BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY SUNDAY, MAY 31, 2015 ALL TIMES ARE IN EASTERN STANDARD TIME MONTH OF MAY COMES TO A CLOSE, SUBSTANTIAL RAIN LOOKS TO PUT A DENT IN MODERATE DROUGHT A brief early morning rain shower brought 0.03 inches of rain right around the 3:00 AM EST mark, adding to what has been an extremely dry month. Substantial rain showers and possible thunderstorms have entered the region this morning with shower activity beginning at the station once more by 9:35 AM EST. By the 1:00 PM EST observation showers over varying intensity were currently moving through the region, with heavy showers and thunderstorms north of the city. Visibility was reduced to 25 miles or less in all directions thanks to thin fog and showers. Although precipitation through the 1:00 PM EST observation had brought the monthly total to just 0.66 inches for the month of May, currently making this the third driest May on record. Rain, which may fall heavily at times tonight before midnight may well drop this month of further down the list. BHO Driest Mays, inches (1885-2014) 1) 0.50 in 1944 2) 0.62 in 1964 3) 0.89 in 1911 4) 1.11 in 1899 5) 1.20 in 1959 Today's Observations: 7 A.M. Weather: Scattered altocumulus, broken altocumulus, few moderate cumulus distant WSW-WNW Temperature: 68F; Dew Point: 61F; Wind: SSW at 14 kts, Sea-level pressure: 30.05 ins. Hg, about the same as 3 hrs ago Visibility: 25 miles, thin fog in all directions 6-hr Max temp: 68F 6-hr Min temp: 64F 24-hr precip: 0.03 inches BHO SA 1155 90 SCT E120 BKN 25 177/68/61/2114/005/ FEW MDT CU DSNT WSW-WNW THN FG ALQDS/ 8/29/ 53001 ASOS 60003 70003 MANUAL 70003 10068 20064 10 A.M. Weather: Light rain shower, beginning 9:35 AM EST, scattered altocumulus, broken cirrostratus, few cumulus fractus in all directions Temperature: 73F; Dew Point: 67F; Wind: SW at 9 kts Sea-level pressure: 30.06 ins. Hg, rising slightly Visibility: 20 miles, except 15 miles W-NW, 12 miles NNW-NNE, obscured by rain showers 3-hr precip: Trace BHO SA 1455 110 SCT E140 BKN 20RW- 179/73/67/2209/006/ RW-B35 VSBY W-NW 15 MI NNW-NNE 12 MI FEW CUFRA ALQDS PRCP VRY LGT/ 8/796 51002 MANUAL 6000/ 1 P.M. Weather: Broken stratocumulus, broken altocumulus, overcast altostratus, showers distant N-E, few stratus fractus in all directions Temperature: 73F; Dew Point: 67F; Wind: SW at 7 kts Sea-level pressure 30.09 ins. Hg, steady, then rising Visibility: 25 miles, except 20 miles N-NNE 6-hr Max temp: 78F 6-hr Min temp: 68F 3-hr precip: Trace 6-hr precip: Trace BHO SA 1755 E31 BKN 110 BKN 140 OVC 25 188/73/67/2407/009/ VSBY N-NNE 20 MI SHWRS DSNT N-E FEW STFRA ALQDS THN FG ALQDS/ 8/52/ 53009 MANUAL 6000/ 10078 20068 SUMMARY FOR SATURDAY, MAY 30, 2015 TEMPERATURE (DEGREES F) MAX.....85 NORMAL.....70 MIN.....55 NORMAL.....52 MEAN....70 NORMAL.....61 DEPARTURE FROM 30-YEAR NORMAL........................+9 TOTAL DEPARTURE FOR THE MONTH......................+159 [+5.1 DEGREES/DAY] HEATING DEGREE DAYS (SEASON JUL TO JUN) TOTAL HEATING UNITS FOR YESTERDAY...............0 DEPARTURE...........-5 TOTAL HEATING UNITS FOR THE MONTH.............130 DEPARTURE.........-133 TOTAL HEATING UNITS FOR THE SEASON...........6401 DEPARTURE.........+103 TOTAL HEATING UNITS LAST SEASON TO DATE......6384 DIFFERENCE.........+17 COOLING DEGREE DAYS (SEASON JAN TO DEC) TOTAL COOLING UNITS FOR YESTERDAY..............5 DEPARTURE..........+4 TOTAL COOLING UNITS FOR THE MONTH.............49 DEPARTURE.........+28 TOTAL COOLING UNITS FOR THE SEASON............49 DEPARTURE.........+26 TOTAL COOLING UNITS LAST SEASON TO DATE.......13 DIFFERENCE........+36 PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY..................37 SSW AT 6:29 P.M. ASOS.......................42 SSW AT 6:29 P.M. DAVIS......................40 SSW AT 6:29 P.M. RMY 42 FASTEST MILE FOR YESTERDAY....................30 SSW AT 4:44 P.M. MAXIMUM 2-MINUTE ASOS AVERAGE.................30 SSW AT 4:45 P.M. MAXIMUM 2-MINUTE DAVIS AVERAGE................30 SSW AT 4:45 P.M. AVERAGE WIND SPEED AND DIRECTION..............17.3 SSW ASOS.......................16.6 DAVIS......................15.7 SSW [207 deg.] PRECIPITATION (INCHES) THROUGH THIS MORNING (EST) TOTAL PRECIPITATION 24 HRS ENDING 7 A.M.....0.03 DEPARTURE.....-0.13 ASOS...............0.03 TOTAL PRECIPITATION FOR THE MONTH...........0.66 DEPARTURE.....-3.30 ASOS...............0.66 TOTAL PRECIPITATION FOR THE YEAR...........18.58 DEPARTURE.....-3.80 ASOS................N/A *** *** ASOS annual totals not available due to erroneous readings SNOWFALL (INCHES) THROUGH THIS MORNING (EST) TOTAL SNOWFALL 24 HRS ENDING 7 A.M...........0.0 DEPARTURE......0.0 TOTAL SNOWFALL FOR THE MONTH.................0.0 DEPARTURE......0.0 TOTAL SNOWFALL FOR THE SEASON..............150.8 DEPARTURE....+88.1 PRELIMINARY CLIMATE SUMMARY FOR MAY CALENDAR DAY DATA DATA REPORTED: DATE: MAX/MIN/MEAN/DEP/PRECIP/SNOWFALL/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 5/1 52/37/45/-8/0.00/0.0/354/42 21 NE RMY 20 5/2 63/35/49/-4/0.00/0.0/668/79 20 S RMY 20 5/3 74/44/59/+6/0.00/0.0/509/60 22 S RMY 22 5/4 83/47/65/+11/0.00/0.0/783/92 39 SSW RMY 45 5/5 77/56/67/+13/0.03/0.0/222/26 29 SW RMY N/A 5/6 74/54/64/+10/0.00/0.0/574/67 24 SSW RMY 25 5/7 84/52/68/+13/0.00/0.0/824/96 29 S RMY 32 5/8 74/44/59/+4/0.00/0.0/809/94 27 NNE RMY 26 5/9 77/44/61/+6/0.00/0.0/509/59 30 S RMY 32 5/10 88/60/74/+19/0.00/0.0/692/80 28 SSW RMY 30 5/11 84/48/66/+10/0.00/0.0/529/61 30 NE RMY 31 5/12 84/47/66/+10/0.24/0.0/287/33 33 WNW RMY 37 5/13 67/47/57/+1/0.00/0.0/820/94 31 WNW RMY N/A 5/14 70/44/57/+0/0.00/0.0/848/97 22 NW RMY 22 5/15 73/51/62/+5/0.00/0.0/491/56 20 WSW RMY 21 5/16 68/53/61/+4/T/0.0/053/06 23 S RMY 24 5/17 79/50/65/+8/T/0.0/783/89 21 NE RMY N/A 5/18 62/48/55/-3/..../0.0/538/61 25 NE RMY N/A 5/19 63/50/57/-1/0.36/0.0/000/00 24 S RMY 26 5/20 66/46/56/-2/0.00/0.0/.../.. 32 WNW RMY 37 5/21 66/43/55/-4/..../0.0/.../.. 24 S RMY 24 5/22 73/49/61/+2/T/0.0/.../.. 32 NW RMY 36 5/23 64/40/52/-7/0.00/0.0/.../.. 28 WNW RMY 32 5/24 81/50/66/+7/0.00/0.0/.../.. 28 SSW RMY 31 5/25 80/56/68/+8/0.00/0.0/.../.. 29 SSW RMY 31 5/26 83/61/72/+12/0.00/0.0/.../.. 30 SSW RMY N/A 5/27 82/62/72/+12/T/0.0/.../.. 36 SSW RMY 41 5/28 83/61/72/+11/0.00/0.0/.../.. 30 SSW RMY 34 5/29 77/58/68/+7/0.00/0.0/.../.. 18 ENE RMY 19 5/30 85/55/70/+9/0.00/0.0/.../.. 37 SSW RMY 42 5/31 low since midnight is 64F; normal low is now 52F DAILY RECORDS FOR MAY 2015 NONE SO FAR. DAILY EXTREMES Temperature and precipitation records back to 1885, and wind records back to 1940 (e = estimated): RECORDS FOR MAY 31 HIGH 92F IN 1944,1987 LOW 35F IN 1961 PRECIP 5.02 INS 1984 (RECORD FOR MAY) PEAK GUST 54e MPH WNW IN 1945 RECORDS FOR JUNE 1 HIGH 90F IN 1937,2013 LOW 36F IN 1945 [Record for month] PRECIP 2.28 INS IN 1992 PEAK GUST 51e MPH SE IN 1952 TODAY'S REPORT PREPARED BY: Brian Fitzgerald