BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY TUESDAY, SEPTEMBER 4, 2012 ALL TIMES ARE IN EASTERN STANDARD TIME OCCASIONAL SHOWERS BRING 0.29 INCH OF RAIN SO FAR; SUMMIT IN AND OUT OF FOG; DEW POINT TEMP. ON THE RISE Occasional rain showers that began early this morning have provided the summit with 0.29 inch of precipitation so far today, with light rain continuing to fall. A very brief and fleeting moment of sunshing occurred shortly before 10 AM EDT this morning. Since then, the summit has been in and out of the fog, which has reduced visibility to 1/4 mile or less at times. The afternoon high thus far has struggled to reach 70F with a SE flow, occasional but persistent rain, and extensive cloud cover. The dew point temperature has risen in step with the air temperature today, reaching the upper 60s to near 70F. There is a noticeably more humid feel to the air this afternoon. Today's observations: 7 A.M. Weather: Broken stratocumulus, overcast stratocumulus, few stratus fractus drifting below summit, partial undercast over city to the N, lone cumulus over city to the N, thin line of lower stratocumulus lenticularis extending NNE-ESE, few lower cumulus distant SW and distant NW, few stratocumulus lenticularis distant S, thin fog/haze all quadrants, smoke layer along horizon NW-NNW, rain shower distant all quadrants moving E, light drizzle continued from the previous hour very light and intermittent, light rain shower began at 6:07 AM EST and ended at 6:28 AM EST, light drizzle continued very light and intermittent and ended at an unknown time Temperature: 63F; Dew Point: 62F; Wind: ESE at 10 kts. Sea-level pressure: 30.12 ins. Hg, falling Visibility: 20 miles, rain showers and thin fog/haze all quadrants 24-hour precip: 0.09 inch 6-hour precip: 0.09 inch 6-hour min. temp: 62F BHO SA 1155 E30 BKN 50 OVC 20 201/63/62/1210/012/ FEW STFRA DRFTNG BLO SMT PRTL UNDERCAST OVR CTY N LONE CU OVR CTY N THN LINE LWR SCSL XTNDNG NNE-ESE FEW LWR CU DSNT SW AND DSNT NW FEW SCSL DSNT S THN FG/HZ ALQDS K LYR ALG HRZN NW-NNW SHRA DSNT ALQDS MOVG E L-CTD VRY LGT AND INTMT RW-B07E28 L-CTD VRY LGT AND INTMT EUKN/ 8/8// 58007 MANUAL 70009 ASOS 70008 MANUAL 60009 ASOS 60008 10063 20062 10 A.M. Weather: Light rain, scattered cumulus and stratus fractus, broken stratocumulus, overcast nimbostratus, cumulus N-ENE, stratus fractus in the vicinity of the station, light drizzle began at 9:10 AM EST, light rain began at 9:45 AM EST and continued Temperature: 66F; Dew Point: 65F; Wind: SE at 9 kts. Sea-level pressure: 30.10 ins. Hg, falling Visibility: 8 miles, light rain, ESE-SW-NNW 4 miles, NNE-ENE 20 miles 3-hour precip: Trace BHO SA 1455 10 SCT E30 BKN 50 OVC 8R- 193/66/65/1409/010/ CU N-ENE STFRA VCTY STN VSBY ESE-SW-NNW 4 NNE-ENE 20 L-B10 LGT R-B45 CTD/ 8/8// 56008 MANUAL 6000/ 1 P.M. Weather: Light rain, fog, sky partially obsured, stratus drifting over summit, higher stratocumulus and nimbostratus occasionally visible, light rain continued from previous hour Temperature: 69F; Dew Point: 69F; Wind: SSE at 8 kts, Sea-level pressure: 30.04 ins. Hg, falling Visibility: 1 mile, light rain and fog, variable 1/4 mile to 4 miles, increasing 6-hour precip: 0.20 inch 6-hour max. temp: 69F BHO SA 1755 -X 1VR-F 174/69/69/1508/004/ F6 STRA DRFTNG OVR SMT HIER SC/NS OCNLY VSBL VSBY 1/4V4 VSBY INCRSNG R-CTD/ 8/7// 56019 MANUAL 60020 ASOS 60020 10069 20063 WEATHER SUMMARY FOR MONDAY, SEPTEMBER 3 TEMPERATURE (DEGREES F) MAX.....76 NORMAL.....76 MIN.....57 NORMAL.....59 MEAN....67 NORMAL.....67 DEPARTURE FROM 30-YEAR NORMAL......................0 TOTAL DEPARTURE FOR THE MONTH.....................+2 [+0.5 deg/day] PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY.............20 SE AT 7:04 P.M. * AERO..................20 S AT 5:35 P.M. * ASOS..................18 S AT 5:35 P.M. DAVIS.................18 S AT 5:34 P.M. RMY 21 THE FASTEST MILE FOR YESTERDAY...........13 SSE AT 10:52 P.M. * MAXIMUM 2-MINUTE ASOS AVERAGE............13 SSE AT 10:53 P.M. MAXIMUM 2-MINUTE DAVIS AVERAGE...........14 SSE AT 10:53 P.M. AVERAGE WIND SPEED AND DIRECTION........7.5 SSE ASOS.................6.8 DAVIS................6.6 ESE [105 deg] * last of several occurrences... PRECIPITATION (INCHES) THROUGH THIS MORNING (EST) TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.09 DEPARTURE...........-0.03 ASOS..............0.08 TOTAL PRECIPITATION FOR THE MONTH..........0.09 DEPARTURE...........-0.25 ASOS..............0.08 TOTAL PRECIPITATION FOR THE YEAR..........25.44 DEPARTURE...........-9.92 ASOS.............25.34 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 our morning low temp: 62F; the normal low is now 59F 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 4 HIGH 90F IN 1953, 1973 LOW 46F IN 1987 PRECIP 3.22 INCHES IN 1922 PEAK GUST 47 MPH SE IN 1966 RECORDS FOR SEPTEMBER 5 HIGH 90F IN 1971 LOW 45F IN 1906 PRECIP 1.37 INCHES IN 1907 PEAK GUST 46 MPH NW IN 1994 TODAY'S REPORT PREPARED BY: Sean Fankhauser