BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY THURSDAY, SEPTEMBER 6, 2012 ALL TIMES ARE IN EASTERN STANDARD TIME TWO-DAY RAIN EVENT ENDED YESTERDAY MORNING WITH SOME LIGHT SHOWERS AND THUNDERSHOWERS PARTIAL SUNHSINE, WARM AND MODERATLY HUMID The two-day rain event brought 0.71 inch for September 4-5 here at the Observatory. The showers ended with a couple of light thundershowers. Conditions have remained warmer than normal but a lot less humid today with dew points in the 60's. Today's observations: 7 A.M. Weather: Broken stratocumulus, broken altocumulus, broken dense cirrus, and broken cirrus, line of lower stratocumulus with moderate cumuloform tops NW-N, patches of altocumulus lenticularis, altocumulus castellanus SSE-SW-WNW, patches of dense cirrus Temperature: 66F; Dew Point: 61F; Wind: ESE at 1 kt. (estimated) Sea-level pressure: 29.92 ins. Hg, rising then more rapidly Visibility: 50 miles, except 60 miles NW, patches thin fog mostly distant SE-SW, with few patches dense ground fog, distant haze 24-hour precip: 0.11 inch 6-hour min. temp: 62F BHO SA 1155 E50 BKN 80 BKN 220 BKN 250 BKN 50 133/66/61/E1201/992/ LINE LWR SC MDT CUFRM TOPS NW-NW ACC SSE-SW-WNW PTCHS ACSL PTCHS DNS CI MSTLY PTCHY DSNT THN FG SE-SW FEW DSNT DNS PTCHS GF SE-SW/ 8/582 53018 ASOS 70010 MANUAL 70011 10067 20062 10 A.M. Weather: Scattered altocumulus, (2 levels), broken dense cirrus, broken cirrus, cumulus forming line moderate cumulus NW-N, few lower stratocumulus Temperature: 73F; Dew Point: 63F; Wind: WSW @ 4 kts, Wind: Light Sea-level pressure: 29.93 ins. Hg, rising slightly Visibility: 50 miles, distant haze BHO SA 1455 150 SCT 180 SCT E200 BKN 250 BKN 50 134/73/63/2404/993/ CU FRMG ALQDS LINE OF MDT CU NW-N FEW LWR SC DSNT HZ WND LGT/ 8/832 53001 1 P.M. Weather: Scattered occasionally broken cumulus/stratocumulogenitus, except distant NE-E, overcast dense cirrostratus, thin spots in overcast, Temperature: 75F; Dew Point: 65F; Wind: WSW at 8 kts, Wind: Direction variable, SSW-W Sea-level pressure: 29.90 ins. Hg, falling then more slowly Visibility: 55 miles, distant haze 6-hour max. temp: 76F BHO SA 1755 25 SCT E220 OVC 55 125/75/65/2508/990/ 25 SCT OCNL BKN FEW MDT CU SCCU ALQDS XCPT DSNT NE-E OVC PTLY THN DSNT HZ WND 20V28/ 8/407 56009 10076 20066 WEATHER SUMMARY FOR WEDNESDAY, SEPTEMBER 5 TEMPERATURE (DEGREES F) MAX.....79 NORMAL.....75 MIN.....64 NORMAL.....58 MEAN....72 NORMAL.....67 DEPARTURE FROM 30-YEAR NORMAL.....................+5 TOTAL DEPARTURE FOR THE MONTH.....................+7 [+1.2 deg/day] PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY.............33 SSW AT 9:03 A.M. * AERO..................35 SSW AT 9:03 A.M. ASOS..................33 SSW AT 6:03 A.M. DAVIS.................33 SSW AT 3:51 A.M. RMY 33 THE FASTEST MILE FOR YESTERDAY...........24 SSW AT 8:21 A.M. MAXIMUM 2-MINUTE ASOS AVERAGE............25 SSW AT 8:22 A.M. MAXIMUM 2-MINUTE DAVIS AVERAGE...........24 SSW AT 8:42 A.M. AVERAGE WIND SPEED AND DIRECTION.......13.8 S ASOS................13.1 DAVIS...............12.9 S [190 deg] * last of several occurrences... PRECIPITATION (INCHES) THROUGH THIS MORNING (EST) TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.11 DEPARTURE...........-0.01 ASOS..............0.10 TOTAL PRECIPITATION FOR THE MONTH..........0.71 DEPARTURE...........+0.13 ASOS..............0.69 TOTAL PRECIPITATION FOR THE YEAR..........26.06 DEPARTURE...........-9.54 ASOS.............25.95 PRELIMINARY CLIMATE SUMMARY FOR SEPTEMBER 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/.../.. 27 ENE AERO 25 MPH ENE RMY 23 9/2 80/60/70/+2/0.00/.../.. 21 ENE AERO 20 MPH ENE RMY 20 9/3 76/57/67/0/0.00/.../.. 20 SE AERO 20 MPH S RMY 21 9/4 72/62/67/0/..../000/00 25 S AERO 23 MPH S RMY N/A 9/5 79/64/72/+5/..../.../.. 33 SSW AERO 35 MPH SSW RMY 33 9/6 morning low temp: 62F; the normal low is now 58F DAILY RECORDS FOR SEPTEMBER 2012 None so far. DAILY EXTREMES Temperature and precipitation records back to 1885, and wind records back to 1940 (e = estimated): RECORDS FOR SEPTEMBER 6 HIGH 92F IN 1900 LOW 39F IN 1888 PRECIP 3.19 INCHES IN 1890 PEAK GUST 78e MPH SE IN 1979 (TROPICAL STORM DAVID) RECORDS FOR SEPTEMBER 7 HIGH 92F IN 2007 LOW 40F IN 1888 PRECIP 2.95 INCHES IN 1891 PEAK GUST 58e MPH W IN 1941 TODAY'S REPORT PREPARED BY: Robert Skilling