BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS 02186 ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY MONDAY, DECEMBER 28, 2009 ALL TIMES ARE IN EASTERN STANDARD TIME THAW QUICKLY MELTS AWAY ALL OF OUR SNOW SOUTHEAST WINDS PEAK GUSTS REACH NEAR 50 MPH AND TEMPERATURES REACH 52F BY NOON SUNDAY SUNDAY'S RAINFALL WAS JUST SHORT OF HALF INCH TODAY’S WEATHER UPDATE: 1:25 p.m. All but a few scattered small patches remain of a 9-inch snow cover on Christmas remain this morning. Temperatures were rising steadily on increasing east winds Saturday evening reaching 41F by midnight and then rising through the 40's as light rain began between 2 and 3 a.m. early Sunday morning. Winds veered to east-southeast and southeast and became increasingly gusty with the highest speeds averaging 30 to 35 MPH and gusting to 50 MPH from the east-southeast to southeast between 7 and 8 a.m. High temperatures reached 52F around noon. UPDATE: Light rain began just after noon today and Began mixing with and possibly changing to snow as Of 1:25 p.m. as the temp. dropped to 34F. Today's observations: 7 A.M. Weather: Scattered altocumulus and altocumulus lenticularis Temperature: 31F, Dew point: 26F, Wind: S at 10 kts Sea-level pressure: 29.71 inches Hg, rising slightly Visibility: 25 miles, very thin fog below inversion 6-hour minimum temp: 31F 24-hour precipitation: 0.20 inch Average snow depth: None (few small patches around summit) BHO SA 1155 95 SCT 25 062/31/26/1810/971/ PTCHS ACSL ALQDS VRY THN FG BLO INVSN/ 8/040 55014 MANUAL 70020 ASOS 70023 10036 20031 10 A.M. Weather: Overcast altocumulus with virga, break in overcast distant NE-SE, higher clouds visible distant SE-S and altocumulus layer invading sky Temperature: 37F, Dew point: 29F, Wind: SE at 10 kts, Wind: Direction gradually backing past hour Sea-level pressure: 29.63 inches Hg, falling Visibility: 40 miles, lower SW-NW BHO SA 1455 E75 OVC 40 034/37/29/1410/963/ BINOVC DSNT NE-SE HIER CLD VSB DSNT SE-S VIRGA ALQDS VSBY LWR SW-NW WND GRLY BACKING PST HR 8/05/ 58028 1 P.M. Weather: Overcast stratus fractus, light rain and fog, rain began 12:10 p.m. Temperature: 37F, Dew point: 36F, Wind: S at 18G27 kts, Wind: Direction suddenly veering Sea-level pressure: 29.48 inches Hg, falling Visibility: 4 miles with light rain and fog 6-hour maximum temp: 41F 6-hour precipitation: 0.20 inches BHO SA 1755 E12 OVC 4R-F 982/37/36/1718G27/948/ PK WND 1827/53/ WND SUDDEN VEERING RB10/ 8/7// 56052 MANUAL 6003/ ASOS 60004 10041 20030 WEATHER SUMMARY FOR SUNDAY, DECEMBER 27 TEMPERATURE (DEGREES F) MAX.....52 NORMAL.....36 MIN.....35 NORMAL.....21 MEAN....44 NORMAL.....28 DEPARTURE FROM 30-YEAR AVERAGE............+16 TOTAL DEPARTURE FOR THE MONTH.............-20 [-0.9 DEGREES/DAY] HEATING DEGREE DAYS TOTAL HEATING UNITS FOR YESTERDAY............21 DEPARTURE.......-16 TOTAL HEATING UNITS FOR THE MONTH...........919 DEPARTURE.......+27 TOTAL HEATING UNITS FOR THE SEASON.........2079 DEPARTURE......-102 TOTAL HEATING UNITS LAST SEASON TO DATE....2111 DIFFERENCE......-32 PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY.............50 ESE AT 7:23 A.M. AEROVANE..............51 ESE AT 7:07 A.M. ASOS..................49 SE AT 7:24 A.M. DAVIS.................49 SE AT 7:07 A.M. THE FASTEST MILE FOR YESTERDAY...........35 SE AT 7:22 A.M. MAXIMUM 2-MINUTE ASOS AVERAGE............32 SE AT 7:22 A.M. MAXIMUM 2-MINUTE DAVIS AVERAGE...........35 ESE AT 7:22 A.M. AVERAGE WIND SPEED AND DIRECTION.......21.0 WSW ASOS................19.2 DAVIS...............19.2 SSE [150 DEG] PRECIPITATION (INCHES) THROUGH THIS MORNING (EST) TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.20 DEPARTURE....+0.05 ASOS..............0.23 TOTAL PRECIPITATION FOR THE MONTH..........5.47 DEPARTURE....+1.51 ASOS..............5.65 TOTAL PRECIPITATION FOR THE YEAR..........55.04 DEPARTURE....+4.42 ASOS.............56.41 SNOWFALL (INCHES) THROUGH THIS MORNING (EST) TOTAL SNOWFALL 24 HRS ENDING 7 A.M..........0.0 DEPARTURE.....-0.4 TOTAL SNOWFALL FOR THE MONTH...............25.0 DEPARTURE....+15.9 TOTAL SNOWFALL FOR THE SEASON..............28.0 DEPARTURE....+16.0 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 36/14/25/-4/0/0/.../.. 31 NW 12/25 35/25/30/+1/0.02/0.1/.../.. 18 NNE 12/26 42/30/36/+8/0.01/0.1./.../.. 38 E 12/27 52/35/44/+16/0.45/0/000/00 50 ESE AERO 51 MPH SE 12/28 our morning low temp. thru 7 a.m. is 31F and 30F thru 8 a.m.; the normal low is now 20F 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 28 HIGH 60 IN 1982 LOW -2 IN 1933 PRECIP 2.16 INS. IN 1967 SNOWFALL 9.5 INS. IN 1967 PEAK GUST 89 MPH SSE IN 1983 RECORDS FOR DECEMBER 29 HIGH 72 IN 1984 LOW -19 IN 1933 (RECORD FOR DECEMBER) PRECIP 1.91 INS. IN 1945 SNOWFALL 18.4 INS. IN 1945 PEAK GUST 95 MPH S IN 1966 (RECORD FOR DECEMBER) TODAY'S REPORT PREPARED BY: Robert Skilling