BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY FRIDAY, MAY 31, 2013 ALL TIMES ARE IN EASTERN STANDARD TIME TIED RECORD HIGH TEMP AND FIRST 90F READING OF THE SEASON; METEOROLOGICAL SPRING ENDS ON A HAZY, HOT, AND HUMID NOTE The maximum temperature has reached 92F so far today, but may push higher later this afternoon. That's good enough to tie the existing record of 92F set in 1944 and 1987. This is also Blue Hill's first 90F reading of the season. Today's low temperature only bottomed out at 68F, leaving today's average temperature nearly 20 degrees above the 30-year normal for the date! It has also been quite humid today with dew point temperatures in the mid 60s. The moisture in the air is also apparent with the hazy conditions which have kept visibility in the 25-45 mile range today. May 31 marks the end of meteorological spring, and June 1 will mark the beginning of meteorological summer. Statistics about May 2013 and Spring 2013 will be included in the daily discussion over the next few days. With hot conditions today and tomorrow, below are the existing record high temperatures at Blue Hill: May 31 92F in 1944, 1987 June 1 90F in 1937 Today's observations: 7 A.M. Weather: Thin scattered cirrus distant NW-NNE, inversion present with an estimated top of 400 ft over the city to the N, smoke/haze layer below inversion all quadrants, smoke layer aloft SE-W-NNE, hazy Temperature: 76F; Dew Point: 66F; Wind: W at 7 kts. Sea-level pressure: 30.11 ins. Hg, rising Visibility: 25 miles, WNW 30 miles above inversion, hazy 6-hr min. temp: 68F BHO SA 1155 300 –SCT 25 196/76/66/2807/011/ FEW CI DSNT NW-NNE INVSN PRSNT ESTMTD TOP 4 HND OVR CTY N K/HZ LYR BLO INVSN ALQDS K LYR ALF SE-W-NNE VSBY WNW 30 ABV INVSN HAZY/ 8/001 53007 10076 20068 10 A.M. Weather: Clear, few small cumulus forming all quadrants, few moderate cumulus distant ESE-SSE, thin smoke/hazy layer aloft all quadrants, hazy Temperature: 87F; Dew Point: 65F; Wind: W at 8 kts, Wind: Direction variable SSW-WNW Sea-level pressure: 30.09 ins. Hg, falling Visibility: 25 miles, hazy BHO SA 1455 CLR 25 188/87/65/2608/009/ FEW SML CU FRMG ALQDS FEW MDT CU DSNT ESE-SSE THN K/HZ LYR ALF ALQDS HAZY WND 21V29/ 8/200 58008 1 P.M. Weather: Scattered cumulus, moderate cumulus all quadrants, cumulus congestus ESE-S-W, hazy Temperature: 91F; Dew Point: 64F; Wind: WSW at 10 kts, Wind: Direction variable SW-W Sea-level pressure: 30.04 ins. Hg, falling Visibility: 35 miles, WNW 45 miles, hazy 6-hour max temp: 92F BHO SA 1755 60 SCT 35 173/91/64/2510/004/ MDT CU ALQDS CU CONGESTUS ESE-S-W HAZY VSBY WNW 45 WND 22V28/ 8/300 58015 10092 20076 WEATHER SUMMARY FOR THURSDAY, MAY 30, 2013 TEMPERATURE (DEGREES F) MAX.....86 NORMAL.....70 MIN.....63 NORMAL.....52 MEAN....75 NORMAL.....61 DEPARTURE FROM 30-YEAR NORMAL...................+14 TOTAL DEPARTURE FOR THE MONTH...................+44 [+1.3 DEGREE/DAY] HEATING DEGREE DAYS TOTAL HEATING UNITS FOR YESTERDAY.............0 DEPARTURE..........-5 TOTAL HEATING UNITS FOR THE MONTH...........212 DEPARTURE.........-51 TOTAL HEATING UNITS FOR THE SEASON.........5734 DEPARTURE........-564 TOTAL HEATING UNITS LAST SEASON TO DATE....4888 DIFFERENCE.......+846 PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY...............25 W AT 1:22 P.M. AERO....................25 W AT 1:22 P.M. ASOS....................28 W AT 1:22 P.M. DAVIS...................25 W AT 1-2 P.M. RMY: 27 FASTEST MILE FOR YESTERDAY.................19 W AT 1:21 P.M. * MAXIMUM 2-MINUTE ASOS AVERAGE..............20 W AT 1:24 P.M. MAXIMUM 2-MINUTE DAVIS AVERAGE.............19 W AT 1:24 P.M. AVERAGE WIND SPEED AND DIRECTION.........12.0 W ASOS..................11.4 DAVIS.................10.9 W [259 deg] *last of several occurrences PRECIPITATION (INCHES) THROUGH THIS MORNING (EST) TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.00 DEPARTURE...........-0.16 ASOS..............0.00 TOTAL PRECIPITATION FOR THE MONTH..........3.71 DEPARTURE...........-0.25 TOTAL ASOS PRECIPITATION FOR MONTH.........3.66 TOTAL PRECIPITATION FOR THE YEAR..........20.09 DEPARTURE...........-2.42 ASOS..............N/A* *ASOS malfunctioned during storm on 2/8-9, leading to erroneous totals 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.............99.0 DEPARTURE...........+36.3 PRELIMINARY CLIMATE SUMMARY FOR MAY 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 5/1 67/45/56/+3/0.00/845/100 18 E AERO 16 MPH E RMY 17 5/2 75/43/59/+6/T/669/79 29 NE AERO 26 MPH NE RMY 29 5/3 54/42/48/-5/0.00/706/83 24 NE AERO 25 MPH NE RMY 28 5/4 55/40/48/-6/0.00/843/99 21 NE AERO 23 MPH NE RMY 23 5/5 58/37/48/-6/0.00/752/88 17 ENE AERO 17 MPH ENE RMY 20 5/6 66/40/53/-1/0.00/600/70 17 S AERO 18 MPH S RMY 20 5/7 77/50/64/+9/0.00/807/94 21 S AERO 23 MPH S RMY 25 5/8 71/55/63/+8/0.42/112/13 31 SSE AERO 35 MPH SSE RMY 35 TSTM 5/9 66/56/61/+6/0.41/078/09 16 NE AERO 16 MPH NE RMY 18 TSTM 5/10 79/54/67/+12/T/333/63 18 S AERO 21 MPH S RMY N/A 5/11 70/56/63/+7/0.06/026/03 43 SSW AERO 44 MPH SSW RMY 46 5/12 71/47/59/+3/0.05/339/39 30 W AERO 32 MPH W RMY 32 5/13 60/41/51/-5/0.00/821/94 25 WSW AERO 28 MPH WSW RMY 30 5/14 58/38/48/-9/T/385/44 22 W AERO 24 MPH W RMY 25 5/15 65/41/53/-4/0.02/456/52 35 S AERO 38 MPH S RMY 40 5/16 80/51/66/+9/0.00/844/96 40 W AERO 45 MPH W RMY 42 5/17 69/50/60/+3/0.00/872/99 24 NW AERO 28 MPH NW RMY 27 5/18 73/47/60/+2/0.00/689/78 21 SE AERO 24 MPH SE RMY 24 5/19 71/50/61/+3/0.11/407/46 21 S AERO 23 MPH S RMY 24 5/20 81/54/68/+10/0.01/496/56 21 S AERO 21 MPH S RMY N/A 5/21 81/49/65/+6/0.14/506/57 29 NE AERO 31 MPH NE RMY 32 TSTM 5/22 66/48/57/-3/0.04/009/01 27 WNW AERO 25 MPH WNW RMY N/A 5/23 74/53/64/+5/0.09/036/04 35 S AERO 39 MPH S RMY 40 5/24 68/49/59/0/0.57/000/00 33 S AERO 35 MPH S RMY N/A 5/25 50/39/45/-15/0.59/000/00 32 NW AERO 35 MPH NW RMY 32 5/26 58/37/48/-12/0.03/332/37 44 NW AERO 44 MPH NW RMY 45 5/27 70/41/56/-4/0.00/880/98 33 WNW AERO 33 MPH WNW RMY 36 5/28 74/55/65/+4/0.00/639/71 20 S AERO 20 MPH S RMY 21 5/29 71/56/61/+3/1.17/045/05 25 W AERO 27 MPH W RMY 27 TSTM 5/30 86/63/75/+14/0.00/.../.. 25 W AERO 25 MPH W RMY 27 5/31 morning low temp: 68F; the normal low is now 52F DAILY RECORDS FOR MAY 2013 5/26- TIED DAILY RECORD MINIMUM TEMPERATURE OF 37F; record of 37F set in 1972. 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 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: Sean Fankhauser