BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY SATURDAY, JULY 23, 2011 ALL TIMES ARE IN EASTERN STANDARD TIME HIGH TEMPERATURE ON FRIDAY OF 99 TIES RECORD FOR DATE... THUNDERSTORMS AND RAIN SHOWERS MOVE THROUGH THIS MORNING.. The oppressive heat and humidity on Friday brought high temperatures of 100 degrees or more to many places in southern New England. On the summit of Blue Hill, the maximum temperature of 99 at around 3:30 PM EDT tied the record high for the date previously set in 1926. This was also the highest temperature since 99 was recorded on July 6th, 2010. Thunderstorms moved through eastern Massachusetts this morning, with the first thunder on Blue Hill occurring at 8:26 AM EDT. Thunder was continuous for several hours until finally ending at 11:15 AM EDT. Rainfall was mostly light from about 8:30 to 10 AM EDT, though there was a brief heavy rain shower from 9:46-9:48 AM EDT. For the three hours ending at 11 AM EDT, a total of 0.05 inch of precipitation was measured. Numerous lightning strikes from cloud to cloud and from cloud to ground were observed as the thunderstorms passed, though none was closer than about 7-8 miles. After dropping to the 50s on Friday afternoon, the dew point has climbed back to the upper 60s as of mid-day today following the morning rainfall. Today's observations: 7 A.M. Weather: Scattered cumulus, broken stratocumulus/altocumulus, overcast altocumulus, breaks in overcast ESE-SE, thin spots in overcast overhead, higher clouds visible, sun dimly visible, hazy, distant cloud to ground lightning occuring WNW Temperature: 77F, Dew point: 60F; Wind: N at 10 kts Sea-level pressure: 29.92 inches Hg, rising Visibility: 35 miles, W-NNE 20, SE-SSW 50, hazy 6-hour min. temp: 75F BHO SA 1155 55 SCT E80 BKN 140 OVC 35 131/77/60/0110/992/ BINOVC ESE-SE THN SPTS IOVC OVHD HIR CLDS VSBL SUN DMLY VSBL VSBY W-NNE 20 SE-SSW 50 HAZY LTGCG DSNT WNW/ 8/131 51017 10077 20075 10 A.M. Weather: Scattered cumulus, broken stratocumulus, broken altocumulus, few lower cumulus distant WSW, few higher clouds visible WNW-N, hazy, thunderstorm, rain shower with cloud to cloud and cloud to ground lightning SE-SSE moving ESE Temperature: 75F, Dew Point: 71F; Wind: S at 9 kts Sea-level pressure: 29.90 inches Hg, falling Visibility: 35 miles, WNW-NW 50, SE 15, hazy 3-hour precip.: 0.05 inch BHO SA 1455 50 SCT E65 BKN 100 BKN 35T 126/75/71/1809/990/ FEW LWR CU DSNT WSW FEW HIR CLDS VSBL WNW-N VSBY WNW-NW 50 SE 15 HAZY TRW LTGCGCC SE-SSE MVNG ESE/ 8/260 58005 6005/ 1 P.M. Weather: Scattered dense cirrus, thin broken cirrus, few moderate cumulus distant N, few altocumulus distant E-S, hazy Temperature: 85F, Dew Point: 68F; Wind: S at 10 kts Sea-level pressure: 29.87 inches Hg, falling Visibility: 40 miles, hazy 6-hour max. temp: 86F 6-hour precip.: 0.05 inch BHO SA 1755 200 SCT 250 –BKN 40 116/85/68/1910/987/ FEW MDT CU DSNT N FEW AC DSNT E-S HAZY/ 8/231 58010 6005/ 10086 20068 WEATHER SUMMARY FOR FRIDAY, JULY 22 TEMPERATURE (DEGREES F) MAX.....99 NORMAL.....82 MIN.....76 NORMAL.....63 MEAN....88 NORMAL.....72 DEPARTURE FROM 30-YEAR NORMAL...................+16 TOTAL DEPARTURE FOR THE MONTH...................+81 [+3.5 DEGREES/DAY] PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY..............28 W AT 4:22 P.M. * AEROVANE...............36 W AT 4:33 P.M. ASOS...................30 W AT 4:28 P.M. DAVIS..................32 WSW AT 3:20 P.M. THE FASTEST MILE FOR YESTERDAY............23 W AT 4:37 P.M. MAXIMUM 2-MINUTE ASOS AVERAGE.............22 W AT 4:39 P.M. MAXIMUM 2-MINUTE DAVIS AVERAGE............22 SSW AT 11:22 A.M. AVERAGE WIND SPEED AND DIRECTION........13.3 W ASOS.................12.7 DAVIS................13.0 WSW [240 deg] * Last of several occurrences... PRECIPITATION (INCHES) THROUGH THIS MORNING (EST) TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.00 DEPARTURE.........-0.12 ASOS..............0.00 TOTAL PRECIPITATION FOR THE MONTH..........1.73 DEPARTURE.........-0.93 ASOS..............1.71 TOTAL PRECIPITATION FOR THE YEAR..........29.04 DEPARTURE.........+0.71 ASOS..............29.57** **ASOS data is in error due to system failure on 1/12-13 PRELIMINARY CLIMATE SUMMARY FOR JULY 2011 CALENDAR DAY DATA DATA REPORTED: DATE: MAX/MIN/MEAN/DEP/PRECIP/SUN(MIN.)/SUN(%)/ PEAK GUST/AERO GUST AERO: Aerovane wind recording system gust when significant TSTM: Thunderstorm day (thunder heard some time during day) ....: Data not yet available, records not finalized 7/1 78/59/69/-1/0.01/530/58 15 WNW 7/2 80/61/71/+1/0.00/603/66 17 SE 7/3 79/64/72/+2/0.02/018/02 22 S 7/4 86/68/76/+6/0.00/583/64 18 SW 7/5 89/66/78/+7/0.00/784/86 15 S 7/6 88/68/78/+7/T/792/87 30 WNW AERO 35 MPH TSTM 7/7 86/67/77/+6/0.00/481/53 17 WNW 7/8 74/65/70/-1/0.47/027/03 16 ESE TSTM 7/9 81/63/72/+1/0.11/698/77 29 WNW 7/10 83/59/71/0/0.00/860/95 21 SSW 7/11 89/65/77/+5/0.00/814/90 23 S 7/12 90/72/83/+9/0.00/777/86 25 W 7/13 85/61/73/+1/0.73/469/52 21 NE 7/14 70/58/64/-8/0.37/801/89 28 NNE TSTM 7/15 79/59/69/-3/0.00/692/77 17 SSW TSTM 7/16 85/61/73/+1/0.00/834/93 15 SW 7/17 88/67/78/+6/0.00/797/89 30 SSW 7/18 84/70/77/+5/0.02/188/21 38 WSW AERO 43 MPH 7/19 86/69/78/+6/0.00/777/87 18 WNW AERO 24 MPH 7/20 88/69/79/+7/0.00/.../.. 29 SSW 7/21 93/68/81/+9/0.00/.../.. 37 SSW AERO 43 MPH 7/22 99/76/88/+16/0.00/.../.. 28 W AERO 36 MPH 7/23 morning low 75F; normal low is now 63F; thunder in AM DAILY RECORDS FOR JULY 2011 7/22 - RECORD HIGH MAXIMUM TEMPERATURE OF 99F; ties the previous record of 99F set in 1926 DAILY EXTREMES Temperature and precipitation records back to 1885, and wind records back to 1940 (e = estimated): 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 RECORDS FOR JULY 24 HIGH 96F IN 1987 LOW 49F IN 1893,1912 PRECIP 2.27 INCHES IN 2008 PEAK GUST 46 MPH NE IN 2009 TODAY'S REPORT PREPARED BY: Mike Iacono/George Tabeek