Saturday, December 5, 2015

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

DAILY DISCUSSION AND CLIMATE SUMMARY
SATURDAY, DECEMBER 5, 2015
ALL TIMES ARE IN EASTERN STANDARD TIME

TEMPERATURE WARMS TO NEAR 50 AFTER A COOL START
THIS MORNING…COMPLETELY CLOUDLESS SKY TODAY WITH
HAZE LIMITING VISIBILITY…NOVEMBER MAXIMUM SEA-LEVEL
PRESSURE TIES RECORD FOR MONTH…

A low-level inversion this morning held the minimum
temperature to 33F on the summit today, while the low
temperature was 24F at nearby Norwood Airport. As
temperatures have climbed through the 40s during the
day, haze trapped below the inversion has reduced
visibility, especially to the west through northeast.

The sky has been completely free of clouds today with
generally light winds.

The maximum sea-level pressure for November of 30.88
inches, which occurred late on the 25th, ties the
highest pressure ever measured in the month that was
previously set on November 28, 1932.

BHO Warmest Novembers, deg F (1885-2015):

1) 47.9 in 2011
2) 47.4 in 1975
3) 47.1 in 2006
4) 46.4 in 1948
46.4 in 1979
46.4 in 2009
7) 46.1 in 2015
8) 46.0 in 2001
9) 45.7 in 1953
45.7 in 1999

BHO Highest November Sea-Level Pressure, inches (1885-2015):

1) 30.88 in 1932
30.88 in 2015
3) 30.86 in 1887
4) 30.83 in 1896
5) 30.82 in 1891
6) 30.80 in 1996
7) 30.79 in 2013
8) 30.77 in 1914

PRELIMINARY STATS FOR NOVEMBER 2015

TEMPERATURE, Deg. F
Avg. Max. 54.3 [+4.3] Avg. Min. 38.6 [+5.1] Mean      46.5 [+4.8] Corrected mean: 46.1
Max. for month: 72 on 5th
Min. for month: 23 on 24th

COOLING DEGREE DAYS
Total cooling units: 1 [+1] Total for the season: 811 [+209] Total for last season: 595

HEATING DEGREE DAYS
Total heating units: 548 [-150] Total for the season: 1002 [-259] Total for last season: 1159

PRECIPITATION, Inches
Total: 2.59 [-2.18] Greatest in 24 hrs: 1.18 from 20th
Snowfall: Trace [-2.3] Seasonal: Trace [-2.6]

WIND, mph
Avg. uncorrected wind speed: 12.4
Avg. corrected wind speed: 12.7
Prevailing wind direction: W @ 13%
Peak gust and direction: 43 SSE on the 20th

SUNSHINE:
Campbell-Stokes card minutes: 9222/17010 or 54%
Astronomical total minutes:   9562/17644 or 54%

Today’s Observations:

7 A.M.
Weather: Clear, no clouds, hazy
Temperature: 35F; Dew Point: 32F; Wind: W at 12 kts
Sea-level pressure: 30.62 ins. Hg, rising
Visibility: 40 miles
6-hr Max temp: 35F
6-hr Min temp: 33F
24-hr precip: 0.00
BHO SA 1155 CLR 40 369/35/32/2812/062/ SKC HAZY/ 52015
10035 20033

10 A.M.
Weather: Clear, no clouds, hazy
Temperature: 43F; Dew Point: 35F; Wind: W at 6 kts,
Wind Speed: Light
Sea-level pressure: 30.66 ins. Hg, rising, then more slowly
Visibility: 35 miles
BHO SA 1455 CLR 35 381/43/35/2606/066/ SKC HAZY WND LGT/
51012

1 P.M.
Weather: Clear, no clouds, hazy, visibility lower NW-NE
Temperature: 49F; Dew Point: 33F; Wind: W at 5 kts,
Wind Speed: Light
Sea-level pressure: 30.62 ins. Hg, falling, then more slowly
Visibility: 45 miles
6-hr max. temp: 49F
6-hr min. temp: 35F
BHO SA 1755 CLR 45 370/49/33/2705/062/ SKC HAZY VSBY LWR NW-NE
WND LGT/ 56011 10049 20035

SUMMARY FOR FRIDAY, DECEMBER 4, 2015

TEMPERATURE (DEGREES F)
MAX…..47   NORMAL…..43
MIN…..32   NORMAL…..28
MEAN….40   NORMAL…..35

DEPARTURE FROM 30-YEAR NORMAL………………….+5
TOTAL DEPARTURE FOR THE MONTH…………………+22  [+5.3 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY…………..25   DEPARTURE……….-5
TOTAL HEATING UNITS FOR THE MONTH…………..94   DEPARTURE………-22
TOTAL HEATING UNITS FOR THE SEASON………..1096   DEPARTURE……..-282
TOTAL HEATING UNITS LAST SEASON TO DATE……1259   DIFFERENCE…….-163

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY……………….32  NW  AT  4:29 P.M.
ASOS……………………31  NW  AT  4:29 P.M.
DAVIS…………………..28  NW  AT  4:28 P.M. RMY 32
FASTEST MILE FOR YESTERDAY…………………22  NW  AT  4:29 P.M. *
MAXIMUM 2-MINUTE ASOS AVERAGE………………21 WNW  AT  4:30 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE……………..19 WNW  AT  4:30 P.M.
AVERAGE WIND SPEED AND DIRECTION………….12.3 WNW
ASOS………………….11.4
DAVIS…………………10.3 WNW [302 Deg.] * Last of several occurrences

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M…..0.00  DEPARTURE……-0.16
ASOS……………0.00
TOTAL PRECIPITATION FOR THE MONTH………..0.37  DEPARTURE……-0.28
ASOS……………0.36
TOTAL PRECIPITATION FOR THE YEAR………..39.79  DEPARTURE……-9.40
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……-0.3
TOTAL SNOWFALL FOR THE MONTH…………….0.0  DEPARTURE……-1.1
TOTAL SNOWFALL FOR THE SEASON………….TRACE  DEPARTURE……-3.7

PRELIMINARY CLIMATE SUMMARY FOR NOVEMBER & 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

11/1  59/45/52/+6/T/006/01                  30 SSW RMY 31
11/2  62/47/55/+9/0.00/476/77               24 W   RMY N/A
11/3  71/44/58/+12/0.00/616/100             25 W   RMY 25
11/4  66/49/58/+13/0.00/601/98              22 SSW RMY N/A
11/5  72/51/62/+17/0.00/281/46              31 SW  RMY 36
11/6  71/60/66/+21/0.00/109/18              35 SSW RMY 38
11/7  64/46/55/+10/0.00/029/04              33 WNW RMY 35
11/8  54/39/47/+3/0.00/591/98               26 NW  RMY 30
11/9  59/38/49/+5/0.00/577/96               20 W   RMY 21
11/10 53/45/49/+5/0.11/000/00               28 NE  RMY N/A
11/11 48/43/46/+3/0.60/000/00               41 NE  RMY N/A
11/12 55/42/49/+6/0.07/000/00               28 S   RMY 30
11/13 57/41/49/+6/0.02/385/65               40 WSW RMY 47
11/14 45/31/38/-4/0.00/425/72               40 NW  RMY 47
11/15 51/31/41/-1/0.00/241/41               25 W   RMY 27
11/16 59/36/48/+6/0.00/416/71               25 NNW RMY 29
11/17 45/28/37/-4/0.00/572/98               18 NNE RMY N/A
11/18 50/35/43/+2/0.00/575/99               17 SSE RMY N/A
11/19 55/38/47/+6/T/000/00                  29 SSE RMY N/A
11/20 58/41/50/+10/1.18/416/72              43 SSE RMY N/A
11/21 46/35/41/+1/0.00/380/66               20 ENE RMY 21
11/22 45/35/40/+0/0.40/000/00               26 NW  RMY 28
11/23 40/25/33/-6/0.02/543/95               24 NW  RMY 29
11/24 42/23/33/-6/0.00/564/99               20 WSW RMY 19
11/25 46/31/39/+0/0.00/568/100              18 SSE RMY N/A
11/26 58/37/48/+10/0.00/386/68              33 S   RMY 35
11/27 63/48/54/+18/0.00/249/44              35 SW  RMY 38
11/28 55/38/47/+9/0.19/000/00               23 SW  RMY N/A
11/29 42/28/35/-2/0.00/410/73               17 NNW RMY 21
11/30 37/27/32/-5/T/T/151/27                17 S   RMY 18

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/…/..           43 WNW RMY 42
12/4  47/32/40/+5/0.00/0.0/…/..           32 NW  RMY 32

12/5 low since midnight is 33F; normal low is now 27F

DAILY RECORDS FOR NOVEMBER AND DECEMBER 2015

**11/6 DAILY RECORD MAXIMUM TEMPERATURE OF 71F
TIES PREVIOUS RECORD OF 71F SET IN 1959

**11/6 DAILY RECORD HIGH MINIMUM TEMPERATURE OF 60F
BREAKS PREVIOUS RECORD OF 58F SET IN 1938

**11/6 DAILY RECORD HIGH MINIMUM TEMPERATURE OF 60F
TIES PREVIOUS MONTHLY RECORD OF 60F SET ON
11/8/1996

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

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

RECORDS FOR DECEMBER 6
HIGH 70 IN 2001
LOW 5 IN 1901,1935
PRECIP 2.78 INS. IN 2003
SNOWFALL 17.0 INS. IN 2003
PEAK GUST 74 MPH NW IN 1981

TODAY’S REPORT PREPARED BY: Mike Iacono / Rob Millette