BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY MONDAY, APRIL 29, 2019 ALL TIMES ARE IN EASTERN STANDARD TIME ALMOST CLEAR CONDITIONS THIS MORNING BECOMING MORE CLOUDY FOLLOWING NOONTIME.... We observed excellent visibility of 85 miles today, with increasing afternoon clouds. Wind shifted from NW to SW since this morning, with the speed staying around 10 mph. Pressure was at a steady decline since this morning, decreasing about 2 millibars by the 1 P.M. observation. The high so far today is 57F, 4 degrees below the daily normal maximum of 61F. The low since midnight is 34F, 9 degrees below the daily normal of 43F. BHO Greatest April Precipitation, inches (1885-2019): 1) 10.37 in 1987 2) 9.38 in 2004 3) 8.71 in 1929 4) 8.68 in 2007 5) 8.53 in 1904 6) 7.97 in 2019 (through 7 AM on 4/29) 7) 7.57 in 1935 7.57 in 1983 9) 7.31 in 1901 The calendar day rainfall on Monday, 4/22, was more than two and a half inches, which made it one of the wettest calendar days ever observed in April. The finalized amount for the day will be reported when available. BHO Greatest April Calendar Day Precipitation, inches (1885-2019): 1) 3.47 on April 1, 2004 2) 3.18 on April 21, 1991 3) 2.63 on April 16, 2018 4) 2.51 on April 24, 1898 2.51 on April 13, 2004 6) 2.45 on April 16, 1929 7) 2.41 on April 28, 1904 8) 2.40 on April 10, 1935 Today's Observations: 7 A.M. Weather: Clear, few distant cirrostratus Temperature: 42F; Dew Point: 33F; Wind: NW at 10G17 kts Sea-level pressure: 30.38 ins. Hg, rising then more rapidly Visibility: 80 miles 6-hr Max temp: 42F 6-hr Min temp: 34F 24-hr Precip: 0.08 ins. 24-hr snowfall: 0.0 ins. Snow depth: 0 ins. BHO SA 1155 CLR 80 288/42/33/3210G17/038/ FEW DSNT CS ALQDS/ 8/005 70008 51027 10042 20034 10 A.M. Weather: Clear, few cirrostratus in all directions Temperature: 50F; Dew Point: 23F; Wind: NW at 10G20 kts Sea-level pressure: 30.37 ins. Hg, falling steadily Visibility: 85 miles 3-hr Precip: 0.00 BHO SA 1455 300 SCT 85 285/50/23/3210G20/037/ 8/005 58003 1 P.M. Weather: Broken cirrus Temperature: 57F; Dew Point: 20F; Wind: SW at 10G17 kts Sea-level pressure: 30.33 ins. Hg, falling steadily Visibility: 85 miles 6-hr Max temp: 57F 6-hr Min temp: 42F 6-hr Precip: 0.00 ins. 6-hr snowfall: 0.0 ins. BHO SA 1755 E250 BKN 85 272/57/20/2410G17/033/ 8/002 55013 10057 20042 SUMMARY FOR SUNDAY, APRIL 28, 2019 TEMPERATURE (DEGREES F) MAX.....51 NORMAL.....61 MIN.....38 NORMAL.....42 MEAN....45 NORMAL.....52 DEPARTURE FROM 30-YEAR NORMAL........................-7 TOTAL DEPARTURE FOR THE MONTH.......................+66 [+2.2 DEGREES/DAY] HEATING DEGREE DAYS (SEASON JUL TO JUN) TOTAL HEATING UNITS FOR YESTERDAY..............20 DEPARTURE.........+7 TOTAL HEATING UNITS FOR THE MONTH.............457 DEPARTURE........-68 TOTAL HEATING UNITS FOR THE SEASON...........5862 DEPARTURE.......-147 TOTAL HEATING UNITS LAST SEASON TO DATE......5653 DIFFERENCE......+209 PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY....................28 W AT 1:37 A.M. AERO.........................28 W AT 3:32 A.M. ASOS.........................28 W AT 12:09 A.M. DAVIS........................28 W AT 2:57 A.M. RMY N/A FASTEST MILE FOR YESTERDAY......................22 W AT 2:46 A.M. MAXIMUM 2-MINUTE ASOS AVERAGE...................22 W AT 12:09 A.M. MAXIMUM 2-MINUTE DAVIS AVERAGE..................22 W AT 2:38 A.M. AVERAGE WIND SPEED AND DIRECTION..............10.3 W ASOS.......................10.4 DAVIS......................10.5 WSW [247 deg.] PRECIPITATION (INCHES) THROUGH THIS MORNING (EST) TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.08 DEPARTURE.......-0.06 ASOS..............0.07 TOTAL PRECIPITATION FOR THE MONTH..........7.97 DEPARTURE.......+3.68 ASOS..............7.90 TOTAL PRECIPITATION FOR THE YEAR..........21.01 DEPARTURE.......+2.72 ASOS.............21.01 SNOWFALL (INCHES) THROUGH THIS MORNING (EST) TOTAL SNOWFALL 24 HRS ENDING 7 A.M.........0.0 DEPARTURE........-0.1 TOTAL SNOWFALL FOR THE MONTH.............TRACE DEPARTURE........-3.0 TOTAL SNOWFALL FOR THE SEASON.............47.6 DEPARTURE.......-15.1 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 04/01 45/29/37/-4/0.00/0.0/748/98 40 WNW AERO 37 W RMY 42 04/02 50/27/39/-2/..../0.0/605/79 29 S AERO 25 S RMY 31 04/03 62/35/49/+7/..../0.0/484/63 54 W AERO 58 W RMY 56 04/04 50/34/42/0/..../0.0/717/93 46 W AERO 41 W RMY N/A 04/05 47/27/37/-6/..../0.0/341/44 23 SSW AERO 17 SSW RMY 23 04/06 64/32/48/+5/..../0.0/536/69 24 NW AERO 18 W RMY 26 04/07 66/41/54/+11/0.00/0.0/320/41 24 S AERO 18 S RMY 25 04/08 48/34/41/-3/0.49/0.0/000/00 25 NE AERO 20 NE RMY 26 04/09 40/32/36/-8/0.08/0.0/000/00 23 NE AERO 16 N RMY 25 04/10 43/30/37/-8/T/T/000/00 32 NW AERO 26 NW RMY 36 04/11 51/29/40/-5/0.00/0.0/403/51 23 NW AERO 18 NW RMY N/A 04/12 53/38/46/+1/..../0.0/000/00 35 SSW AERO 29 SSW RMY 39 04/13 71/54/63/+17/..../0.0/167/21 38 SSW AERO 32 SSW RMY N/A 04/14 71/51/61/+15/..../0.0/224/28 25 S AERO 18 S RMY N/A 04/15 67/40/54/+7/..../0.0/168/21 46 W AERO 52 W RMY 50 04/16 58/37/48/+1/0.00/0.0/.../.. 46 W AERO 44 W RMY 44 04/17 62/36/49/+2/0.00/0.0/.../.. 26 ESE AERO 25 S RMY 28 04/18 63/39/51/+3/0.00/0.0/.../.. 44 S AERO 44 S RMY 50 04/19 71/58/65/+17/..../0.0/.../.. 47 SSW AERO 51 SSW RMY 52 04/20 68/60/64/+15/..../0.0/.../.. 50 SSW AERO 54 SSW RMY 52 04/21 68/51/60/+11/..../0.0/.../.. 35 S AERO 35 S RMY N/A 04/22 53/45/49/0/..../0.0/.../.. 35 NNE AERO 32 NNE RMY 35 04/23 52/44/48/-2/..../0.0/.../.. 30 NNE AERO 26 NNE RMY N/A 04/24 65/44/55/+5/..../0.0/.../.. 29 WNW AERO 29 WNW RMY 30 04/25 61/39/50/0/0.00/0.0/.../.. 22 S AERO 22 S RMY 21 04/26 53/42/48/-3/..../0.0/.../.. 35 ESE AERO 30 W RMY 33 04/27 54/39/47/-4/..../.../.../.. 41 W AERO 44 W RMY 47 04/28 51/38/45/-7/0.08/0.0/.../.. 28 W AERO 28 W RMY N/A 04/29 Low temp since midnight is 34F; normal low is 43F DAILY EXTREMES Temperature and precipitation records back to 1885, and wind records back to 1940 (e = estimated): RECORDS FOR APRIL 29 HIGH 85 IN 1974 LOW 26 IN 1909 PRECIP 1.65 IN 1923 SNOWFALL 1.0 IN. IN 1987 PEAK GUST 55 MPH WNW IN 2010 RECORDS FOR APRIL 30 HIGH 86 IN 1942 LOW 30 IN 1931 PRECIP 1.41 IN 1991 SNOWFALL 0.3 IN. IN 1909 PEAK GUST 64e MPH NW IN 1978 TODAY'S REPORT PREPARED BY: Benjamin Turner