BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY SUNDAY, MAY 5, 2019 ALL TIMES ARE IN EASTERN STANDARD TIME FOG LIFTS IN THE MORNING, AND CLOUDY SKIES, BETTER VISIBILITY AND DECREASING HUMIDITY PERSIST THROUGH THE LATER MORNING AND EARLY AFTERNOON.... At 7 AM today, visibility was limited to just one mile due to fog in the area. Shortly after, the fog began to lift, and visibility increased to 40 miles by the 10 AM observation. By 1 PM, visibility was decent at 70 miles. Overcast conditions have persisted, with no breaks in overcast observed so far. Our high temperature so far today has been 50F, which is 13 degrees below our normal daily maximum temperature of 63F. 0.03 inches of precipitation have been measured in the past 24 hours before 1 PM. PRELIMINARY STATS FOR APRIL 2019 TEMPERATURE, Deg. F Avg. Max. 57.2 [+1.5] Avg. Min. 39.3 [+1.6] Mean 48.3 [+1.6] 24-hour corrected mean: 48.5 Max. for month: 71F on the 13th, 14th, and 19th Min. for month: 27F on the 2nd and 5th HEATING DEGREE DAYS Total heating units: 496 [-55] Total for the season: 5901 [-134] Total for last season: 5693 PRECIPITATION, Inches Total: 8.14 [+3.59] Greatest in 24 hrs: N/A SNOWFALL, Inches Total: Trace [-3.0] Greatest in 24 hrs: N/A WIND, mph Avg. uncorrected wind speed: 13.2 Avg. corrected wind speed: 13.6 Prevailing wind direction: S at 15% Peak gust and direction: 54 W on 3rd SUNSHINE: Campbell-Stokes card minutes: N/A Astronomical total minutes: N/A BHO Greatest April Precipitation, inches (1886-2019): 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) 8.14 in 2019 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 is now available. BHO Greatest April Calendar Day Precipitation, inches (1886-2019): 1) 3.47 on April 1, 2004 2) 3.18 on April 21, 1991 3) 2.63 on April 16, 2018 4) 2.57 on April 22, 2019 5) 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: Light drizzle, overcast stratus Temperature: 46F; Dew Point: 46F; Wind: NE at 7 kts Sea-level pressure: 29.91 ins. Hg, falling then rising Visibility: 1 mile, fog 6-hr Max temp: 49F 6-hr Min temp: 45F 24-hr Precip: 0.04 ins. 24-hr snowfall: 0.0 ins. Snow depth: 0 ins. BHO SA 1155 E005 OVC 1F 130/46/46/0507/991/ L-CTD FOG/ 8/6// 53009 70004 10049 20045 10 A.M. Weather: Overcast altostratus, few cumulus in all directions Temperature: 47F; Dew Point: 45F; Wind: NE at 7 kts Sea-level pressure: 29.93 ins. Hg, rising then steady Visibility: 40 miles, distant haze in all directions 3-hr Precip: 0.02 ins. BHO SA 1455 E120 OVC 40 136/47/45/0507/993/ FEW CU ALQDS DSNT HZ ALQDS/ 8/11/ 51006 6002/ 1 P.M. Weather: Overcast stratus, few cumulus in all directions Temperature: 49F; Dew Point: 46F; Wind: NE at 7 kts Sea-level pressure: 29.92 ins. Hg, rising then falling Visibility: 70 miles, distant haze in all directions 6-hr Max temp: 50F 6-hr Min temp: 46F 6-hr Precip: 0.02 ins. BHO SA 1755 E050 OVC 70 132/49/46/0507/992/ FEW CU ALQDS DSNT HZ ALQDS/ 8/6// 58004 6002/ 10050 20046 SUMMARY FOR SATURDAY, MAY 4, 2019 TEMPERATURE (DEGREES F) MAX.....54 NORMAL.....63 MIN.....46 NORMAL.....44 MEAN....50 NORMAL.....54 DEPARTURE FROM 30-YEAR NORMAL........................-4 TOTAL DEPARTURE FOR THE MONTH.......................-19 [-5.0 DEGREES/DAY] HEATING DEGREE DAYS (SEASON JUL TO JUN) TOTAL HEATING UNITS FOR YESTERDAY..............15 DEPARTURE.........+3 TOTAL HEATING UNITS FOR THE MONTH..............66 DEPARTURE........+18 TOTAL HEATING UNITS FOR THE SEASON...........5967 DEPARTURE.......-116 TOTAL HEATING UNITS LAST SEASON TO DATE......5706 DIFFERENCE......+281 PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY....................14 ENE AT 4:50 A.M. AERO.........................16 ENE AT 5:50 A.M. ASOS.........................15 ENE AT 5:03 A.M. DAVIS........................15 ENE AT 4:51 A.M. RMY N/A FASTEST MILE FOR YESTERDAY......................12 ENE AT 4:42 A.M. MAXIMUM 2-MINUTE ASOS AVERAGE...................13 ENE AT 5:49 A.M. MAXIMUM 2-MINUTE DAVIS AVERAGE..................12 ENE AT 5:04 A.M. AVERAGE WIND SPEED AND DIRECTION...............4.8 ENE ASOS........................5.7 DAVIS.......................5.5 E [82 deg.] PRECIPITATION (INCHES) THROUGH THIS MORNING (EST) TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.04 DEPARTURE.......-0.09 ASOS..............0.01 TOTAL PRECIPITATION FOR THE MONTH..........0.16 DEPARTURE.......-0.33 ASOS..............0.13 TOTAL PRECIPITATION FOR THE YEAR..........21.34 DEPARTURE.......+2.30 ASOS.............21.34 SNOWFALL (INCHES) THROUGH THIS MORNING (EST) TOTAL SNOWFALL 24 HRS ENDING 7 A.M.........0.0 DEPARTURE.........0.0 TOTAL SNOWFALL FOR THE MONTH...............0.0 DEPARTURE.........0.0 TOTAL SNOWFALL FOR THE SEASON.............47.6 DEPARTURE.......-15.1 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 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 60/34/47/-5/0.00/0.0/.../.. 23 NW AERO 24 WNW RMY 24 04/30 48/40/44/-8/0.17/0.0/.../.. 26 NW AERO 23 NW RMY 25 PRELIMINARY CLIMATE SUMMARY FOR MAY 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 05/01 57/40/49/-4/0.00/0.0/.../.. 21 S AERO 21 SSE RMY 21 05/02 45/41/43/-10/0.02/0.0/.../.. 21 NE AERO 21 SSW RMY 20 05/03 60/43/52/-1/..../.../.../.. 23 S AERO 23 S RMY 22 05/04 54/46/50/-4/..../../.../.. 14 ENE AERO 16 ENE RMY N/A 05/05 Low temp since midnight is 45F; normal low is 45F DAILY EXTREMES Temperature and precipitation records back to 1885, and wind records back to 1940 (e = estimated): RECORDS FOR MAY 5 HIGH 92F IN 1949 LOW 30F IN 1891 PRECIP 2.74 INCHES IN 1922 SNOWFALL 3.0 INCHES IN 1917 PEAK GUST 58 MPH S IN 1966 & 58e MPH SW IN 1976 RECORDS FOR MAY 6 HIGH 90F IN 1930 LOW 29F IN 1891 PRECIP 1.04 INCHES IN 1890 SNOWFALL TRACE IN 1917,1996 PEAK GUST 65 MPH SSE IN 1989 TODAY'S REPORT PREPARED BY: Samantha Richard