Thursday, April 6, 2017

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

DAILY DISCUSSION AND CLIMATE SUMMARY
THURSDAY, APRIL 6, 2017
ALL TIMES ARE IN EASTERN STANDARD TIME

LIGHT RAIN TOTALS 0.47 INCHES AT 1:00PM EST,
HEAVIER RAINFALL ON THE WAY

Light rain began near 5:00AM EST and continued on and
off through the morning, becoming more steady by early
afternoon.  Precipitation totaled 0.47 inches at the
1:00PM observation.  Heavier rainfall and thunder were
reported south of the area moving northward.

Fog limited visibility at the observatory from 3/16 mile
to 2 miles today.  Skies remained obscured at each
observation.  Temperatures have varied little since last
evening reaching a minimum of 35F and a max. of 38F.

PRELIMINARY STATS FOR MARCH 2017

TEMPERATURE, Deg. F
Avg. Max. 39.8 [-4.5] Avg. Min. 23.4 [-3.2] Mean      31.6 [-3.9] 24-hour corrected mean: 31.6
Max. for month: 61F on 1st
Min. for month:  4F on 12th

HEATING DEGREE DAYS
Total heating units: 1025 [+109] Total for the season: 4902 [-582] Total for last season: 4419

PRECIPITATION, Inches
Total: 4.84 [-0.74] Greatest in 24 hrs: 2.15 on the 14th

SNOWFALL, Inches
Total: 11.4 [-1.3] Greatest in 24 hrs: 7.3 in. on 14th

WIND, mph
Avg. uncorrected wind speed: 14.3
Avg. corrected wind speed: 14.6
Prevailing wind direction: W at 18%
Peak gust and direction: 60 NE on 14th

SUNSHINE:
Campbell-Stokes card minutes: 11,490 minutes of possible 21,516 or 53%
Astronomical total minutes: 11,899 minutes of possible 22,264 or 53%

March 2017’s average temperature measured 31.6F which was
colder than each of the last three winter months. March has
been colder than February of the same year three times in
the past, and colder than all three preceding winter months
only once before in 1936-1937.

BHO Lowest Mar-Feb 24-hour Mean Temperature Difference, deg F (1885-2017):

1) -5.4 in 1984
2) -3.1 in 1960
3) -2.2 in 2017
4) -0.3 in 1937
5) +0.8 in 1890
+0.8 in 1997
7) +0.9 in 1939
8) +1.2 in 1954

Today’s Observations:

7 A.M.
Weather: Light rain, sky obscurement due to fog
Temperature: 35F; Dew Point: 35F; Wind: ENE at 12G20 kts
Sea-level pressure: 29.96 ins. Hg, rising then falling
Visibility: 3/16 mile
6-hr Max temp: 36F
6-hr Min temp: 35F
24-hr precip: Trace
24-hr snowfall: 0.0 in.
BHO SA 1155 W3 X 3/16R-F 147/35/35/0712G20/996/ 8//// 58020 10036 20035

10 A.M.
Weather: Sky obscurement due to fog
Temperature: 37F; Dew Point: 37F; Wind: E at 15 kts
Sea-level pressure: 29.88 ins. Hg, falling, then more quickly
Visibility: 1/4 mile
3-hr precip: 0.11 in.
3-hr snowfall: 0.0 in.
BHO SA 1455 W3 X 1/4F 120/37/37/0815/988/ 8//// 58027
MANUAL 6011/ ASOS 60012

1 P.M.
Weather: Light rain, sky obscurement due to fog
Temperature: 37F; Dew Point: 37F; Wind: E at 11 kts
Sea-level pressure: 29.74 ins. Hg, falling, then more slowly
Visibility: 2 miles
6-hr Max temp: 38F
6-hr Min temp: 35F
6-hr precip: 0.47 in.
6-hr snowfall: 0.0 in.
BHO SA 1755 W3 X 2R-F 071/37/37/0811/974/ 8//// 56049
MANUAL 6047/ ASOS 60042 10038 20035

SUMMARY FOR WEDNESDAY, APRIL 5, 2017

TEMPERATURE (DEGREES F)
MAX…..41   NORMAL…..51
MIN…..35   NORMAL…..34
MEAN….38   NORMAL…..43

DEPARTURE FROM 30-YEAR NORMAL…………………….-5
TOTAL DEPARTURE FOR THE MONTH…………………….-9 [-2.0 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY…………..27   DEPARTURE……….+5
TOTAL HEATING UNITS FOR THE MONTH………….125   DEPARTURE……….+9
TOTAL HEATING UNITS FOR THE SEASON………..5027   DEPARTURE……..-573
TOTAL HEATING UNITS LAST SEASON TO DATE……4553   DIFFERENCE…….+474

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY……………….21 NNW AT  1:14 A.M.
AERO……………………20 NNW AT  1:14 A.M.*
ASOS……………………22  N  AT  1:05 A.M.
DAVIS…………………..19  N  AT  1:14 A.M. RMY N/A
FASTEST MILE FOR YESTERDAY…………………13 NNW AT 12:53 A.M.
MAXIMUM 2-MINUTE ASOS AVERAGE………………15  E  AT  9:12 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE……………..13 NNW AT 12:53 A.M.
AVERAGE WIND SPEED AND DIRECTION…………..7.5 ENE
ASOS…………………..7.9
DAVIS………………….6.3 NE [050 deg.] *Last of multiple occurrences

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M…Trace  DEPARTURE……-0.17
ASOS…………..0.00
TOTAL PRECIPITATION FOR THE MONTH……….2.99  DEPARTURE……+2.14
ASOS…………..2.94
TOTAL PRECIPITATION FOR THE YEAR……….17.11  DEPARTURE……+2.26
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…….-0.1
TOTAL SNOWFALL FOR THE MONTH…………….2.7  DEPARTURE…….+1.8
TOTAL SNOWFALL FOR THE SEASON…………..66.4  DEPARTURE…….+5.8

PRELIMINARY CLIMATE SUMMARY FOR MARCH 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

3/1  61/46/54/+23/0.01/0.0/000/00          41 S   AERO 45 S   RMY 45
3/2  55/26/41/+10/T/T/509/75               58 W   AERO 61 W   RMY 59
3/3  36/19/28/-4/T/T/592/87                38 W   AERO 44 W   RMY N/A
3/4  20/7/14/-18/T/T/622/91                45 NW  AERO 48 NW  RMY 51
3/5  29/5/17/-15/0.00/0.0/687/100          35 WNW AERO 43 WNW*RMY N/A
3/6  40/11/26/-6/0.00/0.0/641/93           18 WNW AERO 17 NW* RMY N/A
3/7  47/29/38/+5/0.01/0.0/000/00           32 S   AERO 35 S   RMY 36
3/8  55/43/49/+16/0.05/0.0/320/46          35 W   AERO 36 W   RMY 37
3/9  49/35/42/+9/0.0/0.0/684/98            53 W   AERO 59 W   RMY 58
3/10 35/20/28/-5/0.27/2.9/000/00           35 WNW AERO 44 WNW RMY 40
3/11 20/7/14/-20/0.02/0.2/612/87           43 W   AERO 47 W   RMY 50
3/12 25/4/15/-19/0.00/0.0/679/96           32 W   AERO 40 WNW RMY N/A
3/13 33/8/21/-13/0.00/0.0/667/94           25 WNW AERO 29 WNW RMY N/A
3/14 38/23/31/-4/2.15/7.3/000/00           60 NE  AERO 62 NE  RMY 62
3/15 27/15/21/-14/0.00/0.0/536/75          36 W   AERO 37 W   RMY N/A
3/16 33/17/25/-10/0.00/0.0/696/97          36 W   AERO 37 W   RMY 38
3/17 40/22/31/-5/0.00/0.0/577/80           25 WNW AERO 24 WNW RMY 27
3/18 36/24/30/-6/0.00/0.0/557/77           26 ENE AERO 24 ENE RMY 26
3/19 35/28/32/-4/0.01/T/153/21             39 N   AERO 37 N   RMY 39
3/20 49/29/39/+2/0.00/0.0/686/94           31 N   AERO 35 N   RMY 36
3/21 52/34/43/+6/0.00/0.0/418/57           28 W   AERO 26 W   RMY N/A
3/22 38/15/27/-10/T/T/603/82               46 NW  AERO 50 NW  RMY 51
3/23 36/13/25/-13/0.00/0.0/716/97          36 WNW AERO 35 WNW RMY 38
3/24 44/25/35/-3/0.02/T/000/00             37 S   AERO 38 S   RMY 39
3/25 44/31/38/0/0.07/0.07/000/00           22 NE  AERO 20 NE  RMY 21
3/26 42/29/36/-3/0.00/0.0/232/31           25 ENE AERO 23 ENE RMY 25
3/27 43/33/38/-1/0.51/0.0/000/00           22 E   AERO 18 E   RMY N/A
3/28 40/33/37/-2/0.69/0.0/000/00           16 N   AERO 15 N   RMY N/A TSTM
3/29 46/33/40/0/0.11/0.0/053/07            37 NW  AERO 36 NW  RMY 37  TSTM
3/30 50/30/40/0/0.00/0.0/659/87            23 NW  AERO 21 NW  RMY N/A
3/31 37/32/35/-6/0.92/1.0/000/00           25 E   AERO 30 E   RMY N/A

DAILY RECORDS FOR MARCH 2017

3/11/17: DAILY RECORD LOW MAXIMUM TEMPERATURE OF 20F,
TIES PREVIOUS RECORD SET IN 1885

3/14/17: DAILY RECORD MAXIMUM SNOWFALL OF 7.3 INS,
BREAKS PREVIOUS RECORD OF 6.7 INS SET IN 1958

PRELIMINARY CLIMATE SUMMARY FOR APRIL 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

4/1  35/31/33/-8/2.21/2.7/000/00           40 ENE AERO 41 ENE RMY 41
4/2  53/30/42/+1/0.00/0.0/…/..           32 NW  AERO 33 NW  RMY 34
4/3  60/35/48/+6/0.00/0.0/…/..           21 W*  AERO 20 NW  RMY N/A
4/4  42/35/39/-3/0.78/0.0/…/..           41 ESE AERO 43 ESE RMY 42
4/5  41/35/38/-5/0.00/0.0/000/00           21 NNW AERO 20 NNW RMY N/A

4/6  Low temp since midnight is 35F; normal low is now 34F

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

RECORDS FOR APRIL 6
HIGH 82 IN 1921
LOW 16 IN 1982
PRECIP 1.72 INS IN 1886
SNOW 12.3 INS IN 1982
WIND 71e MPH WNW IN 1940

RECORDS FOR APRIL 7
HIGH 90 IN 2010
LOW 13 IN 1982
PRECIP 1.72 IN. IN 1924
SNOWFALL 4.5 IN. IN 1967, 1996
PEAK GUST 65 MPH WNW IN 1982

TODAY’S REPORT PREPARED BY: Cecilia Borries-Strigle