BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA TUESDAY, DECEMBER 21, 2021 ALL TIMES ARE IN EASTERN STANDARD TIME SUNRISE: 0710E SUNSET: 1615E INCREASING CLOUDS AND NOT AS CHILLY.... The day started with plenty of sunshine, however high clouds have been increasing and thickening as the day progresses. Despite this, the temperature has been able to reach 40 degrees early this afternoon, definitely a milder day than yesterday. The dew point has been gradually increasing from the mid teens to the mid 20s, indicative of the arctic air mass moving out of the region. Winds have been fairly light today, decreasing from around 12 mph early this morning to only around 5-6 mph early this afternoon, mainly out of a west-southwest direction. Visibility hasn't been as great as one would expect with the dry air in place. Maximum visibility has only been 40 miles today, up from 30 miles early this morning. The high so far today is 40F, which is 1 degree above the normal max of 39F. The low since midnight is 27F, which is 3 degrees above the normal low of 24F. -------------------------------------------------------------- Today's Observations: 7 A.M. Weather: Clear, few altocumulus N-E-SE, few cirrus all quadrants Temperature: 28F; Dew Point: 17F; Relative Humidity: 63% Wind: SW @ 10G17 kts Sea-level pressure: 1018.1 mb; 30.06 in. Hg: rising then falling Visibility: 30 miles, hazy 6-hr Max temp: 30F 6-hr Min temp: 27F 24-hr Precip: 0.00 ins. 24-hr Snowfall: 0.0 ins. Snow Depth: 0 ins. BHO SA 1155 CLR 30 181/28/17/2310G17/006/ FEW AC N-E-SE FEW CI ALQDS HAZY/ 8/051 50009 10030 20027 10 A.M. Weather: Thin broken cirrus, few cirrostratus distant W-NW Temperature: 35F; Dew Point: 20F; Relative Humidity: 54% Wind: WSW @ 7 kts Sea-level pressure: 1019.8 mb; 30.11 in Hg; rising, then more slowly Visibility: 40 miles, hazy 3-hr Precip: 0.00 ins. 3-hr Snowfall: 0.0 ins. BHO SA 1455 E250 -BKN 40 198/35/20/2407/011/ FEW CS DSNT W-NW HAZY/ 8/005 51017 1 P.M. Weather: Broken cirrostratus/cirrus Temperature: 39F, Dew point: 25F; Relative Humidity: 56% Wind: WSW @ 5 kts, wind light Sea-level pressure: 1017.8 mb; 30.06 in Hg; falling, then more slowly Visibility: 40 miles, hazy 6-hr Max temp: 40F 6-hr Min temp: 28F 6-hr Precip: 0.00 ins. 6-hr Snowfall: 0.0 ins. Snow Depth: 0.0 ins. BHO SA 1755 E250 BKN 40 178/39/25/2505/006/ HAZY WND LGT/ 8/006 56020 10040 20028 SUMMARY FOR MONDAY, DECEMBER 20, 2021 TEMPERATURE (DEGREES F) MAX.......32 NORMAL.....39 MIN.......15 NORMAL.....24 MEAN......24 NORMAL.....31 DEPARTURE FROM 30-YEAR (1991-2020) NORMAL............... -7 TOTAL DEPARTURE FOR THE MONTH...........................+89 [+4.3 DEGREES/DAY] HEATING DEGREE DAYS (SEASON: JUL 2021 THRU JUN 2022) TOTAL HEATING UNITS FOR YESTERDAY...............41 DEPARTURE........+7 TOTAL HEATING UNITS FOR THE MONTH..............530 DEPARTURE.......-89 TOTAL HEATING UNITS FOR THE SEASON............1537 DEPARTURE......-286 TOTAL HEATING UNITS LAST SEASON TO DATE.......1600 DEPARTURE........-63 PEAK WIND GUST (MPH): Official (1-Sec AVG).......29 SSW @ 9:52 P.M. AEROVANE...................30 SSW @ 9:54 P.M. VECTOR #2 (Instantaneous)..30 @ 9:52 P.M. DAVIS #2 ..................28 SW @ 11:30 P.M. RMY #2 (Instantaneous).....30 SW @ 9:52 P.M. ASOS...........OUT OF SERVICE D/T RENOVATIONS VECTOR #1......OUT OF SERVICE D/T RENOVATIONS DAVIS #1.......OUT OF SERVICE D/T RENOVATIONS RMY #1.........OUT OF SERVICE D/T RENOVATIONS MERLIN.........OUT OF SERVICE D/T RENOVATIONS FASTEST MILE: CONTACTING ANEMOMETER/OFFICIAL..................22 SSW @ 11:29 P.M. MAXIMUM 2-MINUTE VECTOR #2 AVERAGE..............21 @ 9:53 P.M. MAXIMUM 2-MINUTE DAVIS #2 AVERAGE...............21 SW @ 9:53 P.M. MAXIMUM 2-MINUTE RMY #2 AVERAGE.................21 SW @ 9:53 P.M. MAXIMUM 2-MINUTE ASOS AVERAGE.......OUT OF SERVICE D/T RENOVATIONS MAXIMUM 2-MINUTE DAVIS #1 AVERAGE...OUT OF SERVICE D/T RENOVATIONS MAXIMUM 2-MINUTE VECTOR #1 AVERAGE..OUT OF SERVICE D/T RENOVATIONS MAXIMUM 2-MINUTE RMY #1 AVERAGE.....OUT OF SERVICE D/T RENOVATIONS AVERAGE WIND SPEED AND DIRECTION: CONTACTING/OFFICIAL.....10.1 NNW [242 total miles] VECTOR #2...............10.6 DAVIS #2................10.5 W RMY #2..................10.7 W RMY #1..............OUT OF SERVICE D/T RENOVATIONS ASOS................OUT OF SERVICE D/T RENOVATIONS VECTOR #1...........OUT OF SERVICE D/T RENOVATIONS DAVIS #1............OUT OF SERVICE D/T RENOVATIONS PRECIPITATION (INCHES) THROUGH THIS MORNING (EST): TOTAL PRECIPITATION 24 HRS ENDING 7 A.M.......0.00 DEPARTURE.....-0.17 TOTAL PRECIPITATION FOR THE MONTH.............1.95 DEPARTURE.....-1.61 TOTAL PRECIPITATION FOR THE YEAR.............58.72 DEPARTURE.....+6.95 SNOWFALL (INCHES) THROUGH THIS MORNING (EST): TOTAL SNOWFALL 24 HRS ENDING 7 A.M.............0.0 DEPARTURE......-0.5 TOTAL SNOWFALL FOR THE MONTH...................1.4 DEPARTURE......-5.7 TOTAL SNOWFALL FOR THE SEASON (2021-2022)......2.4 DEPARTURE......-7.2 PRELIMINARY CLIMATE SUMMARY FOR DECEMBER 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 12/01 44/30/37/0.00/0.0/263/47 35 W AERO 35 W RMY 34 12/02 58/35/47/10/T/0.0/106/19 56 WNW AERO 59 WNW RMY 62 TSTM 12/03 41/28/35/-1/0.00/0.0/512/92 46 NW AERO 44 NW RMY 46 12/04 39/25/32/-4/0.00/0.0/233/42 25 SW AERO 23 SW RMY 26 12/05 45/32/39/+3/0.00/0.0/460/83 25 SE AERO 25 SE RMY 25 12/06 59/37/48/+13/0.34/0.0/077/14 59 WNW AERO 59 NW RMY 60 12/07 40/29/35/0/T/0.0/436/79 47 WNW AERO 36 WNW RMY 48 12/08 34/25/30/-5/0.05/0.6/000/00 26 NNE AERO 25 NE RMY 26 12/09 35/20/28/-6/0.05/0.6/319/58 32 NW AERO 30 NW RMY 33 12/10 43/27/35/+1/0.00/0.0/000/00 21 SE AERO 20 SE RMY 21 12/11 62/37/50/+16/0.34/0.0/000/00 57 SSW AERO 59 SSW RMY 58 12/12 58/36/47/+13/0.05/0.0/416/76 55 WNW AERO 55 WNW RMY 58 12/13 50/35/43/+10/0.00/0.0/224/41 32 WSW AERO 33 WSW RMY 33 12/14 50/33/42/+9/0.00/0.0/442/81 31 WSW AERO 30 WSW RMY 32 12/15 42/28/35/+2/T/0.0/153/28 35 SSE AERO 35 SSE RMY 36 12/16 58/42/50/+18/0.21/0.0/016/03 35 SW AERO 37 SW RMY 38 12/17 56/39/48/+16/0.00/0.0/518/95 43 WNW AERO 41 WNW RMY 46 12/18 39/31/35/+3/0.52/0.2/000/00 21 NNW AERO 20 NNW RMY 20 12/19 39/20/30/-2/0.39/0.0/.../.. 35 NNW AERO 37 NNW RMY 36 12/20 32/15/24/-7/0.00/0.0/.../.. 29 SSW AERO 30 SSW RMY 30 12/21 The low since midnight is 27F, the daily normal low is 24F DAILY RECORDS FOR DECEMBER 2021 12/16/21: DAILY RECORD HIGH MINIMUM TEMPERATURE OF 42F TIES PREVIOUS RECORD of 42F SET IN 1982 DAILY EXTREMES Temperature and precipitation records back to 1885, and wind records back to 1940 (e = estimated) RECORDS FOR DECEMBER 21 HIGH 62 IN 2018 LOW -10 IN 1942 PRECIP 2.37 INS. IN 1946 SNOWFALL 11.4 INS. IN 1954 PEAK GUST 77 MPH SSE IN 1957 RECORDS FOR DECEMBER 22 HIGH 63 IN 2013 LOW -5 IN 1921 PRECIP 1.52 INS. IN 1975 SNOWFALL 8.8 INS. IN 1975 PEAK GUST 62 MPH WNW IN 1998 TODAY'S REPORT PREPARED BY: Matt Douglas