy white frost formed overnight last
night in a very moist air mass and coated the grass and snow
boards on the summit this morning.

Temperatures reached the normal high for this date
of 43 degrees early this afternoon and December is
off to a slightly milder than normal start.

November, overall, ended up being a cool and relatively dry month
compared to the 30-year normals.  Statistics can be found below.

Meteorological autumn came to a close at the end of November.  The mean
temperature for the September through November period was 51.7F, which was
slightly warmer (+0.7F) than the 120-year mean, and slightly cooler (-0.2F)
than the 30-year mean.  It has been a while since there has been a
whole season below the 30-year normal.  It appears as though winter
2010-2011 was the last time a season finished below the 30-year normal.
The autumn precipitation of 8.59 inches was the 20th driest on record.

For the Jan 1 through Nov 30 period, the mean temperature is tied for 13th
warmest on record.  This year cannot make it into the top ten warmest
unless December has better than record warmth.  The average wind speed for
the Jan 1 through Nov 30 period of 12.2 is tied for second slowest.

NOVEMBER 2013 PRELIMINARY STATISTICS:
(departures relative to 1981-2010 average)

TEMPERATURE:
Average Max Temp: 48.4F [-1.6F] Average Min Temp: 31.2F [-2.3F] Mean Temp: 39.8F [-1.9F] 24-hr. Corr. Mean Temp: 39.7F [-2.4F] Max Temp: 68F on 1st
Min Temp: 14F on 25th

Total heating degree day units (month):    747 [+49] *NCDC method
Total heating degree day units (season): 1,224 [-37] *start July 1 (NCDC)

PRECIPITATION:
Total precipitation: 3.59 inches [-1.17 inch] Greatest 24-hr precipitation: 2.31 inches on 26th and 27th
Total snowfall: 0.2 inch [-2.1 inches]

WIND:
Avg wind speed: 13.6 MPH
Avg corrected wind speed: 13.9 MPH
Prevailing wind direction: WNW [18%] Peak gust: 63 MPH SSE on 27th
Peak fastest mile: 49 MPH SSE on 7th

SUNSHINE:
Total astronomical minutes: 10,313 of possible 17,650 or 58%
Total Campbell Stokes card minutes; 9,966 of possible 17,010 or 59%
* Long term November average is 47%

BHO Highest November Sea Level Pressure, inches (1885-1895, 1942-present)
1. 30.86 in 1887
2. 30.82 in 1891
3. 30.80 in 1996
4. 30.79 in 2013
5. 30.75 in 1888
30.75 in 1993
7. 30.73 in 1986

BHO Greatest November Sunshine, hours (1885-2013)
1) 182.3 in 1939
2) 181.5 in 1917
181.5 in 1976
4) 173.9 in 1905
5) 171.3 in 1964
6) 170.8 in 1941
7) 169.6 in 2011
8) 169.4 in 1975
9) 166.5 in 1994
10) 166.1 in 2013
11) 161.4 in 1965

BHO Greatest Sep-Nov Sunshine, hours (1885-2013)
1) 623.3 in 2001     (63%)
2) 610.7 in 1941     (62%)
3) 605.1 in 1973     (62%)
4) 599.4 in 1966     (61%)
5) 594.5 in 1952     (60%)
6) 592.4 in 1916     (60%)
7) 590.0 in 1978     (60%)
8) 587.8 in 2013     (60%)
9) 587.6 in 1967     (60%)

Today’s Observations:

7 A.M.
Weather: Thin broken cirrus, thin fog, heavy frost grass/boards
Temperature: 30F; Dew Point: 28F; Wind: WNW at 11 kts.
Sea-level pressure: 30.06 ins. Hg, rising then more rapidly
Visibility: 9 mile, thin fog
6-hr min temp: 29F
24-hr precip:  None
BHO SA 1155 250 –BKN 9 179/30/28/2911/006/ THN F ALQDS
HVY FROST GRASS/BOARDS/ 8/001 53021 10032 20029

10 A.M.
Weather: Scattered cirrus, patches dense cirrus all quadrants,
thin fog SE-S, hazy
Temperature: 36F; Dew Point: 29F; Wind: WNW at 8 kts.
Sea-level pressure: 30.11 ins. Hg, rising
Visibility: 20 miles, 10 miles SE-S, 30 miles W-NE, hazy
BHO SA 1455 220 SCT 250 –OVC 20 195/36/29/2908/011/ PTCHS DNS CI
ALQDS THN F SE-S VSBY SE-S 10 W-N-NE 30 HAZY / 8/002 51016

1 P.M.
Weather: Scattered altocumulus/altocumulus lenticularis all
quadrants, scattered dense cirrus (layer distant NE-SE,
thin broken cirrus
Temperature: 41F; Dew Point: 25F; Wind: WNW at 7 kts,
Wind: Direction variable WSW-NNW
Sea-level pressure: 30.10 ins. Hg, falling slightly
Visibility: 35 miles, hazy, except 40 miles WNW, hazy
6-hr max. temp: 42F
BHO SA 1755 100 SCT 150 SCT 200 SCT 250 –BKN 35 189/41/25/3007/010/
ACSL ALQDS DNS CI LYR DSNT NE-SE VSBY WNW 40 DSNT HZ ALQDS
WND 25V34/ 8/042 56006 10042 20030

WEATHER SUMMARY FOR TUESDAY, DECEMBER 3, 2013

TEMPERATURE (DEGREES F)
MAX…..45    NORMAL…..44
MIN…..32    NORMAL…..28
MEAN….39    NORMAL…..36

DEPARTURE FROM 30-YEAR NORMAL………………….+3
TOTAL DEPARTURE FOR THE MONTH………………….+4 [+1.1 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY…………..26  DEPARTURE………-3
TOTAL HEATING UNITS FOR THE MONTH…………..82  DEPARTURE………-5
TOTAL HEATING UNITS FOR THE SEASON………..1386  DEPARTURE……..-42
TOTAL HEATING UNITS LAST SEASON TO DATE……1223  DIFFERENCE…….+83

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY………………18 NNW AT  2:57 P.M. *
AERO…………………..20 NNW AT  2:40 P.M.
ASOS…………………..20 NNW AT  2:41 P.M.
DAVIS………………….18 WNW AT  8:01 P.M. RMY 20
FASTEST MILE FOR YESTERDAY………………..15 NW  AT  8:04 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………..15 NW  AT  8:04 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE…………….14 WNW AT  8:03 P.M.
AVERAGE WIND SPEED AND DIRECTION………….8.7 NNW
ASOS………………….9.1
DAVIS…………………7.5 NW [320 degrees] * last of several occurrences

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M… 0.00  DEPARTURE………….-0.17
ASOS…………..0.00
TOTAL PRECIPITATION FOR THE MONTH……….0.28  DEPARTURE………….-0.21
ASOS…………..0.28
TOTAL PRECIPITATION FOR THE YEAR……….46.88  DEPARTURE………….-2.14
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………….-0.3
TOTAL SNOWFALL FOR THE MONTH………..Trace     DEPARTURE………….-0.8
TOTAL SNOWFALL FOR THE SEASON…………0.2     DEPARTURE………….-3.2

PRELIMINARY CLIMATE SUMMARY FOR NOVEMBER & 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

11/1  68/56/62/+16/0.10/0.0/012/02        60 SSW AERO N/A N/A    RMY 66
11/2  65/49/57/+11/0.00/0.0/296/48        22 WSW AERO N/A N/A    RMY 23
11/3  49/30/40/-6/0.06/T/135/22           23 N   AERO N/A N/A    RMY N/A
11/4  42/27/35/-10/0.00/0.0/588/96        24 NNE AERO N/A N/A    RMY 25
11/5  50/29/40/-5/0.00/0.0/487/80         16 SSW AERO N/A N/A    RMY 17
11/6  59/40/50/+5/0.00/0.0/419/69         30 SSW AERO 31 MPH SSW RMY 33
11/7  65/37/51/+6/0.31/0.0/079/13         33 SW  AERO 37 MPH SW  RMY 37
11/8  48/31/40/-4/T/T/0.0/421/70          37 WNW AERO 37 MPH WNW RMY 39
11/9  44/29/37/-7/0.00/0.0/366/61         25 WNW AERO 25 MPH WNW RMY 29
11/10 52/40/46/+2/0.08/0.0/108/18         31 WNW AERO 33 MPH WNW RMY N/A
11/11 51/36/44/+1/0.00/0.0/500/84         36 WNW AERO 37 MPH WNW RMY 37
11/12 48/24/36/-7/0.11/0.2/000/00         42 SW  AERO 43 MPH SW  RMY 43
11/13 35/21/28/-15/0.00/0.0/591/100       29 NW  AERO 30 MPH NW  RMY 30
11/14 49/26/38/-4/0.00/0.0/536/91         25 SW  AERO 25 MPH SW  RMY 28
11/15 59/38/49/+7/0.00/0.0/393/67         24 S   AERO 25 MPH S   RMY 26
11/16 59/40/50/+8/0.00/0.0/363/62         20 WSW AERO 20 MPH WSW RMY N/A
11/17 59/42/51/+10/0.07/0.0/000/00        23 SSE AERO 25 MPH SSE RMY N/A
11/18 65/46/56/+15/0.28/0.0/400/69        40 SSW AERO 40 MPH S   RMY N/A
11/19 46/28/37/-4/0.00/0.0/428/74         46 WNW AERO 46 MPH WNW RMY 46
11/20 40/25/33/-7/0.00/0.0/565/98         23 NW  AERO 22 MPH NW  RMY 22
11/21 46/26/36/-4/0.00/0.0/460/80         16 SW  AERO 16 MPH SW  RMY N/A
11/22 46/39/43/+3/0.22/0.0/000/00         17 WSW AERO 18 MPH SW  RMY 19
11/23 46/27/37/-2/0.00/0.0/451/79         40 WNW AERO 44 MPH WNW RMY 48
11/24 27/17/22/-17/0.00/0.0/552/97        53 NW  AERO 59 MPH NW  RMY 57
11/25 32/14/23/-16/0.00/0.0/568/100       29 W   AERO 29 MPH WNW RMY N/A
11/26 42/29/36/-2/0.13/T/000/00           25 SW  AERO 27 MPH SW  RMY 28
11/27 61/34/48/+10/2.23/0.0/000/00        63 SSE AERO 68 MPH SSE RMY 67
11/28 35/21/28/-10/0.00/0.0/557/99        43 W   AERO 46 MPH W   RMY 45
11/29 33/19/26/-11/0.00/0.0/527/94        23 NNW AERO 23 MPH NNW RMY 24
11/30 32/15/24/-13/0.00/0.0/510/91        18 SE  AERO 19 MPH SE  RMY N/A

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  morning low temp: 29F; the normal low is now 28F

DAILY RECORDS FOR NOVEMBER 2013
11/27 – NEW RECORD MAXIMUM DAILY PRECIPITATION OF 2.23 INCHES;
surpasses the previous record of 1.92 inches in 1898

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 4
HIGH 67 IN 1998
LOW -4 IN 1940
PRECIP 1.87 INS. IN 1968
SNOWFALL 6.0 INS. IN 1907
PEAK GUST 73 MPH WNW IN 1980

RECORDS FOR DECEMBER 5
HIGH 65 IN 2001
LOW -1 IN 1926
PRECIP 2.86 INS. IN 1993
SNOWFALL 7.0 INS. IN 1926, 1981
PEAK GUST 67 MPH WNW IN 1961, S IN 1973

TODAY’S REPORT PREPARED BY: Robert Skilling