BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY SUNDAY, APRIL 26, 2015 ALL TIMES ARE IN EASTERN STANDARD TIME COOLER TEMPERATURES CONTINUE AS CLOUDS MOVE IN ON VERY LIGHT WINDS Temperatures weren't quite as cold this morning after remaining above freezing overnight but they should remain below normal today. The continued colder tempertures could potentially aim for the record for latest freeze at the summit if the pattern continues. The average date for the last spring freeze at the summit is April 20. Another record we are getting close to is the latest first 70-degree day at the summit. It is unusual to not hit 70 at least once by the end of April at the summit (it has not happened since April 1975), and it looks like we will not be doing so this year until May. Today's Observations: 7 A.M. Weather: Clear, few cumulus distant NW, few altocumulus distant S-ESE, few cirrus distant SE-SW Temperature: 46F; Dew Point: 32F; Wind: WNW at 8 kts, Sea-level pressure: 29.71 ins. Hg, increasing then decreasing Visibility: 60 miles, light distant haze 6-hr Max temp: 46F 6-hr Min temp: 39F 24-hr precip: 0.00 inch BHO SA 1155 CLR 60 060/46/32/3408/971/ FEW CU DSNT NW FEW AC S-ESE FEW CI SE-SW LGT DSNT HZ ALQDS/ 8/131 50006 10046 20039 10 A.M. scattered cumulus and stratocumulus ESE-NE, thin overcast altocumulus Temperature: 52F; Dew Point: 31F; Wind: NW at 4 kts, Wind: Light Sea-level pressure: 29.68 ins. Hg, decreasing then more slowly Visibility: 70 miles, light distant haze BHO SA 1455 50 SCT E80 -OVC 70 052/52/31/3004/968/ 8/550 56008 1 P.M. Weather: Overcast Stratocumulus with breaks in overcast ENE-SE Virga WNW-ENE Light distant Haze. Temperature: 52F; Dew Point: 31F; Wind: WNW at 9 kts, Sea-level pressure: 29.66 ins. Hg, steady then decreasing Visibility: 70 miles 6-hr Max temp: 52F 6-hr Min temp: 46F BHO SA 1755 E65 OVC 70 045/52/31/3009/966/ 8/050 58007 10052 20046 SUMMARY FOR SATURDAY, APRIL 25, 2015 TEMPERATURE (DEGREES F) MAX.....56 NORMAL.....60 MIN.....30 NORMAL.....41 MEAN....43 NORMAL.....50 DEPARTURE FROM 30-YEAR NORMAL.......................-7 TOTAL DEPARTURE FOR THE MONTH......................+28 [+0.9 DEGREES/DAY] HEATING DEGREE DAYS (SEASON JUL TO JUN) TOTAL HEATING UNITS FOR YESTERDAY..............22 DEPARTURE...........-7 TOTAL HEATING UNITS FOR THE MONTH.............441 DEPARTURE..........-30 TOTAL HEATING UNITS FOR THE SEASON...........6196 DEPARTURE.........+230 TOTAL HEATING UNITS LAST SEASON TO DATE......6057 DIFFERENCE........+139 PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY..................26 NW AT 13:53 P.M. * ASOS.......................29 NW AT 7:31 A.M. DAVIS......................25 WNW AT 11:37 A.M. RMY 29 FASTEST MILE FOR YESTERDAY....................19 WNW AT 11:37 A.M. MAXIMUM 2-MINUTE ASOS AVERAGE.................20 NW AT 1:53 P.M. MAXIMUM 2-MINUTE DAVIS AVERAGE................19 NW AT 2:54 P.M. AVERAGE WIND SPEED AND DIRECTION.............10.4 WNW ASOS......................11.0 DAVIS.....................9.0 WNW [305 degrees] * Last of several occurrences... PRECIPITATION (INCHES) THROUGH THIS MORNING (EST) TOTAL PRECIPITATION 24 HRS ENDING 7 A.M.....0.00 DEPARTURE.....-0.14 ASOS...............0.00 TOTAL PRECIPITATION FOR THE MONTH...........3.08 DEPARTURE.....-0.81 ASOS...............3.05 TOTAL PRECIPITATION FOR THE YEAR...........17.67 DEPARTURE.....-0.09 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...............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 56/30/43/-7/0.00/0.0/.../.. 26 NW RMY 29 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 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 RECORDS FOR APRIL 27 HIGH 93 IN 1990 LOW 28 IN 1919 PRECIP 1.89 IN 1979 SNOWFALL 2.7 IN. IN 1993 PEAK GUST 65e MPH N IN 1941 TODAY'S REPORT PREPARED BY: Robert Millette/Brian Fitzgerald