BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS 02186 ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY TUESDAY, DECEMBER 23, 2008 ALL TIMES ARE IN EASTERN STANDARD TIME LARGE HIGH PRESSURE PASSING OVER US TODAY COLDEST MORNING OF THE MONTH TO DATE ANOTHER VERY SUNNY AND COLD DAY AS WINDS CONTINUE TO DIMINISH The morning low of 9F is our coldest reading of December to date. Under a completely sunny sky the high temperature had made it up to 25F. That's better than the high of 20F yesterday afternoon. Today and yesterday have been completely sunny during a very cloudy month. 7 A.M. Weather: Clear, stratocumulus offshore distant NE-SSE Temperature: 9F, Dew point: 2F, Wind: W at 18 kts, Sea-level pressure: 30.53 ins. Hg and rising Visibility: 60 miles 6-hour minimum temperature: 9F Snow on ground: 14 inches BHO SA 1155 CLR 60 339/9/2/2616/053/ SC OFFSHR ALG HRZN DSNT NE-SSE LONE ACSL DSNT NNE/ 8/500 4/014 51039 100// 20009 10 A.M. Weather: Thin scattered cirrus Temperature: 17F, Dew point: 5F, Wind: W at 10 kts, Sea-level pressure: 30.59 inches Hg, rising Visibility: 70 miles BHO SA 1455 300 -SCT 70 359/17/5/2810/059/ THN CI SW-NW-N/ 53020 1 P.M. Weather: Clear, few stratocumulus offshore NE-E, cirrus, cirrostratus SW-NW Temperature: 25F, Dew point: 7F, Wind: W at 7 kts, Sea-level pressure: 30.58 inches Hg, falling Visibility: 70 miles 6-hour maximum temperature: 25F BHO SA 1755 CLR 70 354/25/7/2607/058/ FEW SC OFFSHR DSNT NE-E CI DSNT S-NW CS LYR DSNT SW-NW/ 8/505 58005 10025 20009 WEATHER SUMMARY FOR MONDAY, DECEMBER 22 TEMPERATURE (DEGREES F) MAX.....22 NORMAL.....37 MIN.....12 NORMAL.....22 MEAN....17 NORMAL.....29 DEPARTURE FROM 30-YEAR NORMAL..............-12 TOTAL DEPARTURE FOR THE MONTH..............+17 [+0.6 DEGREES/DAY] HEATING DEGREE DAYS TOTAL HEATING UNITS FOR YESTERDAY.............48 DEPARTURE........+13 TOTAL HEATING UNITS FOR THE MONTH............700 DEPARTURE........-11 TOTAL HEATING UNITS FOR THE SEASON..........1950 DEPARTURE........-50 TOTAL HEATING UNITS LAST SEASON TO DATE.....1916 DIFFERENCE.......+34 PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY............47 W AT 3:52 P.M. AEROVANE.............45 W AT 3:52 P.M. ASOS.................46 W AT 3:52 P.M. DAVIS................41 W AT 3:51 P.M. FASTEST MILE FOR YESTERDAY..............35 W AT 3:51 P.M. MAXIMUM 2-MINUTE ASOS AVERAGE...........36 W AT 3:53 P.M. MAXIMUM 2-MINUTE DAVIS AVERAGE..........33 W AT 3:53 P.M. AVERAGE............23.4 W ASOS...............22.2 DAVIS..............19.1 W [280 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...........7.72 DEPARTURE........+4.51 ASOS...............7.75 TOTAL PRECIPITATION FOR THE YEAR...........58.01 DEPARTURE........+8.14 ASOS..............60.76 # # Includes erroneous ASOS precipitation data on 2/13/08. SNOWFALL (INCHES) THROUGH THIS MORNING (EST) TOTAL SNOWFALL 24 HRS ENDING 7 A.M..........0.0 DEPARTURE.....-0.4 TOTAL SNOWFALL FOR THE MONTH...............22.5 DEPARTURE....+15.4 TOTAL SNOWFALL FOR THE SEASON..............22.5 DEPARTURE....+12.5 PRELIMINARY CLIMATE SUMMARY FOR DECEMBER 2008 CALENDAR DAY DATA DATA REPORTED: DATE: MAX/MIN/MEAN/DEP/PRECIP/SNOW/SUN(MIN.)/SUN(%)/ PEAK GUST/AERO GUST AERO: Aerovane recording wind system gust when significant TSTM: Thunderstorm day (thunder heard some time during day) ....: Data not yet available, records not finalized 12/1 59/43/51/+15/0.12/0.0/374/67 43 SSW 12/2 47/32/40/+4/0.00/0.0/451/81 33 SSW 12/3 44/29/37/+2/0.00/0.0/556/100 24 SSW 12/4 53/33/43/+8/T/0.0/122/22 42 SSW Aero 43 MPH S 12/5 38/26/32/-3/0.00/0.0/404/73 26 WNW 12/6 37/23/30/-4/0.00/0.0/309/56 21 S 12/7 32/20/26/-8/0.12/1.6/000/00 54 W Aero 53 MPH W 12/8 21/10/16/-17/0.00/0.0/462/84 50 W Aero 50 MPH W 12/9 53/13/33/0/0.01/T/000/00 48 S Aero 50 MPH S 12/10 60/37/49/+16/0.43/0.0/000/00 55 S Aero 58 MPH S 12/11 37/34/36/+4/1.52/T/000/00 38 NNE Aero 35 MPH NNE 12/12 61/28/45/+13/2.32/0.0/088/16 75 SSE Aero 76 MPH SSE 12/13 28/17/23/-9/0.00/0.0/531/97 33 W 12/14 43/17/30/-1/0.00/0.0/328/60 36 S 12/15 61/43/52/+21/T/0.0/076/15 55 S Aero 56 MPH S 12/16 57/26/42/+11/.../../000/00 43 W 12/17 38/25/32/+1/.../../000/00 26 E Aero 22 MPH E 12/18 37/28/33/+3/0.00/0.0/.../.. 23 WSW 12/19 29/14/22/-8/.../../000/00 46 NE Aero 45 MPH NE 12/20 20/11/16/-14/.../../000/00 30 NNW 12/21 33/17/25/-5/.../../000/00 43 W Aero 44 MPH W 12/22 22/12/17/-12/0.00/0.0/544/100 47 W Aero 45 MPH W 12/23 morning low temp: 9F; our normal low is now 22F NEW DAILY RECORDS FOR DECEMBER 2008... 12/12 PEAK GUST 75 MPH SSE; PREVIOUS 74 MPH W IN 2000 DAILY EXTREMES Temperature and precipitation records back to 1885, and wind records back to 1940 (e = estimated): RECORDS FOR DECEMBER 23 HIGH 62 IN 1990 LOW -1 IN 1989 PRECIP 1.70 INS. IN 1947 SNOWFALL 11.9 INS. IN 1947 PEAK GUST 67 SSE IN 2004 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 TODAY'S REPORT PREPARED By: Robert Skilling