Wednesday, April 18, 2018

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

DAILY DISCUSSION AND CLIMATE SUMMARY
WEDNESDAY, APRIL 18, 2018
ALL TIMES ARE IN EASTERN STANDARD TIME

A BELOW SEASONABLE DAY WITH FAIR WEATHER WITH GOOD
VISIBILITY ON GREAT BLUE HILL….

Visibility stayed at 70 miles for most of the day
today, with humidity decreasing throughout. Winds
remained westerly, and were lighter compared to
yesterday, staying around 15 mph. Temperatures continue to
remain below seasonable. The maximum observed
so far today is 52F, 5 degrees below the normal of 57F.
The low since midnight was 32F, 7 degrees below the
daily normal of 39F.

Today’s Observations:

7 A.M.
Weather: Broken stratocumulus, few cumulus NW-SSE
Temperature: 35F; Dew Point: 22F; Wind: W at 12G24 kts
Sea-level pressure: 29.66 ins. Hg, rising, then more slowly
Visibility: 70 miles
6-hr Max temp: 35F
6-hr Min temp: 32F
24-hr precip: 0.00 ins.
24-hr snowfall: 0.0 ins.
Snow depth: 0 ins.
BHO SA 1155 E38 BKN 70 043/35/22/2712G24/966/ FEW CU NW-SSE/
8/800 51011 10035 20032

10 A.M.
Weather: Scattered cumulus, broken cirrostratus
Temperature: 43F; Dew Point: 25F; Wind: W at 15G24 kts,
Peak Wind: 26 kts (30 MPH) W at 9:08 A.M.
Sea-level pressure: 29.66 ins. Hg, rising steadily
Visibility: 70 miles
3-hr precip: 0.00 ins.
3-hr snowfall: 0.0 ins.
BHO SA 1455 40 SCT E250 BKN 70 045/43/25/2815G24/966/ PK WND 2826/08/
8/108 51002

1 P.M.
Weather: Broken cumulus
Temperature: 52F; Dew Point: 30F; Wind: W at 14G22 kts
Sea-level pressure: 29.67 ins. Hg, steady
Visibility: 70 miles
6-hr Max temp: 52F
6-hr Min temp: 35F
6-hr precip: 0.00 ins.
6-hr snowfall: 0.0 ins.
Snow depth: 0 ins.
BHO SA 1755 E50 BKN 70 047/52/30/2814G22/967/ 8/100 50002 10052 20035

SUMMARY FOR TUESDAY, APRIL 17, 2018

TEMPERATURE (DEGREES F)
MAX…..48   NORMAL…..56
MIN…..36   NORMAL…..38
MEAN….42   NORMAL…..47

DEPARTURE FROM 30-YEAR NORMAL……………………..-5
TOTAL DEPARTURE FOR THE MONTH……………………..-71 [-4.4 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY………….23   DEPARTURE……….+5
TOTAL HEATING UNITS FOR THE MONTH…………425   DEPARTURE………+71
TOTAL HEATING UNITS FOR THE SEASON……….5483   DEPARTURE……..-355
TOTAL HEATING UNITS LAST SEASON TO DATE…..5159   DIFFERENCE…….+324

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY……………….37 W   AT  10:08 P.M.
AERO……………………33 W   AT  9:13  A.M.
ASOS……………………37 W   AT  10:08 P.M.
DAVIS…………………..37 W   AT  10:08 P.M ** RMY 37
FASTEST MILE FOR YESTERDAY…………………26 W   AT  10:09 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE………………25 W   AT  10:09 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE……………..26 M   AT  10:41 P.M.**
AVERAGE WIND SPEED AND DIRECTION………….15.7 E
ASOS………………….15.8
DAVIS…………………14.7 M**
** Davis direction malfunctioning

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……….4.10  DEPARTURE……+1.30
ASOS…………..4.24
TOTAL PRECIPITATION FOR THE YEAR……….22.90  DEPARTURE……+6.28
ASOS………….24.48

SNOWFALL (INCHES) THROUGH THIS MORNING (EST)
TOTAL SNOWFALL 24 HRS ENDING 7 A.M……….0.0  DEPARTURE……..-0.1
TOTAL SNOWFALL FOR THE MONTH…………….2.6  DEPARTURE……..+0.2
TOTAL SNOWFALL FOR THE SEASON…………..92.8  DEPARTURE…….+30.6

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/…./0.0/336/44   45 SSW AERO 43 SSW RMY N/A
4/02 38/30/34/-7/…./1.6/077/10   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 41/25/33/-10/0.25/1.0/…/..  37 S   AERO 36 S   RMY 38
4/07 46/32/35/-4/0.00/0.0/…/..   32 WNW AERO 35 WNW RMY 34
4/08 41/29/35/-9/0.00/0.0/…/..   35 WNW*AERO 31 WNW RMY 34
4/09 45/24/35/-9/0.00/0.0/…/..   28 WNW*AERO 25 WNW RMY 29
4/10 39/31/35/-10/T/T/…/..       14 SSW AERO 13 SSW RMY N/A
4/11 48/29/39/-6/T/0.0/…/..      24 SSE AERO 23 SSE RMY 25
4/12 61/33/47/+2/…./0.0/…/..   39 SSW AERO 38 SSW RMY 41
4/13 65/47/56/+10/T/0.0/…/..     37 SSW AERO 37 SSW RMY N/A
4/14 51/36/44/-2/…./0.0/…/..   33 ENE AERO 31 ENE RMY N/A
4/15 36/30/33/-14/…./T/…/..    39 ENE AERO 39 ENE RMY N/A
4/16 55/32/44/-3/…./…/..       41 ENE AERO 43 ENE RMY 41
4/17 48/36/42/-5/0.00/0.0/…/..   37 W   AERO 33 W   RMY 37

4/18 Low temp since midnight is 32F; normal low is now 39F

*Estimated

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

RECORDS FOR APRIL 18
HIGH 92 IN 1976
LOW 23 1887
PRECIP 1.48 IN 1954
SNOWFALL 3.7 IN. IN 1965
PEAK GUST 59 MPH S IN 1982

RECORDS FOR APRIL 19
HIGH 94 IN 1976 [RECORD FOR MONTH] LOW 21 IN 1890
PRECIP 1.71 IN 1969
SNOWFALL 6.0 IN. IN 1887
PEAK GUST 66 MPH E IN 1984

TODAY’S REPORT PREPARED BY: Benjamin Turner