BLUE HILL OBSERVATORY MILTON, MA MILTON, MASSACHUSETTS 02186 ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY MONDAY, OCTOBER 18, 2010 ALL TIMES ARE IN EASTERN STANDARD TIME PLEASANT MOSTLY SUNNY OCTOBER WEATHER CONTINUES TEMPERATURES SLIGHTLY COOLER TODAY WINDS OCCASIONALLY GUSTING PAST 30 MPH TODAY Sunshine with just some mostly scattered clouds and temperatures which are running close to 5 degrees cooler than yesterday prevails today. Winds have diminished after a rather windy day yesterday. A brief period of very gusty west winds had peak gusts over 40 mph shortly after 5 PM yesterday afternoon. Today's observations: 7 A.M. Weather: Thin scattered cirrocumulus radiatus/cirrus radiatus, few altocumulus SSW-W, few altocumulus lenticularis and cirrocumulus lenticularis ESE-SE Temperature: 42F, Dew point: 36F; Wind: W at 12 kts Sea-level pressure: 29.82 inches Hg, rising Visibility: 75 miles 6-hour minimum temp: 41F BHO SA 1155 250 –SCT 75 115/42/36/2612/987/ FEW ACSL SSW-W CC OVHD-E-S FEW ACSL/CCSL ESE-SE/ 8/049 53012 10046 20041 10 A.M. Weather: Scattered cirrocumulus and cirrocumulus lenticularis (south thru southwest) and cirrus, cumulus forming distant west thru north Temperature: 52F, Dew point: 29F; Wind: W at 12 kts Sea-level pressure: 29.89 inches Hg, falling Visibility: 80 miles BHO SA 1455 250 SCT 80 122/52/29/2910/989/ CU FRMG DSNT W-N CCSL S-SW AND CI N-NE WND 25V33/ GST TO 20 KTS PST HR/ 8/109 50007 1 P.M. Weather: Scattered cumulus, scattered altocumulus lenticularis, scattered cirrocumulus lenticularis Temperature: 57F, Dew point: 31F; Wind: WSW at 13G21 kts. Peak Wind: 28 kts W @ 12:18 P.M. EST Wind: Direction variable SSW to WNW Sea-level pressure: 29.83 inches Hg, falling Visibility: 70 miles 6-hour max. temp: 58F BHO SA 1755 55 SCT 200 SCT 250 SCT 70 101/57/31/2513G21/983/ ACSL/CCSL ALQDS PK WND 2828/18 WND 22V30/ 8/149 58021 10058 20042 WEATHER SUMMARY FOR SUNDAY, OCTOBER 17 TEMPERATURE (DEGREES F) MAX.....63 NORMAL.....60 MIN.....38 NORMAL.....42 MEAN....51 NORMAL.....51 DEPARTURE FROM 30-YEAR NORMAL.............. 0 TOTAL DEPARTURE FOR THE MONTH.............-12 [-0.9 DEGREE/DAY] HEATING DEGREE DAYS TOTAL HEATING UNITS FOR YESTERDAY............14 DEPARTURE.........0 TOTAL HEATING UNITS FOR THE MONTH...........204 DEPARTURE.......+11 TOTAL HEATING UNITS FOR THE SEASON..........283 DEPARTURE.......-79 TOTAL HEATING UNITS LAST SEASON TO DATE.....417 DIFFERENCE.....-134 PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY.............43 W AT 4:05 P.M. AEROVANE..............47 W AT 4:04 P.M. ASOS..................45 W AT 4:05 P.M. DAVIS.................47 W AT 4:04 P.M. THE FASTEST MILE FOR YESTERDAY...........32 W AT 4:10 P.M. MAXIMUM 2-MINUTE ASOS AVERAGE............32 W AT 4:10 P.M. MAXIMUM 2-MINUTE DAVIS AVERAGE...........35 W AT 4:10 P.M. AVERAGE WIND SPEED AND DIRECTION.......14.5 ASOS................13.9 DAVIS...............13.6 W [260 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..........5.50 DEPARTURE........+3.12 ASOS..............5.53 TOTAL PRECIPITATION FOR THE YEAR..........53.52 DEPARTURE.......+13.54 ASOS.............53.37** ** ASOS missing rainfall due to system failure on 6/24-25 PRELIMINARY CLIMATE SUMMARY FOR OCTOBER 2010 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 80/55/68/+11/0.56/035/05 55 SSE AERO 63 MPH SSE 10/2 65/46/56/0/0.00/688/98 28 WNW AERO 31 MPH WNW 10/3 55/43/49/-7/T/133/19 35 NNE AERO 39 MPH NNE 10/4 54/48/51/-5/0.78/000/00 39 NNE AERO 43 MPH NNE 10/5 57/51/54/-1/0.40/000/00 37 NE AERO 39 MPH NNE 10/6 57/49/53/-2/1.63/000/00 47 NE AERO 51 MPH NE 10/7 62/47/55/0/0.00/275/40 37 W AERO 40 MPH W 10/8 70/47/59/+5/0.00/610/89 35 WSW AERO 37 MPH WSW 10/9 62/43/53/-1/0.00/675/99 33 WNW AERO 37 MPH WNW 10/10 64/38/51/-3/0.00/679/100 25 SW AERO 29 MPH SSW 10/11 68/47/58/+5/0.00/542/80 28 W 10/12 61/43/52/-1/0.01/297/44 24 ENE 10/13 61/38/50/-2/0.00/663/99 18 NW 10/14 59/45/52/0/.../294/44 29 ENE 10/15 51/39/45/-7/.../033/05 48 WSW AERO 50 MPH WSW 10/16 55/39/47/-4/0.00/544/82 47 WNW AERO 54 MPH WNW 10/17 63/38/51/0/0.00/.../.. 43 W AERO 47 MPH W 10/18 our morning low temp: 41F; the normal low temp. is now 42F NEW DAILY RECORDS FOR OCTOBER 2010 None so far. DAILY EXTREMES Temperature and precipitation records back to 1885, and wind records back to 1940 (e = estimated): RECORDS FOR OCTOBER 18 HIGH 82F IN 1908 LOW 26F IN 1939 PRECIP 2.79 INCHES IN 1975 SNOWFALL 3.0 INCHES IN 2009 PEAK GUST 66 MPH S IN 1967 RECORDS FOR OCTOBER 19 HIGH 81F IN 1945 LOW 21F IN 1922 PRECIP 3.64 INCHES IN 1932 SNOWFALL 1.0 INCHES IN 1972 PEAK GUST 66 MPH SSW IN 1967 TODAY'S REPORT PREPARED BY: Robert Skilling