Friday, April 21, 2017

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

DAILY DISCUSSION AND CLIMATE SUMMARY
FRIDAY, APRIL 21, 2017
ALL TIMES ARE IN EASTERN STANDARD TIME

WET AND RAW CONDITIONS ON TOP OF GREAT BLUE HILL

The rain which began overnight has been decreasing in intensity during
today’s observations. The total amount of precipitation measured for this
storm is 0.40 inches. Visibility was limited today due to the light rain
and fog the farthest we could see was 6 miles at 10 AM. Temperatures for
yesterday were normal with a high of 58F which is also the normal the day.
Today the high was 45F by 1 PM but the wet damp air made it feel colder
than the recorded temperatures. The humidity stayed around 100% all day.
Winds have been moderate today and from the west.

Today’s Observations:

7 A.M.
Weather: Rain and fog
Temperature: 42F; Dew Point: 41F; Wind: ESE at 13G20 kts,
Sea-level pressure: 30.10 ins. Hg, rising unsteadily
Visibility: 3 miles
6-hr Max temp: 43F
6-hr Min temp: 42F
24-hr precip: 0.25 in.
24-hr snowfall: 0.0 in.
BHO SA 1155 W3 X 3RF 192/42/41/1013G20/010/ 8//// MANUAL
70025 ASOS 70024 52011 10043 20042

10 A.M.
Weather: Light rain and fog
Temperature: 44F; Dew Point: 44F; Wind: ESE at 11 kts,
Sea-level pressure: 30.14 ins. Hg, falling, then more slowly
Visibility: 2 miles, SSE-NW 6 miles
BHO SA 1455 W3 X 2R-F 198/44/44/1211/011/ VSBY SSE-NW 6/ 8////
MANUAL 6009/ ASOS 60011 58005

1 P.M.
Weather: Light rain and fog
Temperature: 44F; Dew Point: 44F; Wind: ESE at 11G18 kts
Sea-level pressure: 30.11 ins. Hg, falling, then more quickly
Visibility: 3/4 mile
6-hr Max temp: 45F
6-hr Min temp: 42F
BHO SA 1755 W3 X 3/4R-F 188/44/44/1011G18/009/ 8//// MANUAL 6015/
ASOS 60018 56010 10045 20042

SUMMARY FOR THURSDAY, APRIL 20, 2017

TEMPERATURE (DEGREES F)
MAX…..58   NORMAL…..58
MIN…..42   NORMAL…..40
MEAN….50   NORMAL…..49

DEPARTURE FROM 30-YEAR NORMAL…………………….+1
TOTAL DEPARTURE FOR THE MONTH……………………+99 [+5.0 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY…………..15   DEPARTURE……….-1
TOTAL HEATING UNITS FOR THE MONTH………….314   DEPARTURE………-91
TOTAL HEATING UNITS FOR THE SEASON………..5216   DEPARTURE……..-673
TOTAL HEATING UNITS LAST SEASON TO DATE……4864   DIFFERENCE…….+360

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY……………….25 SSW AT 2:51 A.M.
AERO……………………24 SSW AT 2:51 A.M.
ASOS……………………26 S   AT 2:51 A.M.
DAVIS…………………..24 SW  AT 1:24 A.M. RMY 23
FASTEST MILE FOR YESTERDAY…………………18 SSW AT 2:47 A.M.
MAXIMUM 2-MINUTE ASOS AVERAGE………………18 ENE AT 2:57 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE……………..18 SW  AT 2:21 A.M.
AVERAGE WIND SPEED AND DIRECTION…………..9.8 NE
ASOS………………….10.8
DAVIS………………….8.7 ESE [109 deg.] *LAST OF MULTIPLE OCCURRENCES

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M….0.25  DEPARTURE……+0.11
ASOS…………..0.24
TOTAL PRECIPITATION FOR THE MONTH……….4.64  DEPARTURE……+1.43
ASOS…………..4.40
TOTAL PRECIPITATION FOR THE YEAR……….18.76  DEPARTURE……+1.55
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……..0.0
TOTAL SNOWFALL FOR THE SEASON…………..66.4  DEPARTURE…….+4.0

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/+1/0.00/0.0/552/72           32 NW  AERO 33 NW  RMY 34
4/3  60/35/48/+6/0.00/0.0/685/89           21 W*  AERO 20 NW  RMY N/A
4/4  42/35/39/-3/0.78/0.0/000/00           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  55/35/45/+2/1.27/0.0/000/00           35 SSE AERO 37 S   RMY 37  TSTM
4/7  53/38/46/+3/0.00/0.0/226/29           43 SSW AERO 47 SSW RMY 48
4/8  50/34/42/-2/0.00/0.0/666/85           37 WNW AERO 40 WNW RMY 39
4/9  65/34/50/+6/0.00/0.0/716/91           23 W   AERO 23 W   RMY N/A
4/10 77/45/61/+16/0.00/0.0/560/71          37 S   AERO 37 S   RMY 39
4/11 85/50/68/+23/0.00/0.0/642/81          28 S   AERO 28 S   RMY 30
4/12 68/47/58/+13/0.01/0.0/…/..          26 WNW AERO 28 WNW RMY N/A
4/13 58/39/49/+3/0.00/0.0/…/..           28 WNW AERO 31 NW  RMY 30
4/14 62/40/51/+5/0.00/0.0/…/..           22 NNW AERO 22 NNW RMY 24
4/15 68/40/54/+7/0.01/0.0/…/..           40 SSW AERO 45 SSW RMY 45
4/16 86/55/71/+24/T/0.0/…/..             38 W*  AERO 39 SW  RMY 42
4/17 75/48/62/+15/0.00/0.0/…/..          37 W   AERO 37 W   RMY 43
4/18 52/35/44/-4/0.00/0.0/…/..           25 ENE AERO 23 ENE RMY 25
4/19 54/34/44/-4/…./0.0/…/..           31 S   AERO 33 S   RMY 34
4/20 58/42/50/+1/…./0.0/…/..

4/21 Low temp since midnight is 42F; normal low is now 40F

DAILY RECORDS FOR APRIL 2017

4/11/17: DAILY RECORD MAXIMUM TEMPERATURE OF 85F,
BREAKS PREVIOUS RECORD OF 78F SET IN 1945

4/11/17: DAILY RECORD HIGH MINIMUM TEMPERATURE OF 50F,
TIES WITH PREVIOUS RECORD SET IN 1955

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

RECORDS FOR APRIL 21
HIGH 85 IN 1923
LOW 22 IN 1908
PRECIP 3.18 IN. IN 1991
SNOWFALL 0.8 IN. IN 1947
PEAK GUST 76e MPH NE IN 1940

RECORDS FOR APRIL 22
HIGH 85 IN 1977, 2001
LOW 26 IN 1981
PRECIP 1.85 IN. IN 2000
SNOWFALL 3.0 IN. IN 1940
PEAK GUST 68e MPH NW IN 1945

TODAY’S REPORT PREPARED BY: Kaitlin Ann Geagan