BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY SUNDAY, OCTOBER 18, 2015 ALL TIMES ARE IN EASTERN STANDARD TIME CLEAR AND COLD THIS MORNING BUT GIVING WAY TO FAIR WEATHER CLOUDS While several areas saw their first snowfalls of the year yesterday, Blue Hills was not among them with only a trace of rain earlier in the day. Temperatures have struggled to climb out of the lower 40's despite sunny conditions on the summit. Cumulus and Stratocumulus clouds are now moving into the area ahead of another light batch of rain and snow showers currently to our west bring showers and virga into the area obscuring small sectors of visibility. This morning’s low of 28.9 degrees is the coldest low so far this season and marks the first time we have been below freezing since last winter. The cold air was very clear this morning with visibility reaching 80 miles for a time and areas that do not have obscuring virga continue to have visibilities at 70 miles. Today's Observations: 7 A.M. Weather: Few stratus NNW-N, Few Cumulus ENE-SSE over ocean Temperature: 31F; Dew Point: 23F; Wind: NW at 10 kts, Sea-level pressure: 30.21 ins. Hg, rising, then more slowly Visibility: 80 miles 6-hr Max temp: 34F 6-hr Min temp: 28F 24-hr precip: 0.00 ins. BHO SA 1155 CLR 80 232/31/23/3210/021/ FEW S NNW-N DSNT FEW CU ENE-SSW DSNT 8/800 53019 10034 20029 10 A.M. Weather: Few Cumulus Temperature: 41F; Dew Point 20F; Wind: NW at 7 kts, Sea-level pressure: 30.21 ins. Hg, falling slightly Visibility: 70 miles BHO SA 1455 CLR 70 234/41/20/3107/021/ FEW CU DSNT ALQDS 8/100 50002 1 P.M. Weather: Broken Cumulus and Stratocumulus Temperature: 42F; Dew Point 17F; Wind: W at 07G18 kts, Wind: Peak gust 18 knots Sea-level pressure: 30.19 ins. Hg, falling then steady Visibility: 65 miles, except 70 ENE-SSE BHO SA 1755 E60 BKN 65 225/42/17/3207G18/019/ SHWRS AND VIRGA DSNT SSE-ENE VSBY 70 ENE-SSE 56009 10042 20031 SUMMARY FOR SATURDAY, OCTOBER 17, 2015 TEMPERATURE (DEGREES F) MAX.....54 NORMAL.....60 MIN.....35 NORMAL.....42 MEAN....45 NORMAL.....51 DEPARTURE FROM 30-YEAR NORMAL.......................-6 TOTAL DEPARTURE FOR THE MONTH.......................+4 [+0.2 DEGREES/DAY] COOLING DEGREE DAYS (SEASON JAN TO DEC) TOTAL COOLING UNITS FOR YESTERDAY...............0 DEPARTURE...........0 TOTAL COOLING UNITS FOR THE MONTH...............0 DEPARTURE..........-5 TOTAL COOLING UNITS FOR THE SEASON............810 DEPARTURE........+208 TOTAL COOLING UNITS LAST SEASON TO DATE.......595 DIFFERENCE.......+215 HEATING DEGREE DAYS (SEASON JUL TO JUN) TOTAL HEATING UNITS FOR YESTERDAY..............20 DEPARTURE..........+6 TOTAL HEATING UNITS FOR THE MONTH.............168 DEPARTURE.........-10 TOTAL HEATING UNITS FOR THE SEASON............211 DEPARTURE........-109 TOTAL HEATING UNITS LAST SEASON TO DATE.......240 DIFFERENCE........-15 PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY...................30 WNW AT 12:08 P.M. ASOS........................33 W AT 12:14 P.M. DAVIS.......................31 W AT 1:14 P.M. RMY 33 FASTEST MILE FOR YESTERDAY.....................23 WNW AT 10:22 A.M. MAXIMUM 2-MINUTE ASOS AVERAGE..................25 WNW AT 12:58 P.M. MAXIMUM 2-MINUTE DAVIS AVERAGE.................22 WNW AT 11:22 A.M. AVERAGE WIND SPEED AND DIRECTION.............12.8 WNW ASOS......................12.7 DAVIS.....................11.0 WNW [294 Deg.] PRECIPITATION (INCHES) THROUGH THIS MORNING (EST) TOTAL PRECIPITATION 24 HRS ENDING 7 A.M........T DEPARTURE.....-0.15 ASOS...............0.00 TOTAL PRECIPITATION FOR THE MONTH...........1.06 DEPARTURE.....-1.46 ASOS...............1.04 TOTAL PRECIPITATION FOR THE YEAR...........35.20 DEPARTURE.....-6.40 ASOS................N/A *** *** ASOS annual total not available due to erroneous readings PRELIMINARY CLIMATE SUMMARY FOR OCTOBER CALENDAR DAY DATA DATA REPORTED: DATE: MAX/MIN/MEAN/DEP/PRECIP/SUN(MIN.)/SUN(%)/ PEAK GUST/RMY GUST RMY: R.M. Young wind gust recording system TSTM: Thunderstorm day (thunder heard some time during day) ....: Data not yet available, records not finalized 10/1 55/51/53/-4/..../000/00 39 NE RMY N/A 10/2 51/47/49/-8/..../000/00 40 NE RMY 43 10/3 51/45/48/-8/..../000/00 38 NE RMY N/A 10/4 55/49/52/-4/0.00/474/68 35 E RMY 40 10/5 59/46/53/-3/T/125/18 21 NE RMY 20 10/6 68/43/56/+1/0.00/663/96 17 NW RMY 17 10/7 69/46/58/+3/0.00/640/93 20 W RMY 20 10/8 63/49/56/+2/0.00/678/99 21 S RMY N/A 10/9 68/50/59/+5/0.27/.../.. 45 S RMY 49 10/10 59/44/53/-2/0.00/.../.. 33 NNW RMY N/A 10/11 67/46/57/+4/0.00/.../.. 26 SW RMY 28 10/12 76/50/63/+10/0.00/.../.. 22 SSW RMY 24 10/13 70/55/63/+10/0.27/.../.. 23 S RMY 24 10/14 66/46/56/+4/0.00/.../.. 26 W RMY 29 10/15 60/41/51/-1/0.00/.../.. 20 SW RMY 27 10/16 60/44/52/+1/T/.../.. 31 W RMY 34 10/17 54/35/45/-6/T/.../.. 30 WNW RMY 33 10/18 low since midnight is 29F; normal low is now 42F DAILY RECORDS FOR OCTOBER 2015 -NONE SO FAR. DAILY EXTREMES Temperature and precipitation records back to 1885, and wind records back to 1940 (e = estimated): RECORDS FOR OCTOBER 18 HIGH 82F IN 1908 LOW 26F IN 1939 PRECIP 2.79 INCHES IN 1975 SNOWFALL 3.0 INCHES IN 2009 PEAK GUST 66 MPH S IN 1967 RECORDS FOR OCTOBER 19 HIGH 81F IN 1945 LOW 21F IN 1922 PRECIP 3.64 INCHES IN 1932 SNOWFALL 1.0 INCHES IN 1972 PEAK GUST 66 MPH SSW IN 1967 TODAY'S REPORT PREPARED BY: Robert Millette