BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY WEDNESDAY, JULY 3, 2013 ALL TIMES ARE IN EASTERN STANDARD TIME WARM AND VERY HUMID WEATHER REPLACED BY MUCH COOLER AIR ARRIVING WITH A BACK-DOOR COLD FRONT LATE TUESDAY AFTERNOON FRONT PASSES BACK OVER US AS A WARM FRONT EARLY TODAY The high temperature yesterday of 82 degrees was reached at 5:14 P.M. EDT just ahead of a slowly moving back-door cold front. The front passed inland moving southwestward over the coastal 7 to 10 miles to our east and northeast just after 4 P.M. EDT and took an hour to reach Blue Hill. The temperature drop was as great as 10 degrees in just 10 minutes along the coast going from 81 to 71 degrees by 4:15 P.M. EDT. As the front passed over Blue Hill the temperature dropped from 82F to 68F in about 45 minutes and then continued on down to a low for the day of 61F by around 8:30 P.M. last evening. The front began moving back to the east overnight with temperatures rising up from 62 degrees in the early hours of today to 70 degrees by 7 A.M. EDT. A few mostly very light rain showers preceded and followed the frontal passage. Warm to hot and very humid weather resumes today. JUNE 2013 FINISHED AS 10TH WETTEST OF ALL MONTHS The very wet June 2013 saw measurable precipitation on 16 out of 30 days, and a trace of precipitation or greater on 21 out of 30 days. June preliminary statistics can be found below. Blue Hill Wettest Junes, inches (1886-2013) 1) 17.32 in 1998 2) 13.73 in 1982 3) 12.31 in 2006 4) 12.11 in 2013 5) 10.78 in 1922 Blue Hill Wettest Months, inches (1886-2013): 1) 18.81 in March 2010 2) 18.78 in August 1955 3) 17.32 in June 1998 4) 14.72 in October 2005 5) 13.73 in June 1982 6) 13.07 in March 2001 7) 12.60 in December 1969 8) 12.37 in September 1999 9) 12.31 in June 2006 10) 12.11 in June 2013 JUNE 2013 PRELIMINARY STATISTICS: (departures relative to 1981-2010 average) TEMPERATURE: Average Max Temp: 76.6F [+1.6F] Average Min Temp: 58.0F [+0.9F] Mean Temp: 67.3F [+1.3F] 24-hr. Corr. Mean Temp: 66.4F [+1.1F] Max Temp: 91F on 24th Min Temp: 48F on 4th Total heating degree day units (month): 48 [ -25] *NCDC method Total heating degree day units (season): 5,782 [-594] *start July 1 (NCDC) Total cooling degree day units (month): 125 [ +20] *NCDC method Total cooling degree day units (season): 156 [ +27] *start Jan 1 (NCDC) PRECIPITATION: Total precipitation: 12.11 inches [+7.80 inches] Greatest 24-hr precipitation: 3.98 on 7th/8th WIND: Avg wind speed: 11.5 MPH Avg corrected wind speed: 11.9 MPH Prevailing wind direction: SSW [14%] Peak gust: 45 MPH NW on 17th Peak fastest mile: 40 MPH NW on 17th SUNSHINE: Astronomical minutes: 15,232 of a possible 27,362 or 56% Campbell-Stokes sunshine card minutes: 14,640 of a possible 26,376 or 56% Today's Observations: 7 A.M. Weather: Scattered variable to broken stratocumulus, broken altocumulus, (2 levels), altcumulus lenticularis all quadrants Temperature: 73F; Dew Point: 69F; Wind: SW at 13G20 kts. Sea-level pressure: 30.22 ins. Hg, rising Visibility: 25 miles, thin fog/haze all quadrants 6-hour precip: none 24-hour precip: Trace 6-hour min. temp: 62F BHO SA 1155 13V SCT 70 SCT E160 BKN 25 234/73/69/2313G20/022/ 13 SCT V BKN ACSL ALQDS/ 8/570 53009 MANUAL 70000 10073 20062 10 A.M. Weather: Overcast altocumulus, few stratocumulus distant NNW-NNE, breaks in overcast distant SW, break in the overcast, clear sky band, NNE-ESE Temperature: 77F; Dew Point: 70F; Wind: WSW at 11 kts, Wind: Direction variable SSW-W Sea-level pressure: 30.23 ins. Hg, rising slightly Visibility: 35 miles, except 30 miles NE-SE, WNW 40 miles, distant haze 3-hour precip: trace BHO SA 1455 E130 OVC 35 237/77/70/2411/023/ FEW SC DSNT NNW-NNE BINOVC DSNT SW AND BINOVC/CLR SKY BND NNE-ESE VSBY NE-SE 30 VSBY WNW 40 WND 20V28 DSNT HZ REB45E50/ 8/57/ 53003 MANUAL 6000/ 1 P.M. Weather: Scattered cumulus, broken moderate cumulus/includes few towering cumulus and dark bases, broken altocumulus (2 levels) includes some altocumumuls lenticularis, broken cirrus Temperature: 85F; Dew Point: 71; Wind: WSW at 13G211 kts. Wind: Direction variable, SSW-W Sea-level pressure: 30.20 ins. Hg, falling then more rapidly Visibility: 40 miles, except 35 miles NE-SE, 50 miles WNW, distant haze 6-hour max. temp: 86F 6-hour precip: trace BHO SA 1755 38 SCT E45 BKN 70 BKN 150 BKN 250 BKN 40 228/85/71/2413G21/020/ NMRS MDT CU ALQDS FEW TCU DRK BASES FEW ACSL VSBY NE-SE 35 WMW 50 DSNT HZ WND 20V28/ 8/240 58009 MANUAL 6000/ 10086 20073 WEATHER SUMMARY FOR TUESDAY, JULY 2, 2013 TEMPERATURE (DEGREES F) MAX.....82 NORMAL.....79 MIN.....61 NORMAL.....62 MEAN....72 NORMAL.....70 DEPARTURE FROM 30-YEAR NORMAL.....................+2 TOTAL DEPARTURE FOR THE MONTH.....................+8 [+3.8 DEGREES/DAY] PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY................23 SSW AT 1:22 A.M. * AERO.....................23 SSW AT 12:36 P.M. ASOS.....................24 SSW AT 12:35 P.M. DAVIS....................24 SSW AT 1:21 A.M. RMY N/A FASTEST MILE FOR YESTERDAY..................19 SSW AT 12:36 P.M. MAXIMUM 2-MINUTE ASOS AVERAGE...............20 SSW AT 12:36 P.M. MAXIMUM 2-MINUTE DAVIS AVERAGE..............19 SSW AT 12:36 P.M. AVERAGE WIND SPEED AND DIRECTION..........10.5 SSW ASOS....................9.7 DAVIS..................10.1 S [190 deg] * last of several occurrences.... PRECIPITATION (INCHES) THROUGH THIS MORNING (EST) TOTAL PRECIPITATION 24 HRS ENDING 7 A.M...Trace DEPARTURE...........-0.11 ASOS..............0.00 TOTAL PRECIPITATION FOR THE MONTH..........0.05 DEPARTURE...........-0.17 ASOS..............0.05 TOTAL PRECIPITATION FOR THE YEAR..........32.25 DEPARTURE...........+5.06 ASOS..............N/A* *ASOS malfunctioned during storm on 2/8-9, leading to erroneous totals PRELIMINARY CLIMATE SUMMARY FOR JUNE AND 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 6/1 90/69/80/+18/0.00/905/100 30 SW AERO 32 MPH SW RMY 33 6/2 86/64/75/+13/T/761/84 42 SSW AERO 44 MPH SSW RMY 46 6/3 75/57/66/+4/0.47/154/17 22 WNW AERO 22 MPH SSW RMY 22 6/4 70/48/59/-4/0.00/899/99 25 W AERO 25 MPH W RMY 25 6/5 73/51/62/-1/0.00/727/80 20 SSW AERO 21 MPH S RMY 22 6/6 74/54/64/+1/0.03/455/50 22 SSE AERO 22 MPH S RMY 22 6/7 57/51/54/-10/3.28/000/00 33 NE AERO 32 MPH NE RMY 34 6/8 77/52/65/+1/0.78/356/39 29 W AERO 29 MPH W RMY 29 6/9 78/57/68/+4/0.00/886/97 25 W AERO 23 MPH W RMY 25 6/10 69/55/62/-3/0.76/119/13 24 E AERO 24 MPH E RMY N/A 6/11 65/53/59/-6/1.61/000/00 29 E AERO 29 MPH E RMY N/A 6/12 69/54/62/-3/0.01/320/35 38 NW AERO 41 MPH NW RMY 41 6/13 65/50/58/-7/0.93/110/12 32 NE AERO 33 MPH NE RMY 34 6/14 70/51/61/-5/1.38/421/46 32 NE AERO 32 MPH NE RMY 29 6/15 77/56/67/+1/0.00/907/99 23 NW AERO 24 MPH NW RMY 26 6/16 74/57/66/0/0.00/266/29 25 S AERO 24 MPH S RMY 27 6/17 84/60/72/+5/1.27/734/80 45 NW AERO 51 MPH NW RMY 48 TSTM 6/18 74/56/65/-2/0.61/440/48 32 ENE AERO 32 MPH ENE RMY 33 TSTM 6/19 71/53/62/-5/T/761/83 20 NNE AERO 20 MPH NNE RMY N/A 6/20 78/53/66/-2/0.00/889/97 18 SSW AERO 20 MPH SSW RMY N/A 6/21 82/57/70/+2/0.00/724/79 22 SW AERO 22 MPH SW RMY 23 6/22 82/62/72/+4/0.00/743/81 23 SW AERO 24 MPH SW RMY 25 6/23 87/63/75/+7/T/834/91 29 SW AERO 31 MPH SW RMY 32 6/24 91/68/80/+11/0.06/752/82 28 W AERO 30 MPH W RMY 30 TSTM 6/25 90/67/79/+10/T/669/73 32 W AERO 33 MPH W RMY 39 TSTM 6/26 83/65/74/+5/0.02/330/36 20 NNE AERO 20 MPH NNE RMY 20 6/27 66/61/64/-5/T/000/00 20 ENE AERO 17 MPH ENE RMY 20 6/28 78/61/70/0/0.59/329/36 32 S AERO 36 MPH S RMY 36 TSTM 6/29 80/68/74/+4/T/0.14/458/50 30 S AERO 32 MPH S RMY N/A 6/30 83/68/76/+6/0.17/283/31 23 S AERO 24 MPH S RMY 29 7/1 82/69/76/+6/0.05/.../.. 29 S AERO 31 MPH SSW RMY 32 7/2 82/61/72/+2/T/.../.. 23 SSW AERO 23 MPH SSW RMY 25 7/3 morning low temp: 62F; the normal low is now 62F DAILY RECORDS FOR JUNE 2013 6/1 - TIED DAILY RECORD MAXIMUM TEMPERATURE OF 90F; previous record of 90F set in 1937 6/1 - NEW DAILY RECORD HIGH MINIMUM TEMPERATURE OF 69F; surpasses previous record of 68F set in 1944, 1987 6/24 - TIED DAILY RECORD MAXIMUM TEMPERATURE OF 91F; previous record of 91F set in 1914, 1976 DAILY RECORDS FOR JULY 2013 None so far. DAILY EXTREMES Temperature and precipitation records back to 1885, and wind records back to 1940 (e = estimated): RECORDS FOR JULY 3 HIGH 99F IN 1911 LOW 47F IN 1914 PRECIP 1.36 IN 1985 PEAK GUST 52 MPH NW IN 1963 RECORDS FOR JULY 4 HIGH 98F IN 1911, 1919, 1949 LOW 48F IN 1914 PRECIP 1.78 IN 1950 PEAK GUST 50e MPH WNW IN 1949 TODAY'S REPORT PREPARED BY: Robert Skilling