BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS 02186 ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY THURSDAY, DECEMBER 24, 2009 ALL TIMES ARE IN EASTERN STANDARD TIME Today's observations: 7 A.M. Weather: Overcast stratocumulus Temperature: 26F, Dew point: 21F, Wind: NW at 8kts, Wind: Peak gust 27 kts NW at 6:04 A.M. Sea-level pressure: 30.22 inches Hg, rising Visibility: 55 miles 6-hour minimum temp: 16F 24-hour precipitation: 0.00 in. 24-hour snowfall: 0.0 Average snow depth: 10 ins. BHO SA 1155 E20 OVC 50 232/26/21/3108/022/ PK WND 3127/04/ 8/5// 4/010 53027 10026 20016 10 A.M. Weather: Overcast stratocumulus with breaks NW to N and S, virga visible NE to SE Temperature: 32F, Dew point: 26F, Wind: NNW at 12 kts, Wind: Direction variable W to NNE Sea-level pressure: 30.32 inches Hg, rising Visibility: 50 miles, 20 miles NE to SE BHO SA 1455 E20 OVC 50 267/32/26/3312/032/ BRKS IOVC NW-N AND S VIRGA NE-SE VSBY NE-SE 20 WND 27V02/ 8/5// 51035 1 P.M. Weather: Overcast stratocumulus Temperature: 35F, Dew point: 27F, Wind: NW at 10G17 kts, Wind: Direction variable W to NNE Sea-level pressure: 30.30 inches Hg, falling Visibility: 70 miles, visibility lower NE-SE 6-hour max. temp: 35F BHO SA 1755 E18 OVC 70 272/35/27/3210G17/030/ VSBY LWR NE-SE WND 26V02/ 8/5// 50005 10035 20026 WEATHER SUMMARY FOR WEDNESDAY, DECEMBER 23 TEMPERATURE (DEGREES F) MAX.....23 NORMAL.....37 MIN.....10 NORMAL.....22 MEAN....17 NORMAL.....29 DEPARTURE FROM 30-YEAR AVERAGE............-12 TOTAL DEPARTURE FOR THE MONTH.............-41 [-2.0 DEGREES/DAY] HEATING DEGREE DAYS TOTAL HEATING UNITS FOR YESTERDAY............48 DEPARTURE.......+12 TOTAL HEATING UNITS FOR THE MONTH...........794 DEPARTURE.......+47 TOTAL HEATING UNITS FOR THE SEASON.........1954 DEPARTURE.......-82 TOTAL HEATING UNITS LAST SEASON TO DATE....1997 DIFFERENCE......-43 PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY.............29 W AT 11:37 A.M. AEROVANE..............29 WNW AT 2:34 P.M. * ASOS..................28 W AT 11:37 A.M. DAVIS.................29 W AT 11:43 A.M. THE FASTEST MILE FOR YESTERDAY...........22 W AT 11:00 A.M. MAXIMUM 2-MINUTE ASOS AVERAGE............21 W AT 12:17 P.M. MAXIMUM 2-MINUTE DAVIS AVERAGE...........22 W AT 12:17 P.M. AVERAGE WIND SPEED AND DIRECTION...... 14.0 W ASOS................12.9 DAVIS...............14.2 W [276 DEG] * last of several occurrences.... PRECIPITATION (INCHES) THROUGH THIS MORNING (EST) TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.00 DEPARTURE....-0.15 ASOS..............0.00 TOTAL PRECIPITATION FOR THE MONTH..........4.99 DEPARTURE....+1.63 ASOS..............5.14 TOTAL PRECIPITATION FOR THE YEAR..........54.56 DEPARTURE....+4.54 ASOS.............55.90 SNOWFALL (INCHES) THROUGH THIS MORNING (EST) TOTAL SNOWFALL 24 HRS ENDING 7 A.M..........0.0 DEPARTURE.....-0.4 TOTAL SNOWFALL FOR THE MONTH...............24.8 DEPARTURE....+17.3 TOTAL SNOWFALL FOR THE SEASON..............27.8 DEPARTURE....+17.4 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/-14/0/0/540/99 37 W AERO 37 MPH W 12/19 30/14/22/-8/0.01/0.1/000/00 38 N 12/20 26/16/21/-9/1.04/13.7/000/00 42 NNW 12/21 30/15/23/-7/0/0/409/75 45 WNW AERO 45 MPH WNW 12/22 28/14/21/-8/0/0/.../.. 35 W 12/23 23/10/17/-12/0/0/.../.. 29 W 12/24 our morning low temp: 14F; the normal low is now 21F NEW DAILY RECORD FOR DECEMBER 2009 12/3 NEW RECORD HIGH MAXIMUM TEMPERATURE of 67F; surpasses previous record of 61F in 1932, 1950. 12/20 NEW RECORD DAILY SNOWFALL 13.7 INCHES; surpasses previous record of 8.3 inches in 1995 DAILY EXTREMES Temperature and precipitation records back to 1885, and wind records back to 1940 (e = estimated): RECORDS FOR DECEMBER 24 HIGH 58 IN 1996 LOW -6 IN 1943 PRECIP 2.21 INS. IN 1994 SNOWFALL 12.3 INS. IN 1961 PEAK GUST 79e MPH SE IN 1941 RECORDS FOR DECEMBER 25 HIGH 62 IN 1889 LOW -11 IN 1980 PRECIP 1.37 INS. IN 2002 SNOWFALL 8.5 INS. IN 2002 PEAK GUST 80 MPH NW IN 1971 TODAY'S REPORT PREPARED BY: Stephanie Radner