Monday, December 30, 2019

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

DAILY DISCUSSION AND CLIMATE SUMMARY
MONDAY, DECEMBER 30, 2019
ALL TIMES ARE IN EASTERN STANDARD TIME

A MIXED BAG OF WINTRY WEATHER ENDS THE DRY STRETCH….

The stretch of consecutive days without measurable precipitation
came to an end overnight at 11 days! Rain overspread the area
last evening and continued into this morning before mixing with
and changing over to sleet and snow. Total liquid equivalent of
precipitation was 0.48″ ending at 7 A.M. this morning. There was
no frozen precipitation prior to 7 A.M.

Total sleet/snow accumulation at 1 P.M. was 0.4″, the total
liquid equivalent for the 6 hours ending at 1 P.M. is 0.45″. The
storm total so far is 0.93″.

Also of note was the rapid increase in wind this morning. A peak
gust so far today is 35 knots (40 mph) out of the East, occuring
at 9:52 A.M.

We haven’t had much range in temperature so far today with a high
that occurred around 8 A.M. this morning of 35F, which is exactly
normal for the day. The low since midnight is 32F, which is 13
degrees above the normal minimum of 20F.

Today’s Observations:

7 A.M.
Weather: Overcast stratus fractus, light rain
Temperature: 34F; Dew Point: 34F; Wind: E at 14G23 kts
Sea-level pressure: 30.03 ins. Hg, falling, then more slowly
Visibility: 1 mile, fog
6-hr Max temp: 34F
6-hr Min temp: 32F
24-hr Precip:  0.48 ins.
24-hr Snowfall: 0.0 ins.
Snow Depth: 0 ins.
BHO SA 1155 E2 OVC 1R-F 168/34/34/0814G23/003/ STRAFRA OCCLY DRFTG
OVR SMT/ 8/7// 57021 6/// 70048 10034 20032

10 A.M.
Weather: Overcast stratus fractus, light sleet and rain
Temperature: 33F; Dew Point: 33F; Wind: E at 23G35 kts
Sea-level pressure: 30.02 ins. Hg, steady, then falling
Visibility: 2 miles, fog
3-hr Precip:  0.24 ins.
3-hr Snowfall: Trace.
BHO SA 1455 E3 OVC 2IP-R-F 167/33/33/0823G35/002/ STRAFRA OCCLY DRFTG
OVR SMT PK WND 0835/52/ TOTAL NEW SLEET LAST 3 HRS TRACE/ 8/7// 55001
6024

1 P.M.
Weather: Overcast stratus fractus, light sleet and snow
Temperature: 32F; Dew Point: 32F; Wind: E at 18G28 kts
Sea-level pressure: 29.99 ins. Hg, falling, then more slowly
Visibility: 2 miles, fog
6-hr Max temp: 35F
6-hr Min temp: 32F
6-hr Precip:  0.45 ins.
6-hr Snowfall: 0.4 ins.
Snow Depth: Trace
BHO SA 1755 E2 OVC 2IP-S-F 157/32/32/0818G28/999/ STRAFRA OCCLY DRFTG
OVR SMT PK WND 0830/42/ TOTAL NEW SLEET/SNOW LAST 6 HRS 0.4 INS/ 8/7//
4/000 56010 6045 10035 20032

SUMMARY FOR SUNDAY, DECEMBER 29, 2019

TEMPERATURE (DEGREES F)
MAX…..42   NORMAL…..35
MIN…..28   NORMAL…..20
MEAN….35   NORMAL…..27

DEPARTURE FROM 30-YEAR NORMAL………………… +8
TOTAL DEPARTURE FOR THE MONTH…………………+11 [+0.1 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY……………30  DEPARTURE……. -8
TOTAL HEATING UNITS FOR THE MONTH…………..954  DEPARTURE…….-13
TOTAL HEATING UNITS FOR THE SEASON…………2191  DEPARTURE…….-38
TOTAL HEATING UNITS LAST SEASON TO DATE…….2228  DEPARTURE…….-37

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY………………..22 WNW AT  12:26 A.M.
AERO…………………….21 WNW AT  12:46 A.M.
ASOS…………………….22 WNW AT  12:25 A.M.
DAVIS……………………23 W   AT  12:02 A.M. RMY 23
FASTEST MILE FOR YESTERDAY………………….17 WNW AT  12:36 A.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………….16 NW  AT   3:25 A.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE………………17 W   AT  12:04 A.M.
AVERAGE WIND SPEED AND DIRECTION………….. 7.5 NW
ASOS………………….. 7.6
DAVIS…………………. 7.8 WNW [302 deg.]

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M….0.48  DEPARTURE……+0.34
ASOS…………..0.46
TOTAL PRECIPITATION FOR THE MONTH……….6.54  DEPARTURE……+1.93
ASOS…………..6.97
TOTAL PRECIPITATION FOR THE YEAR……….55.62  DEPARTURE……+2.47
ASOS………….56.37

SNOWFALL (INCHES) THROUGH THIS MORNING (EST)
TOTAL SNOWFALL 24 HRS ENDING 7 A.M……….0.0  DEPARTURE…….-0.5
TOTAL SNOWFALL FOR THE MONTH……………19.1  DEPARTURE…….+6.7
TOTAL SNOWFALL FOR THE SEASON…………..19.2  DEPARTURE…….+4.2

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/…./5.8/011/02           33 ENE AERO 32 ENE RMY N/A
12/02  37/25/31/-5/…./2.7/000/00            52 NE  AERO 47 NE  RMY 53
12/03  30/23/27/-9/…./4.6/000/00            32 N   AERO 35 N   RMY 36
12/04  34/22/28/-7/…./0.0/000/00            23 WNW AERO 23 NNW RMY N/A
12/05  41/26/34/-1/…./0.0/343/62            33 NW  AERO 35 NW  RMY 37
12/06  33/23/28/-7/0.02/0.1/000/00            25 NW  AERO 23 NW  RMY 29
12/07  31/18/25/-9/0.00/0.0/519/94            25 NW  AERO 23 NW  RMY N/A
12/08  36/15/26/-8/0.00/0.0/…/..            31 SSW AERO 32 SSW RMY N/A
12/09  57/36/47/+13/…./0.0/…/..           53 S   AERO 52 S   RMY 54
12/10  58/37/48/+15/…./0.0/…/..           35 SW  AERO 39 SW  RMY N/A
12/11  36/23/30/-3/…./3.0/…/..            25 NW  AERO 25 NW  RMY N/A
12/12  29/17/23/-10/…./1.8/…/..           29 W   AERO 30 W   RMY 25
12/13  46/22/34/+2/…./0.0/…/..            25 SSE AERO 25 SSE RMY N/A
12/14  58/46/52/+20/…./0.0/…/..           45 S   AERO 41 S   RMY N/A
12/15  48/28/38/+6/0.00/0.0/…/..            53 W   AERO 53 W   RMY 50
12/16  30/25/28/-3/0.00/0.0/…/..            36 W   AERO 36 W   RMY N/A
12/17  35/23/29/-2/…./1.0/…/..            22 NNW AERO 21 NE  RMY 23
12/18  33/18/26/-5/…/0.0/…/..             44 WNW AERO 45 WNW RMY N/A
12/19  20/9/15/-15/…/0.0/…/..             51 W   AERO 47 W   RMY N/A
12/20  29/11/20/-10/0.00/0.0/…./..          32 W   AERO 30 W   RMY 29
12/21  31/16/24/-6/0.00/0.0/…./..           16 SSE AERO 15 SSE RMY N/A
12/22  40/26/33/+4/0.00/0.0/…./..           23 SW  AERO 21 SW  RMY 23
12/23  54/33/44/+15/0.00/0.0/…./..          30 WSW AERO 30 SW  RMY 30
12/24  42/29/36/+7/0.00/0.0/…./..           30 NW  AERO 27 NW  RMY 30
12/25  42/25/34/+6/0.00/0.0/…./..           16 NNE AERO 16 N   RMY N/A
12/26  39/29/34/+6/0.00/0.0/…./..           22 ENE AERO 20 ENE RMY 22
12/27  47/31/39/+11/0.00/0.0/…./..          32 SSW AERO 30 SSW RMY 34
12/28  47/30/39/+11/0.00/0.0/…./..          23 W   AERO 22 W   RMY N/A
12/29  42/28/35/+8/…./0.0/…./..           22 WNW AERO 21 WNW RMY 23

12/30 The low since midnight is 32F, daily normal minimum is 20F

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 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

RECORDS FOR DECEMBER 31
HIGH 62 IN 1965
LOW -12 IN 1917
PRECIP 0.96 INS. IN 1906
SNOWFALL 7.5 INS. IN 2008
PEAK GUST 78 MPH NW IN 1990

TODAY’S REPORT PREPARED BY: Matt Douglas