BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY SATURDAY, APRIL 25, 2015 ALL TIMES ARE IN EASTERN STANDARD TIME UNSEASONABLY COLD LATE APRIL WEATHER CONTINUES LOW TEMPERATURE OF 30F THIS MORNING AFTER 32F YESTERDAY THE LOW OF 30F THIS MORNING IS 11 DEG. COLDER THAN AVERAGE BRIGHT SUNSHINE WITH JUST FEW CLOUDS AND VISIBILITY 70-75 MILES FROM THE SUMMIT THIS MORNING--W-NW WINDS CONTINUE TO DIMINISH This morning's low temperature of 30.1F (30F) was the second consecutive morning minimum temperature. It fell 11 degrees colder than the average low of 41F for this date. The average date for the last spring freeze at the summit is April 20. The record low for this date is 24F in 1892. Still awaiting our first 70-degree reading of the year; could rank among the top ten latest I would think. Today's Observations: 7 A.M. Weather: Clear, altocumulus/altocumulus lenticularis mostly distant to the NW-E Temperature: 37F; Dew Point: 23F; Wind: W at 10 kts, Sea-level pressure: 29.78 ins. Hg, rising slightly Visibility: 70 miles, light distant haze 6-hr Max temp: 37F 6-hr Min temp: 30F 24-hr precip: 0.00 inch BHO SA 1155 CLR 70 086/37/23/2810/978/ AC/ACSL MSTLY DSNT NW-E LGT DSNT HZ/ 50006 8/040 10037 20030 10 A.M. Weather: Clear, cumulus fractus/cumulus distant WNW-N, altocumulus distant NW-NE, few lenticulars NW-ESE Temperature: 45F; Dew Point: 24F; Wind: W at 14 kts, Sea-level pressure: 29.75 ins. Hg, decreasing then more rapidly Visibility: 75 miles, light distant haze BHO SA 1455 CLR 75 074/48/24/2814/975/ CUFRA/CU FRMG DSNT WNW-N AC DSNT NNW-NE FEW ACSL NNW-ESE LGT DSNT HZ/ 8/140 58012 1 P.M. Weather: Broken stratucumulus generated by cumulus with a few cumuloform tops Temperature: 53F; Dew Point: 26F; Wind: NW at 9 kts, Wind: Direction variable W-N Sea-level pressure: 29.71 ins. Hg, decreasing then more slowly Visibility: 80 miles 6-hr Max temp: 55F 6-hr Min temp: 37F BHO SA 1755 E55 BKN 80 060/53/26/3109/971/ SC FEW CU TOPS SCCG ALQDS WND 28V01/ 8/400 56014 10055 20037 SUMMARY FOR FRIDAY, APRIL 24, 2015 TEMPERATURE (DEGREES F) MAX.....50 NORMAL.....59 MIN.....32 NORMAL.....41 MEAN....41 NORMAL.....50 DEPARTURE FROM 30-YEAR NORMAL.......................-9 TOTAL DEPARTURE FOR THE MONTH......................+35 [+1.3 DEGREES/DAY] HEATING DEGREE DAYS (SEASON JUL TO JUN) TOTAL HEATING UNITS FOR YESTERDAY..............24 DEPARTURE...........+9 TOTAL HEATING UNITS FOR THE MONTH.............431 DEPARTURE..........-37 TOTAL HEATING UNITS FOR THE SEASON...........6174 DEPARTURE.........+222 TOTAL HEATING UNITS LAST SEASON TO DATE......6044 DIFFERENCE........+130 PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY..................32 NW AT 7:30 A.M. ASOS.......................34 NW AT 7:31 A.M. DAVIS......................32 NW AT 7:30 A.M. RMY 36 FASTEST MILE FOR YESTERDAY....................26 WNW AT 7:31 P.M. MAXIMUM 2-MINUTE ASOS AVERAGE.................24 WNW AT 7:32 A.M. MAXIMUM 2-MINUTE DAVIS AVERAGE................23 WNW AT 7:32 A.M. AVERAGE WIND SPEED AND DIRECTION.............15.7 WNW ASOS......................15.2 DAVIS.....................13.5 WNW [300 degrees] * Last of several occurrences... PRECIPITATION (INCHES) THROUGH THIS MORNING (EST) TOTAL PRECIPITATION 24 HRS ENDING 7 A.M.....0.00 DEPARTURE.....-0.13 ASOS...............0.03 TOTAL PRECIPITATION FOR THE MONTH...........3.08 DEPARTURE.....-0.67 ASOS...............3.05 TOTAL PRECIPITATION FOR THE YEAR...........17.67 DEPARTURE.....+0.05 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......0.1 TOTAL SNOWFALL FOR THE MONTH...............TRACE DEPARTURE.....-2.9 TOTAL SNOWFALL FOR THE SEASON..............150.8 DEPARTURE....+88.2 PRELIMINARY CLIMATE SUMMARY FOR APRIL 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 4/1 44/26/35/-6/0.00/0.0/748/98 30 WNW RMY 31 4/2 59/29/44/+3/T/0.0/375/49 39 SSW RMY 43 4/3 56/47/52/+10/0.02/0.0/000/00 36 SW RMY N/A 4/4 49/32/41/-1/..../0.0/501/65 54 NW RMY 64 4/5 47/30/39/-4/..../0.0/464/60 40 W RMY 45 4/6 48/33/41/-2/0/00/0.0/544/70 18 NE RMY N/A 4/7 39/34/37/-6/..../0.0/000/00 21 NE RMY N/A 4/8 41/32/37/-7/..../T/000/00 30 ENE RMY 32 4/9 35/32/34/-10/..../0.0/000/00 31 ENE RMY 32 4/10 53/35/44/-1/..../0.0/000/00 31 SW RMY N/A 4/11 56/38/46/+1/0.00/0.0/744/94 39 WNW RMY 48 4/12 68/35/52/+7/0.00/0.0/762/96 23 WNW RMY 23 4/13 69/47/58/+12/0.00/0.0/764/96 35 SSW RMY N/A 4/14 65/51/58/+12/0.05/0.0/072/09 37 SSW RMY N/A 4/15 67/45/56/+9/0.00/0.0/786/98 32 NW RMY 33 4/16 64/42/53/+6/0.00/0.0/765/95 31 S RMY 21 4/17 64/45/55/+8/0.05/0.0/065/08 31 SSW RMY 32 4/18 64/43/54/+6/0.00/0.0/770/95 31 N RMY 36 4/19 55/39/47/-1/0.00/0.0/724/89 25 NNW RMY N/A 4/20 55/38/47/-2/..../0.0/000/00 36 SE RMY 40 4/21 67/51/59/+10/..../0.0/417/51 30 SSE RMY N/A 4/22 67/45/56/+7/0.03/0.0/.../.. 44 SSW RMY 52 4/23 49/34/42/-8/0.00/0/0/.../.. 32 W RMY N/A 4/24 50/32/41/-9/0.00/0.0/.../.. 32 NW RMY 36 4/25 low since midnight is 30F normal low is 41F DAILY RECORDS FOR APRIL 2015 4/3 - NEW RECORD DAILY HIGH MINIMUM TEMPERATURE: 47F surpasses the previous record of 46F in 1892 DAILY EXTREMES Temperature and precipitation records back to 1885, and wind records back to 1940 (e = estimated): RECORDS FOR APRIL 25 HIGH 83 IN 2009 LOW 24 IN 1892 PRECIP 1.38 IN. IN 1901 SNOWFALL 0.7 IN. IN 2002. PEAK GUST 66 MPH SE IN 1968 RECORDS FOR APRIL 26 HIGH 88 IN 2009 LOW 23 IN 1919 PRECIP 1.64 IN. IN 1931 SNOWFALL 1.0 IN. IN 2000 PEAK GUST 53 MPH SSW IN 1996 TODAY'S REPORT PREPARED BY: Robert Skilling