Thursday, April 21, 2016

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

DAILY DISCUSSION AND CLIMATE SUMMARY
THURSDAY, APRIL 21, 2016
ALL TIMES ARE IN EASTERN STANDARD TIME

TEMPERATURES RISE TO 16F ABOVE NORMAL, PRESSURE
DECREASES AHEAD OF PASSING COLD FRONT

A morning low temperature of 38F was recorded, 2F below
average.  Temperatures rapidly rose throughout the day
from 46F at the 7:00AM EST observation to 73F at the
1:00PM EST observation.  The 6-hour maximum temperature
was 74F, 16F above the average of 58F.

Pressure decreased as the day progressed in front of an
advancing cold front and low pressure system.
Today’s Observations:

7 A.M.
Weather: Scattered cirrus
Temperature: 46F; Dew Point: 32F; Wind: W at 8 kts,
Sea-level pressure: 30.16 ins. Hg, rising, then  more quickly
Visibility: 70 miles, except 40 miles SE-WSW, thing smoke
layer along horizon
6-hr Max temp: 46F
6-hr Min temp: 38F
24-hr precip: 0.00 ins.
BHO SA 1155 300 SCT 70 212/46/32/2708/016/ VSBY SE-WSW 40
THN K LYR ALG HRZN/ 8/001 53001 10046 20038

10 A.M.
Weather: Scattered cirrus
Temperature: 65F; Dew Point: 25F; Wind: WSW at 8 kts,
Sea-level pressure: 30.11 ins. Hg, falling, then  more quickly
Visibility: 70 miles
BHO SA 1455 300 SCT 70 196/65/25/2508/011/ 8/001 58016

1 P.M.
Weather: Scattered cirrus
Temperature: 73F; Dew Point: 21F; Wind: WSW at 12G20 kts,
Sea-level Pressure: 30.01 ins. HG, falling, then more quickly
Visibility: 70 miles
6-hr Max temp: 73F
6-hr Min temp: 46F
BHO SA 1755 300 SCT 70 163/73/21/2512G20/001/
8/001 58033 10073 20046
SUMMARY FOR WEDNESDAY, APRIL 20, 2016

TEMPERATURE (DEGREES F)
MAX…..57   NORMAL…..58
MIN…..41   NORMAL…..40
MEAN….49   NORMAL…..49

DEPARTURE FROM 30-YEAR NORMAL…………………….+0
TOTAL DEPARTURE FOR THE MONTH……………………-33 [-1.9 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY…………..16   DEPARTURE……….-1
TOTAL HEATING UNITS FOR THE MONTH………….437   DEPARTURE………+32
TOTAL HEATING UNITS FOR THE SEASON………..4856   DEPARTURE…….-1033
TOTAL HEATING UNITS LAST SEASON TO DATE……6112   DIFFERENCE……-1256

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY……………….29 NNW AT  6:40 A.M.
ASOS……………………31  N  AT  6:40 A.M.
DAVIS…………………..26 NNW AT  6:40 A.M. RMY 29
FASTEST MILE FOR YESTERDAY…………………18  S  AT  8:36 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE………………18  S  AT  8:57 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE……………..18  S  AT  8:36 P.M.
AVERAGE WIND SPEED AND DIRECTION……………10.6 NNW
ASOS……………………10.1
DAVIS…………………..9.1 NW [310 Deg.]

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……….3.59  DEPARTURE……+0.39
ASOS…………..3.88
TOTAL PRECIPITATION FOR THE YEAR……….16.17  DEPARTURE……-1.03
ASOS………….16.89

SNOWFALL (INCHES) THROUGH THIS MORNING (EST)
TOTAL SNOWFALL 24 HRS ENDING 7 A.M……….0.0  DEPARTURE…….-0.1
TOTAL SNOWFALL FOR THE MONTH……………15.0  DEPARTURE……+12.3
TOTAL SNOWFALL FOR THE SEASON…………..57.5  DEPARTURE…….-5.4

PRELIMINARY CLIMATE SUMMARY FOR APRIL CALENDAR DAY DATA
DATE: MAX/MIN/MEAN/DEP/PRECIP/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

4/1  66/54/60/+19/…./0.0/092/12          39 SSW AERO N/A    RMY 43
4/2  54/40/47/+6/…./0.0/023/03           23 SSW AERO N/A    RMY N/A
4/3  40/23/32/-10/…./7.7/354/46          46 W   AERO N/A    RMY 55
4/4  28/21/25/-17/0.68/7.3/000/00          29 NNE AERO N/A    RMY 25
4/5  35/19/27/-16/0.00/0.0/660/85          25 NW  AERO N/A    RMY 27
4/6  41/21/31/-12/…./0.0/483/62          44 S   AERO N/A    RMY N/A
4/7  56/41/49/+6/…./0.0/000/00           53 SSE AERO 59 SSE RMY 55
4/8  52/32/42/-2/T/0.0/353/45              41 WSW AERO 45 WSW RMY 42
4/9  47/29/38/-6/0.00/0.0/417/53           33 NW  AERO 39 NW  RMY 32
4/10 49/26/38/-7/0.01/0.0/735/93           30 NW  AERO 32 NW  RMY 31
4/11 58/40/49/+4/0.00/T/182/23             47 S   AERO 52 S   RMY N/A
4/12 59/37/48/+3/0.30/0.0/040/05           53 S   AERO 60 S   RMY 54
4/13 53/33/43/-3/0.00/0.0/798/100          21 NNW AERO 25 NNW RMY 21
4/14 48/33/41/-5/0.00/0.0/793/99           28 ENE AERO 28 NNE RMY 26
4/15 54/35/45/-2/0.00/0.0/804/100          26 NNE AERO 28 NNE RMY N/A
4/16 52/39/46/-1/0.00/0.0/…/…          36 NNE AERO 31 NNE RMY 34
4/17 62/36/49/+2/0.00/0.0/…/…          20 NNE AERO 20 NNE RMY 19
4/18 67/45/56/+8/…/0.0/…/…           28 ENE AERO 29 NE  RMY 28
4/19 55/41/48/0/…/0.0/…/…            25 NW  AERO 30 NW  RMY N/A
4/20 57/41/49/0/0.00/0.0/…/…           29 NNW AERO 30 NNW RMY 29

4/21  low temp since midnight is 38; normal now 40F

DAILY RECORDS FOR APRIL 2016

4/1/16: NEW DAILY RECORD HIGH MINIMUM TEMPERATURE OF 54F,
BREAKS PREVIOUS RECORD OF 51F SET IN 1948

4/4/16: NEW DAILY RECORD SNOWFALL OF 7.3 INS,
BREAKS PREVIOUS RECORD OF 3.7 INS SET IN 1975

4/4/16: NEW DAILY RECORD LOW MAXIMUM TEMPERATURE OF 28F,
BREAKS PREVIOUS RECORD OF 32F SET AND TIED IN 1896, 1908, 1975

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: Cecilia Borries-Strigle