Friday, April 6, 2018

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

DAILY DISCUSSION AND CLIMATE SUMMARY
FRIDAY, APRIL 6, 2018
ALL TIMES ARE IN EASTERN STANDARD TIME

AFTER A PARTLY SUNNY MORNING, THE PRESSURE
BEGAN DROPPING, CLOUDS INCREASED AND LIGHT
SNOW BEGAN FALLING…

Yesterday was a below seasonable day with clear
skies due to high pressure. We had a max temp.
yesterday of 40F, which is 11 degrees below the
daily normal of 51F. Today temperatures remained
below seasonable with a high of 39F so far today.
The low since midnight of 25F is 10 degrees below
the daily normal of 35F. Clear skies remained
until late morning today and we had overcast skies
by 10:00 A.M. EST
Snow began today around 11:40 A.M. EST and continued
through the 1:00 P.M. observation. So far we have
measured a total of 0.2 ins. of snow and 0.07 ins of
liquid precipitation. This squall does not compare
to “The Blizzard of 1982” which left 12.3 ins. of
snow on top of Great Blue Hill on April 6th, 1982.

PRELIMINARY STATS FOR MARCH 2018

TEMPERATURE, Deg. F
Avg. Max. 41.2 [-3.1] Avg. Min. 27.9 [+1.3] Mean      34.6 [-0.9] 24-hour corrected mean: 33.9
Max. for month: 62F on 30th
Min. for month: 10F on 18th

HEATING DEGREE DAYS
Total heating units:   941  [+25] Total for the season: 4063 [-421] Total for last season: 4902

PRECIPITATION, Inches
Total: 8.68 [+3.29] Greatest in 24 hrs: 3.47 on the 2nd

SNOWFALL, Inches
Total: 45.5 [+32.8] Greatest in 24 hrs: 23.0 in. on 13th

WIND, mph
Avg. uncorrected wind speed: 13.9
Avg. corrected wind speed: 14.3
Prevailing wind direction: NW at 14%
Peak gust and direction: 73 NNE on 2nd

SUNSHINE:
Campbell-Stokes card minutes: 8742 minutes of possible 21516 or 41%
Astronomical total minutes: 9023 minutes of possible 22243 or 41%

Blue Hill Observatory Greatest March Snowfall Totals,
Inches (1885-2018)

1) 52.0 in 1956
2) 45.5 in 2018
3) 42.2 in 1916
4) 41.4 in 2001
5) 41.0 in 1967
6) 37.8 in 2013
7) 35.5 in 1993

BHO Greatest March Monthly Precipitation,
inches (1885-2018):

1) 18.81 in 2010
2) 13.07 in 2001
3) 10.96 in 1968
4) 10.02 in 1983
5) 9.53 in 1953
6) 9.00 in 1984
7) 8.72 in 1993
8) 8.69 in 2018
9) 8.09 in 1956
10) 7.98 in 1994

Today’s Observations:

7 A.M.
Weather: Scattered cirrostratus, scattered cirrus, thin
smoke layer SSE-SSW and NNW-NNE
Temperature: 30F; Dew Point: 14F; Wind: SW at 8G15 kts
Sea-level pressure: 30.16 ins. Hg, rising then falling
Visibility: 75 miles
6-hr Max temp: 30F
6-hr Min temp: 25F
24-hr precip:  0.00 ins.
24-hr snowfall: 0.0 ins.
Snow depth: 0 ins.
BHO SA 1155 E200 SCT 300 SCT 75 212/30/14/2208G15/016/
THN K LYR SSE-SSW AND NNW-NNE/ 8/005 50006 10030 20025

10 A.M.
Weather: Overcast altostratus, few altocumulus NNW-S
Temperature: 38F; Dew Point: 22F; Wind: S at 14G22 kts
Sea-level pressure: 30.09 ins. Hg, falling, then more rapidly
Visibility: 70 miles
3-hr precip: 0.00 ins.
3-hr snowfall: 0.0 ins.
BHO SA 1455 E200 OVC 70 190/38/22/1914G22/009/
FEW AC NNW-S/ 8/01/ 58022

1 P.M.
Weather: Light snow and fog, overcast nimbostratus
Temperature: 32F; Dew Point: 32F; Wind: SSE at 13G20 kts
Sea-level pressure: 29.95 ins. Hg, falling, then more rapidly
Visibility: 1/2 mile
6-hr Max temp: 39F
6-hr Min temp: 30F
6-hr precip: 0.07 ins.
6-hr snowfall: 0.2 ins.
Snow depth: 0 ins.
BHO SA 1755 E6 OVC 1/2S-F 142/32/32/1613G20/995/ NEW SNW PST 6
HRS 0.2 INS/ 8/6// 58048 MANUAL 6007/ ASOS 60005 10039 20030

SUMMARY FOR THURSDAY, APRIL 5, 2018

TEMPERATURE (DEGREES F)
MAX…..40   NORMAL…..51
MIN…..27   NORMAL…..34
MEAN….34   NORMAL…..43

DEPARTURE FROM 30-YEAR NORMAL………………………-9
TOTAL DEPARTURE FOR THE MONTH……………………..-11 [-2.4 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY………….31   DEPARTURE……….+9
TOTAL HEATING UNITS FOR THE MONTH………….96   DEPARTURE………+11
TOTAL HEATING UNITS FOR THE SEASON……….5159   DEPARTURE……..-410
TOTAL HEATING UNITS LAST SEASON TO DATE…..5000   DIFFERENCE…….+163

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY……………….53 WNW AT  1:29 A.M.
AERO……………………53 WNW AT  4:00 A.M.
ASOS……………………53 W   AT 12:58 A.M.
DAVIS…………………..51 M   AT  4:02 A.M ** RMY 52
FASTEST MILE FOR YESTERDAY…………………36 WNW AT  1:31 A.M.
MAXIMUM 2-MINUTE ASOS AVERAGE………………37 W   AT  1:42 A.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE……………..35 M   AT  4:03 A.M.**
AVERAGE WIND SPEED AND DIRECTION………….23.6 WNW
ASOS………………….21.9
DAVIS…………………20.1 M

** Davis direction malfunctioning

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M….0.21  DEPARTURE……-0.17
ASOS…………..0.28
TOTAL PRECIPITATION FOR THE MONTH……….0.88  DEPARTURE……+0.03
ASOS…………..0.70
TOTAL PRECIPITATION FOR THE YEAR……….19.68  DEPARTURE……+5.01
ASOS………….21.07

SNOWFALL (INCHES) THROUGH THIS MORNING (EST)
TOTAL SNOWFALL 24 HRS ENDING 7 A.M……….0.0  DEPARTURE……..-0.1
TOTAL SNOWFALL FOR THE MONTH…………….1.6  DEPARTURE……..+0.7
TOTAL SNOWFALL FOR THE SEASON…………..91.8  DEPARTURE…….+31.1

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

3/01 61/37/49/+18/0.00/0.0/378/56    39 ENE AERO 37 ENE RMY N/A
3/02 40/32/36/+5/3.47/0.7/000/00     73 NNE AERO 70 NNE RMY N/A
3/03 40/32/26/+4/T/T/034/05          52 NNE AERO 50 NNE RMY 49
3/04 39/34/37/+5/T/T/000/00          36 NNE AERO 32 NNE RMY 32
3/05 40/29/35/+3/0.12/1.2/261/38     40 NE  AERO 39 NE  RMY 40
3/06 34/29/32/0/0.00/0.0/062/09      20 N   AERO 16 N   RMY N/A
3/07 35/31/33/0/1.49/10.0/000/00     52 ENE AERO 53 ENE RMY 50
3/08 34/28/31/-2/0.67/5.0/000/00     44 NNE AERO 47 NNE RMY N/A
3/09 36/24/30/-3/T/T/265/38          28 W   AERO 26 W   RMY N/A
3/10 37/28/33/0/0.00/0.0/343/49      38 WNW AERO 38 WNW RMY 41
3/11 42/26/34/0/0.00/0.0/583/83      28 NW  AERO 26 NW  RMY 29
3/12 39/26/33/-1/T/T/155/22          36 ENE AERO 33 ENE RMY N/A
3/13 35/26/31/-3/2.20/23.0/000/00    60 N   AERO 60 N   RMY 64
3/14 36/24/30/-5/0.00/0.0/470/66     38 WSW AERO 38 WSW RMY 41
3/15 40/29/35/0/0.01/0.2/422/59      44 W   AERO 44 W   RMY 44
3/16 35/23/29/-6/0.00/0.0/308/43     41 NW  AERO 41 NW  RMY 45
3/17 40/15/28/-8/0.00/0.0/533/74     46 W   AERO 45 W   RMY 49
3/18 31/10/21/-15/0.00/0.0/694/96    39 NW  AERO 38 NW  RMY 40
3/19 35/13/24/-12/0.00/0.0/704/97    32 WNW AERO 32 WNW RMY 34
3/20 40/18/29/-8/0.00/0.0/372/51     23 NW  AERO 21 NW  RMY N/A
3/21 35/31/33/-4/0.04/0.2/000/00     43 NE  AERO 44 NE  RMY N/A
3/22 39/30/35/-2/0.41/3.4/000/00     28 NNW AERO 26 NNW RMY 30
3/23 44/28/36/-2/0.00/0.0/539/73     21 NNW AERO 18 NNW RMY 21
3/24 45/32/39/+1/T/T/185/25          23 NE  AERO 21 NE  RMY N/A
3/25 36/29/33/-5/0.18/1.8/134/18     35 NNE AERO 30 NNE RMY 33
3/26 38/27/33/-6/0.00/0.0/701/94     33 NE  AERO 26 NE  RMY 30
3/27 44/25/35/-4/0.00/0.0/592/79     24 NE  AERO 17 NE  RMY 20
3/28 55/33/44/+5/0.01/0.0/293/39     21 SSW AERO 14 SSW RMY 18
3/29 55/39/47/+7/T/0.0/242/32        24 SSE AERO 21 SSE RMY N/A
3/30 62/42/52/+12/0.08/0.0/000/00    32 NW  AERO 30 NW  RMY N/A
3/31 56/35/46/+5/T/0.0/731/96        37 NW  AERO 36 NW  RMY N/A

DAILY RECORDS FOR MARCH 2018

3/02/18: NEW DAILY RECORD MAXIMUM PRECIPITATION OF 3.47 INS.
PREVIOUS RECORD WAS 2.15 INS. SET IN 1983

3/13/18: NEW DAILY RECORD MAXIMUM SNOWFALL OF 23.0 INS.
PREVIOUS RECORD WAS 10.0 INS. SET IN 1993

3/13/18: NEW MONTHLY RECORD MAXIMUM DAILY SNOWFALL OF 23.0 INS.
PREVIOUS RECORD WAS 18.0 INS. SET ON 8 MARCH 2013

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

4/01 58/33/46/+5/…./0.0/…/..   45 SSW AERO 43 SSW RMY N/A
4/02 38/30/34/-7/…./1.6/…/..   20 SSW AERO 15 SSW RMY 17
4/03 48/30/39/-3/…./0.0/…/..   28 SSE AERO 25 SSE RMY 25
4/04 54/36/45/+3/…./0.0/…/..   56 WNW AERO 56 WNW RMY 54
4/05 40/27/34/-9/0.00/0.0/…/..   53 WNW AERO 53 WNW RMY 52

4/06 Low temp since midnight is 27F; 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
PRE 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: K.A. Geagan