Tuesday, April 4, 2017

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

DAILY DISCUSSION AND CLIMATE SUMMARY
TUESDAY, APRIL 4, 2017
ALL TIMES ARE IN EASTERN STANDARD TIME

RAIN AND FOG RETURN, WINDS GUSTING OVER 30 MPH

Chilly temperatures, steady rain, and gusting winds have
made for an unpleasant spring day.  Rain began shortly
after 2:00AM EST this morning and has been steady through
the early afternoon.  Precip. amounts measured 0.25 in.
at the 7:00AM ob and 0.34 in. at the 1:00PM ob.  Distant
fog arrived at the observatory by the 10:00AM ob limiting
visibility to 3-5 miles.

Temperatures varied very slightly between a max. of 37F
and a minimum of 35F.  Gusty winds made the day feel even
colder.  East-southeast winds had shifted east by 1:00PM.
A peak gust of 39 MPH was recorded at 9:08AM, with multiple
30 MPH gusts throughout the day.

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, broken stratus, overcast nimbostratus
Temperature: 37F; Dew Point: 36F; Wind: ESE at 14G21 kts,
Peak Wind: 26 kts (30 MPH) ESE at 6:12AM EST
Sea-level pressure: 29.89 ins. Hg,falling unsteadily
Visibility: 10 miles, distant fog in all directions
6-hr Max temp: 42F
6-hr Min temp: 37F
24-hr precip: 0.25 in.
24-hr snowfall: 0.0 in.
BHO SA 1155 E43 BKN 54 OVC 10R- 122/37/36/1214G21/989/ DSNT FG ALQDS
PK WND 1226/12/ 8/6// 57011 MANUAL 70025 ASOS 70021 10042 20037

10 A.M.
Weather: Light rain, fog, overcast nimbostratus
Temperature: 35F; Dew Point: 35F; Wind: ESE at 18G27 kts,
Peak Wind: 34 kts (39 MPH) ESE at 9:08AM EST
Sea-level pressure: 29.81 ins. Hg, falling then steady
Visibility: 5 miles
3-hr precip: 0.20 in.
3-hr snowfall: 0.0 in.
BHO SA 1455 E5 OVC 5R-F 096/35/35/1118G27/981/ PK WND 1134/08/
8/6// 55026 MANUAL 6020/ ASOS 60021

1 P.M.
Weather: Light rain, fog, overcast nimbostratus
Temperature: 37F; Dew Point: 37F; Wind: E at 16G24 kts,
Peak Wind: 26 kts (30 MPH) E at 12:22PM EST
Sea-level pressure: 29.75 ins. Hg, falling unsteadily
Visibility: 3 miles
6-hr Max temp: 37F
6-hr Min temp: 35F
6-hr precip: 0.34 in.
6-hr snowfall: 0.0 in.
BHO SA 1755 E7 OVC 3R-F 074/37/37/1016G24/975/ PK WND 1026/22/
8/6// 57022 MANUAL 6034/ ASOS 60036 10037 20035

SUMMARY FOR MONDAY, APRIL 3, 2017

TEMPERATURE (DEGREES F)
MAX…..60   NORMAL…..51
MIN…..35   NORMAL…..33
MEAN….48   NORMAL…..42

DEPARTURE FROM 30-YEAR NORMAL…………………….+6
TOTAL DEPARTURE FOR THE MONTH…………………….-1 [-0.5 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY…………..17   DEPARTURE……….-6
TOTAL HEATING UNITS FOR THE MONTH…………..72   DEPARTURE……….+1
TOTAL HEATING UNITS FOR THE SEASON………..4974   DEPARTURE……..-581
TOTAL HEATING UNITS LAST SEASON TO DATE……4475   DIFFERENCE…….+499

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY……………….21 W   AT 12:33 P.M.*
AERO……………………20 NW  AT 12:37 P.M.
ASOS……………………22 W   AT 12:33 P.M.
DAVIS…………………..20 NW  AT 12:26 P.M. RMY N/A
FASTEST MILE FOR YESTERDAY…………………16 W   AT 12:32 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE………………16 NW  AT 12:38 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE……………..15 WNW AT 12:32 P.M.
AVERAGE WIND SPEED AND DIRECTION…………..9.1 WNW
ASOS…………………..8.6
DAVIS………………….7.9 NW [320 deg.] *Last of multiple occurrences

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M….0.25  DEPARTURE……+0.08
ASOS…………..0.21
TOTAL PRECIPITATION FOR THE MONTH……….2.46  DEPARTURE……+1.95
ASOS…………..2.38
TOTAL PRECIPITATION FOR THE YEAR……….16.58  DEPARTURE……+2.07
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…….-0.2
TOTAL SNOWFALL FOR THE MONTH…………….2.7  DEPARTURE…….+2.1
TOTAL SNOWFALL FOR THE SEASON…………..66.4  DEPARTURE…….+6.1

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  Low temp since midnight is 37F; normal low is now 33F

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

RECORDS FOR APRIL 4
HIGH 76 IN 2010
LOW 12 IN 1954
PRECIP 1.45 IN. IN 1987
SNOWFALL 7.3 IN. IN 2016
PEAK GUST 80 MPH WNW IN 1963

RECORDS FOR APRIL 5
HIGH 81 IN 1928
LOW 15 IN 1995
PRECIP 2.15 IN. IN 1987
SNOWFALL 4.0 IN. IN 1898
PEAK GUST 76 MPH WNW IN 1963

TODAY’S REPORT PREPARED BY: Cecilia Borries-Strigle