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