BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS 02186 ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY WEDNESDAY, DECEMBER 21, 2005 ALL TIMES ARE IN EASTERN STANDARD TIME Today's observations: 7 A.M. Weather: Clear Temperature: 15F, Dew point: 11F, Wind: NNW at 10 kt Sea-level pressure: 30.14 inches Hg, rising Visibility: 20 miles BHO SA 1155 CLR 20 207/15/11/3310/014/ FEW SC NE-SE FEW CI DSNT NE-S THN K LYR ALNG HRZN N-NE/ 8/401 4/001 53015 10020 20015 10 A.M. Weather: Clear Temperature: 21F, Dew point: 12F, Wind: W at 10 kt Sea-level pressure: 30.18 inches Hg, rising Visibility: 40 miles BHO SA 1455 CLR 40 220/21/12/2710/018/ FEW SC NE-SE LONE CU N OVR BOS FEW CI DSNT S-NE/ 8/401 51013 WEATHER SUMMARY FOR TUESDAY, DECEMBER 20: TEMPERATURE (DEGREES F) MAX.....31 NORMAL.....37 ASOS....30 AT 3:29 P.M. MIN.....17 NORMAL.....22 ASOS....17 AT 7:53 A.M. MEAN....24 NORMAL.....30 DEPARTURE FROM 30-YEAR NORMAL......- 6 TOTAL DEPARTURE FOR THE MONTH......-108 [- 5.6 DEGREES/DAY] HEATING DEGREE DAYS TOTAL HEATING UNITS FOR YESTERDAY..........41 DEPARTURE......+6 TOTAL HEATING UNITS FOR THE MONTH.........754 DEPARTURE....+116 TOTAL HEATING UNITS FOR THE SEASON.......1819 DEPARTURE....-111 TOTAL HEATING UNITS LAST SEASON TO DATE..1825 DIFFERENCE.....-6 PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY.........27 WSW AT 11:55 A.M. AEROVANE..........28 WSW AT 1:55 A.M. ASOS..............24 WSW AT 2:49 A.M. FASTEST MILE FOR YESTERDAY...........23 WSW AT 11:55 A.M. MAXIMUM 2-MINUTE ASOS AVERAGE........20 WSW AT 11:57 A.M. AVERAGE WIND SPEED AND DIRECTION...14.2 WSW ASOS............14.6 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....-0.57 ASOS..............2.27 TOTAL PRECIPITATION FOR THE YEAR..........64.62 DEPARTURE...+15.19 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....+ 6.8 TOTAL SNOWFALL FOR THE SEASON..............15.2 DEPARTURE....+ 6.0 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 31/17/24/-6/0/0/.../.. 27 MPH WSW 12/21 MORNING LOW 15 DEGREES 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 21 HIGH 60F IN 1957 LOW -10F IN 1942 PRECIP 2.01 INCHES IN 1946 SNOWFALL 11.4 INCHES IN 1954 PEAK GUST 77 MPH SSE IN 1957 RECORDS FOR DECEMBER 22 HIGH 62F IN 1994 LOW -5F IN 1921 PRECIP 1.52 INCHES IN 1975 SNOWFALL 8.8 INCHES IN 1975 PEAK GUST 62 MPH WNW IN 1998 TODAY'S REPORT BY: Andrew Hoell