BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY MONDAY, OCTOBER 24, 2011 ALL TIMES ARE IN EASTERN STANDARD TIME LONG PERIOD OF ABOVE NORMAL TEMPS. ENDED YESTERDAY FIRST FREEZE EXPECTED TO BE QUITE LATE THIS YEAR On Sunday, October 13, our high of only 53F and low of 40F gave a daily mean of 47 degrees so the day average 2 degrees cooler than normal, the first time since it was 5 degrees below normal on October 7. In addition, yesterday was only the 4th day to average cooler than normal thus far this fall season or since September 20th! Over the long term (1886-2010), the average date of the first occurrence of a freezing temperature (32F) or lower is October 20. The earliest recorded 32F temperature or lower occurred on September 22, 1904. The latest occurred on November 15, 1938. The first freeze of the fall season has yet to occur on the summit. Today's observations: 7 A.M. Weather: Scattered dense cirrostratus, overcast cirrostratus, thin spots in overcast Temperature: 46F, Dew point: 35F; Wind: S at 8 kts Sea-level pressure: 30.14 inches Hg, steady Visibility: 25 miles, thin fog below inversion, thin ground fog, patchy, few dense patches, thin steam fog over pond SE 6-hour min. temp: 44F BHO SA 1155 220 SCT E250 OVC 25 208/46/35/1708/014/ THN SPTS IOVC DNS PTCHS CS PTCHY THN GF BLO INVSN/SMT/ THN STEAM FOG OVER POND SE FEW DNS PTCHS ALQDS VSBY W-NW 20 NE-S 35/ 8/007 55005 10048 20044 10 A.M. Weather: Scattered dense cirrus, thin broken cirrus, 2 layers Temperature: 57F, Dew Point: 43F; Wind: SSW at 8 kts, Wind: Light and variable SW-NW Sea-level pressure: 30.13 inches Hg, falling Visibility: 30 miles, distant haze BHO SA 1455 220 SCT 250 –BKN 300 –BKN 30 204/57/43/2108/013/ PTCHS DNS CI VSBY W-NW 25 NE-S 35 DSNT HZ ALQDS/ 8/002 58004 1 P.M. Weather: Scattered cumulus/stratocumulus, few moderate tops, scattered dense cirrostratus layer, overcast dense cirrostratus layer, few thin spots in overcast Temperature: 59F, Dew Point: 41F; Wind: SSW at 12 kts, Wind: Direction variable S-SW Sea-level pressure: 30.07 inches Hg, falling Visibility: 35 miles, distant haze 6-hour max. temp: 61F BHO SA 1755 40 SCT 200 SCT E220 OVC 35 182/59/41/2012/007/ CUSC FEW MDT TOPS FEW THN SPTS IOVC DSNT HZ WND 17V23/ 8/407 58022 10061 20046 WEATHER SUMMARY FOR SUNDAY, OCTOBER 23 TEMPERATURE (DEGREES F) MAX.....53 NORMAL.....58 MIN.....40 NORMAL.....41 MEAN....47 NORMAL.....49 DEPARTURE FROM 30-YEAR NORMAL.....................-2 TOTAL DEPARTURE FOR THE MONTH...................+121 [+5.1 DEGREES/DAY] HEATING DEGREE DAYS TOTAL HEATING UNITS FOR YESTERDAY............18 DEPARTURE........+2 TOTAL HEATING UNITS FOR THE MONTH...........169 DEPARTURE......-115 TOTAL HEATING UNITS FOR THE SEASON..........244 DEPARTURE......-209 TOTAL HEATING UNITS LAST SEASON TO DATE.....388 DIFFERENCE.....-144 PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY..............17 NW AT 2:54 A.M. AERO...................18 NW AT 2:54 A.M. ASOS...................17 NW AT 2:54 A.M. DAVIS..................16 WNW AT 2:36 A.M. RMY N/A THE FASTEST MILE FOR YESTERDAY............14 NW AT 2:49 A.M. MAXIMUM 2-MINUTE ASOS AVERAGE.............14 NW AT 2:52 A.M. MAXIMUM 2-MINUTE DAVIS AVERAGE............13 NW AT 2:47 A.M. AVERAGE WIND SPEED AND DIRECTION.........6.2 W ASOS..................6.8 DAVIS.................5.9 WNW [290 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..........6.57 DEPARTURE..........+3.35 ASOS..............6.58 TOTAL PRECIPITATION FOR THE YEAR..........50.63 DEPARTURE..........+9.81 ASOS..............51.04** **ASOS data is in error due to system failure on 1/12-13 PRELIMINARY CLIMATE SUMMARY FOR OCTOBER 2011 CALENDAR DAY DATA DATA REPORTED: DATE: MAX/MIN/MEAN/DEP/PRECIP/SUN(MIN.)/SUN(%)/ PEAK GUST/AERO GUST AERO: Aerovane wind recording system gust when significant RMY: R.M. Young wind gust recording system added 8/9/2011 TSTM: Thunderstorm day (thunder heard some time during day) ....: Data not yet available, records not finalized 10/1 70/55/63/+6/0.88/085/12 24 NE AERO N/A RMY 25 TSTM 10/2 64/54/59/+3/0.03/000/00 24 NNE AERO 27 MPH NNE RMY 26 10/3 67/53/60/+4/0.04/329/47 20 S AERO 22 MPH S RMY 22 10/4 65/52/59/+3/1.87/307/44 24 NW AERO 25 MPH NNW RMY 25 TSTM 10/5 63/42/53/-2/T/468/70 43 WNW AERO 42 MPH WNW RMY 44 10/6 60/40/50/-5/0.00/677/98 31 NW AERO 35 MPH WNW RMY 36 10/7 61/39/50/-5/0.00/654/95 17 SW AERO 18 MPH SW RMY N/A 10/8 78/49/64/+10/0.00/651/95 22 WSW AERO 23 MPH WSW RMY 24 10/9 82/61/72/+18/0.00/663/97 21 W AERO 23 MPH W RMY 24 10/10 81/59/70/+16/0.00/653/96 23 NW AERO 23 MPH NW RMY 23 10/11 65/52/59/+6/0.00/433/64 17 E AERO 17 MPH E RMY 18 10/12 59/51/55/+2/0.06/.../.. 23 ENE AERO 23 MPH ENE RMY N/A 10/13 62/55/59/+7/1.00/000/00 28 NNE AERO 28 MPH NNE RMY 27 10/14 69/57/63/+11/0.58/000/00 36 SSW AERO 38 MPH SSW RMY 39 TSTM 10/15 64/51/58/+6/0.00/566/85 42 SSW AERO 44 MPH SSW RMY 44 10/16 63/51/57/+6/0.00/550/83 42 WSW AERO 43 MPH WSW RMY 41 10/17 63/50/57/+6/0.01/575/87 36 SSW AERO 38 MPH SSW RMY 37 10/18 67/51/59/+8/T/211/32 27 SW AER0 27 MPH SW RMY N/A 10/19 57/54/56/+5/1.70/000/00 40 NE AERO 40 MPH NE RMY 42 10/20 68/53/61/+11/0.40/.../.. 44 S AERO 48 MPH S RMY 48 10/21 63/46/55/+5/0.00/.../.. 27 SSW AERO 31 MPH SSW RMY 31 10/22 60/43/52/+2/T/.../.. 20 W AERO 20 MPH W RMY 20 10/23 53/40/47/-2/0.00/.../.. 17 NW AERO 18 MPH NW RMY N/A 10/24 morning low temp: 44F; the normal low is now 40F DAILY RECORDS FOR OCTOBER 2011 10/4 - NEW DAILY RECORD PRECIPITATION OF 1.87 INCHES; surpasses the previous record of 1.07 set in 1986. 10/9 - NEW DAILY RECORD MAXIMUM TEMP OF 82F; surpasses the previous record of 81F set in 1909. 10/9 - NEW DAILY RECORD HIGH MINIMUM TEMP OF 61F; surpasses the previous record of 60F set in 1970. DAILY EXTREMES Temperature and precipitation records back to 1885, and wind records back to 1940 (e = estimated): RECORDS FOR OCTOBER 24 HIGH 79F IN 1963 LOW 22F IN 1969 PRECIP 2.96 INCHES IN 1890 SNOWFALL 1.8 INCHES IN 1960 PEAK GUST 70 MPH SE IN 1959 RECORDS FOR OCTOBER 25 HIGH 81F IN 1963 LOW 26F IN 1922,1939 PRECIP 2.45 INCHES IN 2005 SNOWFALL 1.2 INCHES IN 1960 PEAK GUST 72 MPH ESE IN 1980 TODAY'S REPORT PREPARED BY: Robert Skilling/Patrick Peters