BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY THURSDAY, JANUARY 17, 2019 ALL TIMES ARE IN EASTERN STANDARD TIME A COLD AND DRY DAY WITH GOOD VISIBILITY ATOP  GREAT BLUE HILL...   Clouds have increased considerably since this morning,  with the majority of the sky becoming covered by a  cirrostratus layer following the 1 P.M. observation. Cool and dry air has moved into the region, with a  minimum humidity so far today of 25%. Winds died down after noontime, becoming light and variable. The high so far today is 25F, eight degrees below the normal  maximum of 33F. The low since midnight is 13F, four  degrees below the daily normal minimum of 17.   Today's Observations: 7 A.M. Weather: Scattered cirrus Temperature: 14F; Dew Point: 3F; Wind: NNW at 13G17 kts Sea-level pressure: 29.65 ins. Hg, rising steadily Visibility: 40 miles, thin smoke layer 6-hr Max temp: 26F 6-hr Min temp: 14F 24-hr Precip: 0.00 24-hr snowfall: 0.0 Snow depth: 0 ins.  BHO SA 1155 200 SCT 40 265/14/3/3313G17/031/ THN K LYR ALQDS/ 8/050 51023 10026 20014 10 A.M. Weather: Scattered cirrus Temperature: 19F; Dew Point: 0F; Wind: NNW at 8 kts Sea-level pressure: 30.38 ins. Hg, rising steadily Visibility: 75 miles 3-hr Precip: 0.00 ins. BHO SA 1455 250 SCT 75 288/19/0/3408/038/ 8/002 53023 1 P.M. Weather: Broken cirrostratus Temperature: 25F; Dew Point: -5F; Wind: WNW at 3 kts, Wind: Light and variable  Sea-level pressure: 30.33 ins. Hg, falling steadily Visibility: 75 miles 6-hr Max temp: 26F 6-hr Min temp: 13F 6-hr Precip: 0.00 ins. 6-hr snowfall: 0.0 ins.   Snow depth: 0 ins. BHO SA 1755 250 SCT 75 272/25/-5/3003/033/ WND L/V/ 8/008 58016 10026 20013 SUMMARY FOR WEDNESDAY, JANUARY 16, 2019  TEMPERATURE (DEGREES F) MAX.....34   NORMAL.....33 MIN.....23   NORMAL.....17 MEAN....29   NORMAL.....25 DEPARTURE FROM 30-YEAR NORMAL........................+4 TOTAL DEPARTURE FOR THE MONTH.......................+50 [+2.9 DEGREES/DAY] HEATING DEGREE DAYS (SEASON JUL TO JUN) TOTAL HEATING UNITS FOR YESTERDAY..............36   DEPARTURE.........-4 TOTAL HEATING UNITS FOR THE MONTH.............579   DEPARTURE........-48 TOTAL HEATING UNITS FOR THE SEASON...........2875   DEPARTURE........-57 TOTAL HEATING UNITS LAST SEASON TO DATE......2818   DIFFERENCE.......+57 PEAK GUST AND AVERAGE WIND SPEED (MPH)  PEAK WIND GUST FOR YESTERDAY....................33  W AT 8:53 P.M.                    AERO.........................32  W AT 8:51 P.M.                    ASOS.........................35  W AT 8:55 P.M.                     DAVIS........................36  W AT 8:53 P.M. RMY 35 FASTEST MILE FOR YESTERDAY......................25  W AT 8:48 P.M.  MAXIMUM 2-MINUTE ASOS AVERAGE...................24  W AT 8:55 P.M. MAXIMUM 2-MINUTE DAVIS AVERAGE..................27  W AT 8:55 P.M. AVERAGE WIND SPEED AND DIRECTION...............13.4 W                    ASOS........................13.9                    DAVIS.......................13.6 W [259 deg.]    PRECIPITATION (INCHES) THROUGH THIS MORNING (EST) TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.00  DEPARTURE.......-0.14                          ASOS..............0.00 TOTAL PRECIPITATION FOR THE MONTH..........2.14  DEPARTURE.......-0.14                          ASOS..............2.15 TOTAL PRECIPITATION FOR THE YEAR...........2.14  DEPARTURE.......-0.14                          ASOS..............2.15  SNOWFALL (INCHES) THROUGH THIS MORNING (EST) TOTAL SNOWFALL 24 HRS ENDING 7 A.M..........0.0  DEPARTURE........-0.5 TOTAL SNOWFALL FOR THE MONTH..............Trace  DEPARTURE........-9.0 TOTAL SNOWFALL FOR THE SEASON...............7.7  DEPARTURE.......-17.3 PRELIMINARY CLIMATE SUMMARY FOR JANUARY 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 01/01 54/29/42/+15/..../0.0/.../..         53 W   AERO 53 W   RMY 54 01/02 34/24/29/+2/..../.../.../..          22 NW  AERO 22 NW  RMY N/A 01/03 42/28/35/+9/0.01/T/.../..            28 WNW AERO 30 WNW RMY 30 01/04 43/30/37/+11/..../.../.../..         29 SW  AERO 29 SW  RMY 29 01/05 41/32/37/+11/1.19/.../.../..         26 NE  AERO 25 NNW RMY 27 01/06 42/21/32/+6/0.00/0.0/.../..          42 NW  AERO 46 NW  RMY 50 01/07 26/14/20/-6/.../.../.../.. 37 NW  AERO 41 NW  RMY N/A 01/08 40/24/32/+6/.../.../.../..           24 SSE AERO 23 SSE RMY N/A 01/09 42/31/37/+11/.../.../.../..          44 W   AERO 46 WNW RMY 45 01/10 32/20/26/+1/T/T/.../..               37 NW  AERO 41 NW  RMY 43 01/11 26/12/19/-6/0.00/0.0/.../..          36 WNW AERO 37 WNW RMY 38 01/12 26/9/18/-7/0.00/0.0/.../..           32 NW  AERO 32 NW  RMY 29 01/13 25/11/18/-7/0.00/0.0/.../..          18 NNW AERO 16 NW  RMY N/A 01/14 27/20/24/-1/0.00/0.0/.../..          20 NNE AERO 17 N   RMY N/A 01/15 34/18/26/+1/0.00/0.0/.../.. 22 NW  AERO 21 NNW RMY N/A 01/16 34/23/29/+4/0.00/0.0/.../.. 33 W AERO 32 W RMY 35 01/17 Low temp since midnight is 13F; normal low is 17F DAILY EXTREMES Temperature and precipitation records back to 1885, and wind records back to 1940 (e = estimated): RECORDS FOR JANUARY 17 HIGH 55F IN 1973,1995 LOW -8F IN 1907,1982 PRECIP 1.43 INS. IN 1956 SNOWFALL 13.4 INS. IN 1956 PEAK GUST 62 MPH S IN 1994 RECORDS FOR JANUARY 18 HIGH 62F IN 1973,1990 LOW -10F IN 1982 PRECIP 1.68 INS. IN 1915 SNOWFALL 13.0 INS. IN 1948 PEAK GUST 85 MPH SSE IN 2006 TODAY'S REPORT PREPARED BY: Ben Turner and Nicholas Rousseau