BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS 02186 ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY MONDAY, SEPTEMBER 22, 2008 ALL TIMES ARE IN EASTERN STANDARD TIME UNLESS NOTED Today's observations: BRIEF WIND SQUALL EARLY LAST EVENING AUTUMNAL EQUINOX AT 11:44 A.M. EDT TODAY WITH LOW OVERCAST AND VERY COOL WEATHER An outflow wind gust front from an area of showers, which were briefly heavy over Boston early last evening, brought yesterday's peak wind gust of 25 MPH NW at 8:36 p.m. EDT. No rain was recorded here at Blue Hill but Boston's Logan Airport received 0.31 inch. Autumn began this morning at 11:44 a.m. EDT under overcast skies and very cool temperatures held to the 50's today with a dense low cloud cover and northeast winds as a large high pressure system was building into New England. 8 A.M. EDT Weather: Low overcast with stratus clouds Temperature: 57F, Dew point: 54F, Wind: NNE at 11 kts, Wind: direction variability NNW-ENE Sea-level pressure: 30.39 inches Hg, rising Visibility: 15 miles, 20 miles northeast, thin fog 6-hourly minimum temperature: 56F 24-hourly rainfall: 0.00 inch BHO SA 1155 E6 OVC 15 292/57/54/0211/039/ CIG RGD THN F ALQDS VSBY NE 20 WND 34V06/ 8/6// 53018 10057 20056 11 A.M. EDT Weather: Low overcast stratus Temperature: 56F, Dew point: 50F, Wind: NNE at 13 kts, Wind: direction variability N-ENE, gust 20 kts past hour Sea-level pressure: 30.43 inches Hg, rising Visibility: 35 miles, lower NE-SE BHO SA 1455 E12 OVC 35 305/56/50/0213/043/ VSBY LWR NE-SE GST 20 KTS PST HR WND 35V06/ 8/6// 51013 2 P.M. EDT Weather: Overcast statocumulus clouds, few lower cumulus, bright spots in overcast Temperature: 57F, Dew point: 48F, Wind: NNE at 13 kts, Wind: direction variability from N-ENE Sea-level pressure: 30.43 inches Hg, steady Visibility: 40 miles 6-hour max. temp: 58F BHO SA 1755 E18 OVC 40 305/57/48/0313/043/ FEW LWR CU BRGHT SPTS IOVC WND 35V07/ 8/8// 50000 10058 20055 WEATHER SUMMARY FOR SUNDAY, SEPTEMBER 21 TEMPERATURE (DEGREES F) MAX.....77 NORMAL.....69 MIN.....49 NORMAL.....51 MEAN....63 NORMAL.....60 DEPARTURE FROM 30-YEAR NORMAL.............+3 TOTAL DEPARTURE FOR THE MONTH............+31 (+1.3 DEGREES/DAY) PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY............25 NW AT 7:36 P.M. AEROVANE.............23 NW AT 7:36 P.M. ASOS.................23 NW AT 7:36 P.M. DAVIS................25 NW AT 7:36 P.M. FASTEST MILE FOR YESTERDAY..............19 NW AT 7:37 P.M. MAXIMUM 2-MINUTE ASOS AVERAGE...........18 NW AT 7:37 P.M. MAXIMUM 2-MINUTE DAVIS AVERAGE..........20 WNW AT 7:37 P.M. AVERAGE.............7.6 W ASOS................7.2 DAVIS...............7.9 W [270 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 SEPT..............3.13 DEPARTURE.......+0.26 ASOS..............3.15 TOTAL PRECIPITATION FOR THE YEAR..........38.59 DEPARTURE.......+2.25 ASOS.............41.15 # # Includes erroneous ASOS precipitation data on 2/13/08. PRELIMINARY CLIMATE SUMMARY FOR SEPTEMBER 2008 CALENDAR DAY DATA DATA REPORTED: DATE: MAX/MIN/MEAN/DEP/PRECIP/SUN(MIN.)/SUN(%)/ PEAK GUST/AERO GUST AERO: Aerovane recording wind system gust when significant TSTM: Thunderstorm day (thunder heard some time during day) ....: Data not yet available, records not finalized 9/1 81/57/69/+2/0.00/787/100 29 NW 9/2 74/60/67/+1/0.00/604/77 27 N 9/3 75/57/66/0/0.00/766/98 22 N 9/4 85/62/74/+8/0.00/748/96 23 SSW 9/5 86/67/77/+12/0.00/575/74 32 SSE 9/6 82/68/75/+10/1.88/039/05 44 SE Aero 39 MPH SE * 9/7 78/61/70/+5/0.31/655/85 43 NW Aero 43 MPH NW * 9/8 78/58/68/+3/0.00/753/98 23 WSW 9/9 73/60/67/+3/0.32/054/07 43 SW Aero 46 MPH SW TSTM # 9/10 68/52/60/-4/0.00/748/98 25 WNW 9/11 69/48/59/-5/0.00/616/81 23 S 9/12 66/54/60/-3/0.22/008/01 33 S 9/13 74/62/68/+5/T/113/15 21 S 9/14 70/64/67/+4/0.40/000/00 35 S 9/15 79/60/70/+8/0.00/697/93 45 WSW Aero 45 MPH WSW ** 9/16 64/54/59/-3/0.00/045/06 21 NNW 9/17 72/53/63/+1/0.00/.../.. 20 S Aero 17 MPH S 9/18 65/49/57/-4/0.00/.../.. 31 NNE Aero 28 MPH NNE 9/19 57/47/52/-9/0.00/.../.. 28 NE 9/20 64/46/55/-6/0.00/.../.. 16 SSW 9/21 77/49/63/+3/0.00/.../.. 25 NW 9/22 morning low temp: 56F; our normal low is now 51F * Tropical Storm Hanna # Thunderstorm gust ** Ike remnants NEW DAILY RECORDS FOR SEPTEMBER None to date.. DAILY EXTREMES Temperature and precipitation records back to 1885, and wind records back to 1940 (e = estimated): RECORDS FOR SEPTEMBER 22 HIGH 90F IN 1895, 1914 LOW 30F IN 1904 (Earliest freeze) PRECIP 1.16 INCHES IN 2001 PEAK GUST 60 MPH SSW IN 1989 RECORDS FOR SEPTEMBER 23 HIGH 93F IN 1895,1914 LOW 33F IN 1904 PRECIP 2.67 INCHES IN 1994 PEAK GUST 62 MPH SSW IN 1989 TODAY'S REPORT PREPARED By: Robert Skilling