Thursday, December 5, 2019

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

DAILY DISCUSSION AND CLIMATE SUMMARY
THURSDAY, DECEMBER 5, 2019
ALL TIMES ARE IN EASTERN STANDARD TIME

SUNSHINE FINALLY RETURNED THIS MORNING, BUT WAS SHORT-LIVED…

After days of cloudiness and inclement weather, the sun has
finally made it’s first appearance since Sunday morning.
However as we’ve moved into the afternoon, an increase in
stratocumulus clouds has once again caused the sun to vanish.

Before the clouds took over early this afternoon, we did
manage to make it into the low 40s, however with a WNW wind
gusting over 20-25mph, it feels rather chilly.

Visibility was rather limited this morning, only around 20
miles under hazy condition, has since improved to around 70
miles early this afternoon as the relative humidity lowers.

The high so far today is 41F, which is 2 degrees below the
daily normal maximum of 43F. The low since midnight is 28F,
which is 1 degree above the normal minimum of 27F.

PRELIMINARY STATS FOR NOVEMBER 2019

TEMPERATURE, Deg. F
Avg. Max. 46.0 [-4.0] Avg. Min. 30.3 [-3.2] Mean      38.2 [-3.5] 24-hour corrected mean: 38.0
Max. for month: 67F on the 1st
Min. for month: 15F on the 13th

HEATING DEGREE DAYS
Total heating units:    761 [+99] Total for the season:  1237 [-24] Total for last season: 1319

PRECIPITATION, Inches
Total: 3.74 [-1.02] Greatest in 24 hrs: N/A

SNOWFALL, Inches
Total: 0.1 [-2.2] Greatest in 24 hrs: 0.1 ins. on the 12th

WIND, mph
Avg. uncorrected wind speed: 12.5 mph
Avg. corrected wind speed:   12.9 mph
Prevailing wind direction:   W [16%] Peak gust and direction:     67 S on the 1st

SUNSHINE:
Campbell-Stokes card minutes: N/A
Astronomical total minutes:   N/A

Today’s Observations:

7 A.M.
Weather: Scattered altocumulus, thin scattered cirrus
Temperature: 29F; Dew Point: 26F; Wind: W at 10 kts
Sea-level pressure: 29.55 ins. Hg, rising, then more rapidly
Visibility: 20 miles, hazy
6-hr Max temp: 30F
6-hr Min temp: 28F
24-hr Precip:  0.00 ins.
24-hr Snowfall: 0.0 ins.
BHO SA 1155 140 SCT 250 –SCT 20 008/29/26/2710/955/ VIRGA S-SW
HAZY/ 8/071 4/005 53021 10030 20028

10 A.M.
Weather: Clear, few stratocumulus distant SW-NNW, few cirrus
distant WSW-NW-NE and E-SE
Temperature: 35F; Dew Point: 26F; Wind: WNW at 10G20 kts
Sea-level pressure: 29.59 ins. Hg, rising, then more slowly
Visibility: 50 miles
3-hr Precip: 0.00 ins.
3-hr Snowfall: 0.0 ins.
BHO SA 1455 CLR 50 022/35/26/2910G20/959/ FEW SC DSNT SW-NNW
FEW CI DSNT WSW-NW-NE AND E-SE/ 8/501 51014

1 P.M.
Weather: Broken stratocumulus, few cirrus distant N-NE
Temperature: 41F; Dew Point: 26F; Wind: WNW at 15G22 kts
Sea-level pressure: 29.61 ins. Hg, steady, then rising
Visibility: 70 miles
6-hr Max temp: 41F
6-hr Min temp: 29F
6-hr Precip:  0.00 ins.
6-hr Snowfall: 0.0 ins.
BHO SA 1755 E35 BKN 70 027/41/26/2915G22/961/ FEW CI DSNT N-NE/
8/501 4/005 53005 10041 20029

SUMMARY FOR WEDNESDAY, DECEMBER 4, 2019

TEMPERATURE (DEGREES F)
MAX…..34   NORMAL…..44
MIN…..22   NORMAL…..28
MEAN….28   NORMAL…..35

DEPARTURE FROM 30-YEAR NORMAL………………… -7
TOTAL DEPARTURE FOR THE MONTH…………………-34 [-8.7 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY……………37  DEPARTURE……..+7
TOTAL HEATING UNITS FOR THE MONTH…………..150  DEPARTURE…….+34
TOTAL HEATING UNITS FOR THE SEASON…………1387  DEPARTURE……..+9
TOTAL HEATING UNITS LAST SEASON TO DATE…….1423  DEPARTURE…….-36

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY………………..23 WNW AT 12:26 A.M.
AERO…………………….22 WNW AT 12:26 A.M.
ASOS…………………….25 WNW AT 12:26 A.M.
DAVIS……………………25 WNW AT 12:22 A.M. RMY N/a
FASTEST MILE FOR YESTERDAY………………….19 WNW AT 12:26 A.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………….17 WNW AT 12:26 A.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE………………18 W   AT 12:16 A.M.
AVERAGE WIND SPEED AND DIRECTION……………9.9 WSW
ASOS…………………..10.0
DAVIS………………….10.4 W [259 deg.]

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……….2.43  DEPARTURE……+1.78
ASOS…………..2.57
TOTAL PRECIPITATION FOR THE YEAR……….51.51  DEPARTURE……+2.32
ASOS………….51.97

SNOWFALL (INCHES) THROUGH THIS MORNING (EST)
TOTAL SNOWFALL 24 HRS ENDING 7 A.M……….0.0  DEPARTURE…….-0.3
TOTAL SNOWFALL FOR THE MONTH……………13.1  DEPARTURE……+12.0
TOTAL SNOWFALL FOR THE SEASON…………..13.2  DEPARTURE…….+9.5

PRELIMINARY CLIMATE SUMMARY FOR NOVEMBER CALENDAR DAY DATA
DATE: MAX/MIN/MEAN/DEP/PRECIP/SNOW/SUN(MIN.)/SUN(%)/PEAK GUST/AERO/RMY GUST
AERO: Aerovane wind recording system 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
M:    Missing data

11/01  67/35/51/+5/0.12/0.0/534/86            67 S   AERO M  M   RMY N/A
11/02  50/31/41/-5/0.00/0.0/612/99            17 WNW AERO 14 W   RMY N/A
11/03  53/35/44/-2/0.00/0.0/567/92            25 WSW AERO 23 W   RMY 26
11/04  53/33/43/-2/0.00/0.0/546/89            24 S   AERO 20 S   RMY 24
11/05  54/44/49/+4/0.33/0.0/000/00            22 S   AERO 18 WNW RMY 28
11/06  51/36/44/-1/0.00/0.0/596/98            28 WSW AERO 23 W   RMY 27
11/07  55/38/47/+2/0.27/0.0/000/00            30 S   AERO 26 SSW RMY 32
11/08  38/23/31/-13/0.00/0.0/555/92           38 NW  AERO 37 WNW RMY 44
11/09  39/20/30/-14/0.00/0.0/583/97           22 S   AERO 18 S   RMY N/A
11/10  51/30/41/-3/0.00/0.0/174/29            30 SW  AERO 30 SW  RMY 31
11/11  52/39/46/+3/T/0.0/000/00               23 NE  AERO 22 NE  RMY 23
11/12  42/20/31/-12/0.08/0.1/000/00           37 WNW AERO 37 WNW RMY 41
11/13  28/15/22/-21/0.00/0.0/592/100          32 WNW AERO 32 WNW RMY 35
11/14  36/17/28/-14/0.00/0.0/136/23           18 SW  AERO 17 SW  RMY 20
11/15  51/32/42/0/0.00/0.0/553/94             25 WNW AERO 25 WNW RMY N/A
11/16  35/22/29/-13/0.00/0.0/580/99           35 NNW AERO 35 NNW RMY N/A
11/17  40/21/31/-10/T/T/…/..                28 ENE AERO 27 ENE RMY 29
11/18  36/32/34/-7/…./0.0/…/..            28 NNE AERO 29 N   RMY 31
11/19  42/36/39/-2/…./0.0/…/..            12 SSW AERO  9 NNW RMY N/A
11/20  38/33/36/-4/…./T/…/..              20 NW  AERO 18 NW  RMY 21
11/21  46/30/38/-2/0.00/0.0/…/..            21 NW  AERO 21 NW  RMY N/A
11/22  52/32/42/+2/0.12/0.0/…/..            46 W   AERO 47 W   RMY 47
11/23  44/27/36/-3/0.00/0.0/…/..            29 WNW AERO 29 WNW RMY N/A
11/24  44/35/40/+1/1.49/0.0/…/..            45 N   AERO 44 NE  RMY 46 TSTM
11/25  50/34/42/+3/0.00/0.0/…/..            32 WNW AERO 35 WNW RMY 23
11/26  59/39/49/+11/0.00/0.0/…/..           28 SSW AERO 27 SSW RMY 29
11/27  50/42/46/+8/…./0.0/…/..            30 W   AERO 32 W   RMY N/A TSTM
11/28  48/30/39/+1/…./T/…/..              42 NW  AERO 44 NW  RMY 44
11/29  39/27/33/-4/0.00/0.0/…/..            35 NW  AERO 36 NW  RMY 39
11/30  35/22/29/-8/0.00/0.0/…/..            30 NW  AERO 28 WNW RMY 31

DAILY RECORDS FOR NOVEMBER

11/13/19: DAILY RECORD LOW MAXIMUM TEMPERATURE OF 28F,
BREAKS PREVIOUS RECORD OF 30F SET IN 1920.
It was also the third earliest maximum temperature
colder than 30F on record, behind only 28F on 11/8/1894
and 29F on 11/12/1894.

PRELIMINARY CLIMATE SUMMARY FOR DECEMBER CALENDAR DAY DATA
DATE: MAX/MIN/MEAN/DEP/PRECIP/SNOW/SUN(MIN.)/SUN(%)/PEAK GUST/AERO/RMY GUST
AERO: Aerovane wind recording system 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
M:    Missing data

12/01  32/16/24/-13/…./5.8/…/..           33 ENE AERO 32 ENE RMY N/A
12/02  37/25/31/-5/…./2.7/…/..            52 NE  AERO 47 NE  RMY 53
12/03  30/23/27/-9/…./4.6/…/..            32 N   AERO 35 N   RMY 36
12/04  34/22/28/-7/…./0.0/…/..            23 WNW AERO 23 NNW RMY N/A

12/05  The low since midnight is 28F, daily normal minimum is 27F

DAILY RECORDS FOR DECEMBER

12/01/19: DAILY RECORD SNOWFALL OF 5.8 INS.,
BREAKS PREVIOUS RECORD OF 2.0 INS. SET IN 1902.

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: Matt Douglas