BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY TUESDAY, SEPTEMBER 11, 2012 ALL TIMES ARE IN EASTERN STANDARD TIME TASTE OF FALL: COOL, DRY, CALM, AND SUNNY; 58TH ANNIVERSARY OF HURRICANE EDNA Yesteday's high of 66F and low of 50F averaged 7 degrees below the 30 year normal. This was the largest daily negative temperature departure since July 29. Temperatures today started out a few degrees cooler than yesterday, with a low on the summit of 47F. Nearby Norwood bottomed out at 41F, with a few upper 30s readings in other parts of the state. Temperatures have warmed nicely this afternoon into the upper 60s, and a few degrees warmer than yesterday. Along with the pleasantly cool conditions, the air remains fairly dry, the winds are relatively low, and sunshine has been abundant today. Scattered high, thin cirrus have been invading the sky from the NW. Visibility has been great, near 80 miles much of the day. Today, September 11, marks the 58th anniversary of Hurricane Edna, which packed quite a punch on the region back in 1954. A peak wind gust of 101 mph was measured on the summit, along with more than 5 inches of rain. Tomorrow marks the 52nd anniversay of Hurricane Donna which brought a peak wind gust to the summit of 140 mph in 1960! Today's observations: 7 A.M. Weather: Clear, few cumulus along/offshore distant ENE-ESE, few cirrus distant W-NNW invading the sky, thin smoke layer distant all quadrants Temperature: 50F; Dew Point: 43F; Wind: NW at 9 kts, Sea-level pressure: 30.20 ins. Hg, rising Visibility: 85 miles, 6-hour min. temp: 47F BHO SA 1155 CLR 85 227/50/43/3109/020/ FEW CU ALG/OFFSHR DSNT ENE-ESE FEW CI DSNT W-NNW INVADING THN K LYR DSNT ALQDS/ 8/104 52030 10050 20047 10 A.M. Weather: Scattered thin cirrus, few cumulus along/offshore distant E-SE, cirrus S-W-NNE invading the sky, few patches of dense cirrus distant WNW-NW, clear sky overhead, thin smoke layer distant NNW-E Temperature: 62F; Dew Point: 44F; Wind: Estimated WNW at 3 kts, Wind: Light and variable Sea-level pressure: 30.24 ins. Hg, rising Visibility: 80 miles BHO SA 1455 250 –SCT 80 240/62/44/E2903/024/ FEW CU ALG/OFFSHR DSNT E-SE CI S-W-NNE INVADING FEW PTCHS DNS CI DSNT WNW-NW CLR SKY OVHD THN K LYR DSNT NNW-E WND LGT AND VRB/ 8/104 51013 1 P.M. Weather: Scattered dense cirrus, broken thin cirrus (2 levels), few small altocumulus lenticularis distant N, few patches of dense cirrus all quadrants, thin smoke/haze layer aloft distant N-ESE, light distant haze Temperature: 69F; Dew Point: 44F; Wind: W at 4 kts, Wind: Light and variable Sea-level pressure: 30.22 ins. Hg, falling Visibility: 75 miles, light distant haze 6-hour max. temp: 69F BHO SA 1755 220 SCT 250 –BKN 300 –BKN 75 234/69/44/2704/022/ FEW SML ACSL DSNT N FEW PTCHS DNS CI ALQDS THN K/HZ LYR ALF DSNT N-ESE LGT DSNT HZ WND LGT AND VRB/ 8/042 58006 10069 20050 WEATHER SUMMARY FOR MONDAY, SEPTEMBER 10 TEMPERATURE (DEGREES F) MAX.....66 NORMAL.....74 MIN.....50 NORMAL.....57 MEAN....58 NORMAL.....65 DEPARTURE FROM 30-YEAR NORMAL.....................-7 TOTAL DEPARTURE FOR THE MONTH....................+18 [+1.6 DEGREES/DAY] PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY.............33 NW AT 2:25 P.M. * AERO..................32 NW AT 1:50 P.M. ASOS..................32 NNW AT 2:26 P.M. DAVIS.................32 NW AT 1:50 P.M. RMY 34 THE FASTEST MILE FOR YESTERDAY...........21 NW AT 4:31 P.M. * MAXIMUM 2-MINUTE ASOS AVERAGE............20 NW AT 4:35 P.M. MAXIMUM 2-MINUTE DAVIS AVERAGE...........20 NW AT 2:53 P.M. AVERAGE WIND SPEED AND DIRECTION.......12.3 NW ASOS................12.0 DAVIS...............10.5 NNW [327 deg] * last of several occurrences... PRECIPITATION (INCHES) THROUGH THIS MORNING (EST) TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.00 DEPARTURE...........-0.13 ASOS..............0.00 TOTAL PRECIPITATION FOR THE MONTH..........1.11 DEPARTURE...........-0.11 ASOS..............1.09 TOTAL PRECIPITATION FOR THE YEAR..........26.46 DEPARTURE...........-9.78 ASOS.............26.35 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/+2/0.00/455/58 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/..../453/59 45 S AERO 45 MPH S RMY 45 9/9 72/58/65/-1/0.00/283/37 25 WNW AERO 23 MPH WNW RMY N/A 9/10 66/50/58/-7/0.00/.../.. 33 NW AERO 32 MPH NW RMY 34 9/11 morning low temp: 47F; the normal low is now 56F 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 11 HIGH 93F IN 1983 LOW 37F IN 1917 PRECIP 5.23 INCHES IN 1954 (HURRICANE EDNA) PEAK GUST 101 MPH NW IN 1954 (HURRICANE EDNA) RECORDS FOR SEPTEMBER 12 HIGH 92F IN 1961 LOW 42F IN 1958,1967,1985 PRECIP 2.79 INCHES IN 1960 (HURRICANE DONNA) PEAK GUST 140 MPH SSE IN 1960 (HURRICANE DONNA) TODAY'S REPORT PREPARED BY: Sean Fankhauser