BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY THURSDAY, OCTOBER 4, 2012 ALL TIMES ARE IN EASTERN STANDARD TIME DENSE FOG WITH VERY LOW VISIBILITY FOR A 2ND DAY LIGHT DRIZZLE BRINGS JUST A FEW HUNDREDTHS OF AN INCH TEMPERATURES STUCK AROUND 58 TO 61F WITH LIGHT WINDS Today, like yesterday, was another very gloomy day at the summit with the visibility ranging from zero to 1/8 mile in fog and periods of drizzle for over 24 hours starting yesterday morning. Drizzle has produced only about 0.03 or 0.04 of precipitation. Temperatures remain in a very narrow range around 60 degrees. SEPTEMBER 2012 PRELIMINARY STATS TEMPERATURE: Average Max Temp: 71.5F [-0.1F] Average Min Temp: 54.8F [+0.2F] Mean Temp: 63.2F [+0.1F] 24-hr. Corr Mean Temp: 62.5F Max Temp: 85F on 7th Min Temp: 45F on 24th Total heating degree day units (month): 99 [-18] Total heating degree day units (season): 99 [-43] *start July 1 PRECIPITATION:Total precipitation: 3.27 ins. [-0.79 in.] Greatest 24-hr precipitation: 1.03 ins. on 18th/19th WIND: Avg wind speed: 10.8 MPH Avg corrected wind speed: 11.3 MPH Prevailing wind direction: S [16%] Peak gust: 60 MPH S on 18th Peak gust: Aerovane 62 MPH S on 18th Peak fastest mile: 47 MPH S on 18th SUNSHINE: Total astronomical minutes: 12,680 of possible 22,440 or 57% Total Campbell-Stokes card minutes: 12,228 of possible 21,582 or 57% Today's observations: 7 A.M. Weather: Obscurement, light drizzle and heavy fog Temperature: 58F; Dew Point: 58F; Wind: NNE at 9 kts. Wind: Direction variable N-ENE Sea-level pressure: 30.16 ins. Hg, rising slightly Visibility: zero variable to 1/16 mile, light drizzle and heavy fog 6-hour precip: 0.03 24-hour precip: 0.03 inch 6-hour min. temp: 58F BHO SA 1150 W2 X 0VL-F 212/58/58/0309/016/ VSBY 0V1/16 WND 36V06/ 8//// 53001 MANUAL 6001/ MANUAL 70003 ASOS 70001 10058 20058 10 A.M. Weather: Obscurement with light drizzle and heavy fog, Temperature: 60F; Dew Point: 60F; Wind: NE at 5 kts, Sea-level pressure: 30.15 ins. Hg, falling slightly Visibility: 1/8 variable to 1/16, light drizzle, heavy fog, 3-hour precip: 0.01 inch BHO SA 1450 W3 X 1/8VL-F 210/60/60/0405/015/ VSBY 1/8V1/16/ 8//// 58002 MANUAL 6001/ 1 P.M. Weather: Obscurement heavy fog, light drizzle, very light rain shower began 12:01 P.M. and ended 12:05 P.M. EST, precipitation very light Temperature: 60F; Dew Point: 60F; Wind: ENE at 10 kts. Wind: Direction variable NNE-E Sea-level pressure: 30.10 ins. Hg, falling then more rapidly Visibility: 1/16 variable zero in heavy fog 6-hour precip: 0.01 inch 6-hour max. temp: 61F BHO SA 1755 W2 X 1/16VL-F 193/60/60/0610/010/ VSBY 1/16V0 WND 02V08 PCPN VRY LGT/ 8//// 58001 MANUAL 60001 ASOS 60001 10061 20058 WEATHER SUMMARY FOR WEDNESDAY, OCTOBER 3 TEMPERATURE (DEGREES F) MAX.....62 NORMAL.....65 MIN.....58 NORMAL.....48 MEAN....60 NORMAL.....56 DEPARTURE FROM 30-YEAR NORMAL.....................+4 TOTAL DEPARTURE FOR THE MONTH.....................+8 [2.5 DEGREES/DAY] HEATING DEGREE DAYS TOTAL HEATING UNITS FOR YESTERDAY.............5 DEPARTURE........-4 TOTAL HEATING UNITS FOR THE MONTH............17 DEPARTURE........-9 TOTAL HEATING UNITS FOR THE SEASON..........116 DEPARTURE.......-53 TOTAL HEATING UNITS LAST SEASON TO DATE......88 DIFFERENCE......+28 PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY.............20 NE AT 4:20 P.M. * AERO..................17 NE AT 4:20 P.M. * ASOS..................17 NE AT 4:12 P.M. DAVIS.................17 NE AT 2:35 P.M. RMY 18 THE FASTEST MILE FOR YESTERDAY...........12 NE AT 4:08 P.M. MAXIMUM 2-MINUTE ASOS AVERAGE............13 NE AT 4:24 P.M. MAXIMUM 2-MINUTE DAVIS AVERAGE...........13 NE AT 3:26 P.M. AVERAGE WIND SPEED AND DIRECTION........8.2 NE ASOS.................8.6 DAVIS................7.5 ENE [060 deg] *last of several occurrences PRECIPITATION (INCHES) THROUGH THIS MORNING (EST) TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.03 DEPARTURE...........-0.11 ASOS..............0.01 TOTAL PRECIPITATION FOR THE MONTH......... 0.15 DEPARTURE...........-0.30 ASOS..............0.12 TOTAL PRECIPITATION FOR THE YEAR..........28.77 DEPARTURE..........-10.76 ASOS.............28.67 PRELIMINARY CLIMATE SUMMARY FOR SEPTEMBER & OCTOBER 2012 CALENDAR DAY DATA DATA REPORTED: DATE: MAX/MIN/MEAN/DEP/PRECIP/SUN(MIN.)/SUN(%)/ PEAK GUST/AERO GUST AERO: Aerovane wind recording system gust RMY: 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 9/1 75/60/68/0/0.00/637/81 27 ENE AERO 25 MPH ENE RMY 23 9/2 80/60/70/+2/0.00/455/58 21 ENE AERO 20 MPH ENE RMY 20 9/3 76/57/67/0/0.00/485/62 20 SE AERO 20 MPH S RMY 21 9/4 72/62/67/0/0.40/000/00 25 S AERO 23 MPH S RMY N/A 9/5 79/64/72/+5/0.31/171/22 33 SSW AERO 35 MPH SSW RMY 33 9/6 77/62/70/+3/0.00/279/36 20 SSW AERO 20 MPH SSW RMY 19 9/7 85/66/76/+10/0.00/463/60 22 SSW AERO 20 MPH SSW RMY N/A TSTM 9/8 81/62/72/+6/0.38/453/59 45 S AERO 45 MPH S RMY 45 9/9 72/58/65/-1/0.02/283/37 25 WNW AERO 23 MPH WNW RMY N/A 9/10 66/50/58/-7/0.00/313/41 33 NW AERO 32 MPH NW RMY 34 9/11 71/47/59/-6/0.00/714/94 23 NW AERO 21 MPH WNW RMY N/A 9/12 77/53/65/0/0.00/719/95 20 S AERO 18 MPH S RMY 18 9/13 81/59/70/+6/0.00/731/97 21 S AERO 18 MPH S RMY 19 9/14 81/59/70/+6/0.00/706/94 25 S AERO 23 MPH S RMY 23 9/15 72/54/63/-1/0.07/441/59 28 NW AERO 27 MPH WNW RMY 27 9/16 70/49/60/-3/0.00/731/98 23 W AERO 20 MPH W RMY 21 9/17 74/51/63/0/0.00/698/94 20 S AERO 17 MPH S RMY N/A 9/18 74/58/66/+4/0.13/044/06 60 S AERO 62 MPH S RMY 63 9/19 70/53/62/0/0.90/472/64 55 S AERO 56 MPH S RMY N/A 9/20 63/50/57/-5/0.00/539/87 24 NE AERO 21 MPH NE RMY 21 9/21 63/48/56/-5/0.01/241/33 18 E AERO 16 MPH E RMY 16 9/22 70/55/63/+2/0.04/306/42 28 S AERO 25 MPH S RMY 27 9/23 69/50/60/0/0.02/653/90 27 WNW AERO 24 MPH WNW RMY 27 9/24 66/45/56/-4/0.00/694/96 23 WSW AERO 21 MPH WSW RMY 22 9/25 72/48/60/0/0.00/691/96 35 SSW AERP 35 MPH SW RMY 36 9/26 70/57/64/+5/T/050/07 31 S AERO 32 MPH S RMY 32 9/27 70/53/62/+3/0.00/557/78 24 NNW AERO 23 MPH NNW RMY 23 9/28 56/53/55/-3/0.64/000/00 29 ESE AERO 29 MPH ESE RMY 30 9/29 56/51/54/-4/0.13/000/00 28 NNE AERO 25 MPH NNE RMY N/A 9/30 57/50/54/-4/0.22/054/08 23 SSW AERO 23 MPH SSW RMY N/A 10/1 66/47/57/0/T/.../.. 36 W AERO 35 MPH WSW RMY 36 10/2 69/53/61/+4/0.12/105/15 18 W AERO 16 MPH W RNT 16 10/3 62/58/60/+4/0.02/000/00 20 NE AERO 18 MPH NE RMY 18 10/4 morning low temp: 58F; the normal low is now 47F DAILY RECORDS FOR SEPTEMBER 2012 9/19 - NEW RECORD PEAK WIND GUST OF 55 MPH S; surpasses previous record of 49 MPH NE IN 1972 DAILY RECORDS FOR OCTOBER 2012 None so far. DAILY EXTREMES Temperature and precipitation records back to 1885, and wind records back to 1940 (e = estimated): RECORDS FOR OCTOBER 4 HIGH 84F IN 2007 LOW 28F IN 1888 PRECIP 1.07 INCHES IN 1986 PEAK GUST 59 MPH SSW IN 1990 RECORDS FOR OCTOBER 5 HIGH 86F IN 2007 LOW 29F IN 1965 PRECIP 3.17 INCHES IN 1962 PEAK GUST 64e MPH S IN 1979 TODAY'S REPORT PREPARED BY: Robert Skilling