BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY MONDAY, JULY 16, 2012 ALL TIMES ARE IN EASTERN STANDARD TIME HUMIDITY STICKS AROUND WITH DEW POINTS IN THE MID TO UPPER 60's BLUE HILL CURRENTLY IN A THREE DAY HEAT WAVE ONLY A TRACE OF PRECIP FOLLOWING LAST NIGHT'S FRONTAL PASSAGE POSSIBLE RECORD HEAT TOMORROW VERY SUNNY AND VERY DRY JULY TO DATE Today marks another humid day here on the summit as dew points remain in the mid to upper 60's. Haze continues to keep visibility down to only about 30 miles. There have now been 14 days this month, including today, where temperatures have averaged above normal. This trend will continue into midweek. Today's maximum temperature of 91F so far makes for a current three-day heat wave which should continue tomorrow. Our overnight minimum temperature for today fell 1 degree shy of tying the record of 71F set back in 1901,1958, and 1968. Due to potential record heat tomorrow, the following records may be in jeopardy: Record high maximum temperature for July 17: 96F set in 1999 Record high minimum temperature for July 17: 74F set in 1900 July has not only been a very dry month to date but also a very sunny one. Through 11 days the 75% of possible bright sunshine is far above the average for the month which is 57%. The record sunniest July was back in 1952 when this month had 75% of the possible bright sunshine. That month was also the driest July on record with just 0.13 inch of rainfall. Today's observations: 7 A.M. Weather: Clear, few cumulus SE-SW, few cumulus fractus ENE-SE moving S, few altocumulus all quadrants except NE, hazy Temperature: 75F; Dew Point 68F; Wind: W at 9 kts Sea-level pressure: 29.83 ins. Hg, increasing then steady Visibility: 30 miles, 30-35 miles E-SE, 20-25 miles SW-W, hazy 6-hour min. temp: 70F BHO SA 1155 CLR 30 102/75/68/2809/983/ FEW CU SE-SW FEW CUFRA ENE-SE MOVG S FEW AC ALQDS XCPT NE HAZY VSBY HIER E-SE 30V35 VSBY LWR SW-W 20V25/ 8/140 51007 10075 20070 10 A.M. Weather: Scattered cumulus, scattered cirrus, few cumulus fractus all quadrants, few moderate cumulus all quadrants, hazy Temperature: 84F; Dew Point: 67F; Wind: NW at 12 kts, Wind: Direction variable W-N Sea-level pressure: 29.80 ins. Hg, decreasing Visibility: 30 miles, hazy BHO SA 1455 40 SCT 250 SCT 30 091/84/67/3112/980/ FEW CUFRA ALQDS FEW MDT CU ALQDS HAZY WND 27V36/ 8/101 58011 1 P.M. Weather: Broken cumulus congestus, moderate cumulus all quadrants, hazy Temperature: 87F; Dew Point 65F; Wind: NW at 12 kts, Wind: Direction variable W-N Sea-level pressure: 29.78 ins. Hg, decreasing Visibility: 30 miles, hazy 6-hour max temp: 91F BHO SA 1755 E50 BKN 30 085/87/65/3112/978/ MDT CU ALQDS HAZY WND 27V35/ 8/200 56006 10091 20075 WEATHER SUMMARY FOR SUNDAY, JULY 15 TEMPERATURE (DEGREES F) MAX.....91 NORMAL.....81 MIN.....68 NORMAL.....63 MEAN....80 NORMAL.....72 DEPARTURE FROM 30-YEAR NORMAL.......................+8 TOTAL DEPARTURE FOR THE MONTH......................+67 [+4.3 DEGREES/DAY] PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY.............18 SW AT 7:22 P.M. * AERO..................18 SSW AT 7:15 P.M. ASOS..................21 SW AT 7:17 P.M. DAVIS.................19 SW AT 7:15 P.M. RMY 20 THE FASTEST MILE FOR YESTERDAY...........15 SW AT 7:17 P.M. MAXIMUM 2-MINUTE ASOS AVERAGE............16 SW AT 7:17 P.M. MAXIMUM 2-MINUTE DAVIS AVERAGE...........16 SW AT 7:17 P.M. AVERAGE WIND SPEED AND DIRECTION........9.0 SW ASOS.................8.7 DAVIS................8.3 SW [227 deg] *...Last of several occurrences PRECIPITATION (INCHES) THROUGH THIS MORNING (EST) TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....Trace DEPARTURE...........-0.14 ASOS..............0.00 TOTAL PRECIPITATION FOR THE MONTH..........0.38 DEPARTURE...........-1.42 ASOS..............0.36 TOTAL PRECIPITATION FOR THE YEAR..........18.07 DEPARTURE..........-10.70 ASOS.............17.98 PRELIMINARY CLIMATE SUMMARY FOR JULY 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 when significant 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 89/67/78/+8/0.01/676/74 33 WSW AERO 32 MPH WSW RMY 34 7/2 84/66/75/+5/T/644/71 23 W AERO 22 MPH W RMY 23 7/3 85/63/74/+3/0.00/787/86 23 W AERO 21 MPH W RMY 20 7/4 85/66/76/+5/0.37/480/53 20 W AERO 20 MPH W RMY 23 7/5 81/68/75/+4/0.00/729/80 23 NW AERO 23 MPH NW RMY 22 7/6 86/64/75/+4/0.00/753/83 18 SSW AERO 18 MPH SSW RMY 19 7/7 81/69/75/+4/T/224/25 23 W AERO 23 MPH W RMY 24 7/8 87/66/77/+5/0.00/814/90 23 W AERO 23 MPH W RMY 25 7/9 82/61/72/0/0.00/738/85 22 W AERO 21 MPH W RMY 23 7/10 83/61/72/0/0.00/852/98 18 W AERO 18 MPH W RMY 18 7/11 84/64/74/+2/0.00/768/88 21 W AERO 21 MPH W RMY 23 7/12 89/64/77/+5/0.00/.../.. 25 SSW AERO 25 MPH SSW RMY 26 7/13 89/66/78/+6/0.00/.../.. 28 S AERO 27 MPH S RMY 29 7/14 90/69/80/+8/0.00/.../.. 24 W AERO 22 MPH W RMY 23 7/15 91/68/80/+8/T/.../.. 18 SW AERO 18 MPH SSW RMY 20 7/16 morning low temp: 70F; the normal low is now 63F DAILY RECORDS FOR JULY 2012 None so far. DAILY EXTREMES Temperature and precipitation records back to 1885, and wind records back to 1940 (e = estimated): RECORDS FOR JULY 16 HIGH 94F IN 1968, 1980, 1983, 1999 LOW 50F IN 1889, 1903 PRECIP 0.89 INS IN 1919 WIND 48e MPH SW 1944 RECORDS FOR JULY 17 HIGH 96F IN 1999 LOW 47F IN 1892 PRECIP 1.39 INS IN 1989 WIND 46 MPH WNW IN 1971 TODAY'S REPORT PREPARED BY: George Tabeek/Patrick Peters