BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY SUNDAY, JANUARY 20, 2019 ALL TIMES ARE IN EASTERN STANDARD TIME FULL SPECTRUM PRECIPITATION ON DISPLAY AS STORM BARRELS THROUGH NEW ENGLAND... With last night's snowfall proving to be the first significant accumulation of the new year, the storm quickly transitioned to rain overnight, and then later to freezing rain as mixing cold air began to produce some observable effects. Rainfall amounts proved to be significant, with 1.07" of liquid precipitation recorded at the 7 A.M. observation, a total which includes the melted down 4.2" of snowfall. Rain began shifting to freezing rain around 9:30 A.M., and gradually transitioning towards precipitation in the form of ice pellets, but not before producing a healthy coating of glaze ice during the freezing rain event. Since then, precipitation has returned back to freezing rain, with the shift occurring around noon, this being a large indicator of warmer air aloft despite surface temperatures remaining largely below freezing. Winds have shifted from easterlies heading into the nighttime hours yesterday, to a more northeasterly direction through the day today. Temperatures continue to drop as cold air streams into the area, with a low temperature of 25 F reached by the time of the 1 P.M. observation. Atmospheric pressure also continues to drop to strikingly low readings with a low station pressure of 967 mb eclipsed just before the 1 P.M. observation. Today's Observations: 7 A.M. Weather: Moderate Rain, fog Temperature: 33F; Dew Point: 33F; Wind: NE at 17G26 kts Sea-level pressure: 29.61 ins. Hg, falling rapidly, then more slowly Visibility: 1/8 mile 6-hr Max temp: 33F 6-hr Min temp: 29F 24-hr Precip: 1.07 24-hr snowfall: 4.2 Snow depth: 4 ins. BHO SA 1155 X W2 1/8RF 026/33/33/0417G26/961/ 8//// 4/004 56069 60/// 70107 10033 20029 10 A.M. Weather: Freezing rain, fog Temperature: 29F; Dew Point: 29F; Wind: N at 11G13 kts Sea-level pressure: 29.47 ins. Hg, falling, then more rapidly Visibility: 1/16 mile 3-hr Precip: 0.53 ins. BHO SA 1455 X W1 1/16ZRF 981/29/29/3511G13/947/ 8//// 56045 6053/ 1 P.M. Weather: Freezing rain, fog Temperature: 26F; Dew Point: 26F; Wind: NE at 16G23 kts, Sea-level pressure: 30.27 ins. Hg, decreasing, then more rapidly Visibility: 1/8 mile 6-hr Max temp: 33F 6-hr Min temp: 25F 6-hr Precip: 0.79 ins. 6-hr snowfall: 0.00 ins. Snow depth: 3 ins. BHO SA 1755 X W2 1/8ZRF 903/26/26/0816G23/924/ 8//// 4/003 58078 6079/ 10033 20025 SUMMARY FOR SATURDAY, JANUARY 19, 2019 TEMPERATURE (DEGREES F) MAX.....31 NORMAL.....33 MIN.....24 NORMAL.....17 MEAN....28 NORMAL.....25 DEPARTURE FROM 30-YEAR NORMAL........................+3 TOTAL DEPARTURE FOR THE MONTH.......................+54 [+2.6 DEGREES/DAY] HEATING DEGREE DAYS (SEASON JUL TO JUN) TOTAL HEATING UNITS FOR YESTERDAY..............37 DEPARTURE.........-3 TOTAL HEATING UNITS FOR THE MONTH.............695 DEPARTURE........-53 TOTAL HEATING UNITS FOR THE SEASON...........2991 DEPARTURE........-61 TOTAL HEATING UNITS LAST SEASON TO DATE..2933 DIFFERENCE.......+58 PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY....................30 E AT 9:18 P.M. AERO.........................30 E AT 9:17 P.M. ASOS.........................33 E AT 9:20 P.M. DAVIS........................33 E AT 9:19 P.M. RMY N/A FASTEST MILE FOR YESTERDAY......................24 E AT 9:15 P.M. MAXIMUM 2-MINUTE ASOS AVERAGE...................25 E AT 9:21 P.M. MAXIMUM 2-MINUTE DAVIS AVERAGE..................24 E AT 9:22 P.M. AVERAGE WIND SPEED AND DIRECTION..............10.7 E ASOS.......................10.6 DAVIS......................10.7 NE [56 deg.] PRECIPITATION (INCHES) THROUGH THIS MORNING (EST) TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....1.07 DEPARTURE.......+0.93 ASOS..............1.05 TOTAL PRECIPITATION FOR THE MONTH..........3.21 DEPARTURE.......+0.51 ASOS..............3.20 TOTAL PRECIPITATION FOR THE YEAR...........3.21 DEPARTURE.......+0.51 ASOS..............3.20 SNOWFALL (INCHES) THROUGH THIS MORNING (EST) TOTAL SNOWFALL 24 HRS ENDING 7 A.M..........4.2 DEPARTURE........+3.7 TOTAL SNOWFALL FOR THE MONTH................4.2 DEPARTURE........-6.5 TOTAL SNOWFALL FOR THE SEASON..............11.9 DEPARTURE.......-14.8 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 27/13/20/-5/0.00/0.0/.../.. 30 NNW AERO 28 NW RMY N/A 01/18 40/21/31/+6/0.00/0.0/.../.. 18 WNW AERO 18 WNW RMY N/A 01/19 31/24/28/+3/.../1.6/.../.. 30 E AERO 30 E RMY N/A 01/20 Low temp since midnight is 25F; normal low is 17F DAILY EXTREMES Temperature and precipitation records back to 1885, and wind records back to 1940 (e = estimated): RECORDS FOR JANUARY 20 HIGH 59F IN 1951 LOW -9F IN 1901 PRECIP 1.95 INS. IN 1978 SNOWFALL 19.0 INS. IN 1978 PEAK GUST 76e MPH NE IN 1978 RECORDS FOR JANUARY 21 HIGH 65F IN 1906 LOW -4F IN 1888,1893 PRECIP 2.49 INS. IN 1979 SNOWFALL 9.0 INS. IN 2014 PEAK GUST 78e MPH SE IN 1979 TODAY'S REPORT PREPARED BY: Nate Iannuccillo