BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA MONDAY, DECEMBER 20, 2021 ALL TIMES ARE IN EASTERN STANDARD TIME SUNRISE: 0710E SUNSET:  1614E COLD AND DRY WITH AN ABUNDANCE OF SUNSHINE.... An arctic air mass is over the region today as temperatures and dew points are running well below normal for the day. Even with plenty of sunshine today, the mercury has been hard pressed to reach 30 so far here on the summit. The dew point has definitely been indicative of the air mass in place with single digits being measured early this morning. It has recovered a tad bit to the mid teens by early this afternoon. Visibility hasn't been as great as one would expect with the dry air in place. Maximum visibility has only been 60 miles today, up from 40 miles early this morning. The Blue Hill Ski area was making snow overnight for the first time this season. Quite late of course. Also of note, the two ponds we observe from the summit, Houghton's and Ponkapoag, have yet to have much ice cover on them. Again, this is quite late as well. The high so far today is 30F, which is 9 degrees below the normal max of 39F. The low since midnight is 15F, which 9 degrees below the normal low of 24F. -------------------------------------------------------------- Today's Observations: 7 A.M. Weather: Clear, few stratocumulus offshore distant NNE-SSE Temperature: 16F; Dew Point: 9F; Relative Humidity: 75% Wind: NW @ 10 kts Sea-level pressure: 1026.6 mb; 30.32 in. Hg: rising then steady Visibility: 40 miles, hazy 6-hr Max temp: 19F 6-hr Min temp: 15F 24-hr Precip:  Trace 24-hr Snowfall: 0.0 ins. Snow Depth: 0 ins. BHO SA 1155 CLR 40 266/16/9/3310/032/ FEW SC OFFSHR DSNT NNE-SSE HAZY/ 8/500 51015 70000 10019 20015 10 A.M. Weather: Thin scattered cirrus, few stratocumulus offshore distant NNE-SE Temperature: 22F; Dew Point: 14F; Relative Humidity: 70% Wind: WNW @ 3 kts, wind light Sea-level pressure: 1028.4 mb; 30.37 in Hg; rising, then more slowly Visibility: 50 miles 3-hr Precip: 0.00 ins. 3-hr Snowfall: 0.0 ins. BHO SA 1455 250 -SCT 50 284/22/14/2903/037/ FEW SC OFFSHR DSNT NNE-SE WND LGT/ 8/501 51018 1 P.M. Weather: Scattered altocumulus, thin scattered cirrus, few stratocumulus offshore distant NE-SE Temperature: 30F, Dew point: 14F; Relative Humidity: 51% Wind: SSW @ 5 kts, wind light Sea-level pressure: 1025.9 mb; 30.29 in Hg; falling, then more rapidly Visibility: 60 miles 6-hr Max temp: 30F 6-hr Min temp: 16F 6-hr Precip:   0.00 ins. 6-hr Snowfall: 0.0 ins. Snow Depth: 0.0 ins. BHO SA 1755 130 SCT 250 -SCT 60 259/30/14/2105/029/ FEW SC OFFSHR DSNT NE-SE WND LGT/ 8/551 58025 10030 20016 SUMMARY FOR SUNDAY, DECEMBER 19, 2021 TEMPERATURE (DEGREES F) MAX.......39     NORMAL.....39 MIN.......20     NORMAL.....24 MEAN......30     NORMAL.....32 DEPARTURE FROM 30-YEAR (1991-2020) NORMAL...............-2 TOTAL DEPARTURE FOR THE MONTH...........................+96 [+4.9 DEGREES/DAY] HEATING DEGREE DAYS (SEASON: JUL 2021 THRU JUN 2022) TOTAL HEATING UNITS FOR YESTERDAY...............35  DEPARTURE........+2 TOTAL HEATING UNITS FOR THE MONTH..............489  DEPARTURE.......-97 TOTAL HEATING UNITS FOR THE SEASON............1496  DEPARTURE......-294 TOTAL HEATING UNITS LAST SEASON TO DATE.......1565  DEPARTURE.......-69 PEAK WIND GUST (MPH):                      Official (1-Sec AVG).......35 NNW @  7:36 P.M.                      AEROVANE...................37 NNW @  4:24 P.M.                      VECTOR #2 (Instantaneous)..37     @  5:08 P.M.                      DAVIS #2 ..................32 N   @  4:48 P.M.                      RMY #2 (Instantaneous).....36 NNW @  5:08 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..................24 NNW @  5:07 P.M. MAXIMUM 2-MINUTE VECTOR #2 AVERAGE..............22     @  5:09 P.M. MAXIMUM 2-MINUTE DAVIS #2 AVERAGE...............22 N   @  5:09 P.M. MAXIMUM 2-MINUTE RMY #2 AVERAGE.................23 NNW @  5:09 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.....13.5 NNW  [325 total miles]                      VECTOR #2............... N/A                      DAVIS #2................12.8 N                      RMY #2..................12.5 NNW                      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......TRACE  DEPARTURE.....-0.18 TOTAL PRECIPITATION FOR THE MONTH.............1.95  DEPARTURE.....-1.44 TOTAL PRECIPITATION FOR THE YEAR.............58.72  DEPARTURE.....+7.12 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......-5.2 TOTAL SNOWFALL FOR THE SEASON (2021-2022)......2.4  DEPARTURE......-6.7 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 The low since midnight is 15F, the daily normal low is 24F DAILY EXTREMES Temperature and precipitation records back to 1885, and wind records back to 1940 (e = estimated) RECORDS FOR DECEMBER 20 HIGH 61 IN 1957 LOW -16 IN 1942 PRECIP 1.69 INS. IN 1936 SNOWFALL 13.7 INS. IN 2009 PEAK GUST 75 MPH S IN 2002   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 TODAY'S REPORT PREPARED BY: Matt Douglas