BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY THURSDAY, APRIL 18, 2013 ALL TIMES ARE IN EASTERN STANDARD TIME FROSTY COLD TEMPERATURES EARLY THIS MORNING IN SURROUNDING AREA BUT WELL ABOVE ATOP BLUE HILL WITH LOW OF 43F CLOUDS INCREASING THIS AFTERNOON AND WIND INCREASE FROM SOUTH Low temperatures this morning under a large high pressure system dropped into the upper 20's to lower 30's around the area. A low of 27F was recorded at Martha's Vineyard Airport while it was down to 33F at Norwood Airport, and the low 30s and Taunton and Plymouth Airports. Clouds are increasing along with south winds as high temperatures rise to the low to middle 60's. Today's observations: 7 A.M. Weather: Clear, few altocumulus and altocumulus lenticularis WSW-N, FEW cirrus east-southeast to southeast, cirrostratus layer distant WNW-NNW, Temperature: 48F; Dew Point: 30F; Wind: ESE at 10 kts, Sea-level pressure: 30.42 ins. Hg, rising slowly Visibility: 75 miles, light distant haze, inversion dissipating 6-hour min. temp: 43F BHO SA 1155 CLR 75 302/48/30/1110/042/ FEW AC/ACSL DSNT WSW-N FEW CI ESE-SE CS LYR DSNT WNW-NNW THN K LYR ALG HRZN DSNT S-SW LGT DSNT HZ INVSN DSSPTNG/ 8/048 53005 10048 20043 10 A.M. Weather: Clear, altocumulus and altocumulus lenticularis distant WSW-NW-NNE, few cirrus SE-overhead and distant WSW=NNE Temperature: 58F; Dew Point: 29F; Wind: SSE at 10 kts, Wind: Direction variable ESE to SSW Sea-level pressure: 30.42 ins. Hg, steady Visibility: 70 miles, light haze increasing BHO SA 1455 CLR 70 301/58/29/1510/042/ AC/ACSL DSNT WSW-NW-NNE FEW CI SE-OVHD AND CI DSNT WSW-N LGT HZ INCRSNG WND 12V20/ 8/041 55001 1 P.M. Weather: Scattered altocumulus layer invading from the SW, numerous altocumulus lenticularis, scattered cirrus mostly thin Temperature: 64F; Dew Point: 33F; Wind: S at 14 kts, Wind: Gust to 20 kts past hour Wind: Direction variable SE-SW Sea-level pressure: 30.34 ins. Hg, falling then more rapidly Visibility: 65 miles, except 70 miles NW, increasing light haze 6-hour max temp: 65F BHO SA 1755 75 SCT 250 -SCT 65 275/64/33/1814/034/ AC LYR INVDNG FRM SW NMRS ACSL SCT CI VSBY NW 70 INCRSNG LGT HZ GST 20 KTS PST HR WND 13V22/ 8/051 58026 10065 20048 WEATHER SUMMARY FOR WEDNESDAY, APRIL 17 TEMPERATURE (DEGREES F) MAX.....67 NORMAL.....56 MIN.....48 NORMAL.....38 MEAN....58 NORMAL.....47 DEPARTURE FROM 30-YEAR NORMAL...................+11 TOTAL DEPARTURE FOR THE MONTH...................+24 [+1.2 DEGREES/DAY] HEATING DEGREE DAYS TOTAL HEATING UNITS FOR YESTERDAY.............7 DEPARTURE.........-11 TOTAL HEATING UNITS FOR THE MONTH...........331 DEPARTURE.........-23 TOTAL HEATING UNITS FOR THE SEASON.........5351 DEPARTURE........-487 TOTAL HEATING UNITS LAST SEASON TO DATE....4543 DIFFERENCE.......+808 PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY...............29 SSW AT 12:02 A.M. AERO....................25 SSW AT 12:05 A.M. ASOS....................32 SSW AT 12:02 A.M. DAVIS...................29 SSW AT 12-1 A.M. RMY: N/A THE FASTEST MILE FOR YESTERDAY.............23 SSW AT 12:14 A.M. MAXIMUM 2-MINUTE ASOS AVERAGE..............23 SSW AT 12:14 A.M. MAXIMUM 2-MINUTE DAVIS AVERAGE.............23 SSW AT 12:1 A.M. AVERAGE WIND SPEED AND DIRECTION.........10.5 NW ASOS...................9.6 DAVIS..................9.8 WNW [300 deg] * 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..........1.18 DEPARTURE...........-1.62 ASOS..............1.13 TOTAL PRECIPITATION FOR THE YEAR..........15.27 DEPARTURE...........-1.53 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............-0.1 TOTAL SNOWFALL FOR THE MONTH.............Trace DEPARTURE............-2.4 TOTAL SNOWFALL FOR THE SEASON.............99.0 DEPARTURE...........+36.9 PRELIMINARY CLIMATE SUMMARY FOR APRIL 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 4/1 61/31/46/+5/0.34/0.0/458/60 40 W AERO 44 MPH WNW RMY 46 TSTM 4/2 40/27/34/-7/T/T/460/60 45 W AERO 42 MPH W RMY 47 4/3 45/27/36/-6/0.00/0.0/755/98 44 W AERO 43 MPH W RMY 47 4/4 55/26/41/-1/0.00/0.0/719/93 30 WSW AERO 27 MPH WSW RMY 31 4/5 59/36/48/+5/0.00/0.0/403/52 33 NNW AERO 28 MPH NNW RMY 38 4/6 47/30/39/-4/0.00/0.0/747/96 38 NW AERO 35 MPH NW RMY 40 4/7 52/31/42/-1/0.00/0.0/391/50 51 S AERO 46 MPH S RMY 50 4/8 65/43/54/+10/T/0.0/494/63 29 SSW AERO 22 MPH SSW RMY N/A 4/9 72/44/58/+14/T/0.0/456/58 35 WNW AERO 35 MPH WNW RMY 39 TSTM 4/10 64/43/54/+9/0.13/0.0/426/54 23 SE AERO 20 MPH SE RMY 25 4/11 52/40/46/+1/0.09/0.0/063/08 18 ENE AERO 14 MPH ENE RMY N/A 4/12 40/34/37/-8/0.58/T/000/00 38 E AERO 32 MPH E RMY 41 4/13 52/34/43/-3/0.04/0.0/128/16 31 NNE AERO 27 MPH NNE RMY 21 4/14 52/36/44/-2/0.00/0.0/216/27 31 WNW AERO 27 MPH WNW RMY 32 4/15 55/35/45/-2/0.00/0.0/514/64 21 ESE AERO 15 MPH S RMY N/A 4/16 62/38/50/+3/0.00/0.0/540/67 44 S AERO 40 MPH S RMY 45 4/17 67/48/58/+11/0.00/0.0/769/95 29 SSW AERO 25 MPH SSW RMY N/A 4/18 morning low temp: 43F; the normal low is now 39F DAILY RECORDS FOR APRIL 2013 None so far. DAILY EXTREMES Temperature and precipitation records back to 1885, and wind records back to 1940 (e = estimated): RECORDS FOR APRIL 18 HIGH 92 IN 1976 LOW 23 1887 PRECIP 1.48 IN 1954 SNOWFALL 3.7 IN. IN 1965 PEAK GUST 59 MPH S IN 1982 RECORDS FOR APRIL 19 HIGH 94 IN 1976 [RECORD FOR MONTH] LOW 21 IN 1890 PRECIP 1.71 IN 1969 SNOWFALL 6.0 IN. IN 1887 PEAK GUST 66 MPH E IN 1984 TODAY'S REPORT PREPARED BY: Robert Skilling/Peter Volpe