BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS 02186 ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY WEDNESDAY, DECEMBER 30, 2009 ALL TIMES ARE IN EASTERN STANDARD TIME GALE FORCE WIND GUSTS FROM W-WNW ON TUESDAYF TEMPERATURE DROPS TO 8F BY MIDNIGHT MORNING LOW OF 7F COLDEST OF SEASON TO DATE Wind gusts from the west and from the west-northwest during yesterday afternoon as follows: Maximum, Inc. Maestro 71 mph @ 3:47 P.M. (time estimated) Maximum, Inc. Merlin 65 MPH WNW @ 3:47 P.M. (time estimated) Davis system: 58 MPH WNW @ 3:08 P.M. 420C system: 58 MPH W @ 1:32 P.M. Aerovane: 58 MPH WNW @ 3:47 P.M. ASOS: 56 MPH WNW @ 3:47 P.M. The strong winds of yesterday have decreased today still coming from the west. The peak gust for the day has been 36 MPH W during the early morning hours. Temperatures dropped to 6.6 degrees at about 5:21 a.m. Today's observations: 7 A.M. Weather: Clear, few stratocumulus distant NE-E offshore, cirrus distant south thru southwest Temperature: 7F, Dew point: -3F, Wind: W at 17G24 kts, Wind: Peak wind gust 27 kts W @ 6:33 a.m. Wind: Direction variable WSW to NW Sea-level pressure: 30.34 inches Hg, rising Visibility: 60 miles, 70 miles northwest 6-hour minimum temp: 7F 24-hour precipitation: 0.00 inch Average snow depth: None BHO SA 1155 CLR 60 274/7/-3/2717G24/034/ FEW SC DSNT OFFSHR NE-E CI DSNT S-SW PK WND 2727/33/ WND 24V31/ 8/501 53026 10008 20007 10 A.M. Weather: Clear, few stratocumulus offshore distant northeast thru east, cirrus layer distant south thru southwest Temperature: 16F, Dew point: 0F, Wind: W at 17G25 kts, Wind: Peak wind gust 26 kts W at 9:22 a.m. Wind: Direction variable WSW to WNW Sea-level pressure: 30.37 inches Hg, rising Visibility: 30 miles, light haze BHO SA 1455 CLR 70 286/16/0/2817G25/037/ FEW SC DSNT OFFSHR NE-E CI LYR DSNT S-SW PK WND 2826/22/ WND 24V30/ 8/501 51012 1 P.M. Weather: Thin scattered and thin broken cirrus and cirrostratus, layers increasing, lower cirrus distant SSE-SW-WNW, layers increasing Temperature: 25F, Dew point: 2F, Wind: W at 14G245 kts, Wind: Peak wind W at 26 kts @ 12:11 p.m., Wind: Direction variable WSW to WNW, Sea-level pressure: 30.34 inches Hg, falling Visibility: 75 miles 6-hour maximum temp: 25F BHO SA 1755 250 –SCT 300 –BKN 75 274/25/2/2714G22/034/ LWR CI LYR DSNT SSE-SW-WNW CI ADVCNG PK WND 2726/11/ WND 24V30/ 8/006 58012 10025 20007 WEATHER SUMMARY FOR TUESDAY, DECEMBER 29 TEMPERATURE (DEGREES F) MAX.....27 NORMAL.....35 MIN......8 NORMAL.....20 MEAN....18 NORMAL.....28 DEPARTURE FROM 30-YEAR AVERAGE............-10 TOTAL DEPARTURE FOR THE MONTH.............-24 [-1.0 DEGREES/DAY] HEATING DEGREE DAYS TOTAL HEATING UNITS FOR YESTERDAY............47 DEPARTURE.......+10 TOTAL HEATING UNITS FOR THE MONTH...........997 DEPARTURE.......+31 TOTAL HEATING UNITS FOR THE SEASON.........2157 DEPARTURE.......-98 TOTAL HEATING UNITS LAST SEASON TO DATE....2155 DIFFERENCE.......+2 PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY.............58 W AT 1:32 P.M. AEROVANE..............58 WNW AT 3:47 P.M. ASOS..................56 WNW AT 3:47 P.M. DAVIS.................58 WNW AT 3:08 P.M. THE FASTEST MILE FOR YESTERDAY...........45 W AT 3:58 P.M. * MAXIMUM 2-MINUTE ASOS AVERAGE............40 W AT 3:58 P.M. MAXIMUM 2-MINUTE DAVIS AVERAGE...........42 WNW AT 3:04 P.M. AVERAGE WIND SPEED AND DIRECTION.......26.0 W ASOS................24.0 DAVIS...............24.4 W [280 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..........5.55 DEPARTURE....+1.29 ASOS..............5.74 TOTAL PRECIPITATION FOR THE YEAR..........55.12 DEPARTURE....+4.20 ASOS.............56.50 SNOWFALL (INCHES) THROUGH THIS MORNING (EST) TOTAL SNOWFALL 24 HRS ENDING 7 A.M..........0.0 DEPARTURE.....-0.4 TOTAL SNOWFALL FOR THE MONTH...............25.1 DEPARTURE....+15.2 TOTAL SNOWFALL FOR THE SEASON..............28.1 DEPARTURE....+15.3 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/-8/0/0/528/97 35 W 12/23 23/10/17/-12/0/0/441/81 29 W 12/24 36/14/25/-4/0/0/055/10 31 NW 12/25 35/25/30/+1/0.02/0.1/185/34 18 NNE 12/26 42/30/36/+8/0.01/0.1/000/00 38 E 12/27 52/35/44/+16/0.45/0/033/06 * 50 ESE AERO 51 MPH SE 12/28 41/27/34/+6/0.08/0.1/.../.. 40 W AERO 42 MPH W 12/29 27/8/18/-10/0/0/.../.. 58 W AERO 58 MPH W 12/30 our morning low temp: 7F; the normal low is now 20F * sunshine added for 27th, was reported as zero 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 30 HIGH 60 IN 1984 LOW -18 IN 1933 PRECIP 1.48 INS. IN 1891 SNOWFALL 7.5 INS. IN 1956 PEAK GUST 81 MPH WNW IN 1962 RECORDS FOR DECEMBER 31 HIGH 62 IN 1965 LOW -12 IN 1917 PRECIP 0.96 INS. IN 1906 SNOWFALL 7.5 INS. IN 2008 PEAK GUST 78 MPH NW IN 1990 TODAY'S REPORT PREPARED BY: Robert Skilling