BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY MONDAY, JULY 22, 2013 ALL TIMES ARE IN EASTERN STANDARD TIME COOLER MORE SEASONABLE TEMPERATURES FOLLOW HEAT WAVE Temperatures bottomed out at 67F this morning, stil running 4 degrees warmer than normal, and had risen to a high of 80 degrees by early this afternoon very close to the average maximum of 81 degrees despite a cooling sea breeze. No precipitation fell at the summit Saturday, though thunder and lightning were observed from thunderstorms that moved to our south. A peak thunderstorm wind gust to 64 KTS or 73 MPH SSW was recorded at Norwood Airport qualifying the thunder- storm as a severe one which passed south of the hill around 4 P.M. EDT The recent heat wave lasted six days at the Observatory. A total of 6 records, all highest minimum temperatures, were tied or broken. For three consecutive days, July 18-20, the temperature at 7 AM EST was 80F or higher. Although higher temperatures have been recorded at this time of day in recent years, this may be the first occurrence on record of three straight days of 80F or higher at that time of day in records checked back about 50 years. In addition, this month has so far seen 10 days with a high temperature of 90F or higher, which is among the greatest number of such days for any month on the entire period of record. BHO Greatest Number of 90-Degree Days per Month, (1885-2013) 1) 14 in July 1952 2) 13 in August 2002 3) 10 in August 1944 10 in July 1949 10 in July 1963 10 in July 2010 10 in July 2013 (through 7/21) 8) 9 in July 1911 9 in August 1928 10) 8 in August 1949 8 in July 1963 8 in July 1988 BHO Longest Heat Waves of Consecutive 90-Degree Days, (1885-2013) 1) 9 on 11-19 August 2002 2) 8 on 10-17 August 1944 3) 6 on 24-29 July 1963 6 on 16-21 July 1977 6 on 6-11 July 1988 6 on 16-21 July 1991 6 on 15-20 July 2013 BHO Highest 7AM EST Temperature, deg F (1960-2013) 1) 84 on 6 July 2010 2) 83 on 22 July 2011 3) 82 on 21 July 1991 82 on 18 July 2012 5) 81 on 2 August 1975 81 on 27 June 1999 81 on 18 July 2013 * 81 on 20 July 2013 * 9) 80 on 23 July 1978 80 on 23 July 1998 80 on 5 July 1999 80 on 6 July 1999 80 on 9 August 2001 80 on 4 July 2002 80 on 30 July 2002 80 on 2 August 2006 80 on 3 August 2006 80 on 21 June 2012 80 on 22 June 2012 80 on 19 July 2013 * Today's Observations: 7 A.M. Weather: Scattered dense cirrus, thin overcast cirrus Temperature: 72F; Dew Point: 66F; Wind: Calm Sea-level pressure: 30.01 ins. Hg, rising Visibility: 12 miles, thin fog and haze 6-hr min. temp: 67F BHO SA 1155 220 SCT 250 –OVC 12 163/72/66/0000/001/ SC/STRA LYR XTDNG ALG HRZN SW-NW-NE FEW MDT TPS W DNS CI MSTLY SE-W FEW PTCHS CC BINOVC THN F AND HAZY ALQDS/ 8/502 53006 10072 20067 10 A.M. Weather: Scattered stratocumulus, scattered moderate cumulus (line W-NW, scattered altocumulus (2 levels), including few altocumulus lenticularis, broken dense cirrus, overcast cirrus (partly thin), stratus/fog bank NNE-NE Temperature: 77F; Dew Point: 69F; Wind: E at 6 kts, Sea-level pressure: 30.02 ins. Hg, rising slightly Visibility: 12 miles, hazy BHO SA 1455 22 SCT 45 SCT 110 SCT E150 BKN 220 BKN 250 OVC 12 167/77/69/1006/002/ LINE MDT CU W-NW STRA/FG BNK NNE-NE FEW ACSL OVC PTLY THN/ 8/242 51004 1 P.M. Weather: Scattered dense cirrus patches, thin broken cirrus, thin overcast cirrus, cumulus distant ESE-SSE, stratocumulus vicinity SSW-SW, distant line cumulus moderate tops W-NE stratus/fog bank offshore NE-ENE, large patch altocumulus lenticularis vicinity S Temperature: 77F; Dew Point: 67F; Wind: E at 9 kts. Sea-level pressure: 29.98 ins. Hg, falling Visibility: 25 miles, NE-E 20 miles, WNW 30 miles, hazy 6-hr max. temp: 80F BHO SA 1755 220 SCT 250 –BKN 300 –OVC 25 153/77/67/0809/998/ CU DSNT ESE-SSE CU/SC VC SSW-SW LINE CU DSNT W-NNE MDT CU TOPS LG PTCH ACSL VCTY S STRA/FG BNK OFFSHR NE-ENE VSBY WNW 30 NE-E 20 HAZY ALQDS 8/841 57014 10080 20072 WEATHER SUMMARY FOR SUNDAY, JULY 21, 2013 TEMPERATURE (DEGREES F) MAX.....82 NORMAL.....81 MIN.....68 NORMAL.....63 MEAN....75 NORMAL.....72 DEPARTURE FROM 30-YEAR NORMAL......................+3 TOTAL DEPARTURE FOR THE MONTH....................+126 [+5.8 DEGREES/DAY] PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY................16 NE AT 5:34 P.M. AERO.....................16 NE AT 5:34 P.M. ASOS.....................17 NE AT 5:34 P.M. DAVIS....................18 WNW AT 12:02 A.M. RMY N/A FASTEST MILE FOR YESTERDAY..................12 WNW AT 12:10 A.M. MAXIMUM 2-MINUTE ASOS AVERAGE...............13 WNW AT 12:11 A.M. MAXIMUM 2-MINUTE DAVIS AVERAGE..............12 WNW AT 12-1 A.M. AVERAGE WIND SPEED AND DIRECTION...........7.5 NE ASOS....................7.3 DAVIS...................7.0 NNE [030 deg.] 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..........1.01 DEPARTURE............-1.58 ASOS..............1.00 TOTAL PRECIPITATION FOR THE YEAR..........33.21 DEPARTURE............+3.65 ASOS..............N/A* *ASOS malfunctioned during storm on 2/8-9, leading to erroneous totals PRELIMINARY CLIMATE SUMMARY FOR JULY 2013 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 7/1 82/69/76/+6/0.05/247/27 29 S AERO 31 MPH SSW RMY 32 7/2 82/61/72/+2/T/100/11 23 SSW AERO 23 MPH SSW RMY 25 7/3 87/62/75/+4/T/556/61 28 SW AERO 30 MPH SW RMY 30 7/4 90/71/81/+10/0.00/811/89 25 WSW AERO 26 MPH SW RMY 28 7/5 92/73/83/+12/0.00/874/96 24 W AERO 25 MPH WSW RMY 25 7/6 90/73/82/+11/0.00/836/92 25 WNW AERO 25 MPH WNW RMY 26 7/7 91/72/82/+11/0.21/508/56 38 SSW AERO 43 MPH SSW RMY 44 TSTM 7/8 82/64/73/+1/0.04/617/68 18 NE AERO 20 MPH NE RMY 20 TSTM 7/9 72/63/68/-4/0.01/054/06 14 ENE AERO 14 MPH ENE RMY 14 7/10 84/65/75/+3/T/335/37 32 S AERO 36 MPH S RMY 35 7/11 79/69/74/+2/0.62/009/01 23 W AERO 23 MPH W RMY N/A TSTM 7/12 70/62/66/-6/0.00/162/18 29 NE AERO 29 MPH NE RMY 30 7/13 75/62/69/-3/0.08/009/01 21 ENE AERO 20 MPH ENE RMY N/A 7/14 89/71/80/+8/0.00/477/53 16 W AERO 16 MPH W RMY 16 7/15 91/72/82/+10/0.00/665/74 17 NW AERO 16 MPH NW RMY 18 7/16 91/71/81/+9/0.00/843/94 18 NNW AERO 16 MPH NNW RMY 16 7/17 93/74/84/+12/0.00/.../.. 22 SW AERO 23 MPH SW RMY 25 7/18 90/75/83/+11/0.00/.../.. 20 S AERO 21 MPH S RMY 22 7/19 95/76/86/+14/0.00/.../.. 36 WSW AERO 38 MPH WSW RMY 38 7/20 93/72/82/+10/0.00/.../.. 29 W AERO 30 MPH W RMY 31 TSTM 7/21 82/68/75/+3/0.00/.../.. 16 NE AERO 16 MPH NE RMY 17 7/22 morning low temp: 67F; the normal low is now 63F DAILY RECORDS FOR JULY 2013 7/14 - TIED DAILY RECORD HIGH MINIMUM TEMPERATURE OF 71F; ties previous record of 71F set in 1997 7/15 - NEW DAILY RECORD HIGH MINIMUM TEMPERATURE OF 72F; surpasses previous record of 70F set in 1901, 1934, 1995 7/16 - TIED DAILY RECORD HIGH MINIMUM TEMPERATURE OF 71F; ties previous record of 71F set in 1901, 1958, 1968 7/17 - TIED DAILY RECORD HIGH MINIMUM TEMPERATURE OF 74F; ties previous record of 74F set in 1900 7/18 - NEW DAILY RECORD HIGH MINIMUM TEMPERATURE OF 75F; surpasses previous record of 73F set in 1900, 1999 7/19 - NEW DAILY RECORD HIGH MINIMUM TEMPERATURE OF 76F; surpasses previous record of 72F set in 1949, 1991, 2005 DAILY EXTREMES Temperature and precipitation records back to 1885, and wind records back to 1940 (e = estimated): RECORDS FOR JULY 22 HIGH 99F IN 1926, 2011 LOW 52F IN 1890 PRECIP 1.73 INCHES IN 1900 PEAK GUST 55 MPH IN 1983 RECORDS FOR JULY 23 HIGH 99F IN 1952 LOW 51F IN 1923,1977 PRECIP 1.82 INCHES IN 1953 PEAK GUST 54e MPH S IN 1946 TODAY'S REPORT PREPARED BY: Robert Skilling/Marc Douglas