BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY THURSDAY, JULY 18, 2013 ALL TIMES ARE IN EASTERN STANDARD TIME HEAT WAVE EXTENDS TO FOURTH DAY The temperature rose to 90F this morning before a seabreeze began shortly before noon EDT, preventing any further temperature increase. Still, this marks the fourth official day of the current heat wave. The record high temperature for today is 96F, so we will fall short of that. Yesterday's minimum temperature of 74F tied the record high minimum temperature for the date set in 1900. This morning's low of 75F would break the record high minimum for the date of 73F set in 1900 and 1999 if the temperature does not drop below 75F by midnight EST tonight. Tomorrow's record high maximum temperature is 96F, and the record high minimum for tomorrow is 72F. Both of these records may be approached or surpassed. Today has been another hazy day, with visibility held to 30 miles or less. The sky has been mostly clear with cumulus developing throughout the late morning and afternoon, along with some cirrus. Winds were light for much of the morning but picked up a little once the seabreeze arrived, though no gusts over 20 mph have been observed so far. The dew point has been high, at or above 70F all day, which has made it feel hotter than it is. Today's Observations: 7 A.M. Weather: Clear, few altocumulus ENE-SW and NW-N, few cirrus ENE-S and NW-N Temperature: 81F; Dew Point: 73F; Wind: NW at 7 kts Sea-level pressure: 30.03 ins. Hg, rising then rising more rapidly Visibility: 15 miles, hazy 6-hr min. temp: 75F BHO SA 1155 CLR 15 168/81/73/3107/003/ FEW AC ENE-SW AND NW-N FEW CI ENE-S AND NW-N HAZY/ 8/051 53007 10081 20075 10 A.M. Weather: Scattered cirrus, few cumulus and cumulus fractus all quadrants Temperature: 89F; Dew Point: 70F; Wind: Estimated NNW at 4 kts, Wind: Light and variable Sea-level pressure: 30.03 ins. Hg, rising then rising more slowly Visibility: 25 miles, distant haze BHO SA 1455 250 SCT 25 171/89/70/E3404/003/ FEW CU AND CUFRA ALQDS DSNT HZ WND LGT AND VRB/ 8/101 51003 1 P.M. Weather: Scattered cirrus, cumulus SSE-NNW, few moderate cumulus S-WSW Temperature: 86F; Dew Point: 70F; Wind: ENE at 8 kts, Wind: Direction variable NNE-E Sea-level pressure: 30.02 ins. Hg, steady then falling Visibility: 30 miles, distant haze 6-hr max. temp: 90F BHO SA 1755 250 SCT 30 167/86/70/0708/002/ CU SSE-NNW FEW MDT CU S-WSW DSNT HZ WND 03V10/ 8/201 58004 10090 20081 WEATHER SUMMARY FOR WEDNESDAY, JULY 17, 2013 TEMPERATURE (DEGREES F) MAX.....93 NORMAL.....81 MIN.....74 NORMAL.....63 MEAN....84 NORMAL.....72 DEPARTURE FROM 30-YEAR NORMAL.....................+12 TOTAL DEPARTURE FOR THE MONTH.....................+88 [+5.0 DEGREES/DAY] PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY................22 SW AT 11:50 P.M. AERO.....................23 SW AT 11:50 P.M. * ASOS.....................24 SSW AT 6:25 P.M. DAVIS....................23 S AT 5:29 P.M. RMY 25 FASTEST MILE FOR YESTERDAY..................18 SSW AT 4:26 P.M. MAXIMUM 2-MINUTE ASOS AVERAGE...............18 SSW AT 4:50 P.M. MAXIMUM 2-MINUTE DAVIS AVERAGE..............17 SSW AT 4:50 P.M. AVERAGE WIND SPEED AND DIRECTION...........8.6 SSW ASOS....................8.4 DAVIS...................7.7 SSW [213 deg.] * last of several occurrences... 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 THE MONTH..........1.01 DEPARTURE............-1.06 ASOS..............1.00 TOTAL PRECIPITATION FOR THE YEAR..........33.21 DEPARTURE............+4.17 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 morning low temp: 75F; the normal low is now 63F DAILY RECORDS FOR JULY 2013 7/17 - TIED DAILY RECORD HIGH MINIMUM TEMPERATURE OF 74F; ties previous record of 74F set in 1900 DAILY EXTREMES Temperature and precipitation records back to 1885, and wind records back to 1940 (e = estimated): RECORDS FOR JULY 18 HIGH 96F IN 1991, 1999 LOW 54F IN 1892, 1956, 1971 PRECIP 1.65 INS IN 2000 WIND 43e MPH SW IN 1949 RECORDS FOR JULY 19 HIGH 96F IN 1977, 1991 LOW 50F IN 1890 PRECIP 1.10 INS IN 1951 WIND 63 MPH SSW IN 1982 TODAY'S REPORT PREPARED BY: Jonathan O'Brien, Mark Medlinskas and Matthew Magann