BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY TUESDAY, AUGUST 13, 2013 ALL TIMES ARE IN EASTERN STANDARD TIME LIGHT RAIN AND SHOWERS PROVIDE ONLY 0.02 INCH OF PRECIPITATION; RELATIVELY COOL AND CALM OTHERWISE Light rain showers began on the summit just before 9 A.M. EDT, remaining relatively light and intermittent until about 11:30 A.M. EDT. At that point, steadier light rain began falling and lasted through about 2 P.M. EDT. The total rainfall today has only reached 0.02 inch. A large batch of heavier rain and embedded t-storms spread to our north, and especially to our south, leaving us in a lull of light rain much of the day. While the low temperature this morning only managed to reach 65F (normal 62F), the high temperature has struggled to reach the lower 70s this afternoon. Today will likely finish a few degrees below the 30-year normal. Interestingly, Monday was the first day since July 29 that the average daily temperature actually finished above the 30-year normal for a given date. As has been the case over the past couple of days, today winds continue to be rather light. The wind direction has gradually backed today, from a SW direction early this morning to a SE direction this afternoon. Today's Observations: 7 A.M. Weather: Scattered altocumulus (2 levels), broken altostratus, broken cirrostratus, lower altocumulus WSW-ENE, higher altocumulus distant ESE-SSE, ground fog/low stratus layer distant ESE-SW-NNW, sun dimly visible, thin smoke layer along horizon N-NNE, thin fog/haze all quadrants Temperature: 68F; Dew Point: 65F; Wind: SSW at 5 kts. Sea-level pressure: 29.86 ins. Hg, rising then falling Visibility: 20 miles, thin fog/haze all quadrants, ground fog/low stratus layer distant ESE-SW-NNW 6-hr min. temp: 65F BHO SA 1155 100 SCT 120 SCT E160 BKN 200 BKN 20 111/68/65/2005/986/ LWR AC WSW-ENE HIER AC DSNT ESE-SSE GF/LW STRA LYR DSNT ESE-SW-NNW SUN DIMLY VSBL THN K LYR ALG HRZN N-NNE THN FG/HZ ALQDS/ 8/677 58007 10068 20065 10 A.M. Weather: Light rain shower, scattered altocumulus (2 levels), overcast altostratus, few lower stratus fractus all quadrants, thin fog/haze all quadrants, light rain shower began at 9:10 A.M. EST and ended at unknown time, light rain shower began at unknown time and continued very light Temperature: 69F; Dew Point: 67F; Wind: S at 8 kts. Sea-level pressure: 29.85 ins. Hg, falling slightly Visibility: 15 miles, light rain and thin fog/haze all quadrants 3-hr precip: Trace BHO SA 1455 80 SCT 100 SCT E140 OVC 15RW- 110/69/67/1808/985/ FEW LWR STFRA ALQDS THN FG/HZ ALQDS RW-B10 EUKN BUKN CTD PCPN VRY LGT/ 8/77/ 56001 MANUAL 6000/ 1 P.M. Weather: Light rain, scattered cumulus, scattered stratocumulus, broken altocumulus (2 levels), overcast altostratus, towering cumulus distant WNW, few cumulus/moderate cumulus distant ESE-S-W, few small cumulus/cumulus fractus distant WNW and distant NW and distant NE-E, thin fog/haze all quadrants, light rain became very light at unknown time and continued Temperature: 67F; Dew Point: 64F; Wind: SSE at 10 kts, Wind: Direction gradually backing (counterclockwise) over the past hour Sea-level pressure: 29.81 ins. Hg, falling Visibility: 25 miles, N-E 20 miles, WNW 25 miles, light rain and thin fog/haze all quadrants 6-hr precip: 0.02 inch 6-hr max. temp: 71F BHO SA 1755 20 SCT 60 SCT E80 BKN 100 BKN 140 OVC 25R- 094/67/64/1510/981/ TCU DSNT WNW FEW CU/MDT CU DSNT ESE-S-W FEW SML CU/CUFRA DSNT WNW AND DSNT NW AND DSNT NE-E THN FG/HZ ALQDS VSBY N-E 20 WNW 25 WND GRDLY BACKING PST HR R- BCMG VRY LGT UKN CTD/ 8/87/ 58016 ASOS 60001 MANUAL 60002 10071 20067 WEATHER SUMMARY FOR MONDAY, AUGUST 12, 2013 TEMPERATURE (DEGREES F) MAX.....81 NORMAL.....80 MIN.....62 NORMAL.....62 MEAN....72 NORMAL.....71 DEPARTURE FROM 30-YEAR NORMAL......................+1 TOTAL DEPARTURE FOR THE MONTH.....................-23 [-2.1 DEGREES/DAY] COOLING DEGREE DAYS (SEASON JAN TO DEC) TOTAL COOLING UNITS FOR YESTERDAY.............7 DEPARTURE.........+1 TOTAL COOLING UNITS FOR THE MONTH............59 DEPARTURE........-25 TOTAL COOLING UNITS FOR THE SEASON..........542 DEPARTURE.......+107 TOTAL COOLING UNITS LAST SEASON TO DATE.....588 DIFFERENCE.......-46 PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY................18 W AT 10:42 A.M. AERO.....................17 WSW AT 10:45 A.M. ASOS.....................18 W AT 10:42 A.M. DAVIS....................18 WSW AT 10:45 A.M. RMY 19 FASTEST MILE FOR YESTERDAY..................13 WSW AT 10:45 A.M. MAXIMUM 2-MINUTE ASOS AVERAGE...............14 W AT 10:46 A.M. MAXIMUM 2-MINUTE DAVIS AVERAGE..............13 WSW AT 10:46 A.M. AVERAGE WIND SPEED AND DIRECTION...........8.1 WSW ASOS....................8.1 DAVIS...................7.4 WSW [241 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..........2.53 DEPARTURE............+0.81 ASOS..............2.59 TOTAL PRECIPITATION FOR THE YEAR..........37.82 DEPARTURE............+5.11 ASOS..............N/A* *ASOS malfunctioned during storm on 2/8-9, leading to erroneous totals PRELIMINARY CLIMATE SUMMARY FOR AUGUST 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 8/1 81/62/72/0/0.01/503/58 25 S AERO 26 MPH S RMY 27 8/2 81/62/72/0/0.23/518/60 26 W AERO 26 MPH W RMY 28 8/3 77/63/70/-2/T/276/32 22 WSW AERO 23 MPH WSW RMY 23 8/4 79/58/69/-3/T/645/75 25 WNW AERO 21 MPH WNW RMY 26 8/5 75/54/65/-7/0.00/858/100 26 WNW AERO 25 MPH WNW RMY 27 8/6 78/56/67/-5/0.00/846/99 17 ESE AERO 15 MPH S RMY 16 8/7 80/59/70/-2/0.00/759/89 21 S AERO 21 MPH S RMY N/A 8/8 79/62/71/-1/0.08/153/18 25 S AERO 25 MPH S RMY N/A 8/9 73/70/72/0/2.21/000/00 37 S AERO 39 MPH S RMY 40 8/10 81/61/71/-1/0.00/795/94 30 WNW AERO 31 MPH WNW RMY 31 8/11 78/58/68/-3/0.00/835/99 18 W AERO 18 MPH W RMY 21 8/12 81/62/72/+1/0.00/.../.. 18 W AERO 17 MPH WSW RMY 19 8/13 morning low temp: 65F; the normal low is now 62F DAILY RECORDS FOR AUGUST 2013 None so far. DAILY EXTREMES Temperature and precipitation records back to 1885, and wind records back to 1940 (e = estimated): RECORDS FOR AUGUST 13 HIGH 98F IN 1944, 2002 LOW 47F IN 1902, 1957 PRECIP 2.92 INCHES IN 1989 PEAK GUST 52 MPH SSE IN 1963 RECORDS FOR AUGUST 14 HIGH 99F IN 2002 LOW 46F IN 1964 PRECIP 3.06 INCHES IN 1919 PEAK GUST 61 MPH WNW IN 1963 TODAY'S REPORT PREPARED BY: Sean Fankhauser