BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS 02186 ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY SUNDAY, DECEMBER 20, 2009 ALL TIMES ARE IN EASTERN STANDARD TIME TOTAL SNOWFALL 13.3 INCHES AT 1 P.M. MODERATE SNOW CONTINUES THROUGH 2 P.M. 13.3 inches of snow were measured at 1 P.M with 1.03 inches of melted precipitation for a snow to liquid ratio of 13:1. Temperatures remained steady in the upper teens through much of the event while winds backed from the north to the west-northwest early this morning. Snow continues to drift here on the summit with wind gusts to 35 MPH. Winds have relaxed slightly since the daily peak gust of 42 MPH NNW at 4:17 A.M. Snow drift maxima are over 17 inches while minima are near 8 inches. Today's observations: 1 P.M. Weather: Sky obscured, moderate snow and fog Temperature: 19F, Dew point: 17F, Wind: WNW at 18G22 kts, Wind: Peak gust 29 kts from the west at 12:23 P.M. Sea-level pressure: 29.53 inches Hg, falling Visibility: 1/4 mile 6-hour max. temp: 19F BHO SA 1755 W5 X 1/4SF 999/19/17/2918G22/953/ PK WND 2729/1723 SNW STRM TOTAL 13.3 IN AND LIQUID EQUIV 1.03 IN/ 8//// 58005 MANUAL 6044/ ASOS 60059/ 10019 20017 WEATHER SUMMARY FOR SATURDAY, DECEMBER 19 TEMPERATURE (DEGREES F) MAX.....30 NORMAL.....38 MIN.....14 NORMAL.....23 MEAN....22 NORMAL.....30 DEPARTURE FROM 30-YEAR AVERAGE.............-8 TOTAL DEPARTURE FOR THE MONTH..............-5 [-0.5 DEGREES/DAY] HEATING DEGREE DAYS TOTAL HEATING UNITS FOR YESTERDAY............43 DEPARTURE........+8 TOTAL HEATING UNITS FOR THE MONTH...........616 DEPARTURE.......+10 TOTAL HEATING UNITS FOR THE SEASON.........1776 DEPARTURE......-119 TOTAL HEATING UNITS LAST SEASON TO DATE....1813 DIFFERENCE......-37 PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY.............38 N AT 10:19 P.M. AEROVANE..............37 N AT 11:15 P.M. ASOS..................38 NNE AT 10:18 P.M. DAVIS.................42 N AT N/A THE FASTEST MILE FOR YESTERDAY...........27 N AT 11:44 P.M. MAXIMUM 2-MINUTE ASOS AVERAGE............25 NNE AT 11:45 P.M. MAXIMUM 2-MINUTE DAVIS AVERAGE...........26 N AT N/A AVERAGE WIND SPEED AND DIRECTION.......11.5 N ASOS................11.3 DAVIS...............11.3 NNW [343 DEG] * Last of several occurrences PRECIPITATION (INCHES) THROUGH THIS MORNING (EST) TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.59 DEPARTURE....+0.45 ASOS..............0.50 TOTAL PRECIPITATION FOR THE MONTH..........4.53 DEPARTURE....+1.76 ASOS..............4.51 TOTAL PRECIPITATION FOR THE YEAR..........54.10 DEPARTURE....+4.67 ASOS.............55.27 SNOWFALL (INCHES) THROUGH THIS MORNING (EST) TOTAL SNOWFALL 24 HRS ENDING 7 A.M..........N/A DEPARTURE......N/A TOTAL SNOWFALL FOR THE MONTH............... N/A DEPARTURE......N/A TOTAL SNOWFALL FOR THE SEASON...............N/A DEPARTURE......N/A PRELIMINARY CLIMATE SUMMARY FOR DECEMBER 2009 CALENDAR DAY DATA DATA REPORTED: DATE: MAX/MIN/MEAN/DEP/PRECIP/SNOW/SUN(MIN.)/SUN(%)/ PEAK GUST/AERO GUST AERO: Aerovane wind recording system gust when significant TSTM: Thunderstorm day (thunder heard some time during day) ....: Data not yet available, records not finalized 12/1 41/28/35/-1/0/0/497/89 29 NW 12/2 51/33/42/+6/0.08/0/345/62 30 SSE 12/3 67/47/57/+22/1.01/0/428/77 69 SSE AERO 73 MPH SSE 12/4 52/40/46/+11/0/0/488/88 26 W 12/5 42/30/36/+1/0.79/4.7/000/00 36 N 12/6 33/25/29/-5/0.09/0.6/513/93 36 NW 12/7 36/25/31/-3/0/0/050/09 22 WSW 12/8 39/25/32/-3/0/0/512/93 27 WNW 12/9 45/29/37/+4/1.23/5.7/000/00 52 ENE AERO 46 MPH ENE 12/10 40/26/33/0/0/0/351/64 46 WSW AERO 39 MPH W 12/11 26/20/23/-9/0/0/395/72 46 WSW AERO 41 MPH WSW 12/12 30/18/24/-8/0/0/548/100 36 W AERO 33 MPH W 12/13 46/23/35/+3/0.74/0/274/50 35 SSE AERO 31 MPH SSE 12/14 41/33/37/+6/0/0/186/34 29 NW 12/15 46/34/40/+9/0/0/006/01 35 W AERO 32 MPH W 12/16 35/22/29/-2/T/T/459/84 43 W AERO 44 MPH W 12/17 22/7/15/-16/0/0/545/100 52 WNW AERO 52 MPH WNW 12/18 26/6/16/-14/0/0/.../.. 37 W AERO 37 MPH W 12/19 30/14/22/-8/0.01/0.1/..../.. 38 N 12/20 morning low temp: 16F; the normal low is now 22F NEW DAILY RECORD FOR DECEMBER 2009 12/3 NEW RECORD HIGH MAXIMUM TEMPERATURE of 67F; surpasses previous record of 61F in 1932, 1950. 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 8.3 INS. IN 1995 PEAK GUST 75 MPH S IN 2002 RECORDS FOR DECEMBER 21 HIGH 60 IN 1957 LOW -10 IN 1942 PRECIP 2.01 INS. IN 1946 SNOWFALL 11.4 INS. IN 1954 PEAK GUST 77 MPH SSE IN 1957 TODAY'S REPORT PREPARED BY: Andy Hoell/Stephanie Radner