BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS 02186 ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY FRIDAY, OCTOBER 16, 2009 ALL TIMES ARE IN EASTERN STANDARD TIME FIRST SNOWFALL OF THE 2009 SEASON RECORD SNOWFALL FOR TODAY'S DATE * RECORD LOW MAXIMUM TEMPERATURE FOR OCTOBER 15 OF 41F UNDER REVIEW * The first few snowflakes of the season were observered on the summit this morning just before 8:00 AM EDT, mixed with rain and sleet. Snow was melting as it fell, so there has been no accumulation on the boards. Today's snow came about a week later than the earliest snow ever observed on Blue Hill; a trace of snow occurred on October 8th in 1988 and 2001. Mixed rain, sleet and snow continue to fall on the summit at 9:00 A.M. EDT, then turned to very light snow flurries for the next hour. Even with just a trace of snow today, we have a new record snowfall amount because no snowfall has been observed on today's date until this year. Yesterday's high temperature only reached 41F, may have set a new record low maximum temperature for the date. However, we are reviewing our documents which indicate the the previous record low maximum for the date of 45F occurred in 1962, which does not appear to be the correct year. We may see another low maximum temperature record for today's date. The high so far is only 40F, and the record low max for the date is 42F in 1940. On a historical note... Chief Observer Bob Skilling recalls October 1979 when there was a record low maximum temperature of 36F on October 10 (the lowest max temperature on record this early in the season). Later that same month, there were record high temperatures of 79F and 85F on the 21st and 22nd! Today's observations: 7 A.M. Weather: Sky obscured with fog, light ran, sleet, and snow mixed, snow melting as it falls Temperature: 34F, Dew point: 34F, Wind: NNW at 13 kts Wind: Direction variable WNW to NNE Sea-level pressure: 29.92 inches Hg, rising Visibility: 1/16 mile 6-hour minimum temp: 33F 6-hour precipitation: 0.20 in. 24-hour precipitation: 0.40 in. BHO SA 1155 W1 X 1/16R-S-IP-F 132/34/34/3313/992/ SNOW MELTING AS IT FALLS WND 29V02/ 8//// 53009 MANUAL 6020/ ASOS 60018 MANUAL 70040 ASOS 70037 10038 20033 10 A.M. Weather: Overcast stratus, light snow Temperature: 36F, Dew point: 35F, Wind: N at 15G23 kts, Wind: Direction variable WNW to NNE Sea-level pressure: 29.96 inches Hg, falling Visibility: 20 miles, 50 miles W-NNW 3-hour precipitation: 0.03 in. BHO SA 1455 E25 OVC 20S- 145/36/35/3516G23/996/ VSBY W-NNW 55 WND 29V03 PCPN VRY LGT/ 8/7// 51013 MANUAL 6003/ ASOS 60004 1 P.M. Weather: Overcast stratocumulus, breaks in overcast SW-W-N, higher clouds visible Temperature: 40F, Dew point: 33F, Wind: N at 14G25 kts, Wind: Peak gust 28 kts from the north at 12:28 P.M. EST Wind: Direction variable WNW to NE Sea-level pressure: 29.98 inches Hg, rising Visibility: 75 miles 6-hour maximum temp: 40F 6-hour precipitation: 0.03 in. BHO SA 1755 E30 OVC 75 154/40/33/3514G25/998/ BRKS IOVC SW-W-N HIER CLDS VSBL PK WND 3628/28 WND 29V04/ 8/5// 51009 MANUAL 6003/ ASOS 60004 10040 20034 WEATHER SUMMARY FOR THURSDAY, OCTOBER 15 TEMPERATURE (DEGREES F) MAX.....41 NORMAL.....61 MIN.....32 NORMAL.....43 MEAN....37 NORMAL.....52 DEPARTURE FROM 30-YEAR AVERAGE..........-15 TOTAL DEPARTURE FOR THE MONTH...........-47 [-3.3 DEGREES/DAY] HEATING DEGREE DAYS TOTAL HEATING UNITS FOR YESTERDAY............28 DEPARTURE......+15 TOTAL HEATING UNITS FOR THE MONTH...........208 DEPARTURE......+43 TOTAL HEATING UNITS FOR THE SEASON..........365 DEPARTURE......+31 TOTAL HEATING UNITS LAST SEASON TO DATE.....251 DIFFERENCE....+114 PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY.............29 NNE AT 11:57 P.M. * AEROVANE..............28 NE AT 7:30 P.M. ASOS..................29 NE AT 11:57 P.M. DAVIS.................N/A FASTEST MILE FOR YESTERDAY...............22 NNE AT 11:50 P.M. * MAXIMUM 2-MINUTE ASOS AVERAGE............20 ENE AT 11:55 P.M. MAXIMUM 2-MINUTE DAVIS AVERAGE...........N/A AVERAGE WIND SPEED AND DIRECTION.......10.5 NNE ASOS.................9.8 DAVIS................9.2 NNE [14 DEG] * last of several occurrences... PRECIPITATION (INCHES) THROUGH THIS MORNING (EST) TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.40 DEPARTURE....+0.26 ASOS..............0.37 TOTAL PRECIPITATION FOR MONTH..............2.71 DEPARTURE....+0.61 ASOS..............2.71 TOTAL PRECIPITATION FOR THE YEAR..........40.59 DEPARTURE....+0.89 ASOS.............41.77 PRELIMINARY CLIMATE SUMMARY FOR OCTOBER 2009 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 TSTM: Thunderstorm day (thunder heard some time during day) ....: Data not yet available, records not finalized 10/1 56/39/48/-9/0/155/22 27 WSW 10/2 60/40/50/-6/0/442/63 23 SSE 10/3 63/51/57/+1/1.10/000/00 32 ESE AERO 30 MPH ESE 10/4 67/57/62/+6/0/202/29 21 WSW 10/5 64/49/57/+2/0/595/86 33 W AERO 31 MPH W 10/6 65/45/55/0/0/628/91 25 W 10/7 67/51/59/+4/0.70/344/50 54 W AERO 54 MPH W 10/8 61/48/55/+1/0/602/88 43 W AERO 39 MPH W 10/9 60/48/54/0/0.05/000/00 29 SSE 10/10 62/42/52/-2/0.26/205/30 37 NW 10/11 61/39/50/-3/0/655/97 35 WSW AERO 33 MPH W 10/12 53/36/45/-8/T/471/70 23 SSW 10/13 51/36/44/-8/0.20/074/11 35 WNW 10/14 52/32/42/-10/0/.../.. 27 NW 10/15 41/32/37/-15/0.19/000/00 29 NNE 10/16 our morning low temp: 33F; our normal low temp: 43F NEW DAILY RECORDS FOR OCTOBER 2009 10/7: NEW RECORD WIND GUST 54 MPH W AT 2005E; surpasses previous record of 52 MPH ESE in 1972 DAILY EXTREMES Temperature and precipitation records back to 1885, and wind records back to 1940 (e = estimated): RECORDS FOR OCTOBER 16 HIGH 86 IN 1897 LOW 28 IN 1886 PRECIP 2.82 INCHES IN 1974 SNOWFALL (NONE) PEAK GUST 68e MPH SSE IN 1954 (HURRICANE HAZEL) RECORDS FOR OCTOBER 17 HIGH 86F IN 1947 LOW 25F IN 1886 PRECIP 1.87 INCHES IN 1989 SNOWFALL TRACE IN 1970 PEAK GUST 55 MPH NE IN 1964 TODAY'S REPORT PREPARED BY: Stephanie Radner