BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS 02186 ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY TUESDAY, DECEMBER 20, 2005 ALL TIMES ARE IN EASTERN STANDARD TIME Today's discussion.... Very sunny conditions with just a few clouds today while a distant haze layer is limiting visibility to 45 to 50 miles. December continues to be a moderately cold month as Decembers go with an average temperature of 27.2 degrees running 5.6 degrees below normal. At this level it would rank among the three coldest Decembers since the record coldest December 1989 at 17 degrees. Today's observations: 7 A.M. clear with visibility 40 miles and light haze; temp. 18; dewpoint 09; wind WSW 18 MPH; six hourly min. temp. 18 deg; snow depth 1 inch... BHO SA 1155 CLR 40 140/18/9/2416/994/ FEW ACSL WNW-N AND DSNT NE-ENE/ 8/040 4/001 55000 10020 20018 10 A.M. clear with few cirrus clouds and visibility 40 miles with distant haze; temp. 23; dewpoint 11; wind SW at 12 MPH.. BHO SA 1455 CLR 40 147/23/11/2310/996/ FEW CI DSNT WSW AND ENE DSNT HZ/ 8/001 50007 1 P.M. clear with cirrus east through south through southwest; visibility 45 miles with distant haze; temp. 30; dewpoint 13; wind W 17 gusting to 24 MPH; six hourly max. temp. 30 deg. six hourly min. temp. 17 deg. BHO SA 1755 CLR 45 121/30/13/2615G21/989/ FEW CI E-SE-SW DSNT HZ WND 23V29/ 8/001 56026 10030 20017 WEATHER SUMMARY FOR MONDAY, DECEMBER 19: TEMPERATURE (DEGREES F) MAX.....31 NORMAL.....38 HAZEN....30.7 @ 11:25 a.m. MIN.....21 NORMAL.....23 HAZEN....20.7 @ 11:59 p.m. MEAN....26 NORMAL.....30 DEPARTURE FROM 30-YEAR NORMAL......- 4 TOTAL DEPARTURE FOR THE MONTH......-102 [- 5.6 deg per day] HEATING DEGREE DAYS TOTAL HEATING UNITS FOR YESTERDAY..........39 DEPARTURE....+ 4 TOTAL HEATING UNITS FOR THE MONTH.........713 DEPARTURE...+102 TOTAL HEATING UNITS FOR THE SEASON.......1778 DEPARTURE...-117 TOTAL HEATING UNITS LAST SEASON TO DATE..1895 DIFFERENCE...- 1 PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY.........32 WSW AT 1:56 P.M. AEROVANE..........35 WSW AT 1:56 P.M. ASOS..............31 WSW AT 1:57 A.M. DAVIS.............21 W AT 1:41 P.M. FASTEST MILE FOR YESTERDAY...........23 WSW AT 1:56 P.M. MAXIMUM 2-MINUTE ASOS AVERAGE........24 WSW AT 1:57 P.M. MAXIMUM 1-MINUTE DAVIS AVERAGE.......25 W AT 1:57 P.M. AVERAGE WIND SPEED AND DIRECTION...12.7 W ASOS............13.3 WSW [250 deg] DAVIS...........12.5 W [260 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..........2.35 DEPARTURE....-0.42 ASOS..............2.27 TOTAL PRECIPITATION FOR THE YEAR..........64.62 DEPARTURE...+15.34 ASOS.............62.70* *EXCLUDES 3.19 INCHES OF ERRONEOUS PRECIPITATION RECORDED FROM 1/23-1/28. SNOWFALL (INCHES) THROUGH THIS MORNING (EST) TOTAL SNOWFALL 24 HRS ENDING 7 A.M........ 0.0 DEPARTURE....- 0.4 TOTAL SNOWFALL FOR THE MONTH...............13.1 DEPARTURE....+ 7.2 TOTAL SNOWFALL FOR THE SEASON..............15.2 DEPARTURE....+ 6.4 PRELIMINARY CLIMATE SUMMARY FOR DECEMBER 2005......CALENDAR DAY DATA DATA REPORTED IN THE FOLLOWING ORDER: DATE MAX/MIN/MEAN/DEP/PRECIP/SNOW/SUN(MIN.)/SUN(%)/ PEAK GUST/AERO GUST AERO: Aerovane recording wind system when significant TSTM: Thunderstorm day ....: Data not yet available 12/1 43/35/39/+3/0/0/212/38 29 MPH N 12/2 41/31/36/0/0/0/217/39 46 MPH WSW Aero 51 MPH WSW 12/3 33/26/30/-5/0/0/534/96 46 MPH W Aero 50 MPH W 12/4 28/22/25/-10/0.24/2.2/000/00 22 MPH W 12/5 32/21/27/-8/0/0/061/11 23 MPH WSW 12/6 33/23/28/-6/T/0.1/160/29 31 MPH W Aero 36 MPH W 12/7 28/16/22/-12/T/T/479/87 44 MPH WNW Aero 50 MPH WNW 12/8 31/14/23/-10/0/0/545/99 25 MPH NW 12/9 32/22/27/-6/1.23/10.8/000/00 53 MPH NW Aero 63 MPH NW TSTM/SLEET/GLAZE 12/10 34/21/28/-5/0/0/367/67 30 MPH S 12/11 40/27/34/+2/0/0/493/90 27 MPH SSW 12/12 38/21/30/-2/0/0/241/44 25 MPH W 12/13 21/09/15/-17/T/T/361/66 32 MPH WNW Aero 35 MPH WNW 12/14 23/04/14/-17/0/0/513/94 24 MPH NW 12/15 32/07/20/-11/0/0/464/85 21 MPH E 12/16 48/27/38/+7/0.88/T/000/00 55 MPH ESE Aero 61 MPH ESE/SLEET/GLAZE 12/17 37/26/32/+1/0/0/469 86 25 MPH W 12/18 33/23/28/-2/0/0/213/39 21 MPH W 12/19 31/21/26/-4/T/T/164/30 32 MPH WSW Aero 35 MPH WSW 12/20 morning low temp. 17 deg. (about 7:37 a.m.) DAILY EXTREMES Temperature and precipitation records back to 1885, and wind records back to 1940 (e = estimated): A NEW DAILY EXTREME HAS BEEN SET FOR DECEMBER 2005 12/9 - A NEW MAXIMUM DAILY SNOWFALL OF 10.8 INCHES; the previous record was 6.0 inches in 2001 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 BY: Robert Skilling