BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY TUESDAY, MAY 31, 2011 ALL TIMES ARE IN EASTERN STANDARD TIME COOLER AND NOTICEABLY DRIER AIR MASS TODAY; MAY & METEOROLOGICAL SPRING ENDING ON A WARM NOTE Since Monday morning, the wind direction has slowly veered from S to a northerly direction this morning. With wind speeds on the light side, it took a while for the slightly cooler and noticeably drier air mass to arrive. Dew point temperatures are in the lower 50s today, compared to the mid and upper 60s of the past several days. Today marks the 8th consecutive day of above average temperatures. With the recent warm spell, May will end up a little more than 1 degree above average. The streak of 14 at or below average days in the middle of the month were not cool enough to push May below average. With that long, cool, rainy, damp period we endured, it's no surprise that the prevailing wind for the month will likely be NNE. The 3.97 inches of precipitation for the month is slightly above average. Final figures for the month of May and for the spring (March, April, May) will be determined in the next few days. Lowest May Sunshine, hours 1) 136.1 in 1888 2) 147.4 in 2005 3) 150.8 in 1927 4) 152.4 in 1983 5) 155.0 in 2003 6) 155.4 in 1948 7) 169.7 in 1917 8) 170.7 in 1892 Lowest May Sunshine, percent 1) 31 in 1888 2) 34 in 2005 3) 35 in 1927 35 in 1983 35 in 2003 6) 36 in 1948 7) 39 in 1892 39 in 1917 Today's observations: 7 A.M. Weather: Scattered altocumulus, scattered thin cirrus, altocumulus/ altocumulus lenticularis distant NW-E-S, thin smoke layer distant SSW-W-NW, light distant haze Temperature: 70F, Dew point: 52F; Wind: NNE at 8 kts Wind: Direction variable NNW-ENE Sea-level pressure: 30.22 inches Hg, rising Visibility: 45 miles, light distant haze 6-hour min. temp: 64F BHO SA 1155 80 SCT 250 –SCT 45 232/70/52/0208/022/ AC/ACSL DSNT NW-E-S THN K LYR DSNT SSW-W-NW LGT DSNT HZ WND 34V06/ 8/041 51017 10070 20064 10 A.M. Weather: Scattered altocumulus, scattered thin cirrus, altocumulus/ altocumulus lenticularis distant N-ESE, light distant haze Temperature: 74F, Dew point: 51F; Wind: N at 6 kts, Wind: Light and variable Sea-level pressure: 30.24 inches Hg, rising Visibility: 45 miles, light distant haze BHO SA 1455 100 SCT 250 –SCT 45 239/74/51/0106/024/ AC/ACSL DSNT N-ESE LGT DSNT HZ WND LGT AND VRB/ 8/041 51007 1 P.M. Weather: Thin scattered cirrus, thin smoke layer distant N, light distant haze Temperature: 79F, Dew point: 52F; Wind: NE at 6 kts, Wind: Light and variable Sea-level pressure: 30.21 inches Hg, falling Visibility: 45 miles, light distant haze 6-hour max. temp: 79F BHO SA 1755 250 –SCT 45 231/79/52/0506/021/ THN K LYR DSNT N LGT DSNT HZ WND LGT AND VRB/ 8/001 58008 10079 20070 WEATHER SUMMARY FOR MONDAY, MAY 30 TEMPERATURE (DEGREES F) MAX.....87 NORMAL.....71 MIN.....66 NORMAL.....51 MEAN....77 NORMAL.....61 DEPARTURE FROM 30-YEAR NORMAL..................+16 TOTAL DEPARTURE FOR THE MONTH..................+35 [+1.0 DEGREES/DAY] HEATING DEGREE DAYS TOTAL HEATING UNITS FOR YESTERDAY.............0 DEPARTURE........-5 TOTAL HEATING UNITS FOR THE MONTH...........258 DEPARTURE........-8 TOTAL HEATING UNITS FOR THE SEASON.........6153 DEPARTURE......-139 TOTAL HEATING UNITS LAST SEASON TO DATE....5641 DIFFERENCE.....+512 PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY..............24 S AT 2:08 A.M. AEROVANE...............27 W AT 8:02 A.M. ASOS...................22 SSW AT 2:19 A.M. DAVIS..................24 SSW AT 2:19 A.M. THE FASTEST MILE FOR YESTERDAY............17 S AT 2:07 A.M. MAXIMUM 2-MINUTE ASOS AVERAGE.............17 NW AT 10:35 A.M. MAXIMUM 2-MINUTE DAVIS AVERAGE............19 WNW AT 10:35 A.M. AVERAGE WIND SPEED AND DIRECTION.........8.9 S ASOS..................8.9 DAVIS.................9.1 SW [228 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..........3.97 DEPARTURE........+0.31 ASOS..............3.86 TOTAL PRECIPITATION FOR THE YEAR..........22.19 DEPARTURE........+0.58 ASOS..............22.82** **ASOS data is in error due to system failure on 1/12-13 PRELIMINARY CLIMATE SUMMARY FOR MAY 2011 CALENDAR DAY DATA DATA REPORTED: DATE: MAX/MIN/MEAN/DEP/PRECIP/SNOW/SUN(MIN.)/SUN(%)/ PEAK GUST/AERO GUST AERO: Aerovane wind recording system gust when significant TSTM: Thunderstorm day (thunder heard some time during day) ....: Data not yet available, records not finalized 5/1 55/43/49/-3/0.00/0.0/819/97 30 NE 5/2 73/42/58/+6/0.00/0.0/651/77 24 SSW 5/3 74/51/63/+10/0.00/0.0/441/52 31 SSE 5/4 63/44/54/+1/0.57/0.0/000/00 35 SSE 5/5 58/41/50/-3/0.02/0.0/264/31 47 W 5/6 70/43/57/+3/0.00/0.0/667/78 41 SSE AERO 41 MPH SSE 5/7 71/48/60/+6/0.50/0/0/326/38 29 WNW TSTM 5/8 54/48/51/-3/0.00/0.0/238/27 31 NE 5/9 67/47/57/+2/T/0.0/474/55 43 N 5/10 53/46/50/-5/0.07/0.0/000/00 50 N 5/11 59/45/52/-3/0.14/0.0/035/04 37 NNE 5/12 57/48/53/-3/T/0.0/287/33 30 NNE 5/13 64/46/55/-1/0.00/0.0/828/95 22 NE 5/14 64/43/54/-3/T/0.0/035/04 22 SSE 5/15 63/47/55/-2/0.77/0.0/000/00 23 NE 5/16 47/45/46/-11/0.31/000/00 38 NNE 5/17 48/45/47/-10/0.32/000/00 36 NNE 5/18 53/48/51/-7/0.20/000/00 29 NNE 5/19 62/49/56/-2/0.62/035/04 27 NNE 5/20 67/49/58/0/0.01/230/26 18 NE 5/21 69/44/57/-2/T/461/52 28 NE 5/22 54/44/49/-10/0/071/08 28 NNE 5/23 62/47/55/-4/0.12/000/00 40 SSE AERO 45 MPH SSE 5/24 80/62/71/+11/0.31/232/26 43 S AERO 46 MPH S 5/25 75/58/67/+7/0.00/777/87 23 SE 5/26 80/54/67/+7/0.00/644/72 35 SSE AERO 38 MPH SSE 5/27 89/62/76/+15/0.00/628/70 33 SSE AERO 36 MPH SSE 5/28 80/63/72/+11/0.00/584/65 35 SE AERO 38 MPH SE 5/29 82/64/73/+12/0.00/513/57 32 S AERO 35 MPH S 5/30 87/66/77/+16/0.00/.../.. 24 S 5/31 our morning low temp: 64F; the normal low is now 52F DAILY RECORDS FOR MAY 2011 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 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