BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA SUNDAY, OCTOBER 25, 2020 ALL TIMES ARE IN EASTERN STANDARD TIME MUCH COOLER TODAY FOLLOWING A COLD FRONTAL PASSAGE LATE YESTERDAY, LOTS OF CLOUDS LINGERING AS WELL... What a difference a day makes. After temperatures reaching the upper 60s yesterday, we've only briefly made it to 50 so far today. A cold front came through late yesterday shifting the wind from generally southwesterly to north- northwesterly. Temperatures fell steadily last evening from the low 60s to the low 40s by midnight. A gusty north-northwest wind also developed helping to usher in the cooler air mass. Today we've seen mainly cloudy skies with the wind starting the day out of the north-northwest, but has gradually veered over to the east-northeast by early this afternoon. The combination of the onshore wind and cloud cover has helped to hold temperatures mainly in the 40s here on the summit, although we did briefly touch 50 degrees, which as been the maximum so far. As mentioned, the high so far today is 50F, this is 7 degrees below the daily normal maximum of 57F. The low since midnight is 40F, which is exactly normal for the date. Today's Observations: 7 A.M. Weather: Broken stratocumulus, broken altocumulus, broken cirrus/cirrostratus Temperature: 42F; Dew Point: 31F; Relative Humidity: 64% Wind: NNW at 10G17 kts Sea-level pressure: 30.21 ins. Hg: rising unsteadily Visibility: 70 6-hr Max temp: 42F 6-hr Min temp: 40F 24-hr Precip: 0.00 ins. BHO SA 1155 E35 BKN 120 BKN 250 BKN 70 229/42/31/3410G17/021/ 8/538 52026 10042 20040 10 A.M. Weather: Overcast stratocumulus, few breaks in overcast distant NW-NNW, thin spots in overcast all quadrants Temperature: 47F; Dew Point: 35F; Relative Humidity: 62% Wind: N at 6 kts, wind light and variable Sea-level pressure: 30.24 ins. Hg: rising unsteadily Visibility: 70 miles 3-hr Precip: 0.00 ins. BHO SA 1455 E35 OVC 70 242/47/35/0106/024/ FEW BINOVC DSNT NW-NNW FEW THN SPTS IOVC ALQDS SUN OCLY DMLY VSBL WND L/V/ 8/5// 52013 1 P.M. Weather: Overcast stratocumulus, few thin spots in overcast all quadrants, sun occasionally dimly visible Temperature: 49F; Dew Point: 36F; Relative Humidity: 60% Wind: ENE at 7 kts Sea-level pressure: 30.25 ins. Hg: rising, then falling Visibility: 70 miles 6-hr Max temp: 50F 6-hr Min temp: 42F 6-hr Precip: 0.00 inches BHO SA 1755 E35 OVC 70 244/49/36/0707/025/ FEW THN SPTS IOVC ALQDS HIR CLDS OCLY VSBL SUN OCLY DMLY VSBL/ 8/5// 50002 10050 20042 SUMMARY FOR SATURDAY, OCTOBER 24, 2020 TEMPERATURE (DEGREES F) MAX.....68 NORMAL.....58 MIN.....42 NORMAL.....40 MEAN....55 NORMAL.....49 DEPARTURE FROM 30-YEAR NORMAL................ +6 TOTAL DEPARTURE FOR THE MONTH................+98 [+3.9 DEGREES/DAY] HEATING DEGREE DAYS (SEASON JUL TO JUN) TOTAL HEATING UNITS FOR YESTERDAY.............10 DEPARTURE..... -6 TOTAL HEATING UNITS FOR THE MONTH............196 DEPARTURE....-103 TOTAL HEATING UNITS FOR THE SEASON...........294 DEPARTURE....-147 TOTAL HEATING UNITS LAST SEASON TO DATE......364 DEPARTURE.....-70 COOLING DEGREE DAYS (SEASON JAN TO DEC) TOTAL COOLING UNITS FOR YESTERDAY............. 0 DEPARTURE...... 0 TOTAL COOLING UNITS FOR THE MONTH............. 1 DEPARTURE..... -4 TOTAL COOLING UNITS FOR THE SEASON...........831 DEPARTURE....+229 TOTAL COOLING UNITS LAST SEASON TO DATE......682 DEPARTURE....+149 PEAK WIND GUST FOR YESTERDAY (MPH) 420C/Official...............32 NNW AT 9:57 P.M. AEROVANE (south tower)......32 NNW AT 8:48 P.M. ASOS........................32 NW AT 9:31 P.M DAVIS #1....................31 NW AT 9:31 P.M DAVIS #2 (south tower)......30 N AT 9:33 P.M RMY.........................32 MERLIN......................30 FASTEST MILE FOR YESTERDAY.....................23 NNW AT 9:30 P.M. MAXIMUM 2-MINUTE ASOS AVERAGE..................21 NW AT 9:35 P.M MAXIMUM 2-MINUTE DAVIS #1 AVERAGE..............22 NNW AT 9:32 P.M MAXIMUM 2-MINUTE DAVIS #2 AVERAGE..............22 NNW AT 8:54 P.M AVERAGE WIND SPEED AND DIRECTION............. 9.9 NNW [237 total miles] ASOS......................10.2 DAVIS #1..................10.1 W [272 deg.] DAVIS #2..................10.4 W [267 deg.] PRECIPITATION (INCHES) THROUGH THIS MORNING (EST) TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.00 DEPARTURE....-0.15 ASOS..............0.00 TOTAL PRECIPITATION FOR THE MONTH..........4.20 DEPARTURE....+0.61 ASOS..............4.18 TOTAL PRECIPITATION FOR THE YEAR..........38.62 DEPARTURE....-4.05 ASOS.............39.39 PRELIMINARY CLIMATE SUMMARY FOR OCTOBER 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 M: Missing data 10/01 75/56/66/+9/0.00/591/84 28 SW AERO 28 SW RMY N/A 10/02 63/49/56/-1/0.02/203/29 20 NW AERO 21 NW RMY 20 10/03 65/45/55/-1/0.00/676/97 19 WNW AERO 19 WNW RMY 19 10/04 65/45/55/-1/0.00/659/95 17 ESE AERO 18 ESE RMY 18 10/05 62/52/57/+1/0.00/277/40 17 ENE AERO 17 ENE RMY N/A 10/06 69/51/60/+5/0.00/503/73 28 S AERO 28 S RMY 29 10/07 73/50/62/+7/0.14/316/46 76 W AERO 74 W RMY 70 TSTM 10/08 61/42/52/-2/0.00/676/99 41 W AERO 41 W RMY N/A 10/09 60/37/49/-5/0.00/646/95 25 SSW AERO 28 SSW RMY N/A 10/10 75/52/64/+10/0.00/549/81 40 SSW AERO 40 SSW RMY 38 10/11 64/47/56/+3/0.00/574/85 32 NNW AERO 35 NNW RMY N/A 10/12 52/48/50/-3/T/000/00 28 E AERO 27 E RMY N/A 10/13 57/49/53/0/1.74/000/00 32 E AERO 33 E RMY N/A 10/14 67/47/57/+5/0.00/.../.. 23 WNW AERO 25 WNW RMY N/A 10/15 71/50/61/+9/0.00/.../.. 43 S AERO 46 S RMY 42 10/16 68/48/58/+7/1.00/.../.. 28 S AERO 30 S RMY N/A 10/17 56/39/48/-3/1.24/.../.. 35 WNW AERO 40 WNW RMY 37 10/18 60/46/53/+2/0.00/.../.. 20 ESE AERO 21 ESE RMY 20 10/19 61/46/54/+4/0.00/.../.. 16 ESE AERO 16 SSE RMY N/A 10/20 66/49/58/+8/0.00/.../.. 22 S AERO 22 S RMY 22 10/21 71/56/64/+14/0.06/.../.. 26 SSW AERO 26 SSW RMY 26 10/22 70/54/62/+13/0.00/.../.. 18 SSW AERO 17 SSW RMY N/A 10/23 68/52/60/+11/0.00/.../.. 18 ESE AERO 18 ESE RMY 18 10/24 68/42/55/+6/0.00/.../.. 32 NNW AERO 32 NNW RMY 32 10/25 The low since midnight is 40, the daily normal low is 40F DAILY EXTREMES Temperature and precipitation records back to 1885, and wind records back to 1940 (e = estimated): RECORDS FOR OCTOBER 25 HIGH 81F IN 1963 LOW 26F IN 1922,1939 PRECIP 2.45 INCHES IN 2005 SNOWFALL 1.2 INCHES IN 1960 PEAK GUST 72 MPH ESE IN 1980 RECORDS FOR OCTOBER 26 HIGH 80F IN 1963 LOW 24F IN 1933 PRECIP 1.72 INCHES IN 1894 SNOW 3.0 INCHES IN 1962 WIND 59 MPH SSE IN 1967 TODAY'S REPORT PREPARED BY: Matt Douglas