Monday, February 11, 2019

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

DAILY DISCUSSION AND CLIMATE SUMMARY
MONDAY, FEBRUARY 11, 2019
ALL TIMES ARE IN EASTERN STANDARD TIME

FAIR WEATHER AND GOOD VISIBILITY ATOP
GREAT BLUE HILL….

Pressure has begun to trend slightly downward this
afternoon, decreasing a couple millibars between
10 A.M. and 1 P.M. The overcast this morning
broke up, and skies are almost clear following the
1 P.M. observation. We observed 80 miles of visibility
from the roof throughout the day, as relative humidity
dropped from 50% this morning to almost 30% this
afternoon. The high temperature so far today is 33F,
3 degrees below our normal maximum temperature of 36F.
The low since midnight was 23F, 5 degrees above our normal
low of 18F.
PRELIMINARY STATS FOR JANUARY 2019

TEMPERATURE, Deg. F
Avg. Max. 34.3 [+0.5] Avg. Min. 17.9 [+0.8] Mean      26.1 [+0.6] 24-hour corrected mean: 26.6
Max. for month: 57F on  24th
Min. for month: -2F on the 21st and 31st

HEATING DEGREE DAYS
Total heating units:   1200 [-26] Total for the season:  3496 [-35] Total for last season: 3321

PRECIPITATION, Inches
Total: 5.35 [+1.00] Greatest in 24 hrs: 2 inches on the 19th-20th

SNOWFALL, Inches
Total: 4.7 [-12.4] Greatest in 24 hrs: 4.2 inches on the 19th-20th

WIND, mph
Avg. uncorrected wind speed: 13.4
Avg. corrected wind speed: 13.7
Prevailing wind direction: NW at 19%
Peak gust and direction: 77 S on 24th

SUNSHINE:
Campbell-Stokes card minutes: 8988 minutes of possible 17130 or 52%
Astronomical total minutes:   9273 minutes of possible 17650 or 53%

Today’s Observations:

7 A.M.
Weather: Overcast altostratus
Temperature: 24F; Dew Point: 7F; Wind: N at 7 kts
Sea-level pressure: 30.30 ins. Hg, falling then rising
Visibility: 80 miles
6-hr Max temp: 26F
6-hr Min temp: 24F
24-hr Precip: 0.00 ins.
24-hr snowfall: 0.0 ins
Snow depth: 0 ins.
BHO SA 1155 E90 OVC 80 260/24/7/3607/030/ 8/02/
55001 10026 20024

10 A.M.
Weather: Overcast altostratus
Temperature: 26F; Dew Point: 10F; Wind: N at 5 kts,
Wind: Light
Sea-level pressure: 30.32 ins. Hg, falling then rising
Visibility: 80 miles
3-hr Precip: 0.00 ins.
BHO SA 1455 E140 OVC 80 268/26/10/3605/032/ WND LGT/
8/02/ 50008

1 P.M.
Weather: Broken cirrus
Temperature: 32F; Dew Point: 9F; Wind: NNW at 8G14 kts
Sea-level pressure: 30.28 ins. Hg, falling steadily
Visibility: 80 miles
6-hr Max temp: 33F
6-hr Min temp: 23F
6-hr Precip:  0.00 ins.
6-hr snowfall: 0.0 ins.
Snow depth: 0 ins.
BHO SA 1755 E250 BKN 80 255/32/9/3408G14/028/ 8/002
58013 10033 20023

SUMMARY FOR SUNDAY, FEBRUARY 10, 2019

TEMPERATURE (DEGREES F)
MAX…..33   NORMAL…..36
MIN…..18   NORMAL…..18
MEAN….26   NORMAL…..27

DEPARTURE FROM 30-YEAR NORMAL……………………-1
TOTAL DEPARTURE FOR THE MONTH…………………..+56 [+5.4 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY…………..39   DEPARTURE………+1
TOTAL HEATING UNITS FOR THE MONTH………….330   DEPARTURE……..-57
TOTAL HEATING UNITS FOR THE SEASON………..3826   DEPARTURE……..-92
TOTAL HEATING UNITS LAST SEASON TO DATE……3688   DIFFERENCE……+138

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY………………..24 WNW AT 11:34 A.M.
AERO…………………….23 WNW AT 11:34 A.M.
ASOS…………………….24 W   AT 11:35 A.M.
DAVIS……………………25 W   AT  5:11 A.M. RMY 25
FASTEST MILE FOR YESTERDAY………………….18 WNW AT  5:12 A.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………….18 W   AT  4:11 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE………………19 W   AT  5:11 A.M.
AVERAGE WIND SPEED AND DIRECTION…………..11.5 W
ASOS…………………..11.9
DAVIS………………….12.2 WNW [286 deg.]

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M….0.00  DEPARTURE…….-0.14
ASOS…………..0.00
TOTAL PRECIPITATION FOR THE MONTH……….0.77  DEPARTURE…….-0.58
ASOS…………..0.72
TOTAL PRECIPITATION FOR THE YEAR………..6.12  DEPARTURE…….+0.42
ASOS…………..6.20

SNOWFALL (INCHES) THROUGH THIS MORNING (EST)
TOTAL SNOWFALL 24 HRS ENDING 7 A.M……….0.0  DEPARTURE……..-0.5
TOTAL SNOWFALL FOR THE MONTH…………….0.0  DEPARTURE……..-4.9
TOTAL SNOWFALL FOR THE SEASON…………..12.4  DEPARTURE…….-25.6

PRELIMINARY CLIMATE SUMMARY FOR JANUARY 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

01/01 54/29/42/+15/0.37/0.0/386/72         53 W   AERO 53 W   RMY 54
01/02 34/24/29/+2/0.00/T/432/81            22 NW  AERO 22 NW  RMY N/A
01/03 42/28/35/+9/0.01/0.0/228/43          28 WNW AERO 30 WNW RMY 30
01/04 43/30/37/+11/0.00/0.0/354/66         29 SW  AERO 29 SW  RMY 29
01/05 41/32/37/+11/1.15/T/000/00           26 NE  AERO 25 NNW RMY 27
01/06 42/21/32/+6/0.00/T/300/56            42 NW  AERO 46 NW  RMY 50
01/07 26/14/20/-6/0.00/0.0/474/88 37 NW  AERO 41 NW  RMY N/A
01/08 40/24/32/+6/0.02/T/000/00            24 SSE AERO 23 SSE RMY N/A
01/09 42/31/37/+11/0.11/0.0/084/16         44 W   AERO 46 WNW RMY 45
01/10 32/20/26/+1/T/T/090/17               37 NW  AERO 41 NW  RMY 43
01/11 26/12/19/-6/0.00/0.0/366/68          36 WNW AERO 37 WNW RMY 38
01/12 26/9/18/-7/0.00/0.0/486/89           32 NW  AERO 32 NW  RMY 29
01/13 25/11/18/-7/0.00/0.0/456/84          18 NNW AERO 16 NW  RMY N/A
01/14 27/20/24/-1/0.00/0.0/120/22          20 NNE AERO 17 N   RMY N/A
01/15 34/18/26/1/0.00/0.0/402/73 22 NW  AERO 21 NNW RMY N/A
01/16 34/23/29/+4/0.00/0.0/270/47          33 W   AERO 32 W   RMY 35
01/17 27/13/20/-5/0.00/0.0/480/87          30 NNW AERO 28 NW  RMY N/A
01/18 40/21/31/+6/0.00/0.0/156/28          18 WNW AERO 18 WNW RMY N/A
01/19 31/24/28/+3/0.23/1.6/198/36          30 E   AERO 30 E   RMY N/A
01/20 33/3/18/-7/1.77/2.6/000/00           39 ENE AERO 43 ENE RMY 39
01/21 3/-2/1/-24/0.00/0.0/348/62           32*WNW AERO 41 WNW RMY M
01/22 24/0/12/-13/0.00/0.0/522/93          28 NW  AERO 30 NW  RMY 29
01/23 46/15/31/+6/0.00/0.0/000/00          37 SSW AERO 39 SSW RMY N/A
01/24 57/31/44/+19/1.44/0.0/000/00         77 S   AERO 79 S   RMY N/A
01/25 37/23/30/+5/0.00/0.0/378/66          41 WNW AERO 46 WNW RMY N/A
01/26 33/17/25/0/0.00/0.0/534/94           25 W   AERO 25 W   RMY 27
01/27 44/24/34/+9/0.00/0.0/480/84          39 S   AERO 39 S   RMY 41
01/28 30/19/28/+3/0.00/0.0/348/60          28 NW  AERO 28 NW  RMY N/A
01/29 32/19/26/+1/0.06/T/072/13            22 SE  AERO 21 E   RMY N/A
01/30 36/3/20/-6/0.19/0.5/504/88           52 W   AERO 53 W   RMY 57
01/31 14/-2/6/-20/0.00/0.0/570/99          33 WNW AERO 35 WNW RMY N/A

*Official gust chart reading low on 1/21/2019

DAILY RECORDS FOR JANUARY

01/05/19: DAILY RECORD PRECIPITATION OF 1.15 INCHES,
BREAKS PREVIOUS RECORD OF 0.98 INS SET IN 1993

01/21/19: DAILY RECORD LOW MAXIMUM TEMPERATURE OF 3F,
BREAKS PREVIOUS RECORD OF 9F SET IN 1985;
COLDEST DAILY MAXIMUM SINCE 2F ON JAN 8, 1968

PRELIMINARY CLIMATE SUMMARY FOR FEBRUARY 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

02/01 19/5/12/-14/0.00/0.0/…/..          29 W   AERO 28 W   RMY N/A
02/02 30/7/19/-7/0.00/0.0/…/..           32 WSW AERO 32 WSW RMY 31
02/03 38/27/26/+7/0.00/0.0/…/..          26 S   AERO 25 S   RMY N/A
02/04 59/33/46/+20/0.00/0.0/…/..         25 SSW AERO 28 SSW RMY N/A
02/05 62/39/51/+25/0.00/0.0/…/..         30 WNW AERO 29 WNW RMY 32
02/06 39/28/34/+8/…./…/…/..          24 NNW AERO 23 NNW RMY N/A
02/07 37/31/34/+7/…./…/…/.. 28 ENE AERO 24 ENE RMY 28
02/08 51/27/39/+12/…./…/…/..         46 W   AERO 46 WNW RMY 51
02/09 32/20/26/-1/…./0.0/…/..          50 WNW AERO 52 WNW RMY 52
02/10 33/18/26/-1/…./0.0/…/..          24 WNW AERO 23 WNW RMY 25

02/11 Low temp since midnight is 24F; normal low is 18F
DAILY EXTREMES
Temperature and precipitation records back to 1885, and
wind records back to 1940 (e = estimated):

RECORDS FOR FEBRUARY 11
HIGH 60F IN 1981
LOW -10F IN 1899
PRECIP 1.07 INCHES IN 1955
SNOWFALL 9.6 INCHES IN 1933
PEAK GUST 95 MPH S IN 1981

RECORDS FOR FEBRUARY 12
HIGH 56F IN 1999
LOW -14F IN 1914
PRECIP 4.85 INCHES IN 1886 [RECORD FOR MONTH] SNOWFALL 15.0 INCHES IN 2006
PEAK GUST 70 MPH E IN 1985

TODAY’S REPORT PREPARED BY: Benjamin Turner