Thursday, December 27, 2018

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

DAILY DISCUSSION AND CLIMATE SUMMARY
THURSDAY, DECEMBER 27, 2018
ALL TIMES ARE IN EASTERN STANDARD TIME

SECOND CONSECUTIVE BLUE BIRD DAY ATOP GREAT BLUE HILL….

Today’s observation period continued our streak of near seasonal temperatures, with clear skies overhead and visibility continuing to sustain around 70 and 80 miles.  High pressure continued to dominate the atmosphere, with relatively little cloud activity observed throughout the day. Pressure readings peaked around 10 A.M. and are decreasing at the time of the 1 P.M. observation.  Trends for the past two days are in accordance with what is expected on cloudless days, exhibiting a daily oscillation that brings high pressure in the late morning hours, and low pressure in the afternoon. Winds have stayed light for most the day, with directions shifting to increasingly northerly flow.  This cold air advection has kept temperatures cool and seasonal in spite of the sunny skies persisting throughout the day.

Today’s Observations:

7 A.M.
Weather: Few cirrocumulus, few distant stratocumulus S-NE
Temperature: 26F; Dew Point: 22F; Wind: NW at 9G15 kts
Sea-level pressure: 30.58 ins. Hg, rising steadily
Visibility: 70 miles
6-hr Max temp: 31F
6-hr Min temp: 26F
24-hr Precip: 0.00 ins.
24-hr snowfall: 0.0 ins.
Snow depth: 0 ins.
BHO SA 1155 CLR 70 355/26/22/3109G15/058/
FEW DSNT SC S-NE FEW CC/ 8/409 52039 10031 20026

10 A.M.
Weather: Few cirrus, few distant cumulus SE-NE
Temperature: 29F; Dew Point: 17F; Wind: NNW at 13G21 kts
Sea-level pressure: 30.62 ins. Hg, rising, then more slowly
Visibility: 80 miles
3-hr Precip: 0.00 ins.
BHO SA 1455 CLR 80 369/29/17/3311G18/062/
FEW CI FEW DSNT CU SE-NE/ 8/101 51014

1 P.M.
Weather: Few cirrus, few cirrostratus SW-W, few stratocumulus SE-NE
Temperature: 33F; Dew Point: 5F; Wind: NW at 5 kts
Sea-level pressure: 30.60 ins. Hg, falling, then more slowly
Visibility: 80 miles
6-hr Max temp: 33F
6-hr Min temp: 26F
6-hr Precip: 0.00 ins.
6-hr snowfall: 0.0 ins.
Snow depth: 0 ins.
BHO SA 1755 CLR 80 363/33/05/3305/060/
FEW CI FEW DSNT SC SE-NE FEW CS SW-W/ 8/409 55006 10033 20026

SUMMARY FOR WEDNESDAY, DECEMBER 26, 2018

TEMPERATURE (DEGREES F)
MAX…..36   NORMAL…..36
MIN…..20   NORMAL…..20
MEAN….28   NORMAL…..28

DEPARTURE FROM 30-YEAR NORMAL…………………….0
TOTAL DEPARTURE FOR THE MONTH…………………..+24 [+0.7 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY…………..37   DEPARTURE……….0
TOTAL HEATING UNITS FOR THE MONTH………….829   DEPARTURE……..-26
TOTAL HEATING UNITS FOR THE SEASON………..2149   DEPARTURE……..+32
TOTAL HEATING UNITS LAST SEASON TO DATE……1834   DIFFERENCE……+315

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY………………..24 NW  AT  3:02 P.M.
AERO…………………….24 NW  AT 12:18 P.M., 3:02 P.M.
ASOS…………………….25 NW  AT  3:07 P.M.
DAVIS……………………24 WNW AT 12:23 P.M. RMY 25
FASTEST MILE FOR YESTERDAY………………….17 NW  AT  1:19 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………….17 NW  AT  3:19 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE………………19 NW  AT  3:07 P.M.
AVERAGE WIND SPEED AND DIRECTION………….10.8 NW
ASOS………………….11.1
DAVIS…………………11.3 WNW [300 deg.]

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M….0.00  DEPARTURE…….-0.14
ASOS…………..0.01
TOTAL PRECIPITATION FOR THE MONTH……….3.13  DEPARTURE…….-1.05
ASOS…………..3.78 *
TOTAL PRECIPITATION FOR THE YEAR……….66.50  DEPARTURE……+13.98
ASOS………….69.41 *
* ASOS MONTHLY AND ANNUAL PRECIPITATION IS SUSPECT

SNOWFALL (INCHES) THROUGH THIS MORNING (EST)
TOTAL SNOWFALL 24 HRS ENDING 7 A.M……….0.0  DEPARTURE……..-0.5
TOTAL SNOWFALL FOR THE MONTH…………….0.1  DEPARTURE…….-10.6
TOTAL SNOWFALL FOR THE SEASON……………7.7  DEPARTURE……..-5.6

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 41/28/35/-2/0.00/0.0/391/70          20 NNW AERO 18 NNW RMY N/A
12/02 52/35/44/+8/1.04/0.0/000/00          28 ESE AERO 25 ESE RMY 27
12/03 54/38/46/+10/0.00/0.0/178/32         35 W   AERO 35 W   RMY 38
12/04 38/23/31/-4/0.00/0.0/516/93          30 WNW AERO 31 WNW RMY 33
12/05 33/18/26/-9/0.00/0.0/432/78          16 NNW AERO 15 NNW RMY N/A
12/06 37/24/31/-4/0.00/0.0/354/64          29 W   AERO 28 W   RMY 30
12/07 37/21/29/-5/0.00/0.0/546/99          29 NW  AERO 29 NW  RMY 32
12/08 27/15/21/-13/0.00/0.0/518/94         28 NW  AERO 27 NW  RMY 29
12/09 34/17/26/-8/0.00/0.0/391/71          23 SSW AERO 21 SSW RMY 22
12/10 36/22/29/-4/0.00/0.0/544/99          24 NNW AERO 23 NNW RMY 22
12/11 36/17/27/-6/0.00/0.0/543/99          16 WSW AERO 14 WSW RMY N/A
12/12 35/18/27/-6/0.00/0.0/471/86          30 NW  AERO 29 NW  RMY M
12/13 31/16/24/-8/0.00/0.0/088/16          16 NNE AERO 12 SE  RMY N/A
12/14 46/28/37/+5/0.00/0.0/399/73          28 SSW AERO 28 SSW RMY 29
12/15 49/33/43/+11/0.04/0.0/000/00         28 NE  AERO 27 NE  RMY 30
12/16 40/37/39/+8/…./0.0/…/..          38 NE  AERO 38 NE  RMY 40
12/17 37/32/35/+4/…./0.0/…/..          39 NNE AERO 37 NNE RMY N/A
12/18 34/20/27/-4/0.02/0.1/…/..          48 NW  AERO 55 NW  RMY 48
12/19 38/17/28/-2/0.00/0.0/…/..          23 WNW AERO 23 WNW RMY N/A
12/20 47/30/39/+9/0.00/0.0/…/..         23 SW  AERO 22 SW  RMY N/A
12/21 62/43/53/+23/…./0.0/…/..         60 SSE AERO 62 SSE RMY 63
12/22 54/31/43/+14/…./0.0/…/..         41 W   AERO 45 W   RMY 43
12/23 38/27/33/+4/0.00/0.0/…/..          30 WNW AERO 32 WNW RMY N/A
12/24 34/27/31/+2/0.01/T/…/..            21 W   AERO 21 W   RMY N/A
12/25 35/23/29/+1/0.00/0.0/…/..          28 NW  AERO 28 NW  RMY 29
12/26 36/20/28/0/0.00/0.0/…/..           24 NW  AERO 24 NW  RMY 25

12/27 Low temp since midnight is 26F; normal low is 20F

DAILY RECORDS FOR DECEMBER 2018

12/21/18: DAILY RECORD HIGH MAXIMUM TEMPERATURE OF 62F,
BREAKS PREVIOUS RECORD OF 60F SET IN 1957

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

RECORDS FOR DECEMBER 27
HIGH 57 IN 1895,1949
LOW -4 IN 1903
PRECIP 2.43 INS. IN 1969
SNOWFALL 11.2 INS. IN 1947
PEAK GUST 73 S IN 2011

RECORDS FOR DECEMBER 28
HIGH 60 IN 1982
LOW -2 IN 1933
PRECIP 2.16 INS. IN 1967
SNOWFALL 9.5 INS. IN 1967
PEAK GUST 89 MPH SSE IN 1983

TODAY’S REPORT PREPARED BY: Nate Iannuccillo